Concrete Equipment Pads

Revision 8 · Aug 29, 2026 +1171 −1001

SynC Standards Team — Specifier (Platform Standards) ✓ OfficialDiscloses employment SynC (SynC Platform Team)

Neutrality remake campaign: from-scratch field derivation per authoring cheatsheet; project parameters and derived dispositions

Showing changes from Rev 7 to Rev 8 in Concrete Equipment Pads.

−---

−title: Concrete Equipment Pads

−category: Sitework

−toc_depth: 3

−description: >

− When to use: Cast-in-place concrete pads on grade or on slab that support mechanical and electrical equipment located outside the building envelope or in service yards. Typical applications include generator pads, pad-mounted transformer pads, switchgear and section-switch pads, condensing-unit and rooftop unit (RTU) pads where set at grade or on an exterior platform, pump and chiller pads, and similar isolated equipment foundations. Covers subgrade preparation references, formwork, mix selection, reinforcement, embedded anchor bolts, embedded grounding and conduit stubs, pour and consolidation, curing, finishing, tolerances, isolation joints to adjacent flatwork, and inspection.

−

− Not intended for: Structural foundations integral to the building (footings, grade beams, mat foundations, pile caps) — see [[sync/cast-in-place-concrete]]. Interior housekeeping pads inside mechanical and electrical rooms placed as a thin topping on the building slab — use [[sync/cast-in-place-concrete]] for the topping pour. Precast concrete vault pads or precast transformer pads supplied with the equipment. Concrete-encased duct banks. Site flatwork (sidewalks, exterior slabs-on-grade) intended for pedestrian or vehicle traffic. Aggregate base course beneath the pad — see [[sync/aggregate-base-course]]. Mass earthwork and subgrade preparation below the base course — see [[sync/earthwork]].

−---

−

−# Scope {toc}

−

−## This specification covers the materials, formwork, reinforcement, placement, embedded items, and curing of cast-in-place reinforced concrete equipment pads located on grade or on an exterior elevated platform. {note}

−## Equipment pads provide a level, dimensionally controlled, vibration-resistant bearing surface for mechanical and electrical equipment; they isolate the equipment from soil moisture and capillary rise, transfer equipment weight and seismic and wind loads to the subgrade, and provide cast-in-place anchorage for equipment hold-downs and grounding electrodes. {note}

−

−## A pad is small in volume relative to the equipment it carries, so the cost of correcting a defective pad is dominated by the cost of removing and reinstalling the equipment that sits on it; anchor bolts in the wrong location, a pad that is out of level, a missing grounding stub, or a pad that has settled each turns into a multi-day setback once the equipment arrives, and the requirements that follow govern the conditions necessary to receive equipment without rework. {note}

−

−## Inherited and Supplemental Requirements {toc}

−

−### This standard inherits the general requirements of [[sync/cast-in-place-concrete]] for concrete materials, mix design, placement, and quality control. {note}

−### It inherits the requirements of [[sync/concrete-reinforcement]] for reinforcing steel materials, fabrication, placement tolerances, and cover. {note}

−### It inherits the requirements of [[sync/aggregate-base-course]] for the base course on which the pad bears and the requirements of [[sync/earthwork]] for subgrade preparation. {note}

−

−### Requirements specific to equipment pads — anchorage, embedded grounding, coordination with equipment manufacturer dimensions, finish, and isolation from adjacent flatwork — supplement and do not replace the parent standards.

−### Where this standard and a parent standard conflict, the more stringent requirement shall govern.

−

−## Design Basis {toc}

−

−### This standard does not address the structural design of the pad itself. {note}

−### Pad thickness, reinforcement, and pad dimensions shown on the contract drawings are the design basis. {note}

−

−### The Contractor shall not reduce pad thickness, reduce reinforcement, or alter pad dimensions without written approval from the Engineer of Record.

−### Default values in this specification represent typical conditions (a 6 in. thick pad reinforced with #4 bars at 12 in. on center each way, top and bottom, with ASTM F1554 Grade 36 cast-in-place anchor bolts) and are not a substitute for project-specific structural design.

−

−# Referenced Standards {toc}

−

−## Materials, fabrication, and installation shall comply with the latest adopted edition of the following standards and codes.

−## Where the contract documents, the adopted building code, or a referenced standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

−

−| Standard | Title |

−|----------|-------|

−| ACI CODE-318 | Building Code Requirements for Structural Concrete and Commentary |

−| ACI SPEC-301 | Specifications for Structural Concrete |

−| ACI 117 | Specification for Tolerances for Concrete Construction and Materials |

−| ACI 305R | Guide to Hot Weather Concreting |

−| ACI 306R | Guide to Cold Weather Concreting |

−| ACI 308R | Guide to External Curing of Concrete |

−| ACI 347R | Guide to Formwork for Concrete |

−| ASTM C33/C33M | Standard Specification for Concrete Aggregates |

−| ASTM C94/C94M | Standard Specification for Ready-Mixed Concrete |

−| ASTM C150/C150M | Standard Specification for Portland Cement |

−| ASTM C260/C260M | Standard Specification for Air-Entraining Admixtures for Concrete |

−| ASTM C309 | Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete |

−| ASTM C494/C494M | Standard Specification for Chemical Admixtures for Concrete |

−| ASTM A615/A615M | Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement |

−| ASTM A706/A706M | Standard Specification for Deformed and Plain Low-Alloy Steel Bars for Concrete Reinforcement |

−| ASTM F1554 | Standard Specification for Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength |

−| ASTM A153/A153M | Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware |

−| ASTM F2329/F2329M | Standard Specification for Zinc Coating, Hot-Dip, Requirements for Application to Carbon and Alloy Steel Bolts, Screws, Washers, Nuts, and Special Threaded Fasteners |

−| ASTM A194/A194M | Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High-Pressure or High-Temperature Service, or Both |

−| ASTM F436 | Standard Specification for Hardened Steel Washers Inch and Metric Dimensions |

−| ASTM E1155 | Standard Test Method for Determining FF Floor Flatness and FL Floor Levelness Numbers |

−| IEEE 80 | Guide for Safety in AC Substation Grounding |

−| IEEE C2 (NESC) | National Electrical Safety Code |

−| NFPA 70 | National Electrical Code (Article 250 — Grounding and Bonding; Article 110.26 — Working Space) |

−| IBC | International Building Code (locally adopted edition) |

−| ASCE 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |

−| UFGS 03 30 00 | Cast-in-Place Concrete (Unified Facilities Guide Specification) |

−| UFGS 03 30 53 | Miscellaneous Cast-in-Place Concrete |

−

−# Submittals {toc}

−

−## Action Submittals {toc}

−

−### The Contractor shall submit the following for the Engineer of Record's review prior to procurement, fabrication of reinforcement, and concrete placement.

−### No pad shall be placed until the corresponding submittals have been reviewed and returned.

−

−- Concrete mix design for the pad concrete class, prepared in accordance with [[sync/cast-in-place-concrete]], showing cementitious materials, aggregates, admixtures, water content, target water-to-cementitious materials ratio, and the trial batch or field-record documentation establishing the required average strength

−- Reinforcing steel shop drawings and bar lists conforming to [[sync/concrete-reinforcement]], showing bar sizes, grades, lengths, bends, spacing, and concrete cover for each pad type

−- Anchor bolt setting drawings, prepared from the equipment manufacturer's certified anchorage pattern for the specific equipment being supported, showing anchor bolt grade, diameter, embedment length, projection above pad, bolt circle or rectangular pattern dimensions, sleeve or template details, and the orientation of the pattern relative to the building grid or compass direction

−- Formwork shop drawings or product data for proprietary pad forming systems, including provision for chamfer at exposed edges

−- Embedded item layout for each pad type, including conduit stub-ups (size, material, count, orientation), grounding electrode connections (where required), drainage provisions (where required), and any equipment manufacturer-required cooling pits, oil-containment recesses, or cable trenches

−- Curing materials and procedure

−- For transformer pads: the grounding system layout, including ground rod locations, ground ring conductor (where used), and the connection of the grounding electrode conductor to the pad embed

−

−```datasheet

−label: Action Submittals Required

−type: checkbox

−options:

− - "Concrete mix design (per parent CIP standard)"

− - "Reinforcing steel shop drawings"

− - "Anchor bolt setting drawings (per equipment manufacturer pattern)"

− - "Formwork shop drawings or product data"

− - "Embedded item layout (conduits, grounding, drainage)"

− - "Curing materials and procedure"

− - "Transformer pad grounding layout (where applicable)"

−default: "Anchor bolt setting drawings (per equipment manufacturer pattern)"

−```

−

−## Coordination Submittals {toc}

−

−```datasheet

−label: Anchor Bolt Pattern Source

−type: radio

−options:

− - "Equipment manufacturer's certified anchorage drawing for the ordered equipment (required)"

− - "Catalog footprint or generic family drawing (not acceptable)"

−default: "Equipment manufacturer's certified anchorage drawing for the ordered equipment (required)"

−```

−

−### The Contractor shall obtain the equipment manufacturer's certified anchorage drawing for the actual ordered equipment — including the actual generator frame, the actual transformer base, the actual chiller unit — and shall not place anchors based on a catalog footprint, a model-family generic, or a "typical" arrangement.

−

−### The anchor bolt setting drawing is the most consequential submittal for an equipment pad and shall not be inferred from a generic equipment cut sheet; differences in frame size, fuel tank configuration, mounting accessory, or shipping split between catalog and ordered equipment routinely move anchor bolt positions by inches, and a pattern poured to the wrong drawing requires demolition and replacement of the pad.

−

−## Closeout Submittals {toc}

−

−### The Contractor shall provide the following at substantial completion before pad work is accepted:

−

−- As-built dimensions of each pad: plan dimensions, finished top-of-pad elevation, and the as-set anchor bolt pattern measured between bolt centers

−- Field test reports for the pad concrete (compressive strength cylinders) indexed to the corresponding pad

−- Documentation of any deviation from the approved anchor bolt pattern or embedded item layout and the Engineer of Record's written disposition

−

−```datasheet

−label: Closeout Submittals Required

−type: checkbox

−options:

− - "As-built dimensions of each pad (plan, top-of-pad elevation, as-set anchor pattern)"

− - "Field test reports for pad concrete (compressive strength cylinders) indexed to pad"

− - "Documentation of deviations and Engineer of Record's written disposition"

−default:

− - "As-built dimensions of each pad (plan, top-of-pad elevation, as-set anchor pattern)"

− - "Field test reports for pad concrete (compressive strength cylinders) indexed to pad"

− - "Documentation of deviations and Engineer of Record's written disposition"

−```

−

−# Quality Assurance {toc}

−

−## Testing Agency {toc}

−

−### Concrete testing for equipment pads shall be performed by the project's concrete testing agency qualified per [[sync/cast-in-place-concrete]].

−### Compressive strength cylinders shall be cast from each pad placement in accordance with [[sync/cast-in-place-concrete]].

−### A single small pad does not require a full set of cylinders if it is placed from the same truck as a larger element that is tested, but each truck delivered shall be sampled at least once per ACI SPEC-301.

−

−## Special Inspection {toc}

−

−```datasheet

−label: Pre-Set Verification of Anchor Pattern

−type: radio

−options:

− - "Required — Special Inspector or qualified survey before equipment delivery"

− - "Required — Contractor self-verification documented in writing"

− - "Not required — no regulated equipment supported"

−default: "Required — Special Inspector or qualified survey before equipment delivery"

−```

−

−### Special inspection requirements for the pad shall be as set out in the project Statement of Special Inspections and in IBC Chapter 17.

−### Where the equipment supported is regulated (life-safety generators, fire pumps, designated seismic equipment), pre-installation verification of the anchor pattern, anchor embedment, and pad dimensions shall be performed by the Special Inspector before equipment is set.

−

−## Pre-Pour Conference {toc}

−

−### For project sites with more than five equipment pads, or for sites with any single pad supporting equipment heavier than 5,000 lb, a pre-pour conference shall be held attended by the Contractor's superintendent, the concrete subcontractor, the equipment installer, the electrical subcontractor (where embedded conduits or grounding are involved), and the Engineer of Record.

−### The conference shall review the approved anchor bolt setting drawings, the embedded item layout, the relationship of pad finished elevation to surrounding grade and the building floor, the curing duration before equipment may be set, and the procedure for receiving and verifying the equipment manufacturer's anchor template.

−

−# Environmental and Service Conditions {toc}

−

−## Equipment pads located outside the building envelope are exposed to weather and, in cold-climate regions, to freeze-thaw cycling and de-icing chemicals carried in from adjacent driveways and walks. {note}

−

−## Exposure Selection {toc}

−

−```datasheet

−label: Freeze-Thaw Exposure

−type: radio

−options:

− - "F0 — no freezing and thawing exposure"

− - "F1 — freezing and thawing without de-icing chemicals"

− - "F2 — freezing and thawing with de-icing chemicals"

−default: "F1 — freezing and thawing without de-icing chemicals"

−```

−

−```datasheet

−label: Pad Location

−type: radio

−options:

− - "Exterior, on grade — exposed to weather"

− - "Exterior, on elevated platform or roof — exposed to weather"

− - "Interior, in unconditioned space (parking garage, mechanical yard)"

− - "Interior, in conditioned mechanical or electrical room (use parent CIP standard)"

−default: "Exterior, on grade — exposed to weather"

−```

−

−### The exposure category selected for the pad concrete shall reflect these conditions and shall not be reduced because the pad is "isolated" or "not part of the structure."

−

−### The most common durability defect in equipment pads is concrete specified without air entrainment in a freeze-thaw region, which spalls progressively at edges and corners until anchor cover is reduced or the bearing surface becomes uneven. {note}

−

−# Coordination with Equipment Manufacturer {toc}

−

−## Equipment Selection Confirmed Before Pad Construction {toc}

−

−### No pad shall be formed until the equipment manufacturer and model number have been confirmed, the equipment has been released for fabrication, and the equipment manufacturer's certified anchorage drawing has been received and reviewed.

−

−### Pads built on the assumption that the eventually-ordered equipment will conform to a basis-of-design drawing are at significant risk of dimension error. {note}

−

−## Anchor Pattern Sources of Error {toc}

−

−### The following are the most common sources of anchor pattern errors and shall be addressed in the Contractor's pre-pour verification:

−

−- Equipment ordered with a non-standard skid, base, or sub-base (most generators above 60 kW)

−- Equipment ordered with manufacturer accessories that change the footprint (sub-base fuel tank, vibration isolators, weatherproof enclosure)

−- Equipment with multiple shipping splits that recombine on site (large chillers, oversize switchgear lineups)

−- Field-bolted lineups where the as-shipped lineup length differs from the lineup planned during design

−- Pad-mounted transformer base footprints, which vary between utility-owned and project-owned units even at the same kVA rating

−- Imperial-vs-metric anchor pattern dimensions on equipment from international manufacturers

−

−## Anchor Template {toc}

−

−```datasheet

−label: Anchor Bolt Template Type

−type: radio

−options:

− - "Steel plate template fabricated from manufacturer's anchorage drawing"

− - "Plywood template fabricated from manufacturer's anchorage drawing"

− - "Manufacturer-supplied template (where provided with equipment)"

− - "Proprietary anchor bolt setting kit"

−default: "Steel plate template fabricated from manufacturer's anchorage drawing"

−```

−

−### The Contractor shall use a rigid anchor template (steel, plywood, or proprietary template) to position anchor bolts during the pour.

−### The template shall be fabricated from the certified anchorage drawing, not from a tape-measure layout of bolt positions.

−### The template shall hold bolts vertical and at correct elevation during placement and consolidation, and shall remain in place until the concrete has set sufficiently to maintain anchor position.

−

−# Subgrade Preparation {toc}

−

−## Base Course Under Pad {toc}

−

−```datasheet

−label: Aggregate Base Course Thickness Beneath Pad

−type: select

−unit: in

−drawing_ref: true

−options:

− - "4 in. (light equipment, condensing units, small pumps)"

− - "6 in. (standard, generators and transformers)"

− - "8 in. (heavy equipment, large generators, soft subgrade conditions)"

− - "12 in. (per geotechnical report or contract drawings)"

−default: "6 in. (standard, generators and transformers)"

−```

−

−### The subgrade beneath an equipment pad on grade shall be prepared in accordance with [[sync/earthwork]] and shall receive an aggregate base course in accordance with [[sync/aggregate-base-course]].

−### The Contractor shall not place a pad directly on natural undisturbed soil unless the geotechnical report specifically authorizes it for the soil type encountered and the equipment loading anticipated.

−### The aggregate base course beneath the pad shall be at least as thick as the base course shown on the contract drawings, but in no case less than 4 in. for light equipment (condensing units, small pumps) and 6 in. for heavier equipment (generators, transformers).

−### The base shall be compacted to the density required by [[sync/aggregate-base-course]] and shall be proof rolled before the pad is formed.

−

−## Base Course Moisture {toc}

−

−### The subgrade and base course shall be moist (not saturated) at the time of pad placement to prevent the base from drawing water from the fresh concrete.

−### Where dry or hot weather conditions are anticipated, the base shall be lightly sprinkled before placement; standing water shall not be permitted.

−

−# Formwork {toc}

−

−## Form Materials {toc}

−

−```datasheet

−label: Form Material

−type: radio

−options:

− - "Plywood (structural-grade) with timber framing"

− - "Steel forms"

− - "Aluminum forms"

− - "Proprietary pad forming system"

−default: "Plywood (structural-grade) with timber framing"

−```

−

−### Formwork for equipment pads shall be plywood, steel, aluminum, or proprietary pad forming systems sized to the pad dimensions.

−### Forms shall be tight enough to prevent loss of cement paste and shall be braced sufficiently to resist the hydrostatic pressure of fresh concrete without bulging beyond the ACI 117 tolerance on plan dimensions.

−### Earth forms (concrete poured directly against trenched soil walls) are not acceptable for equipment pads.

−### Earth forms do not maintain dimension and do not produce the chamfered or formed edges required at exposed corners. {note}

−

−## Chamfer {toc}

−

−```datasheet

−label: Edge Chamfer

−type: select

−unit: in

−options:

− - "3/4 in. chamfer at all exposed edges (standard)"

− - "1 in. chamfer (heavy traffic or vehicle-adjacent pads)"

− - "Tooled radius edge (where smooth profile is required)"

− - "Square edge (only where chamfer would conflict with equipment skirt)"

−default: "3/4 in. chamfer at all exposed edges (standard)"

−```

−

−### All exposed edges and corners of the pad shall be formed with a 3/4 in. chamfer unless otherwise indicated on the contract drawings.

−### Chamfered edges reduce the likelihood of impact spalling, hide minor edge irregularities, and present a finished appearance; sharp 90-degree corners are vulnerable to chipping under foot traffic, equipment carts, snow shovels, and de-icing salt exposure. {note}

−

−## Form Release {toc}

−

−### Form release agent shall be applied to all form surfaces before placing reinforcement.

−### Form release shall be compatible with any subsequent coating or sealer that will be applied to the pad surface.

−### Diesel fuel and used motor oil shall not be used as form release.

−

−# Concrete Mix {toc}

−

−## The concrete mix shall conform to [[sync/cast-in-place-concrete]] and to the additional requirements below.

−## The pad concrete is typically a single class used throughout all pads on the project; where pad applications differ significantly (e.g., a light condensing-unit pad and a heavy generator pad), separate mix classes may be specified.

−

−## Mix Properties {toc}

−

−```datasheet

−label: Minimum Specified Compressive Strength f'c — Equipment Pad Concrete

−type: select

−unit: psi

−drawing_ref: true

−options:

− - "3000 psi (light pads, non-freezing exposure)"

− - "4000 psi (standard, most equipment pads)"

− - "4500 psi (heavy equipment, F2 exposure)"

− - "5000 psi (severe exposure or per drawings)"

−default: "4000 psi (standard, most equipment pads)"

−```

−

−```datasheet

−label: Maximum Water-to-Cementitious Materials Ratio

−type: radio

−options:

− - "0.55 — F0 exposure, interior or sheltered pads"

− - "0.50 — F1 freeze-thaw, no de-icing chemicals (standard exterior pad)"

− - "0.45 — F2 freeze-thaw with de-icing chemicals"

−default: "0.50 — F1 freeze-thaw, no de-icing chemicals (standard exterior pad)"

−```

−

−```datasheet

−label: Slump at Delivery

−type: range

−unit: in

−options:

− min: 2

− max: 5

− step: 0.5

−default: 4

−```

−

−```datasheet

−label: Air Entrainment

−type: radio

−options:

− - "Not required (F0 exposure only)"

− - "Required — 4.5% ± 1.5% (1 in. max aggregate, F1 or F2)"

− - "Required — 6.0% ± 1.5% (3/4 in. max aggregate, F1 or F2 — standard)"

− - "Required — 7.5% ± 1.5% (3/8 in. max aggregate, F1 or F2)"

−default: "Required — 6.0% ± 1.5% (3/4 in. max aggregate, F1 or F2 — standard)"

−```

−

−```datasheet

−label: Coarse Aggregate Nominal Maximum Size

−type: select

−unit: in

−options:

− - "3/8 in. (thin pads, congested reinforcement)"

− - "3/4 in. (standard equipment pads)"

− - "1 in. (heavy pads with widely spaced reinforcement)"

−default: "3/4 in. (standard equipment pads)"

−```

−

−## Air Entrainment Requirement {toc}

−

−### Exterior pads in any region that experiences a freezing winter shall be air-entrained without exception.

−### Air entrainment is the primary defense against freeze-thaw spalling of edges and corners; specifying f'c alone does not provide freeze-thaw durability, and an unentrained 5000 psi pad spalls just as readily as an unentrained 3000 psi pad. {note}

−

−# Reinforcement {toc}

−

−## Reinforcement shall be furnished, fabricated, and placed in accordance with [[sync/concrete-reinforcement]].

−## The default reinforcement for an equipment pad is a top and bottom mat of deformed bars in each direction, sized and spaced as shown on the contract drawings. {note}

−## Where the contract drawings do not specify reinforcement, the default below shall apply.

−

−## Reinforcement Configuration and Cover {toc}

−

−```datasheet

−label: Reinforcement Configuration

−type: radio

−drawing_ref: true

−options:

− - "Single mat — center of pad (light pads, thickness ≤ 4 in.)"

− - "Top and bottom mats — each way (standard, thickness ≥ 6 in.)"

− - "Top and bottom mats with edge ties (heavy equipment, thickness ≥ 8 in.)"

−default: "Top and bottom mats — each way (standard, thickness ≥ 6 in.)"

−```

−

−```datasheet

−label: Reinforcing Bar Size

−type: select

−drawing_ref: true

−options:

− - "#3 (3/8 in.) — light pads only"

− - "#4 (1/2 in.) — standard equipment pads"

− - "#5 (5/8 in.) — heavy pads"

− - "#6 (3/4 in.) — very heavy generator or transformer pads per drawings"

−default: "#4 (1/2 in.) — standard equipment pads"

−```

−

−```datasheet

−label: Reinforcing Bar Spacing — Each Way

−type: select

−unit: in

−drawing_ref: true

−options:

− - "8 in. o.c. each way"

− - "10 in. o.c. each way"

− - "12 in. o.c. each way (standard)"

− - "16 in. o.c. each way (light pads only)"

−default: "12 in. o.c. each way (standard)"

−```

−

−```datasheet

−label: Reinforcing Bar Grade

−type: select

−options:

− - "Grade 60 (ASTM A615) — standard"

− - "Grade 60 (ASTM A706) — where field welding to embedded anchors is permitted"

−default: "Grade 60 (ASTM A615) — standard"

−```

−

−```datasheet

−label: Concrete Cover to Reinforcement — Bottom (Cast Against Base Course)

−type: select

−unit: in

−options:

− - "3 in. (cast against earth — no vapor barrier or topping mud)"

− - "2 in. (cast on base course with vapor barrier or topping mud)"

−default: "3 in. (cast against earth — no vapor barrier or topping mud)"

−```

−

−```datasheet

−label: Concrete Cover to Reinforcement — Sides and Top (Exposed to Weather)

−type: select

−unit: in

−options:

− - "1-1/2 in. — bars #5 and smaller (standard)"

− - "2 in. — bars #6 and larger"

−default: "1-1/2 in. — bars #5 and smaller (standard)"

−```

−

−## Reinforcement Support and Placement {toc}

−

−### Reinforcement shall be supported on plastic-tipped wire chairs, all-plastic chairs, or precast concrete block chairs in accordance with [[sync/concrete-reinforcement]].

−### Bare wire chairs shall not be used in exterior or F1/F2 exposure pads because they corrode and stain the pad surface.

−### Bars shall be tied at intersections sufficiently to maintain position during anchor bolt installation and concrete consolidation.

−### The reinforcing mat shall be positioned to avoid conflict with anchor bolts and conduit stubs.

−### Where an anchor bolt or conduit conflicts with a planned bar position, the bar shall be cut and replaced with two bars splayed around the embed, splice length per [[sync/concrete-reinforcement]]; bars shall not simply be omitted at conflicts.

−

−# Anchor Bolts {toc}

−

−## Material and Grade {toc}

−

−```datasheet

−label: Anchor Bolt Grade

−type: radio

−drawing_ref: true

−options:

− - "ASTM F1554 Grade 36 (standard, general equipment)"

− - "ASTM F1554 Grade 55 (higher load, weldable variant where indicated)"

− - "ASTM F1554 Grade 105 (high-load, high-seismic applications)"

−default: "ASTM F1554 Grade 36 (standard, general equipment)"

−```

−

−```datasheet

−label: Anchor Bolt Coating

−type: radio

−options:

− - "Plain (no coating) — interior or sheltered exposure only"

− - "Hot-dip galvanized (ASTM F2329 / A153) — standard exterior"

− - "Mechanically galvanized — alternative to hot-dip"

− - "Stainless steel (ASTM F593) — corrosive environment"

−default: "Hot-dip galvanized (ASTM F2329 / A153) — standard exterior"

−```

−

−```datasheet

−label: Anchor Bolt Diameter

−type: select

−unit: in

−drawing_ref: "equipment manufacturer drawing"

−options:

− - "1/2 in."

− - "5/8 in."

− - "3/4 in."

− - "7/8 in."

− - "1 in."

− - "1-1/4 in."

− - "1-1/2 in."

−default: deferred

−```

−

−```datasheet

−label: Anchor Bolt Embedment Length

−type: select

−unit: in

−drawing_ref: "equipment manufacturer drawing"

−options:

− - "12 × bolt diameter (minimum where not calculated)"

−default: deferred

−```

−

−### Anchor bolts shall be ASTM F1554 headed or hooked anchor rods, of the grade required by the structural drawings and the equipment manufacturer's anchorage drawing.

−### ASTM F1554 Grade 36 is the default for general-purpose equipment anchorage; Grade 55 is used where structural calculations require higher capacity; Grade 105 is used for high-load applications such as large transformer anchorage in high-seismic regions and is rarely required for general equipment pads. {note}

−

−## Embedment Length {toc}

−

−### Embedment length shall be the greater of the value shown on the equipment manufacturer's anchorage drawing and the value calculated by the Engineer of Record under ACI 318 Chapter 17 for the design loads.

−### The Contractor shall not reduce embedment depth to fit a thinner pad without written approval from the Engineer of Record and a revised anchorage calculation.

−

−## Cast-in-Place vs. Post-Installed Anchors {toc}

−

−```datasheet

−label: Anchor Bolt Installation Method

−type: radio

−options:

− - "Cast-in-place during pad pour (standard, required for new pads)"

− - "Adhesive (epoxy) anchor in existing pad — requires Engineer approval and certified anchor system"

− - "Mechanical expansion anchor in existing pad — requires Engineer approval"

−default: "Cast-in-place during pad pour (standard, required for new pads)"

−```

−

−### Cast-in-place anchor bolts placed in the wet concrete during the pad pour are the default for new equipment pads.

−### Where post-installed anchors are used, the anchor product shall be certified under ICC-ES AC308 (adhesive) or AC193 (mechanical), shall be selected by the Engineer of Record for the design loads and exposure, and shall be installed by an installer who has completed the manufacturer's certification training for that anchor system.

−### Cast-in-place bolts provide the highest pullout capacity, do not depend on epoxy or expansion mechanisms, and are not subject to seismic anchor reductions that apply to many post-installed anchors; post-installed anchors (mechanical expansion or adhesive) are an acceptable alternative only where the pad already exists, where the anchor pattern is being changed to receive different equipment than originally planned, or where field tolerances cannot be met by cast-in-place installation. {note}

−

−## Anchor Bolt Projection and Hardware {toc}

−

−```datasheet

−label: Anchor Bolt Projection Above Finished Pad

−type: select

−unit: in

−drawing_ref: "equipment manufacturer drawing"

−options:

− - "3 in. (typical, generators and switchgear)"

− - "4 in. (typical, transformers with elevated base)"

− - "6 in. (elevated mounting or grouted bedding)"

−default: deferred

−```

−

−### Each anchor bolt shall project above the finished pad surface as required by the equipment manufacturer's drawing to engage the equipment base, threaded into a leveling nut and a top nut over a hardened washer per ASTM F436.

−### The projection length shall include the equipment base thickness, the grout bed depth (where used), two washers, and the top nut, plus 1/4 in. minimum thread engagement beyond the top nut.

−### Anchor bolt threads above the pad surface shall be protected from damage and contamination during the curing period and through equipment delivery by capping with plastic thread protectors, by wrapping with tape and plastic, or by greasing and wrapping.

−### Threads encrusted with concrete or rusted from neglect shall be cleaned and tested before equipment is set.

−### Insufficient projection forces field cutting of bolts, which damages threads and is grounds for rejection of the installation. {note}

−

−# Embedded Items {toc}

−

−## All embedded items — conduits, grounding electrode conductors, drains, sleeves — shall be positioned and secured before the pad is poured.

−## Field cutting or coring of placed pad concrete to add a missed embed shall not be performed without written approval from the Engineer of Record.

−## Coring after the fact frequently cuts reinforcement or anchor embedment. {note}

−

−## Conduit Stubs {toc}

−

−```datasheet

−label: Conduit Stub Projection Above Pad

−type: select

−unit: in

−drawing_ref: true

−options:

− - "Per equipment manufacturer's conduit entry detail"

− - "Stop flush with pad surface (cable troughs, switchgear with internal raceways)"

− - "Stub up 4 to 6 in. above pad (typical for terminations inside equipment base)"

− - "Stub up to coordinate with equipment cable management"

−default: "Per equipment manufacturer's conduit entry detail"

−```

−

−### Conduit stubs serving the equipment shall enter the pad from below per the contract drawings and shall be terminated above the finished pad surface as required by the equipment manufacturer for that conduit connection.

−### Conduit type and material shall conform to [[sync/raceways-and-conduit]].

−### Conduit shall be capped during concrete placement to prevent debris from entering and shall be supported to resist displacement during pour.

−### Where conduits are clustered (e.g., multiple feeders entering a generator or a transformer secondary), the cluster spacing shall match the manufacturer's cable trough opening; conduits shall not foul the equipment base.

−

−## Grounding Electrode Connections {toc}

−

−### Pad-mounted transformer pads, generator pads, and switchgear pads commonly require a grounding electrode connected at the pad. {note}

−

−### Grounding shall be provided in accordance with [[sync/grounding-and-bonding]] and, for substation-class transformer installations, in accordance with IEEE 80.

−

−```datasheet

−label: Embedded Grounding at Equipment Pad

−type: checkbox

−options:

− - "Ground rod(s) driven adjacent to pad with grounding electrode conductor stubbed through pad"

− - "Ground ring conductor encircling pad below grade with taps stubbed through pad"

− - "Grounding electrode conductor connection to building grounding electrode system"

− - "Concrete-encased electrode (Ufer ground) where pad reinforcement is bonded and connected"

− - "Not applicable — equipment connected to building grounding system only"

−default: "Ground rod(s) driven adjacent to pad with grounding electrode conductor stubbed through pad"

−```

−### For pad-mounted transformers, the grounding electrode conductor shall stub through the pad at the location designated on the manufacturer's anchorage and grounding drawing and shall be left of sufficient length to terminate inside the transformer tank or at the equipment ground bus per [[sync/grounding-and-bonding]].

−### Coiling excess conductor inside the pad cavity is acceptable provided the coil does not interfere with cable termination.

−### For generator pads, the grounding electrode conductor connection shall be coordinated with the generator manufacturer's grounding lug location, with the building grounding electrode system, and with the separately derived system grounding requirements of NFPA 70 Article 250.

−

−## Other Embedded Items {toc}

−

−```datasheet

−label: Additional Embedded Items

−type: checkbox

−options:

− - "Cable pulling sleeves through the pad to a cable trench below"

− - "Drainage opening or sleeve for transformer oil containment"

− - "Lifting inserts (cast-in lifting eyes) — for precast-style pads only"

− - "Equipment-specific embedded sleeves per manufacturer"

− - "None"

−default: "None"

−```

−

−# Pad Dimensions and Layout {toc}

−

−## Plan Dimensions {toc}

−

−### The pad shall extend beyond the equipment footprint by the offset required to provide:

−

−- Foot clearance for service personnel walking around the equipment

−- NEC 110.26 working space dimensions in front of electrical equipment where the working space is to be on the pad rather than on adjacent paving (typically 36 in. for 0–150 V to ground, more for higher voltages)

−- A minimum 3 in. concrete edge beyond the outermost anchor bolt to prevent breakout of the anchor cone

−- Manufacturer-required clearance for cable bending radius at conduit stub-ups, control panel doors, and removable covers

−

−```datasheet

−label: Pad Plan Dimensions

−type: text

−drawing_ref: "pad plan dimensions"

−default: deferred

−```

−

−```datasheet

−label: Working Space Considerations

−type: checkbox

−options:

− - "NEC 110.26 working space on the pad (typically 36 in. minimum front, 0–150 V)"

− - "NEC 110.26 working space on adjacent paving (pad limited to equipment footprint plus 3 in. edge)"

− - "Manufacturer-required service clearance integrated into pad"

− - "Cable bending radius envelope at conduit stub-ups"

−default: "NEC 110.26 working space on adjacent paving (pad limited to equipment footprint plus 3 in. edge)"

−```

−

−### Pad plan dimensions shall be as shown on the contract drawings or as determined by the equipment footprint plus the working clearance offset required by code, whichever is greater.

−### Where the contract drawings show a pad dimensioned with [[drawing: pad plan dimensions]], that dimension is the design basis and shall not be reduced.

−### The Engineer of Record shall confirm whether the NEC 110.26 working space is provided on the pad or on adjacent paving before the pad is dimensioned.

−### The choice between providing the NEC working space on the pad versus on adjacent paving is a design decision that affects both pad size and the location of nearby site work such as curbs, fences, and landscaping. {note}

−

−## Pad Thickness {toc}

−

−```datasheet

−label: Pad Thickness

−type: select

−unit: in

−drawing_ref: true

−options:

− - "4 in. (light equipment only — condensing units, small pumps)"

− - "6 in. (standard, most equipment pads)"

− - "8 in. (medium-heavy equipment, generators ≤ 200 kW, transformers ≤ 750 kVA)"

− - "10 in. (large transformers, generators 200–500 kW)"

− - "12 in. or more (heavy generators ≥ 500 kW, large transformers, per drawings)"

−default: "6 in. (standard, most equipment pads)"

−```

−

−### Reducing pad thickness without re-evaluating anchorage is not permitted.

−### Pad thickness governs anchor embedment, breakout cone development, and stiffness against equipment-induced vibration. {note}

−

−## Top-of-Pad Elevation {toc}

−

−```datasheet

−label: Top-of-Pad Elevation Above Adjacent Grade or Paving

−type: select

−unit: in

−drawing_ref: true

−options:

− - "2 in. (standard, condensing units on paved areas)"

− - "4 in. (standard, generator and transformer pads on grade)"

− - "6 in. (heavy equipment, areas with high snow accumulation)"

−default: "4 in. (standard, generator and transformer pads on grade)"

−```

−

−### The finished top-of-pad elevation shall be set above adjacent grade or adjacent paving such that surface drainage flows away from the pad and that the pad is not submerged under rain or snowmelt.

−### The pad shall be located by reference to the building grid, property line, or other surveyable control as shown on the contract drawings at [[drawing: pad location plan]].

−### Pad rotation (orientation of the equipment relative to compass direction or building face) shall match the contract drawings and the equipment manufacturer's recommended orientation for cable access, ventilation intake and exhaust, and service access.

−### A minimum 4 in. elevation above adjacent grade is typical for transformer and generator pads; a minimum 2 in. is typical for condensing-unit pads on paved areas. {note}

−

−# Pour and Consolidation {toc}

−

−## Placement Method {toc}

−

−```datasheet

−label: Placement Method

−type: radio

−options:

− - "Direct chute from truck"

− - "Concrete pump"

− - "Buggy or wheelbarrow (small inaccessible pads)"

−default: "Direct chute from truck"

−```

−

−### For most equipment pads, concrete shall be placed by direct chute from a ready-mix truck or by concrete pump.

−### Free-fall distance shall not exceed 4 ft.

−### Buggy or wheelbarrow placement is acceptable for small pads not accessible by truck or pump.

−### Placement shall conform to [[sync/cast-in-place-concrete]].

−

−## Anchor Bolt and Embed Verification Immediately Before Pour {toc}

−

−### Immediately before placing concrete, the Contractor shall verify, in the presence of the Special Inspector (where required) or by self-inspection (where not required), that:

−

−- Anchor bolts are correctly positioned per the template and the manufacturer's anchorage drawing, including pattern dimensions, pattern orientation, and bolt elevation

−- All anchor bolts are vertical and at the correct projection

−- Conduit stubs are capped, positioned, and braced

−- Grounding electrode conductors are positioned and protected

−- Reinforcement is in place, supported, tied, and at the correct cover

−- The base course is moist and free of standing water

−- Forms are tight, braced, and treated with release agent

−

−### The pre-pour verification shall be documented in writing.

−### Concrete shall not be placed until any deficiencies are corrected.

−

−## Consolidation {toc}

−

−```datasheet

−label: Internal Vibrator Head Diameter

−type: select

−unit: in

−options:

− - "1 in. (thin pads, congested embeds)"

− - "1-1/2 in. (standard equipment pad)"

− - "2 in. (heavy pad, sparse embeds)"

−default: "1-1/2 in. (standard equipment pad)"

−```

−

−### Concrete shall be consolidated by internal mechanical vibration immediately after placement.

−### A vibrator head of 1-1/2 to 2 in. diameter is appropriate for most equipment pads; the vibrator shall be inserted at intervals not exceeding 18 in. and shall be held until air bubbles cease rising.

−### The vibrator shall not be used to move concrete laterally or to drag concrete into corners.

−### Care shall be taken not to displace anchor bolts during vibration; the anchor template shall be braced sufficiently to resist incidental contact.

−

−# Finish {toc}

−

−## Top Surface {toc}

−

−```datasheet

−label: Top-of-Pad Finish

−type: radio

−options:

− - "Steel-troweled smooth — equipment with continuous base, no grout bed"

− - "Wood-floated — equipment requiring a grout bed for leveling"

− - "Light broom — pedestrian traffic on or alongside the pad"

− - "Heavy broom — equipment that may be walked on during service"

−default: "Steel-troweled smooth — equipment with continuous base, no grout bed"

−```

−

−### The top surface of an equipment pad shall be screeded to elevation, floated to consolidate the surface and embed coarse aggregate, and finished to the texture appropriate for the equipment that will be set on it.

−### A broom finish is required for any surface that a worker may stand on, particularly transformer pads in regions subject to ice.

−### The top surface shall not be steel-troweled to a glass-smooth finish where equipment will be set on a grout bed.

−### Steel troweling is the default for equipment with a continuous, machined base that bears directly on the pad; a wood-floated surface is preferred where the equipment is leveled on a grout bed, because the rougher texture improves grout bond, and over-troweling produces a dense, low-permeability surface to which grout does not bond well. {note}

−

−## Tolerances on Top Surface {toc}

−

−### The top surface shall be level within the tolerances given under Tolerances below, and shall be free of high spots, low spots, and trowel ridges that would prevent uniform bearing of the equipment base on the pad or grout bed.

−

−# Curing and Protection {toc}

−

−## Curing shall conform to [[sync/cast-in-place-concrete]] and ACI 308R.

−

−## Curing Method and Duration {toc}

−

−```datasheet

−label: Curing Method

−type: radio

−options:

− - "Curing compound (ASTM C309 Type 1-D or Type 2)"

− - "Wet burlap covered with polyethylene sheeting"

− - "Polyethylene sheeting only (interior pads, low evaporation)"

− - "Insulated curing blanket (cold weather)"

−default: "Curing compound (ASTM C309 Type 1-D or Type 2)"

−```

−

−```datasheet

−label: Curing Duration Before Equipment May Be Set

−type: select

−unit: days

−options:

− - "3 days — light equipment, no operational loading (condensing units)"

− - "7 days — standard, most equipment"

− - "14 days — heavy equipment, transformers under load, high-vibration generators"

− - "Per field-cured cylinder breaks demonstrating 75% of f'c"

−default: "7 days — standard, most equipment"

−```

−

−### Curing compound shall not be applied to areas where a grout bed, sealer, or coating will subsequently be applied unless the curing compound is demonstrated to be compatible or has fully dissipated before the subsequent application.

−### Where compatibility cannot be confirmed, wet curing shall be used.

−### The pad shall not be loaded with equipment until concrete has reached at least 75% of f'c, demonstrated by field-cured cylinder breaks taken from the same pour.

−### Equipment pads are particularly vulnerable to inadequate curing because their high surface-to-volume ratio causes rapid moisture loss; an uncured pad develops a weak, dusty, permeable surface that subsequently spalls in freeze-thaw exposure. {note}

−### Setting equipment on uncured concrete is among the most common causes of cracking at anchor bolts and edge spalling. {note}

−

−## Weather Precautions {toc}

−

−```datasheet

−label: Hot Weather Concreting Precautions Required

−type: radio

−options:

− - "Not required — ambient < 90°F, moderate humidity"

− - "Required — per ACI 305R and [[sync/cast-in-place-concrete]]"

−default: "Not required — ambient < 90°F, moderate humidity"

−```

−

−```datasheet

−label: Cold Weather Concreting Precautions Required

−type: radio

−options:

− - "Not required — ambient > 40°F through protection period"

− - "Required — per ACI 306R and [[sync/cast-in-place-concrete]]"

−default: "Not required — ambient > 40°F through protection period"

−```

−

−# Tolerances {toc}

−

−## Dimensional tolerances shall comply with ACI 117.

−

−## Tolerance Values {toc}

−

−```datasheet

−label: Plan Dimension Tolerance

−type: select

−unit: in

−options:

− - "± 1/2 in. on overall plan dimensions"

− - "± 1/4 in. on overall plan dimensions (tighter — high-precision equipment)"

−default: "± 1/2 in. on overall plan dimensions"

−```

−

−```datasheet

−label: Anchor Bolt Pattern Tolerance (Bolt to Bolt within Pattern)

−type: select

−unit: in

−drawing_ref: "equipment manufacturer drawing"

−options:

− - "± 1/8 in. from drawing dimension between adjacent bolts (standard)"

− - "± 1/16 in. (high-precision equipment with machined base)"

−default: "± 1/8 in. from drawing dimension between adjacent bolts (standard)"

−```

−

−```datasheet

−label: Anchor Bolt Projection Tolerance

−type: select

−unit: in

−options:

− - "± 1/4 in. on specified projection"

− - "± 1/8 in. (where leveling nut adjustment is limited)"

−default: "± 1/4 in. on specified projection"

−```

−

−```datasheet

−label: Top-of-Pad Levelness

−type: select

−unit: in

−options:

− - "± 1/8 in. under 10-ft straightedge (standard equipment pad)"

− - "± 1/16 in. under 10-ft straightedge (rotating equipment, generators, pumps)"

− - "Per equipment manufacturer's installation tolerance"

−default: "± 1/8 in. under 10-ft straightedge (standard equipment pad)"

−```

−

−```datasheet

−label: Anchor Bolt Verticality (Plumb)

−type: select

−options:

− - "Within 1 in 40 (1.5 degrees) of vertical"

− - "Within 1 in 100 (0.6 degrees) of vertical — high-precision equipment"

−default: "Within 1 in 40 (1.5 degrees) of vertical"

−```

−

−### Equipment pad tolerances are typically tighter than generic slab tolerances because the pad serves as a bearing and anchorage surface for equipment with specified mounting points. {note}

−

−## Pattern Tolerance Measurement and Resolution {toc}

−

−### The pattern tolerance shall be measured against the equipment manufacturer's drawing, not against a tape-measure layout of nominal dimensions.

−### Where pattern tolerance is exceeded, the Contractor shall not bend, heat, or cut anchor bolts to fit the equipment without written approval from the Engineer of Record; the resolution is either to ream the equipment base or to remove and replace the pad.

−

−# Joints — Isolation from Adjacent Flatwork {toc}

−

−## Isolation Joint Configuration {toc}

−

−```datasheet

−label: Isolation Joint at Adjacent Flatwork

−type: radio

−options:

− - "Required — full-depth pre-molded joint filler at all interfaces with adjacent slabs or paving"

− - "Not applicable — pad is freestanding with no adjacent flatwork"

−default: "Required — full-depth pre-molded joint filler at all interfaces with adjacent slabs or paving"

−```

−

−```datasheet

−label: Isolation Joint Filler

−type: radio

−drawing_ref: true

−options:

− - "Closed-cell polyethylene foam filler, compressible (standard)"

− - "Asphalt-impregnated fiber filler"

−default: "Closed-cell polyethylene foam filler, compressible (standard)"

−```

−

−### Where an equipment pad is placed adjacent to a sidewalk, driveway, exterior slab, or building floor slab, an isolation joint shall be provided between the pad and the adjacent flatwork.

−### Isolation joints shall be full-depth pre-molded joint filler in accordance with [[sync/cast-in-place-concrete]].

−### The joint shall be sealed at the surface with an elastomeric joint sealant where the joint is exposed to traffic, water, or where its open condition would be unsightly.

−### The sealant shall be compatible with the joint filler and shall be installed in accordance with the sealant manufacturer's instructions.

−### The pad and the adjacent slab move differently because of differential loading, thermal cycling, and subgrade differences, and a rigid connection between them produces cracking at the interface. {note}

−

−## Construction Joints {toc}

−

−### Construction joints within a single pad shall be avoided.

−### A pad shall be placed monolithically; cold joints, partial placements, or layered pours are not acceptable in an equipment foundation.

−### Cold joints, partial placements, or layered pours produce planes of weakness that are not acceptable in an equipment foundation. {note}

−

−# Inspection and Testing {toc}

−

−## Pre-Placement Inspection {toc}

−

−### Pre-placement inspection requirements are stated above under Pour and Consolidation.

−

−## Field Testing of Concrete {toc}

−

−### Field testing of fresh concrete (slump, air content, temperature) and casting of compressive strength cylinders shall be performed in accordance with [[sync/cast-in-place-concrete]].

−### For project sites with multiple pads placed from a common pour, a single set of acceptance cylinders may serve multiple pads provided the placements occur on the same day from the same delivered concrete.

−

−## Pre-Set Verification {toc}

−

−### Before equipment is set on a pad, the Contractor shall verify and document:

−

−- Pad concrete has reached at least 75% of f'c

−- Anchor bolt pattern dimensions and projections match the equipment manufacturer's anchorage drawing within the specified tolerance

−- Anchor bolt threads are clean, undamaged, and capable of accepting the leveling nut and top nut

−- Top-of-pad elevation and levelness are within tolerance

−- Embedded conduits and grounding stubs are present, clean, and at the correct locations

−- The pad is free of cracks, spalls, exposed reinforcement, or other defects

−

−```datasheet

−label: Pre-Set Verification Required Before Equipment Delivery

−type: radio

−options:

− - "Yes — written verification by Contractor with sign-off"

− - "Yes — Special Inspector observation in addition to Contractor verification"

−default: "Yes — written verification by Contractor with sign-off"

−```

−

−### The pre-set verification protects against the most expensive sequence of failures in equipment installation — equipment delivered to the site, found not to fit, returned to storage at additional cost, the pad demolished and replaced, and the equipment re-delivered — and verification before delivery is inexpensive while the failure mode after delivery is not. {note}

−

−# Delivery, Storage, and Handling of Materials {toc}

−

−## Storage and Handling {toc}

−

−### Reinforcing steel shall be delivered, stored, and handled in accordance with [[sync/concrete-reinforcement]].

−### Anchor bolts shall be delivered to the site in clearly identified bundles or boxes with manufacturer's certification (mill test reports for the bolt steel and zinc coating thickness verification for galvanized bolts) and shall be stored on supports above grade in a manner that prevents thread damage and contamination.

−### Thread protectors shall remain in place from delivery through installation.

−### Concrete shall be delivered in accordance with ASTM C94 and [[sync/cast-in-place-concrete]].

−### Curing compounds, form release, and curing blankets shall be stored in accordance with the manufacturer's recommendations, protected from freezing and from exposure to sunlight where the product is light-sensitive.

−

−# Repair of Defects {toc}

−

−## Defects discovered after form stripping or after pad acceptance shall be evaluated by the Engineer of Record and repaired as directed.

−## Common defects in equipment pads and their typical dispositions: {note}

−

−| Defect | Typical Disposition |

−|--------|---------------------|

−| Hairline shrinkage cracks (< 0.005 in.) | Accept; seal with penetrating sealer if in F2 exposure |

−| Surface cracks > 0.005 in. but not through-thickness | Rout and seal with elastomeric crack sealant |

−| Through-thickness cracks | Engineer evaluation; epoxy injection or replacement |

−| Edge or corner spall | Repair with polymer-modified patching mortar to original profile |

−| Honeycombing in formed surface | Remove loose material, dampen, patch with mortar of same w/cm as parent concrete |

−| Anchor bolt out of pattern tolerance | Engineer evaluation; ream equipment base, relocate bolt, or replace pad |

−| Anchor bolt out of plumb | If within recoverable range, straighten with leveling nut and shim; otherwise replace pad |

−| Embedded conduit missing or wrong location | Core after the fact only with Engineer approval; otherwise modify equipment layout or replace pad |

−

−## Repair Authority {toc}

−

−```datasheet

−label: Repair of Visible Defects Before Equipment Set

−type: checkbox

−options:

− - "Edge and corner spalls repaired with polymer-modified patch"

− - "Surface cracks routed and sealed"

− - "Honeycombing patched in formed surfaces"

− - "Tie holes patched (where formed)"

− - "Anchor pattern deviations evaluated and resolved before equipment delivery"

−default: "Edge and corner spalls repaired with polymer-modified patch"

−```

−

−### The Contractor shall not perform structural repairs (epoxy injection, replacement, anchor relocation) without written direction from the Engineer of Record.

−### Cosmetic repairs to non-structural surface defects may proceed in accordance with [[sync/cast-in-place-concrete]].

−

−# Warranty {toc}

−

−## Installation Warranty {toc}

−

−```datasheet

−label: Installation Warranty Period

−type: select

−options:

− - "1 year from substantial completion (standard)"

− - "2 years from substantial completion"

−default: "1 year from substantial completion (standard)"

−```

−

−### The Contractor shall warrant the pad installation against defects in materials and workmanship — including cracks beyond hairline width, surface spalling, anchor displacement, settlement, and frost heave — for the project warranty period from the date of substantial completion.

−### The warranty shall not apply to damage caused by equipment loads exceeding the design basis, to damage from vehicle impact or other external causes, or to settlement caused by subgrade conditions outside the Contractor's scope.

−### Material warranties for proprietary anchor systems, post-installed anchors, repair mortars, and joint sealants used in the pad work shall be passed through to the Owner and included in the closeout submittals.

−### Coordinate equipment-labeling and pad-mounted equipment identification with [[sync/equipment-labeling]] and the supporting equipment specifications [[sync/generators]] and [[sync/medium-voltage-transformers]].

+---

+title: Concrete Equipment Pads

+category: Structural / Concrete

+description: >

+ When to use: Cast-in-place concrete equipment pads and housekeeping pads that receive mechanical, electrical, and plumbing equipment - generators, pad-mounted and dry-type transformers, switchgear and switchboard lineups, chillers, air handlers, condensing units, pumps, compressors, boilers, and similar equipment - whether the pad bears on grade, on an interior finished floor, on a structural slab, or on an exterior platform. Covers the decisions a pad standard actually owns: pad geometry and height, attachment to the supporting concrete, reinforcement method, cast-in and post-installed equipment anchorage, cast-in raceway and grounding provisions, liquid containment, surface finish and grout bed, isolation from adjacent construction, dimensional and anchorage tolerances, and the verification performed before concrete is placed and before equipment is set.

+ Not intended for: Concrete constituent materials, mixture proportioning, delivery, placement, consolidation, and strength acceptance (see [[sync/cast-in-place-concrete]]); formwork design, form materials, and stripping (see [[sync/concrete-formwork]]); reinforcing steel supply, fabrication, support, and cover (see [[sync/concrete-reinforcement]]); curing methods and duration and surface finishing execution (see [[sync/concrete-curing-and-finishing]]); joint materials, sealing, and waterstops (see [[sync/concrete-joints-and-waterstops]]); anchor rod grades, fabrication, and coatings (see [[sync/structural-steel-anchor-bolts]]); post-installed anchor qualification, hole preparation, and installation (see [[sync/post-installed-anchors]]); non-shrink grout supply and grouted base plate execution (see [[sync/non-shrink-grout]] and [[sync/grouted-base-plates]]); vibration isolator and seismic restraint selection and inertia bases (see [[sync/vibration-isolation-and-seismic-restraint]]); subgrade preparation and aggregate base course (see [[sync/earthwork]] and [[sync/aggregate-base-course]]); building foundations, footings, and pile caps (see [[sync/shallow-foundations]] and [[sync/deep-foundations]]); slabs on grade as building floors (see [[sync/slab-on-grade]]); precast equipment pads and precast transformer pads furnished with the equipment; and repair of hardened or deteriorated concrete (see [[sync/concrete-repair-and-restoration]]).

+---

+# Scope {toc}

+## This standard covers the geometry, substrate attachment, reinforcement method, equipment anchorage, cast-in provisions, finish, tolerances, and acceptance verification of cast-in-place concrete equipment pads and housekeeping pads. {note}

+## An equipment pad is a small volume of concrete carrying a disproportionate amount of risk. The cost of a defective pad is not the cost of the concrete; it is the cost of the equipment that cannot be set on it. An anchor group cast an inch out of pattern, a pad an inch too low for the conduit bend radius, or a missing grounding stub is discovered when a crane and a delivered machine are already on site, and the correction runs through demolition, re-procurement of anchors, and a second delivery. The requirements that follow are ordered around the two moments at which that outcome can still be prevented: before concrete is placed, and before the equipment is released to the pad. {note}

+## The work of the following standards applies to equipment pads and is not restated here. {note}

+- Concrete constituent materials, mixture proportioning and qualification, delivery, placement, consolidation, field testing, and strength acceptance - [[sync/cast-in-place-concrete]].

+- Formwork design, form materials, chamfer and rustication strips, release agents, and stripping - [[sync/concrete-formwork]].

+- Reinforcing bar and welded wire supply, fabrication, support, splicing, and concrete cover - [[sync/concrete-reinforcement]].

+- Curing methods and duration, finishing operations, and surface-defect acceptance - [[sync/concrete-curing-and-finishing]].

+- Joint filler and sealant materials, joint preparation, and waterstops - [[sync/concrete-joints-and-waterstops]].

+- Anchor rod grades, fabrication, threading, coatings, and delivery - [[sync/structural-steel-anchor-bolts]].

+- Post-installed anchor qualification, installer certification, hole drilling and cleaning, and proof loading - [[sync/post-installed-anchors]].

+- Non-shrink grout materials and the execution of a grouted bearing interface - [[sync/non-shrink-grout]] and [[sync/grouted-base-plates]].

+- Vibration isolator selection, inertia bases, and seismic restraint of the supported equipment - [[sync/vibration-isolation-and-seismic-restraint]].

+- Subgrade preparation and the aggregate base course beneath a pad on grade - [[sync/earthwork]] and [[sync/aggregate-base-course]].

+## The structural design of the pad - its thickness, its reinforcement, its plan extent, and the anchorage capacity it develops - is performed by the Engineer of Record and recorded on the contract documents. This standard states how that design is executed and verified; it does not produce it, and no value in it substitutes for a project-specific design. {note}

+## Pads shall comply with [[sync/cast-in-place-concrete]] except as modified by this standard.

+## Where this standard and a standard it references conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

+## The Contractor shall not reduce pad thickness, reduce reinforcement, reduce plan dimensions, or reduce anchor embedment from the values shown on the contract documents without the written approval of the Engineer of Record.

+# Referenced Standards {toc}

+## Materials, fabrication, installation, and testing shall comply with the latest adopted edition of each of the following unless a specific edition is cited.

+## Where the contract documents, the adopted building code, or a referenced standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

+| Standard | Title |

+|----------|-------|

+| ACI 117 | Specification for Tolerances for Concrete Construction and Materials |

+| ACI 301 | Specifications for Concrete Construction |

+| ACI 318 | Building Code Requirements for Structural Concrete and Commentary |

+| ACI 351.1R | Report on Grouting Between Foundations and Bases for Support of Equipment and Machinery |

+| ACI 351.2R | Report on Foundations for Static Equipment |

+| ACI 351.3R | Report on Foundations for Dynamic Equipment |

+| ASCE/SEI 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |

+| ASTM A615/A615M | Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement |

+| ASTM A706/A706M | Deformed and Plain Low-Alloy Steel Bars for Concrete Reinforcement |

+| ASTM A1064/A1064M | Carbon-Steel Wire and Welded Wire Reinforcement, Plain and Deformed, for Concrete |

+| ASTM C881/C881M | Epoxy-Resin-Base Bonding Systems for Concrete |

+| ASTM C1116/C1116M | Fiber-Reinforced Concrete |

+| ASTM F1554 | Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength |

+| ICRI 310.2R | Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, Polymer Overlays, and Concrete Repair |

+| IEEE 80 | Guide for Safety in AC Substation Grounding |

+| IEEE C57.12.28 | Pad-Mounted Equipment - Enclosure Integrity |

+| ICC IBC | International Building Code |

+| NFPA 70 | National Electrical Code |

+# Submittals {toc}

+## Action Submittals {toc}

+### The Contractor shall submit the following for review and acceptance before anchors are procured, before reinforcement is fabricated, and before concrete is placed in any pad:

+- Pad layout drawing for each pad type, showing plan dimensions, thickness, finished top-of-pad elevation, and the pad's relation to the building grid or to site control

+- Anchorage setting drawing for each pad, developed from the reconciled anchorage pattern and showing anchor type, diameter, embedment, projection, pattern dimensions, pattern orientation, and the setting template or jig

+- Reinforcement placing drawings for the pads, including bar designations, spacing, arrangement through the thickness, cover, and the detailing of bars around anchors and embedded items

+- Layout of every item cast into the pad, including raceway stub-ups, grounding conductors, sleeves, troughs, bearing plates, and drainage openings

+- Interface details where the pad is attached to existing or adjacent concrete, including surface preparation method, target surface profile, bonding agent, and dowel size, embedment, and layout

+- Mixture class designation for the pad concrete and the exposure classes the mixture satisfies

+- Product data for the grout, bonding agent, and containment materials used in the pad work

+- Containment details where the supported equipment contains a regulated liquid

+```datasheet

+label: Action Submittals Required

+type: checkbox

+options:

+ - "Pad layout drawing for each pad type"

+ - "Anchorage setting drawing for each pad"

+ - "Reinforcement placing drawings"

+ - "Layout of items cast into the pad"

+ - "Interface and dowel details at attachment to existing concrete"

+ - "Mixture class designation and exposure classes for pad concrete"

+ - "Grout, bonding agent, and containment product data"

+ - "Liquid containment details"

+default:

+ - "Pad layout drawing for each pad type"

+ - "Anchorage setting drawing for each pad"

+ - "Reinforcement placing drawings"

+ - "Layout of items cast into the pad"

+ - "Mixture class designation and exposure classes for pad concrete"

+```

+### Concrete shall not be placed in a pad until the submittals covering that pad have been reviewed and returned.

+## Informational Submittals {toc}

+### The Contractor shall submit the following before the first pad is formed:

+- The equipment manufacturer's certified anchorage drawing for the ordered equipment, identifying the equipment tag and the accessory configuration it applies to

+- Evaluation report and published installation instructions for each post-installed anchor system proposed for the pad work

+- Certification of each installer for the post-installed anchor systems that require certified installation

+- Qualifications of the party that will perform the anchorage pattern verification

+```datasheet

+label: Informational Submittals Required

+type: checkbox

+options:

+ - "Certified anchorage drawing for the ordered equipment"

+ - "Evaluation report and installation instructions for post-installed anchors"

+ - "Installer certification for post-installed anchor systems"

+ - "Qualifications of the party verifying the anchorage pattern"

+default:

+ - "Certified anchorage drawing for the ordered equipment"

+ - "Evaluation report and installation instructions for post-installed anchors"

+ - "Qualifications of the party verifying the anchorage pattern"

+```

+## Closeout Submittals {toc}

+### The Contractor shall submit the following before the pad work is accepted:

+- As-built record for each pad giving plan dimensions, finished top-of-pad elevation, and the as-set anchorage pattern measured center to center between adjacent anchors

+- Verification record made before concrete was placed in each pad

+- Verification record made before the equipment was released to each pad

+- Strength test results for the pad concrete, indexed to the pads each placement served

+- Installation and proof-test records for the post-installed anchors and dowels in the pad work

+- Record of every anchorage or embedment deviation reported to the Engineer of Record and the disposition directed for it

+```datasheet

+label: Closeout Submittals Required

+type: checkbox

+options:

+ - "As-built dimensions, elevation, and as-set anchorage pattern for each pad"

+ - "Verification record made before concrete placement"

+ - "Verification record made before equipment release"

+ - "Strength test results indexed to each pad"

+ - "Post-installed anchor and dowel installation and proof-test records"

+ - "Deviation reports and directed dispositions"

+default:

+ - "As-built dimensions, elevation, and as-set anchorage pattern for each pad"

+ - "Verification record made before concrete placement"

+ - "Verification record made before equipment release"

+ - "Strength test results indexed to each pad"

+ - "Deviation reports and directed dispositions"

+```

+# Quality Assurance {toc}

+## Special Inspection of Pad Anchorage {toc}

+### Anchorage to concrete is one of the few operations whose quality cannot be confirmed after the fact. A cast-in anchor disappears into the pour and a post-installed anchor into a hole nobody can see down; the installation itself is therefore the inspected article rather than the finished product. {note}

+### Special inspection of the pad work shall be performed as set out in the project Statement of Special Inspections and in ICC IBC Chapter 17.

+### The inspection tasks applicable to pad anchorage shall be as indicated in the datasheet.

+```datasheet

+label: Special Inspection of Pad Anchorage

+type: checkbox

+options:

+ - "Periodic inspection of cast-in anchor placement before concrete is placed"

+ - "Continuous inspection of adhesive anchor installation"

+ - "Periodic inspection of mechanical post-installed anchor installation"

+ - "Verification survey of the anchorage pattern before concrete is placed"

+ - "Verification survey of the anchorage pattern after the concrete has set"

+ - "Proof loading of a sample of the post-installed anchors"

+ - "No special inspection of pad anchorage required"

+```

+## Anchorage Pattern Verification {toc}

+### The as-set anchorage pattern shall be verified against the reconciled anchorage pattern dimensions before concrete is placed and again after the forms are stripped.

+### The verification shall be performed by the party indicated in the datasheet.

+```datasheet

+label: Party Performing the Anchorage Pattern Verification

+type: radio

+options:

+ - "Contractor's field engineer"

+ - "Independent registered land surveyor engaged by the Contractor"

+ - "Special Inspector"

+ - "Field representative of the equipment supplier"

+```

+### The party performing the verification shall record the measured pattern dimensions, the measured projections, and the measured orientation of the pattern relative to the control shown on the contract documents.

+## Pre-Placement Conference {toc}

+### A conference shall be held before the first equipment pad is formed.

+### The conference shall be attended by the Contractor's superintendent, the concrete subcontractor, the equipment installer, the electrical subcontractor where raceways or grounding conductors are cast into any pad, and the Engineer of Record.

+### The conference agenda shall cover the reconciled anchorage patterns, the setting method for the anchors, the layout of items cast into the pads, the relation of each finished top-of-pad elevation to the surrounding floor or grade, the strength the pad must attain before equipment is set, and the sequence by which each pad is verified and released.

+# Coordination With the Supported Equipment {toc}

+## Source of the Anchorage Pattern {toc}

+### A published catalog footprint describes a model family. The ordered machine is a member of that family carrying a specific sub-base, enclosure, isolator set, and shipping split, and those accessories move anchor positions. Where the pattern used to set anchors and the pattern on the delivered equipment come from different documents, the discrepancy surfaces at the moment the machine is lowered onto the pad. {note}

+### The anchorage pattern dimensions used to set the anchors shall be taken from the source indicated in the datasheet.

+```datasheet

+label: Source of the Anchorage Pattern Dimensions

+type: radio

+options:

+ - "Certified anchorage drawing issued by the equipment manufacturer for the ordered equipment"

+ - "Published catalog anchorage drawing for the equipment model and accessory configuration"

+ - "Basis-of-design anchorage dimensions carried on the contract documents"

+ - "Field measurement of the delivered equipment before the pad is formed"

+default: "Certified anchorage drawing issued by the equipment manufacturer for the ordered equipment"

+```

+### The Contractor shall reconcile the anchorage pattern against the equipment manufacturer's certified anchorage drawing for the ordered equipment before concrete is placed, whatever source the pattern was developed from.

+### Unless the datasheet designates a source other than the certified anchorage drawing, no pad shall be formed until the equipment manufacturer and model have been confirmed, the equipment has been released for fabrication, and the certified anchorage drawing has been received and reviewed.

+### Where the reconciliation discloses a difference between the pattern used for the setting drawing and the certified anchorage drawing, the Contractor shall notify the Engineer of Record and shall not place concrete until the difference is resolved in writing.

+## Sources of Anchorage Pattern Error {toc}

+### The differences that most often move an anchor pattern between design and delivery are these. {note}

+- A non-standard skid, base, or sub-base furnished with the ordered machine

+- Accessories that change the footprint, such as a sub-base fuel tank, an integral vibration isolation rail, or a weather enclosure

+- Equipment shipped in splits that are recombined on site, where the assembled length differs from the length assumed in design

+- Field-assembled lineups whose as-built length depends on the section count actually ordered

+- Pad-mounted transformer base dimensions, which differ between utility-owned and owner-owned units at the same rating

+- Patterns dimensioned in metric units on equipment from an international manufacturer and converted for the setting drawing

+### The Contractor's verification before concrete is placed shall address each of the conditions listed above that applies to the equipment the pad supports.

+## Anchor Setting Method {toc}

+### An anchor group holds its pattern only as well as whatever holds it during the pour. Fresh concrete around a vibrator moves anything not restrained, and a pattern that was correct when the forms were closed is not evidence that it was correct when the concrete set. {note}

+### Anchors cast into the pad shall be positioned and held by the method indicated in the datasheet.

+```datasheet

+label: Anchor Setting Method

+type: radio

+options:

+ - "Steel plate template spanning the anchor group"

+ - "Plywood or composite panel template spanning the anchor group"

+ - "Template furnished with the equipment"

+ - "Proprietary adjustable anchor setting jig"

+ - "Individually braced anchors positioned by survey"

+```

+### The template or jig shall be fabricated to the reconciled anchorage pattern dimensions and shall not be laid out in the field from nominal dimensions.

+### The template or jig shall hold every anchor within the plumb and projection tolerances of this standard through placement and consolidation.

+### The template or jig shall remain in place until the concrete supports the anchors without it.

+# Pad Geometry {toc}

+## Pad Plan Dimensions {toc}

+### Pad plan dimensions shall be as shown at [[drawing: equipment pad plan]].

+### The pad shall project beyond the perimeter of the equipment base by not less than the projection indicated in the datasheet.

+```datasheet

+label: Minimum Pad Projection Beyond the Equipment Base Perimeter

+type: range

+unit: in

+options:

+ min: 0

+ max: 36

+ step: 0.5

+```

+### The projection that governs is the largest of several unrelated demands: the edge distance the anchors need to develop concrete breakout capacity under ACI 318 Chapter 17, the footing needed by service personnel working around the machine, the swing of access doors and removable panels, the bending radius of the conductors entering at the stub-ups, and any working space that is provided on the pad rather than beside it. A projection of zero puts the equipment base flush with the pad edge, which is buildable where the anchorage develops its capacity without edge reinforcement and where service access is provided on the surrounding surface. {note}

+### Where the pad is dimensioned on the contract documents, the Contractor shall not reduce those dimensions to suit a smaller delivered footprint without the written approval of the Engineer of Record.

+## Working Space at Electrical Equipment {toc}

+### NFPA 70 Article 110 fixes the depth, width, and height of the working space at electrical equipment likely to be examined or serviced while energized, and that space has to sit on a surface a person can stand on. Whether the pad provides it or the surrounding floor or paving does changes the pad's plan size, and it changes where curbs, fences, bollards, and landscaping can be placed around it. {note}

+### Where the pad supports electrical equipment for which NFPA 70 Article 110 requires working space, the surface providing that working space shall be as indicated in the datasheet.

+```datasheet

+label: Surface Providing the Working Space at Electrical Equipment

+type: radio

+options:

+ - "The pad itself"

+ - "The adjacent finished floor or paving outside the pad"

+ - "The pad together with the adjacent finished floor or paving"

+ - "Not applicable, because no equipment on the pad requires working space"

+```

+### The surface providing the working space shall be finished level and shall be clear of the obstructions prohibited by NFPA 70 Article 110 over the full depth, width, and height that Article requires.

+## Pad Thickness {toc}

+### Thickness is the parameter that quietly governs the anchorage. It fixes the depth available for embedment, it fixes the height of the breakout cone the anchor can develop, and it fixes the stiffness with which the pad resists the equipment's operating loads. A pad thinned to save concrete cannot be compensated for anywhere else. {note}

+### Pad thickness shall be as indicated in the datasheet.

+```datasheet

+label: Pad Thickness

+type: range

+unit: in

+drawing_ref: "the equipment pad schedule or details on the structural drawings"

+options:

+ min: 2

+ max: 36

+ step: 0.5

+default: deferred

+```

+### The Contractor shall not reduce pad thickness to accommodate a shorter anchor without the written approval of the Engineer of Record and a revised anchorage calculation.

+## Pad Height Above the Supporting Surface {toc}

+### Height above the surrounding surface is what a pad buys that a painted outline on the floor does not. It lifts the equipment base clear of washdown, spills, and standing water; it gives the raceways entering from below the vertical run their bending radius needs; it keeps snowmelt and surface runoff from reaching the base at an exterior installation; and it gives the housekeeping crew an edge to work to. {note}

+### For a pad bearing on an interior finished floor, the height of the finished pad surface above that floor shall be as indicated in the datasheet.

+```datasheet

+label: Pad Height Above the Finished Floor

+type: range

+unit: in

+options:

+ min: 1

+ max: 12

+ setpoints: [1, 1.5, 2, 3, 4, 6, 8, 12]

+default: 4

+```

+### For a pad bearing on grade or on exterior paving, the height of the finished pad surface above the adjacent finished grade or paving shall be as indicated in the datasheet.

+```datasheet

+label: Pad Height Above Adjacent Exterior Grade or Paving

+type: range

+unit: in

+options:

+ min: 0

+ max: 36

+ setpoints: [0, 2, 3, 4, 6, 8, 12, 18, 24, 36]

+```

+### Exterior height is driven by conditions the template cannot know: the depth of snow that accumulates and drifts against the equipment, the design flood elevation where one applies, the depth of surface flow across the yard in a design storm, and the height of any curb or bollard line the pad has to clear. Where the pad sits flush with surrounding paving, the surrounding paving carries the drainage that the pad height would otherwise provide. {note}

+### Finished grade and paving adjacent to an exterior pad shall be graded to drain away from the pad.

+## Pad Edge Treatment {toc}

+### The arris where the top surface meets a formed face is the part of a pad that gets damaged. It takes the impact from carts, hand trucks, snow shovels, and dropped tools, and at an exterior pad it is where freeze-thaw scaling and de-icing chemical attack begin. {note}

+### The treatment at the exposed edges and corners of the pad shall be as indicated in the datasheet.

+```datasheet

+label: Pad Edge Treatment

+type: select

+options:

+ - "Formed chamfer at exposed edges and corners"

+ - "Tooled radius at exposed edges and corners"

+ - "Square formed edge"

+```

+### Removing the arris, by chamfer or by tooled radius, removes the feature that chips and gives the concrete a thicker section at the corner; keeping it square preserves the full top-surface width out to the formed face, which matters where an equipment skirt, enclosure base, or containment curb lands at the pad edge. {note}

+### Where a formed chamfer is indicated, the chamfer leg shall be as indicated in the datasheet.

+```datasheet

+label: Chamfer Leg Dimension

+type: range

+unit: in

+options:

+ min: 0.25

+ max: 2

+ setpoints: [0.25, 0.5, 0.75, 1, 1.5, 2]

+default: 0.75

+```

+### Chamfer and rustication strips shall be furnished and installed in accordance with [[sync/concrete-formwork]].

+# Pad Support and Attachment {toc}

+## Pads Bearing on Grade {toc}

+### The subgrade beneath a pad bearing on grade shall be prepared in accordance with [[sync/earthwork]].

+### The aggregate base course beneath the pad shall be furnished, placed, and compacted in accordance with [[sync/aggregate-base-course]], to the thickness indicated in the datasheet.

+```datasheet

+label: Aggregate Base Course Thickness Beneath the Pad

+type: range

+unit: in

+drawing_ref: "the geotechnical report or the foundation plan"

+options:

+ min: 0

+ max: 24

+ step: 1

+default: deferred

+```

+### A base course buys three things at once: uniform bearing across a small footprint where a soft spot would otherwise tilt the whole pad, a capillary break between the subgrade and the concrete, and a working platform that survives being walked on while the anchors are set. A thickness of zero places the pad directly on prepared subgrade, which the geotechnical engineer permits for some soils and equipment loads. {note}

+### The base course shall be compacted to the density required by [[sync/aggregate-base-course]] before pad forms are set.

+### The base course shall be moist and free of standing water, ice, snow, and frozen material at the time concrete is placed.

+## Pads Bearing on Concrete {toc}

+### A pad cast on hardened concrete is a second placement against a first, and the decision that governs its behavior is how the two are joined. Joined rigidly, the pad and the slab act together and share load, and every movement of the slab is transmitted through the interface. Left free, the pad moves independently, and the interface becomes a crack that was deliberately located instead of one that appeared. Between those, the interface can transfer shear without developing tension, or develop tension without being bonded. {note}

+### The treatment at the interface between the pad and the supporting concrete shall be as indicated in the datasheet.

+```datasheet

+label: Interface Treatment Between the Pad and the Supporting Concrete

+type: radio

+options:

+ - "Cast monolithically with the supporting concrete"

+ - "Bonded to the prepared surface of the hardened supporting concrete"

+ - "Placed in direct contact on an unprepared surface without a bonded interface"

+ - "Isolated from the supporting concrete by a full-depth bond breaker or isolation layer"

+```

+### The mechanical connection between the pad and the supporting concrete shall be as indicated in the datasheet.

+```datasheet

+label: Mechanical Connection Between the Pad and the Supporting Concrete

+type: radio

+options:

+ - "No mechanical connection"

+ - "Smooth dowels set into the supporting concrete"

+ - "Deformed reinforcing bars set into the supporting concrete and developed into the pad"

+ - "Post-installed anchors through the pad into the supporting concrete"

+```

+### A smooth dowel transfers shear across the interface while permitting the two placements to move apart along the dowel axis. A deformed bar develops tension and ties them together. Post-installed anchors clamp the pad down without developing the interface itself, which is what an equipment pad needs where uplift on the anchor group governs and the pad is otherwise free to shrink. {note}

+### Dowels, reinforcing bars, and anchors set into hardened concrete shall be installed in accordance with [[sync/post-installed-anchors]].

+### The Contractor shall locate existing reinforcement, post-tensioning tendons, and embedded raceways in the supporting concrete before drilling.

+### The Contractor shall not cut existing reinforcement, a post-tensioning tendon, or an embedded raceway.

+### Where a hole cannot be drilled to the indicated location without cutting existing reinforcement, a tendon, or an embedded raceway, the Contractor shall stop and obtain the Engineer of Record's written direction before relocating the hole.

+### Dowel and bar layout at the interface shall be as shown at [[drawing: pad interface dowel layout]].

+### The designation of the dowels or bars set into the supporting concrete shall be as indicated in the datasheet.

+```datasheet

+label: Dowel or Reinforcing Bar Designation at the Pad Interface

+type: range

+drawing_ref: "the pad details on the structural drawings"

+options:

+ min: 3

+ max: 8

+ step: 1

+default: deferred

+```

+### The embedment of the dowels or bars into the supporting concrete shall be as indicated in the datasheet.

+```datasheet

+label: Dowel or Reinforcing Bar Embedment Into the Supporting Concrete

+type: range

+unit: in

+drawing_ref: "the pad details on the structural drawings"

+options:

+ min: 2

+ max: 18

+ step: 0.5

+default: deferred

+```

+## Substrate Preparation at a Bonded Interface {toc}

+### Bond is made by mechanical interlock into a roughened, sound, clean surface, not by an adhesive layer. A profile that exposes the coarse aggregate gives the new concrete something to key into; laitance, curing compound, sealer, and oil sit between the two placements and prevent it, and a bonding agent applied over any of them bonds to the contaminant. {note}

+### Where the interface is bonded, the surface of the supporting concrete shall be prepared by the method indicated in the datasheet.

+```datasheet

+label: Surface Preparation Method at a Bonded Interface

+type: select

+options:

+ - "Mechanical scarification"

+ - "Shot blasting"

+ - "Abrasive blasting"

+ - "High-pressure water jetting"

+ - "Chipping with hand-held tools"

+ - "Needle scaling"

+ - "Grinding"

+```

+### The prepared surface shall achieve not less than the concrete surface profile indicated in the datasheet, evaluated against the ICRI 310.2R concrete surface profile replicas.

+```datasheet

+label: Minimum Concrete Surface Profile at the Bonded Interface

+type: range

+unit: ICRI CSP

+options:

+ min: 1

+ max: 10

+ step: 1

+```

+### Laitance, curing compound, sealer, coating, oil, grease, and loose or unsound material shall be removed from the prepared surface.

+### Concrete loosened or microcracked by the preparation method shall be removed until sound concrete is exposed.

+### The bonding agent at the interface shall be as indicated in the datasheet.

+```datasheet

+label: Bonding Agent at the Bonded Interface

+type: radio

+options:

+ - "Neat portland cement and water slurry scrubbed into the prepared surface"

+ - "Latex- or polymer-modified cement bonding slurry"

+ - "Epoxy bonding agent conforming to ASTM C881/C881M"

+ - "No bonding agent, with the prepared surface brought to a saturated surface-dry condition"

+```

+### Where a bonding agent is used, concrete shall be placed within the open time published by the bonding agent manufacturer for the temperature and humidity at the time of placement.

+### A bonding agent allowed to skin over or dry before the concrete reaches it becomes a bond breaker, so the open time is the operative limit rather than the coverage rate. {note}

+# Pad Concrete {toc}

+## Pad concrete shall be furnished, delivered, placed, consolidated, tested, and accepted in accordance with [[sync/cast-in-place-concrete]].

+## The exposure classes for the pad concrete shall be assigned by the Engineer of Record in accordance with [[sync/cast-in-place-concrete]] for the conditions the pad meets in service.

+## A pad is exposed to its own environment, not to the environment of the structure it is priced with. An exterior generator pad on a project whose structural concrete is entirely interior meets freezing, thawing, and de-icing chemicals that no other placement on the job sees, and a pad concrete assigned the project's interior exposure classes will scale at the edges within a few winters. {note}

+## The specified compressive strength for the pad concrete shall be as indicated in the datasheet.

+```datasheet

+label: Specified Compressive Strength - Pad Concrete

+type: range

+unit: psi

+drawing_ref: "the concrete mixture schedule on the structural drawings"

+options:

+ min: 2500

+ max: 8000

+ setpoints: [2500, 3000, 3500, 4000, 4500, 5000, 6000, 8000]

+default: deferred

+```

+## The nominal maximum coarse aggregate size for the pad concrete shall satisfy the section-dimension and bar-spacing limits of [[sync/cast-in-place-concrete]] evaluated at the most congested location in the pad.

+## The most congested location in an equipment pad is almost always inside the anchor group, where the reinforcing mat, the anchors, the template bracing, and the raceway stub-ups occupy the same few square feet. Aggregate sized against the pad's average congestion bridges there. {note}

+## Each pad shall be placed monolithically, without a construction joint or a cold joint within the pad.

+## A joint through a pad puts a plane of reduced shear transfer somewhere in the volume of concrete that resists anchor breakout and carries the equipment's operating loads, and its location is determined by where the trucks ran out rather than by where the design can tolerate it. {note}

+## Where a pad placement is interrupted long enough that the concrete already in the forms reaches initial set, the Contractor shall notify the Engineer of Record, who shall direct in writing either removal and replacement of the pad or another disposition.

+# Pad Reinforcement {toc}

+## Reinforcement shall be furnished, fabricated, supported, spliced, and placed in accordance with [[sync/concrete-reinforcement]].

+## Reinforcement in an equipment pad does two separate jobs. It controls the width of the shrinkage and thermal cracks that a small, thin, highly restrained placement will develop, and where the anchorage design calls for it, it acts as supplementary reinforcement that carries the breakout load an anchor sheds into the concrete. A pad can need the first without the second, and the two are satisfied by different details. {note}

+## The reinforcement method for the pads shall be as indicated in the datasheet.

+```datasheet

+label: Pad Reinforcement Method

+type: radio

+options:

+ - "Deformed reinforcing bar mat"

+ - "Welded wire reinforcement"

+ - "Steel fiber reinforcement"

+ - "Synthetic macrofiber reinforcement"

+ - "Plain concrete without reinforcement"

+```

+## Bars and welded wire hold a crack closed across a defined plane and can be detailed and developed to carry a specific force. Fibers are distributed through the section and limit crack width without a defined location or a development length, so they answer the shrinkage-control job and not the supplementary-reinforcement job. Plain concrete answers neither and relies on the concrete's own tensile capacity, which is what a small unrestrained pad carrying a light machine has always relied on. {note}

+## Where the anchorage design relies on supplementary reinforcement under ACI 318 Chapter 17, the pad shall be reinforced with deformed bars detailed and developed to carry the anchor forces.

+## Reinforcing bars shall conform to ASTM A615/A615M or ASTM A706/A706M, and welded wire reinforcement shall conform to ASTM A1064/A1064M.

+## Fiber-reinforced concrete shall conform to ASTM C1116/C1116M.

+## The arrangement of the reinforcement through the pad thickness shall be as indicated in the datasheet.

+```datasheet

+label: Reinforcement Arrangement Through the Pad Thickness

+type: radio

+options:

+ - "Single layer at mid-depth"

+ - "Single layer near the bottom of the pad"

+ - "Single layer near the top of the pad"

+ - "Two layers, one near the top and one near the bottom"

+```

+## The designation of the reinforcing bars in the pad shall be as indicated in the datasheet.

+```datasheet

+label: Reinforcing Bar Designation

+type: range

+drawing_ref: "the pad details on the structural drawings"

+options:

+ min: 3

+ max: 8

+ step: 1

+default: deferred

+```

+## The spacing of the reinforcing bars or welded wire in each direction shall be as indicated in the datasheet.

+```datasheet

+label: Reinforcing Bar or Welded Wire Spacing Each Way

+type: range

+unit: in

+drawing_ref: "the pad details on the structural drawings"

+options:

+ min: 3

+ max: 24

+ step: 1

+default: deferred

+```

+## Where fiber reinforcement is indicated, the dosage rate shall be as indicated in the datasheet.

+```datasheet

+label: Fiber Dosage Rate

+type: range

+unit: "lb/yd³"

+options:

+ min: 1

+ max: 100

+ step: 0.5

+```

+## Steel fibers and synthetic macrofibers occupy different parts of that dosage range for the same crack-control effect, because the two materials differ by roughly an order of magnitude in density and in the fiber count delivered per unit mass. {note}

+## Concrete cover over the reinforcement shall be as required by ACI 318 for the exposure of each pad surface and for the condition against which the pad is cast, and shall be maintained in accordance with [[sync/concrete-reinforcement]].

+## Bar supports in a pad assigned a freezing-and-thawing or a chloride exposure class shall not present bare steel at the finished surface.

+## Where a reinforcing bar conflicts with an anchor, a dowel, or an item cast into the pad, the bar shall be relocated, or terminated and replaced with bars splayed around the obstruction and spliced in accordance with [[sync/concrete-reinforcement]].

+## Reinforcement shall not be omitted at a conflict.

+# Equipment Anchorage {toc}

+## Anchor Type {toc}

+### Anchorage to an equipment pad divides into two families with opposite risk profiles. A cast-in anchor develops its capacity through a head, a hook, or a plate bearing on concrete that closes around it, and it has to be positioned before anyone can confirm the pattern against the machine. A post-installed anchor is set after the pad exists and can be laid out against the delivered equipment, and its capacity depends on hole geometry, hole cleaning, and an installation that qualified under a specific evaluation report. {note}

+### The type of anchorage securing the equipment to the pad shall be as indicated in the datasheet.

+```datasheet

+label: Equipment Anchor Type

+type: select

+options:

+ - "Cast-in headed anchor rods"

+ - "Cast-in hooked anchor rods"

+ - "Cast-in threaded rods with a plate washer and nut at the embedded end"

+ - "Cast-in anchor channels"

+ - "Post-installed adhesive anchors"

+ - "Post-installed torque-controlled expansion anchors"

+ - "Post-installed displacement-controlled expansion anchors"

+ - "Post-installed undercut anchors"

+ - "Post-installed concrete screw anchors"

+ - "No anchorage, with the equipment restrained by its own weight"

+```

+### Cast-in anchor rods shall conform to ASTM F1554 and to [[sync/structural-steel-anchor-bolts]] for grade, fabrication, threading, coating, and delivery.

+### Post-installed anchors shall conform to [[sync/post-installed-anchors]] for anchor qualification, installer certification, hole drilling and cleaning, setting, and proof loading.

+### Where the supported equipment is a designated seismic system under ASCE/SEI 7 Chapter 13, the anchors shall be qualified for seismic loading in cracked concrete.

+### Anchorage of vibration isolators, restrained isolators, snubbers, and seismic restraints to the pad shall conform to [[sync/vibration-isolation-and-seismic-restraint]].

+### Where the supported equipment imparts cyclic or impact loads to the pad, the foundation design considerations of ACI 351.3R apply in addition to the static considerations of ACI 351.2R, and the Engineer of Record shall confirm the anchorage is designed for the resulting fatigue and loosening demands.

+## Anchor Size, Embedment, and Projection {toc}

+### The diameter of the equipment anchors shall be as indicated in the datasheet.

+```datasheet

+label: Anchor Diameter

+type: range

+unit: in

+drawing_ref: "the equipment manufacturer's certified anchorage drawing"

+options:

+ min: 0.25

+ max: 2.5

+ setpoints: [0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1, 1.25, 1.5, 1.75, 2, 2.5]

+default: deferred

+```

+### The embedment depth of the equipment anchors shall be as indicated in the datasheet.

+```datasheet

+label: Anchor Embedment Depth

+type: range

+unit: in

+drawing_ref: "the equipment manufacturer's certified anchorage drawing"

+options:

+ min: 2

+ max: 36

+ step: 0.5

+default: deferred

+```

+### The embedment shall be the greater of the depth shown on the equipment manufacturer's certified anchorage drawing and the depth determined by the Engineer of Record under ACI 318 Chapter 17 for the design loads.

+### The projection of each anchor above the finished pad surface shall be as indicated in the datasheet.

+```datasheet

+label: Anchor Projection Above the Finished Pad Surface

+type: range

+unit: in

+drawing_ref: "the equipment manufacturer's certified anchorage drawing"

+options:

+ min: 0

+ max: 12

+ step: 0.25

+default: deferred

+```

+### The projection has to stack up out of parts that are decided by different parties. {note}

+- The thickness of the equipment base, rail, or mounting foot

+- The depth of the grout bed where one is provided

+- The travel of the leveling nut where the equipment is leveled on its anchors

+- The thickness of the washers and of the top nut

+- The thread engagement remaining beyond the top nut after the equipment is set

+### The Contractor shall not cut, heat, bend, or weld an anchor to correct a projection or a pattern deviation without written direction from the Engineer of Record.

+## Anchor Edge Distance and Spacing {toc}

+### Anchor edge distance, anchor spacing, and pad dimensions shall satisfy the concrete breakout provisions of ACI 318 Chapter 17 for the design loads.

+### An anchor in tension sheds its load into a cone of concrete spreading outward and upward from its embedded end. Where the pad edge cuts that cone off, the capacity drops in proportion to the volume removed, which is why a pad sized to the equipment footprint alone can fail an edge distance check that the anchor itself passes comfortably in a larger element. {note}

+### Where the edge distance or spacing available at the pad is less than the anchorage design requires, the Contractor shall notify the Engineer of Record before concrete is placed.

+## Anchor Thread Protection {toc}

+### Anchor threads projecting above the pad shall be protected from concrete, corrosion, and mechanical damage from the time of placement until the equipment is set.

+### Threads fouled with concrete, corroded, or mechanically damaged shall be cleaned or repaired and shall then be verified by running a nut over the full projected length by hand.

+### The cost of cleaning, repairing, or replacing anchors damaged after placement shall be borne by the Contractor, except where the damage is caused by an act of the Owner or by a change directed in writing.

+# Items Cast Into the Pad {toc}

+## Every item to be cast into a pad shall be set, supported, and secured against displacement before concrete is placed.

+## The Contractor shall not core or cut a placed pad to add an omitted item without written direction from the Engineer of Record.

+## A core drilled into a finished pad has no way to avoid what it cannot see. In the congested volume inside an anchor group it will usually find either the reinforcing mat or the embedded length of an anchor, and cutting either one changes the capacity the pad was accepted on. {note}

+## Raceway Stub-Ups {toc}

+### Raceways entering the equipment through the pad shall conform to [[sync/raceways-and-conduit]].

+### The termination of each raceway stub-up at the pad shall be as indicated in the datasheet.

+```datasheet

+label: Raceway Stub-Up Termination at the Pad

+type: radio

+options:

+ - "Terminated flush with the finished pad surface"

+ - "Stubbed above the finished pad surface"

+ - "Terminated below the finished pad surface within a formed recess or trough"

+ - "No raceways enter the equipment through the pad"

+```

+### Where stub-ups project above the finished pad surface, the projection shall be as indicated in the datasheet.

+```datasheet

+label: Raceway Stub-Up Projection Above the Finished Pad Surface

+type: range

+unit: in

+drawing_ref: "the equipment manufacturer's cable entry detail"

+options:

+ min: 0

+ max: 24

+ step: 0.5

+default: deferred

+```

+### Stub-ups shall be capped or plugged before concrete is placed and shall remain closed until the conductors are pulled.

+### Stub-ups shall be positioned clear of the equipment base, clear of the anchor group, and within the cable entry opening of the equipment they serve.

+### Stub-up positions shall allow the bending radius required by the largest conductor entering each raceway.

+### A clustered group of stub-ups has to land inside the equipment's cable entry opening as a group, not individually. A cluster that is correct on average and wrong at its outermost raceway leaves one conduit fouling the base, and the correction after the machine is set is to cut the conduit rather than to move it. {note}

+## Grounding Provisions at the Pad {toc}

+### Grounding and bonding at the pad shall conform to [[sync/grounding-and-bonding]] and to NFPA 70 Article 250.

+### Where the pad supports substation-class equipment, the grounding at the pad shall additionally satisfy the step and touch potential requirements developed under IEEE 80.

+### Where the pad supports pad-mounted equipment energized above 600 V, the pad opening and the equipment enclosure interface shall be coordinated with the enclosure integrity requirements of IEEE C57.12.28.

+### The grounding provisions cast into the pad shall be as indicated in the datasheet.

+```datasheet

+label: Grounding Provisions Cast Into the Pad

+type: checkbox

+options:

+ - "Grounding electrode conductor stubbed through the pad"

+ - "Ground rods driven adjacent to the pad"

+ - "Ground ring conductor encircling the pad below grade with taps stubbed through the pad"

+ - "Pad reinforcement bonded and used as a concrete-encased electrode"

+ - "Grounding bushings and bonding jumpers at the raceway stub-ups"

+ - "No grounding provisions cast into the pad"

+```

+### Each grounding conductor stubbed through the pad shall be long enough to reach the equipment ground bus or ground pad without a splice.

+### Excess grounding conductor length shall be coiled clear of the cable termination space and clear of the equipment base.

+### Where the pad serves a separately derived system, the grounding electrode conductor connection cast into the pad shall be coordinated with the system bonding jumper location required by NFPA 70 Article 250.

+## Other Items Cast Into the Pad {toc}

+### The additional items cast into the pad shall be as indicated in the datasheet.

+```datasheet

+label: Additional Items Cast Into the Pad

+type: checkbox

+options:

+ - "Cable pulling sleeves through the pad"

+ - "Formed cable trough with a removable cover"

+ - "Recessed cable pull section beneath the equipment"

+ - "Embedded steel bearing plates beneath the equipment base"

+ - "Threaded inserts for vibration isolator or seismic restraint attachment"

+ - "Lifting inserts"

+ - "Sleeves for piping penetrations"

+ - "Formed drainage opening through the pad"

+ - "No additional items cast into the pad"

+```

+### Embedded plates, sleeves, and inserts cast into the pad shall be furnished and set in accordance with [[sync/concrete-accessories]].

+# Liquid Containment at the Pad {toc}

+## Equipment that holds a liquid whose release is regulated - a mineral-oil-filled transformer, a diesel day tank, a lubricating oil reservoir - turns its pad into the first line of containment, and the containment volume is set by the liquid volume and by the jurisdiction rather than by the equipment footprint. NFPA 70 Article 450 governs the arrangement for oil-insulated transformers. {note}

+## Where the supported equipment contains a liquid whose release is regulated, containment at the pad shall be as indicated in the datasheet.

+```datasheet

+label: Liquid Containment at the Pad

+type: radio

+options:

+ - "No containment provided at the pad"

+ - "Integral raised curb cast with the pad"

+ - "Containment sump formed within the pad"

+ - "Pad sloped to drain to a separate containment structure"

+ - "Pad set within a containment basin furnished under another standard"

+```

+## The containment volume, curb height, and sump dimensions shall be as shown at [[drawing: equipment containment detail]].

+## Where containment is formed in or on the pad, the pad concrete and any coating applied to it shall be compatible with the contained liquid.

+## The finished pad surface shall be free of depressions that pond water or contained liquid within the equipment footprint or within the anchor group.

+# Pad Surface Finish {toc}

+## Finishing and curing of pad surfaces shall be performed in accordance with [[sync/concrete-curing-and-finishing]].

+## The finish on the top surface of the pad shall be as indicated in the datasheet.

+```datasheet

+label: Pad Top Surface Finish

+type: select

+options:

+ - "Hard steel-troweled finish"

+ - "Float finish"

+ - "Broom finish"

+ - "Screeded and bull-floated finish"

+```

+## The finish has to answer whatever sits on top of it. Where the equipment base bears directly on the concrete, a dense, closed surface gives uniform bearing and resists the point loads at the mounting feet. Where a grout bed follows, an open-textured surface develops grout bond, and a surface troweled to a low-permeability skin does not. Where the pad is walked on during service, a textured finish holds traction when the surface is wet or iced. {note}

+## Exposed formed faces of the pad shall be finished in accordance with [[sync/concrete-curing-and-finishing]], with fins removed and tie holes filled.

+## Curing compound shall not be applied to a surface that will receive a grout bed, a coating, or a sealer unless the curing compound is demonstrated to be compatible with that subsequent application or is fully removed before it.

+# Grout Bed Beneath the Equipment Base {toc}

+## Machinery with a machined base or a specified alignment tolerance cannot bear uniformly on a finished concrete surface, so the base is leveled on shims or leveling nuts and the remaining space is filled with a grout that transfers load without shrinking away from the bearing surface. ACI 351.1R describes that load-transfer function and the conditions under which it is achieved. {note}

+## Whether a grout bed is provided between the equipment base and the pad shall be as indicated in the datasheet.

+```datasheet

+label: Grout Bed Beneath the Equipment Base

+type: radio

+options:

+ - "No grout bed, with the equipment base bearing directly on the finished pad"

+ - "Full-bearing cementitious non-shrink grout bed"

+ - "Full-bearing epoxy grout bed"

+ - "Grout placed beneath leveling plates and soleplates without a full-bearing bed"

+```

+## Where a grout bed is provided, the grout material shall conform to [[sync/non-shrink-grout]].

+## Where a grout bed is provided, the leveling, formwork, placement, curing, and acceptance of the grout shall conform to [[sync/grouted-base-plates]].

+## Where a grout bed is provided, the anchor projection and the finished top-of-pad elevation shall account for the grout bed depth.

+# Isolation From Adjacent Construction {toc}

+## A pad and the flatwork around it are loaded differently, bear on different preparation, and change temperature at different rates. Tied rigidly together, that differential shows up as a crack at the interface, and the crack propagates into whichever placement is weaker rather than staying at the line between them. {note}

+## The treatment at the interface between the pad and adjacent slabs, paving, and building construction shall be as indicated in the datasheet.

+```datasheet

+label: Treatment at the Interface With Adjacent Flatwork

+type: radio

+options:

+ - "Full-depth isolation joint at every interface with adjacent flatwork"

+ - "Full-depth isolation joint where the pad abuts building construction, with adjacent site flatwork cast against the pad"

+ - "Adjacent flatwork cast against the pad without an isolation joint"

+ - "Pad cast monolithically with the adjacent flatwork"

+ - "No adjacent flatwork at the pad"

+```

+## Isolation joint filler, sealant, and joint preparation shall conform to [[sync/concrete-joints-and-waterstops]].

+## Where an isolation joint is indicated at an interface, the pad shall not be bonded, doweled, or otherwise tied to the adjacent construction at that interface.

+# Protection and Loading of the Pad {toc}

+## The pad shall be cured in accordance with [[sync/concrete-curing-and-finishing]].

+## Equipment shall not be set on a pad until the pad concrete has attained the fraction of its specified compressive strength indicated in the datasheet, demonstrated by field-cured specimens taken from that placement or by the maturity method.

+```datasheet

+label: Minimum Fraction of Specified Compressive Strength Before Equipment Is Set

+type: range

+unit: "%"

+options:

+ min: 25

+ max: 100

+ setpoints: [25, 50, 60, 70, 75, 80, 85, 90, 100]

+default: 75

+```

+## Loading a pad early concentrates the load at the mounting feet and at the anchors, which is exactly where the concrete is still gaining the tensile capacity that resists breakout and splitting. The cracking that follows radiates from the anchors and is not repairable by surface treatment. {note}

+## The pad shall be protected from construction traffic, from point loads, from staining, and from mechanical damage at its edges until the equipment is set.

+## The pad shall be protected from freezing until it has attained the strength required by [[sync/cast-in-place-concrete]] for the protection period.

+# Tolerances {toc}

+## Pad Dimensional Tolerances {toc}

+### Dimensional tolerances not stated in this standard shall be as specified in ACI 117.

+### An equipment pad is held tighter than a slab of the same concrete because it is not a floor. It is a bearing surface and an anchorage element for a machine with specified mounting points, and every deviation is consumed by shims, leveling nuts, and base slotting that have finite travel. {note}

+### The plan dimensions of the pad shall be within the tolerance indicated in the datasheet.

+```datasheet

+label: Plan Dimension Tolerance

+type: range

+unit: in

+options:

+ min: 0.0625

+ max: 2

+ setpoints: [0.0625, 0.125, 0.25, 0.5, 1, 2]

+default: 0.5

+```

+### The finished top-of-pad elevation shall be within the tolerance indicated in the datasheet of the elevation shown on the contract documents.

+```datasheet

+label: Top-of-Pad Elevation Tolerance

+type: range

+unit: in

+options:

+ min: 0.125

+ max: 2

+ setpoints: [0.125, 0.25, 0.5, 0.75, 1, 2]

+default: 0.5

+```

+### The levelness of the finished top surface shall be within the tolerance indicated in the datasheet, measured with a 10 ft straightedge laid in any direction on the surface.

+```datasheet

+label: Top-of-Pad Levelness Tolerance Under a 10 ft Straightedge

+type: range

+unit: in

+options:

+ min: 0.0625

+ max: 0.5

+ setpoints: [0.0625, 0.125, 0.1875, 0.25, 0.375, 0.5]

+default: 0.125

+```

+## Anchorage Tolerances {toc}

+### The as-set anchorage pattern shall be within the tolerance indicated in the datasheet, measured center to center between adjacent anchors.

+```datasheet

+label: Anchorage Pattern Tolerance Between Adjacent Anchors

+type: range

+unit: in

+options:

+ min: 0.03125

+ max: 0.5

+ setpoints: [0.03125, 0.0625, 0.125, 0.1875, 0.25, 0.5]

+default: 0.125

+```

+### The as-set anchor projection shall be within the tolerance indicated in the datasheet of the projection indicated for that anchor.

+```datasheet

+label: Anchor Projection Tolerance

+type: range

+unit: in

+options:

+ min: 0.0625

+ max: 1

+ setpoints: [0.0625, 0.125, 0.25, 0.375, 0.5, 1]

+default: 0.5

+```

+### The deviation of each anchor from plumb shall be within the tolerance indicated in the datasheet.

+```datasheet

+label: Anchor Deviation From Plumb

+type: range

+unit: degrees

+options:

+ min: 0.25

+ max: 5

+ step: 0.25

+```

+### The pattern shall be measured against the reconciled anchorage pattern dimensions and shall not be measured against a field layout of nominal dimensions.

+### An anchor out of plumb still measures correctly at the pad surface while its embedded end has moved, so the plumb tolerance is what protects the embedment and edge distance the anchorage was designed on. It also determines whether a nut and washer bear flat on the equipment base. {note}

+## Resolution of Out-of-Tolerance Anchorage {toc}

+### Where the as-set anchorage exceeds a tolerance of this standard, the Contractor shall notify the Engineer of Record and shall not set the equipment on that pad until a disposition is issued in writing.

+### The Engineer of Record shall direct one of the following dispositions:

+- Acceptance of the anchorage as set, where the anchorage design tolerates the measured deviation

+- Reaming or slotting of the equipment base, with the written concurrence of the equipment manufacturer

+- Installation of replacement anchors designed for the condition, in accordance with [[sync/post-installed-anchors]]

+- Removal and replacement of the pad

+### The cost of correcting anchorage set outside tolerance shall be borne by the Contractor, except where the deviation is caused by an act of the Owner, by a change directed in writing, or by equipment information revised after the concrete was placed.

+# Verification Before Concrete Is Placed {toc}

+## Immediately before concrete is placed in a pad, the Contractor shall verify and record the items indicated in the datasheet for that pad.

+```datasheet

+label: Verification Required Before Concrete Is Placed

+type: checkbox

+options:

+ - "Anchorage pattern dimensions and pattern orientation match the reconciled anchorage drawing"

+ - "Anchor projections and embedments are correct and anchors are plumb"

+ - "Setting template or jig is secured against displacement"

+ - "Reinforcement is placed, supported, tied, and at the required cover"

+ - "Raceway stub-ups are positioned, braced, and closed"

+ - "Grounding conductors are positioned and protected"

+ - "Sleeves, troughs, inserts, and bearing plates are positioned and secured"

+ - "Forms are dimensionally correct, tight, braced, and treated with release agent"

+ - "Bearing surface is clean, sound, and in the required moisture condition"

+ - "Prepared bonded interface meets the required surface profile and the bonding agent is within its open time"

+default:

+ - "Anchorage pattern dimensions and pattern orientation match the reconciled anchorage drawing"

+ - "Anchor projections and embedments are correct and anchors are plumb"

+ - "Setting template or jig is secured against displacement"

+ - "Reinforcement is placed, supported, tied, and at the required cover"

+ - "Raceway stub-ups are positioned, braced, and closed"

+ - "Forms are dimensionally correct, tight, braced, and treated with release agent"

+ - "Bearing surface is clean, sound, and in the required moisture condition"

+```

+## Concrete shall not be placed until every deficiency found in the verification has been corrected.

+## The verification record shall identify the pad, the date, and the person who performed it.

+# Verification Before Equipment Is Set {toc}

+## Before the equipment is released for delivery to the pad, the Contractor shall verify and record the items indicated in the datasheet for that pad.

+```datasheet

+label: Verification Required Before Equipment Is Released to the Pad

+type: checkbox

+options:

+ - "Pad concrete has attained the required fraction of its specified compressive strength"

+ - "As-set anchorage pattern is within tolerance of the reconciled anchorage drawing"

+ - "Anchor projections and plumb are within tolerance"

+ - "Anchor threads are clean, undamaged, and accept a nut over the full projection"

+ - "Plan dimensions, top-of-pad elevation, and levelness are within tolerance"

+ - "Raceway stub-ups and grounding conductors are present, clean, and correctly located"

+ - "Containment curb, sump, and drainage provisions are complete"

+ - "Pad is free of cracks, spalls, exposed reinforcement, and surface defects outside the acceptance criteria"

+default:

+ - "Pad concrete has attained the required fraction of its specified compressive strength"

+ - "As-set anchorage pattern is within tolerance of the reconciled anchorage drawing"

+ - "Anchor projections and plumb are within tolerance"

+ - "Anchor threads are clean, undamaged, and accept a nut over the full projection"

+ - "Plan dimensions, top-of-pad elevation, and levelness are within tolerance"

+ - "Raceway stub-ups and grounding conductors are present, clean, and correctly located"

+ - "Pad is free of cracks, spalls, exposed reinforcement, and surface defects outside the acceptance criteria"

+```

+## The verification record shall be transmitted to the Engineer of Record before the equipment is released for delivery to the pad.

+## Everything this verification checks can be corrected while the pad is an isolated piece of work and the machine is still at the supplier. After delivery the same corrections run through demurrage, rigging, storage, demolition, and a second delivery, so the cost of finding a defect rises by orders of magnitude at a single, identifiable moment. {note}

+## Surface defects found during the verification shall be evaluated and repaired in accordance with [[sync/concrete-repair-and-restoration]].

+## The Contractor shall not perform a structural repair to a pad, relocate an anchor, or inject a crack without written direction from the Engineer of Record.

+# Delivery, Storage, and Handling {toc}

+## Reinforcing bars and welded wire reinforcement shall be delivered, stored, and handled in accordance with [[sync/concrete-reinforcement]].

+## Cast-in anchor rods shall be delivered, identified, stored, and handled in accordance with [[sync/structural-steel-anchor-bolts]], with thread protection remaining in place from delivery through installation.

+## Post-installed anchors and their adhesives shall be delivered, stored, and handled in accordance with [[sync/post-installed-anchors]].

+## Grout shall be delivered, stored, and handled in accordance with [[sync/non-shrink-grout]].

+## Bonding agents, curing materials, and containment materials shall be stored within the temperature and humidity limits published by their manufacturers and shall be protected from freezing.

+## Material whose published shelf life has expired shall not be incorporated in the work.

+# Warranty {toc}

+## The Contractor shall warrant the pad work against defects in materials and workmanship for the period indicated in the datasheet, running from the date of substantial completion.

+```datasheet

+label: Installation Warranty Period

+type: range

+unit: years

+options:

+ min: 1

+ max: 10

+ setpoints: [1, 2, 3, 5, 10]

+default: 1

+```

+## The warranty shall cover cracking beyond the acceptance criteria of [[sync/concrete-repair-and-restoration]], surface spalling, displacement or loosening of anchors, loss of anchorage capacity, separation at a bonded interface, and settlement or heave of the pad.

+## The warranty shall not cover damage caused by equipment loads exceeding the design basis recorded on the contract documents, by vehicle or equipment impact, or by settlement of subgrade prepared under a scope other than the Contractor's.

+## Where a warranty repair is performed, the repaired work shall be warranted for the full original warranty period running from the date of the repair, or for the remainder of the original period, whichever ends later.

+## The Contractor shall bear the cost of a warranty repair, of removing and resetting equipment to gain access for it, and of restoring adjacent construction disturbed by it.

+## Material warranties for the anchors, grout, bonding agents, coatings, and repair materials incorporated in the pad work shall be assigned to the Owner and included in the closeout submittals.

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