Slab-on-Grade

Rev 1 · Updated Jun 12, 2026 · View history

1 Scope

NOTE This standard covers cast-in-place concrete slabs supported by and in direct contact with the ground, where the soil and any subbase carry the slab loads rather than a structural frame. (1.1)
NOTE A slab-on-grade (SOG) is a ground-supported floor: the subgrade, not beams or columns, provides the reaction to applied loads. This distinguishes it from a structurally supported slab, where the design and detailing are fundamentally different. Because the slab and the ground act as a system, the quality of the finished floor depends as much on subgrade preparation and joint layout as on the concrete itself. (1.2)
NOTE The slab assembly addressed here includes the prepared subgrade, granular subbase, vapor retarder, reinforcement or fiber, concrete, joints, curing, and surface tolerances as a coordinated whole. (1.3)
NOTE This standard applies to interior building floors, exterior aprons, dock and equipment pads, and utility slabs where the slab bears on the ground. (1.4)
NOTE The following are outside this standard and are governed elsewhere. (1.5)
  • Structural mix proportioning, formwork, and placement for elevated and formed concrete — see Cast In Place Concrete.
  • Reinforcing bar schedules, lap splices, hooks, and bar placement tolerances — see Concrete Reinforcement.
  • Vapor retarder material classification, permeance, and seaming requirements — see Vapor Retarders.
  • Decorative grinding, densifiers, stains, and sealer systems on finished surfaces — see Polished Concrete.
  • Concrete pavements and roadways designed for vehicular traffic under AASHTO methods.
  • Structural mat foundations and post-tensioned transfer slabs that resist column loads.

1.6 Slab classification

NOTE The slab classification shall be selected to match the structural demand and crack-control strategy of the application. (1.6.1)
NOTE Classification drives nearly every downstream decision — thickness, reinforcement, joint spacing, and tolerance. Selecting it first prevents the common error of specifying a reinforcement type that is incompatible with the chosen joint strategy (for example, leaving wide-spaced joints in a plain slab carrying forklift loads). (1.6.2)
Slab classificationradio
Plain (unreinforced) — crack control by joint spacing only
Conventionally reinforced — WWR or rebar for temperature/shrinkage
Steel fiber-reinforced
Synthetic macro-fiber reinforced
Post-tensioned (unbonded tendons)
NOTE Plain slabs rely entirely on closely spaced contraction joints to control random cracking and are appropriate only for lightly and uniformly loaded floors. (1.6.3)
NOTE Conventionally reinforced slabs carry welded wire reinforcement or a light rebar grid sized for temperature and shrinkage, not to prevent cracking but to hold crack widths tight between joints. (1.6.4)
NOTE Steel and synthetic macro-fiber slabs distribute reinforcement three-dimensionally through the section, providing post-crack toughness and allowing wider joint spacing than plain slabs. (1.6.5)
NOTE Post-tensioned slabs on grade use unbonded tendons with edge beams to precompress the slab, controlling cracking over expansive soils and across large jointless areas. (1.6.6)

2 Referenced Standards

2.1Materials, design, and construction shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
Standard Title
ACI 360R-10 Guide to Design of Slabs-on-Ground
ACI 302.1R-15 Guide to Concrete Floor and Slab Construction
ACI 224.3R-95 Joints in Concrete Construction
ACI 117-10 Specification for Tolerances for Concrete Construction and Materials
ASTM E1745 Plastic Water Vapor Retarders Used in Contact with Soil or Granular Fill under Concrete Slabs
ASTM E1643 Selection, Design, Installation, and Inspection of Water Vapor Retarders under Concrete Slabs
ASTM E1155 Determining FF Floor Flatness and FL Floor Levelness Numbers
ASTM C920 Elastomeric Joint Sealants
ASTM D1751 Preformed Expansion Joint Filler (Nonextruding and Resilient Bituminous Types)
ASTM C33 Concrete Aggregates
ASTM C309 Liquid Membrane-Forming Compounds for Curing Concrete
ASTM C1315 Liquid Membrane-Forming Compounds Having Special Properties for Curing and Sealing Concrete
ASTM A1064 Steel Wire and Welded Wire Reinforcement for Concrete
ASTM D698 Laboratory Compaction Characteristics of Soil (Standard Proctor)
ASTM D1557 Laboratory Compaction Characteristics of Soil (Modified Proctor)
ASTM D6938 In-Place Density and Water Content of Soil by Nuclear Methods
IBC 2024 §1907 Concrete Slabs-on-Ground
IRC 2024 §R506 Concrete Floors (On Ground)
PTI DC80.3 Design of Post-Tensioned Slabs-on-Ground

3 Submittals

3.1 Action Submittals

3.1.1The Contractor shall submit the following action items for review before placing concrete:
  • Concrete mix design(s) with compressive strength, w/cm ratio, aggregate gradation, cement type, and supplementary cementitious material proportions.
  • Reinforcement shop drawings or fiber dosage data, including fiber type, length, and aspect ratio.
  • Joint layout drawing showing contraction, isolation, and construction joints with dimensions and saw-cut timing.
  • Vapor retarder product data with ASTM E1745 class, thickness, and permeance.
  • Curing method and product data, including ASTM C309 or C1315 classification.
  • Manufacturer data for dowels, joint filler, and sealant.
Action submittalscheckbox
Concrete mix design(s)
Reinforcement shop drawings / fiber dosage data
Joint layout drawing
Vapor retarder product data
Curing method and product data
Dowel, filler, and sealant data

3.2 Informational Submittals

3.2.1The Contractor shall submit the following informational items:
  • Subgrade and subbase compaction test reports with Proctor reference and field densities.
  • Aggregate source and gradation reports per ASTM C33.
  • Concrete delivery tickets with batch time, water added, and admixture quantities.
  • Field test reports for slump, air, temperature, and compressive strength.
Informational submittalscheckbox
Compaction test reports
Aggregate gradation reports
Concrete delivery tickets
Field test reports (slump, air, strength)

3.3 Closeout Submittals

3.3.1The Contractor shall submit the following closeout items at substantial completion:
  • Floor flatness/levelness (FF/FL) survey reports per ASTM E1155.
  • As-built joint layout reflecting field deviations from the approved layout.
  • Moisture test results where required for flooring installation.
Closeout submittalscheckbox
FF/FL survey reports
As-built joint layout
Moisture test results

4 Quality Assurance

NOTE The slab-on-grade is a single integrated system, and acceptance depends on documented control of the subgrade, the concrete, and the finished surface in equal measure. (4.1)
NOTE The most damaging SOG failures — random cracking, curling, joint spalling, and flooring adhesive failure — usually trace to a controllable process that was never tested, not to a hidden material defect. Quality assurance for SOG is therefore weighted heavily toward field verification at the moment work is performed. (4.2)
4.3The Contractor shall hold a pre-placement conference with the Engineer of Record, testing agency, and finishing crew before the first placement.
4.4The Contractor shall not place concrete on a subgrade or subbase that has not passed compaction testing.
4.5The Contractor shall not place concrete on frozen, saturated, or unstable subgrade.
4.6Subgrade and subbase compaction shall be field-tested at the frequency specified, with each lift verified before the next is placed.
Compaction test frequencyselect
1 test per 2,000 sq ft per lift
1 test per 5,000 sq ft per lift
1 test per 10,000 sq ft per lift
4.7Concrete field tests shall be taken at the frequency required by the project specifications, with a minimum of one set of strength cylinders per 100 cubic yards or per day of placement.
4.8The testing agency shall verify slump, air content, and concrete temperature on each load sampled.

5 Environmental and Service Conditions

NOTE Slab thickness, reinforcement, and joint spacing are governed by the service loads the floor must carry, which must be defined before any element is sized. (5.1)
NOTE A warehouse floor carrying loaded rack posts and narrow-aisle lift trucks demands a completely different design than a retail sales floor carrying uniform live load. Stating the governing loads converts the slab from a guess into an engineered element. (5.2)
5.3The design loads imposed on the slab shall be defined and the slab designed to resist them per ACI 360R-10.
Governing service load typeradio
Uniform distributed load only
Rack / storage post loads
Forklift / hard-wheeled vehicle loads
Concentrated equipment / point loads
Design uniform live loadrange
psf
1001000
Default: 250 psf
NOTE The subgrade modulus of subgrade reaction (k-value) used in design shall be established by geotechnical evaluation of the prepared subgrade. (5.4)
NOTE The k-value quantifies how much the soil deflects under load and is the single most influential soil parameter in slab thickness design. A subbase amplifies the effective k-value, which is one reason a granular subbase is specified even where bearing is otherwise adequate. (5.5)
Design modulus of subgrade reaction (k)range
pci
50400
Default: 150 pci
NOTE Where the slab will receive moisture-sensitive flooring, the design shall account for under-slab moisture control through the vapor retarder and curing method. (5.6)

6 Subgrade and Subbase

NOTE A uniform, properly compacted subgrade is the foundation of a crack-free slab, because differential settlement produces cracks that no concrete quality can prevent. (6.1)
NOTE Slabs do not span; they are supported continuously. When a soft spot or uncompacted backfill settles under a loaded slab, the slab bends to follow it and cracks. Because such cracks look identical to shrinkage cracks, they are routinely and wrongly blamed on the concrete. Verified, uniform compaction is the only defense. (6.2)
6.3The subgrade shall be compacted to the specified percentage of maximum dry density determined by the referenced Proctor method.
Subgrade compaction requirementradio
95% of Standard Proctor maximum dry density (ASTM D698)
98% of Standard Proctor maximum dry density (ASTM D698)
95% of Modified Proctor maximum dry density (ASTM D1557)
98% of Modified Proctor maximum dry density (ASTM D1557)
6.4The subgrade moisture content at compaction shall be maintained within the range specified relative to optimum.
Datasheet
6.5Soft, yielding, or organic material encountered in the subgrade shall be removed and replaced with approved engineered fill compacted to the specified density.
6.6Engineered fill shall be placed in lifts not exceeding the specified maximum loose thickness and compacted before the next lift is placed.
Maximum fill lift thickness (loose)range
in
612
Default: 8 in
NOTE A granular subbase increases the effective subgrade modulus, provides a level working platform for placing concrete, and gives a capillary break above the soil. (6.7)
NOTE Even where the native soil bears adequately, a crushed-stone subbase is specified on most SOG projects because it produces a uniform, free-draining surface that finishers can work from and that protects the vapor retarder during placement. (6.8)
6.9A granular subbase shall be provided where specified, of the type and thickness selected below.
Subbase typeradio
None (slab on prepared subgrade)
Crushed stone / crushed gravel
Lean concrete base (LCB)
Granular subbase thicknessrange
in
412
Default: 4 in
NOTE The subbase shall be compacted and trimmed to the specified elevation tolerance to control slab thickness. (6.10)
NOTE A subbase that is high in spots robs the slab of thickness exactly where it may be thinnest, while low spots waste concrete. Trimming to tolerance protects the design thickness. (6.11)
6.12The compacted subbase surface shall be maintained within the specified elevation tolerance before vapor retarder placement.
Subbase surface elevation tolerancerange
in
01
0.50.75
Default: 0.75 in

7 Vapor Retarder

NOTE The vapor retarder placement plane is a recurring source of RFIs and flooring failures, so this standard states the placement position explicitly. (7.1)
NOTE Two practices exist: placing the retarder directly under the slab, and placing it lower on a granular blotter layer. ACI 302.1R-15 directs placement directly under the slab for floors that will receive moisture-sensitive flooring, because a blotter layer above the retarder traps mix and bleed water that has nowhere to drain, increasing surface bleeding, scaling, and delamination. Material selection, permeance, and seaming are governed by Vapor Retarders. (7.2)
7.3The vapor retarder shall be placed directly beneath the slab, in contact with the bottom of the concrete, unless the Engineer of Record directs a blotter-layer placement in writing.
Vapor retarder placement planeradio
Directly under slab (ACI 302.1R-15 recommendation)
On blotter layer 2 to 4 in. below slab
7.4The vapor retarder class shall be selected per ASTM E1745 to suit the floor covering and moisture sensitivity of the space.
Vapor retarder class (ASTM E1745)radio
Class A
Class B
Class C
7.5The vapor retarder shall be installed per ASTM E1643, with laps, seams, and penetration sealing as required by Vapor Retarders.
NOTE Vapor retarder penetrations for pipes, conduit sleeves, and column anchors shall be sealed so the membrane remains continuous. (7.6)
NOTE An unsealed penetration is a direct moisture path that negates the entire barrier and commonly surfaces as adhesive failure under occupancy. Sealing every penetration is not optional detailing — it is what makes the retarder function. (7.7)
7.8Every penetration through the vapor retarder shall be sealed to maintain continuity of the moisture barrier.

8 Concrete

NOTE Specifying a strength class alone does not produce a durable floor; the water-cementitious ratio and aggregate gradation control the shrinkage and surface quality that determine how the slab performs. (8.1)
NOTE A high-strength mix with an uncontrolled w/cm and a poor gradation will shrink, curl, crack, and dust despite passing its cylinder breaks. The mix design must control strength, water, aggregate, and admixtures together. Structural mix proportioning principles are detailed in Cast In Place Concrete; this section sets the SOG-specific limits. (8.2)
8.3The concrete compressive strength at 28 days shall be not less than the specified value.
Specified compressive strength (f'c) at 28 daysrange
psi
30005000
Default: 4000 psi
8.4The water-cementitious materials ratio shall not exceed the specified maximum.
Maximum water-cementitious materials ratiorange
w/cm
0.40.55
0.450.5
Default: 0.5 w/cm
8.5The nominal maximum aggregate size shall be the largest size consistent with slab thickness and reinforcement clearance, to reduce paste content and shrinkage.
Nominal maximum aggregate sizeselect
3/8 in
1/2 in
3/4 in
1 in
1-1/2 in
8.6Concrete aggregates shall conform to ASTM C33 for grading and quality.
8.7The slump at the point of placement shall be within the specified range, measured after any permitted water or admixture addition.
Slump at point of placementrange
in
36
45
Default: 5 in
NOTE Supplementary cementitious materials may be used within the proportions specified to reduce permeability and heat of hydration. (8.8)
NOTE Fly ash and slag improve workability and long-term durability, but excessive replacement can delay set and bleeding, complicating finishing on a slab where surface quality is paramount. The proportions below bound the substitution. (8.9)
Datasheet
NOTE A shrinkage-reducing admixture should be specified for large jointless placements or floors with tight crack-width limits. (8.10)

9 Reinforcement and Fiber

NOTE Reinforcement in a ground-supported slab controls crack width; it does not prevent cracking, and confusing the two leads to under- or over-designed slabs. (9.1)
NOTE A SOG cracks because concrete shrinks while the subgrade restrains it. Temperature/shrinkage reinforcement does not stop that crack from forming — it holds the crack tight so it stays narrow and does not progress. Fiber reinforcement works the same way at the section level. Structural reinforcement detailing, splices, and placement tolerances are governed by Concrete Reinforcement. (9.2)
9.3Where conventional reinforcement is specified, it shall be welded wire reinforcement conforming to ASTM A1064 or deformed bars as scheduled.
Conventional reinforcement typeradio
Welded wire reinforcement (flat sheets, ASTM A1064)
Deformed reinforcing bar grid
None (fiber or plain slab)
9.4Welded wire reinforcement shall be supported on chairs at the specified height within the slab so it is positioned, not left on the subgrade.
Reinforcement position from top of slabrange
in
1.53
Default: 2 in
NOTE Reinforcement laid directly on the subgrade and "hooked up" during placement ends up at the bottom of the slab where it does nothing for surface crack control. (9.4.1)
9.5Where steel fiber reinforcement is specified, the dosage shall be not less than the specified value, uniformly distributed throughout the mix.
Steel fiber dosagerange
lb/cy
1560
Default: 33 lb/cy
9.6Where synthetic macro-fiber reinforcement is specified, the dosage shall be not less than the specified value.
Synthetic macro-fiber dosagerange
lb/cy
312
Default: 5 lb/cy
9.7Fibers shall be charged and mixed per the manufacturer's procedure so that balling is avoided and distribution is uniform.
NOTE Post-tensioned slabs on grade shall be designed per PTI DC80.3 with unbonded tendons and edge beams as required for the soil and loading. (9.8)

10 Slab Thickness

NOTE Slab thickness is the result of a load analysis, not a rule of thumb, and selecting it from joint-spacing tables alone leaves the slab undersized for concentrated loads. (10.1)
NOTE ACI 360R-10 provides Westergaard and finite-element methods that size the slab for the governing wheel, post, or uniform load against the design k-value. The datasheet below records the design output; it is not a substitute for the analysis. (10.2)
10.3The slab thickness shall be the greater of the thickness required by the load analysis per ACI 360R-10 and the prescriptive minimum of the adopted building code.
Design slab thicknessrange
in
412
568
Default: 6 in
NOTE For commercial slabs-on-ground, IBC 2024 §1907 and IRC 2024 §R506 establish prescriptive minimum thickness and fill requirements that the design shall not fall below. (10.3.1)
10.4The slab thickness shall be held within the tolerance of ACI 117-10, verified against the trimmed subbase elevation.
Slab thickness tolerancerange
in
-0.3750.5
-0.3750.375
Default: -0.375 in

11 Joints

NOTE Joints are the slab's deliberate crack-control plan; a slab will crack, and the only choice is whether it cracks where designed or at random. (11.1)
NOTE Contraction (control) joints create planes of weakness so shrinkage cracks form straight and hidden beneath the joint. Isolation joints separate the slab from columns, walls, and footings so their restraint does not crack the field. Construction joints close out each day's placement. Joint design principles follow ACI 224.3R-95. (11.2)

11.3 Contraction Joints

11.3.1Contraction joints shall be located so that the spacing in feet does not exceed the specified multiple of the slab thickness in inches.
Contraction joint spacing factorrange
× slab thickness (in) = spacing (ft)
2436
243036
Default: 30 × slab thickness (in) = spacing (ft)
NOTE Contraction joint panels shall be kept as close to square as practical, with the long-to-short side ratio not exceeding the specified maximum. (11.3.2)
NOTE Long, narrow panels crack across the middle because shrinkage accumulates along the long dimension faster than the joints can relieve it. Keeping panels near-square keeps cracks at the joints. (11.3.3)
Maximum panel aspect ratiorange
long:short
11.5
Default: 1.5 long:short
11.3.4Saw-cut contraction joints shall be cut to the specified depth as a fraction of the slab thickness to reliably induce cracking at the joint.
Saw-cut joint depthradio
1/4 of slab thickness (early-entry sawing)
1/3 of slab thickness (conventional sawing)
NOTE Saw-cutting shall begin as soon as the concrete will support the saw without raveling and before shrinkage cracking develops. (11.3.5)
NOTE The single most common joint failure is cutting too late. Early-entry saws are used within hours of finishing precisely so the cut precedes the shrinkage crack; waiting for conventional saws often lets the slab crack first, defeating the joint. (11.3.6)
11.3.7Saw-cutting shall be completed within the specified window after final finishing, adjusted for temperature and conditions.
Saw-cut timing window after finishingrange
hours
212
48
Default: 6 hours

11.4 Isolation Joints

NOTE Isolation joints shall be provided at all columns, walls, footings, equipment pads, and fixed penetrations to separate the slab from restraint. (11.4.1)
NOTE Anything that restrains the slab while it shrinks becomes a crack origin. Columns are the classic case: without an isolation joint, cracks radiate diagonally from each column corner. Full-depth isolation lets the field move independently. (11.4.2)
11.4.3A full-depth isolation joint shall be provided around every column and at every junction with a wall or footing.
11.4.4Isolation joints shall be formed with preformed filler conforming to ASTM D1751 at the specified thickness.
Isolation joint filler thicknessselect
1/4 in
3/8 in
1/2 in
NOTE Column isolation joints shall be diamond-shaped (turned 45°) or circular so the slab can shrink away from the column on all sides. (11.4.5)

11.5 Construction Joints

11.5.1Construction joints shall be located at the edges of each placement and shall coincide with planned contraction joints wherever practical.
NOTE Load-transfer devices shall be provided at construction joints and at contraction joints subject to hard-wheeled traffic, sized to transfer load while permitting horizontal movement. (11.5.2)
NOTE Across a joint carrying forklifts, the two panels must deflect together or the joint edges spall under each wheel pass. Smooth dowels or plate dowels transfer the vertical load while still letting the joint open as the slab shrinks. (11.5.3)
11.5.4Where load transfer is required, dowels shall be provided of the type and size selected below.
Load-transfer device typeradio
None (no hard-wheeled traffic)
Smooth round dowel bars
Square / diamond plate dowels
Smooth dowel bar diameterselect
3/4 in
1 in
1-1/4 in
1-1/2 in

11.6 Joint Filling

NOTE Whether and how joints are filled depends on the traffic, and leaving joints unfilled under hard wheels guarantees edge spalling. (11.6.1)
NOTE Contraction joints in a space with hard-wheeled traffic must be filled with a semi-rigid filler that supports the joint edges; leaving them open lets the loaded wheels chip the arrises. In light-traffic spaces, an elastomeric sealant or even an open joint may be acceptable. The filler must not be installed until the slab has done most of its drying shrinkage, or it will be pulled apart as the joint opens. (11.6.2)
11.6.3Contraction joints in areas subject to hard-wheeled traffic shall be filled with a semi-rigid epoxy or polyurea filler that supports the joint edges full depth of the saw cut.
11.6.4Joints not subject to hard-wheeled traffic shall be filled with an elastomeric sealant conforming to ASTM C920 or left open as specified.
Joint filling treatmentradio
Semi-rigid epoxy / polyurea filler (hard-wheeled traffic)
Elastomeric sealant (ASTM C920)
Leave open
11.6.5Joint filling shall be deferred until the slab has undergone the specified minimum drying period so the joint opening has substantially stabilized.
Minimum cure before joint fillingrange
days
2890
286090
Default: 90 days

12 Curing

NOTE Curing keeps water in the concrete during the critical early days when surface strength and abrasion resistance are developing, and inadequate curing is a leading cause of dusting and surface failures. (12.1)
NOTE A slab that dries too fast at the surface ends up with a weak, dusting wear layer no matter how strong the body of the concrete is. The curing method must also be compatible with the planned floor covering — a wax-based compound under adhesive flooring can cause bond failure. (12.2)
12.3Curing shall begin immediately after final finishing and shall continue for the specified minimum duration.
Minimum curing durationrange
days
314
37
Default: 7 days
12.4The curing method shall be selected for compatibility with the finished floor covering and the placement conditions.
Curing methodradio
Wet cure (continuous moisture, burlap/poly)
Curing compound, ASTM C309 (resin or wax base)
Curing/sealing compound, ASTM C1315 (resin base)
NOTE Where slabs will receive adhesive-applied flooring, a resin-based ASTM C1315 compound shall be used or the compound shall be fully removed before flooring installation. (12.5)
12.6Where early solar heat gain or surface temperature is a concern, a white-pigmented (Type 2) curing compound shall be specified to reflect heat.
NOTE In hot, dry, or windy conditions, an evaporation retarder shall be applied to the bleeding surface to prevent plastic shrinkage cracking before final finishing. (12.7)
NOTE Plastic shrinkage cracks form when surface water evaporates faster than bleed water rises, which happens quickly under sun and wind. An evaporation retarder is a temporary film that buys the finishers time; it is not a curing compound and does not replace curing. (12.8)

13 Surface Tolerances

NOTE Floor flatness and levelness are specified with F-numbers, but the numbers are meaningless until the surface class is identified, because conventional and defined-traffic floors are measured and built differently. (13.1)
NOTE FF (flatness) governs bumpiness; FL (levelness) governs tilt. A conventional random-traffic floor is specified with overall FF/FL values per ASTM E1155. A defined-traffic (DT) floor for narrow-aisle, high-rack warehouses is measured directionally along the wheel paths and drives the screeding method and pour sequence. Specifying F-numbers without the class leaves the contractor unable to plan the placement. (13.2)
13.3The floor surface class shall be identified before specifying F-number tolerances.
Floor surface classradio
Conventional (random traffic), ASTM E1155 FF/FL
Defined-traffic (narrow-aisle), directional tolerance
13.4For conventional floors, the specified overall flatness (FF) and levelness (FL) shall be achieved and verified per ASTM E1155.
Specified overall flatness FFrange
FF
2050
2535
Default: 35 FF
Specified overall levelness FLrange
FL
1540
2025
Default: 25 FL
NOTE The F-number survey shall be performed within 72 hours of slab placement, before shoring or curling can alter the result, per ASTM E1155. (13.5)
NOTE Defined-traffic floors shall meet the directional flatness and levelness limits along the defined wheel paths as scheduled. (13.6)
NOTE The defined-traffic limits and aisle locations are layout-specific and cannot be reduced to a single field; they are coordinated on the floor plan. Aisle and wheel-path locations are indicated defined-traffic aisle layout. (13.7)

14 Installation

NOTE The slab shall be placed, struck off, and finished in a continuous operation per section, working from the established screed lines and joints. (14.1)
14.2Concrete shall not be placed when ambient or material temperatures fall outside the specified range without approved cold- or hot-weather protection.
Allowable concrete placement temperaturerange
°F
4090
5080
Default: 70 °F
14.3Water shall not be added to the surface to aid finishing, as it weakens the wear surface and causes dusting and scaling.
NOTE Finishing operations shall not begin while bleed water is present on the surface. (14.4)
NOTE Troweling bleed water back into the surface traps it under a sealed skin and is a direct cause of blistering and delamination. Finishers must wait for the sheen to leave before floating and troweling. (14.5)
14.6The surface finish shall be the type required by the floor's service and any subsequent covering.
Surface finishradio
Steel-troweled (hard, dense)
Float finish
Broom finish (exterior / slip resistance)
NOTE Exterior slabs, aprons, and dock pads shall be sloped to drain as indicated and shall receive a broom finish for slip resistance. (14.7)
NOTE Exterior slab drainage slopes and high/low points are indicated exterior slab drainage. (14.8)

15 Field Quality Control

NOTE Acceptance of the finished slab rests on documented field results, not visual inspection alone, because the defects that matter most are dimensional and below the surface. (15.1)
15.2The testing agency shall record slump, air content, temperature, and unit weight for each sampled load.
15.3Compressive strength cylinders shall be cast, cured, and tested per the project specifications, and results below the specified strength shall be evaluated per ACI 360R-10.
NOTE The finished slab shall be inspected for cracking, and any crack exceeding the specified width shall be evaluated and repaired as directed. (15.4)
Maximum acceptable crack width before evaluationrange
in
0.010.04
Default: 0.02 in

16 Delivery, Storage, and Handling

16.1Reinforcement and welded wire reinforcement shall be stored off the ground and protected from contaminants that impair bond.
16.2Vapor retarder material shall be stored protected from sunlight and physical damage until installation.
NOTE Joint filler, sealant, and curing materials shall be stored within the manufacturer's specified temperature range and shall not be used past their shelf life. (16.3)

17 Warranty

17.1The Contractor shall warrant the slab-on-grade against defective materials and workmanship for the specified period from substantial completion.
Workmanship warranty periodrange
years
15
Default: 1 years
NOTE Cracking, spalling, scaling, or dusting attributable to defective materials or workmanship within the warranty period shall be repaired at no cost to the Owner. (17.2)

18 Spare Parts

NOTE The Contractor shall deliver to the Owner the specified quantity of joint filler and sealant matching that installed, for future joint maintenance. (18.1)
Spare joint filler / sealantrange
gal
010
Default: 2 gal

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