1 Scope
1.1This standard governs the materials, performance, preparation, placement, and curing of non-shrink grout used to transfer structural load from steel base plates, bearing plates, and equipment bases into concrete substrates.
NOTE Non-shrink grout fills the clearance between a leveled base plate and its concrete bearing surface so that the full plate area bears uniformly and load transfers without voids, settlement, or loss of contact. (1.1.1)
NOTE The defining property is dimensional stability: it must maintain bearing contact under sustained compressive load through the life of the connection. (1.1.2)
1.1.3The grout shall not exhibit net shrinkage that would break bearing contact between the plate and the substrate.
1.1.4Any expansion in the grout shall be controlled so that it does not crack the grout shoulder or lift the base plate off its leveling supports.
NOTE This standard covers both cementitious (hydraulic cement-based) and two-component epoxy grout, with selection between the two driven by load magnitude, chemical and thermal exposure, and dynamic service conditions. (1.1.5)
1.2This standard applies to cast-in-place and precast concrete substrates that have reached their specified strength prior to grouting.
NOTE Typical applications include structural steel column base plates, equipment and machinery foundations, crane rail sole plates, precast panel bearing seats, bridge bearing assemblies, and anchor bolt leveling pockets. (1.2.1)
NOTE This standard does not cover the concrete pad, footing, or foundation that receives the grout, nor the design of the steel connection above the base plate. (1.2.2)
NOTE Masonry mortar beds, grout fill in CMU cores, and non-load-bearing tile or decorative grout are outside this standard. (1.2.5)
2 Referenced Standards
2.1Materials, testing, and installation 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.
2.3Where a manufacturer's published data sheet imposes a stricter limit than a referenced standard for a proprietary product, the manufacturer's limit shall govern for that product.
| Standard |
Title |
| ASTM C1107/C1107M-20 |
Packaged Dry, Hydraulic-Cement Grout (Nonshrink) |
| ASTM C579 |
Compressive Strength of Chemical-Resistant Mortars, Grouts, Monolithic Surfacings and Polymer Concretes |
| ASTM C827/C827M |
Change in Height at Early Ages of Cylindrical Specimens of Cementitious Mixtures |
| ASTM C157/C157M |
Length Change of Hardened Hydraulic-Cement Mortar and Concrete |
| ASTM C109/C109M |
Compressive Strength of Hydraulic Cement Mortars (50 mm Cube Specimens) |
| ASTM C413 |
Absorption of Chemical-Resistant Mortars, Grouts, Monolithic Surfacings, and Polymer Concretes |
| ACI PRC-351.1R-12(24) |
Report on Grouting between Foundations and Bases for Support of Equipment and Machinery |
| ACI 318-19 |
Building Code Requirements for Structural Concrete (Section 26.11) |
| AISC 360-22 |
Specification for Structural Steel Buildings (Commentary J8) |
| CRD-C 621 |
Corps of Engineers Specification for Nonshrink Grout |
| ICRI 310.2R |
Selecting and Specifying Concrete Surface Preparation (CSP profiles) |
3 Submittals
3.1The Contractor shall submit the following action submittals for review and acceptance before any grout is delivered to the site:
- Product data sheet for each proposed grout, including grade, consistency range, and mixing-water limits
- Manufacturer's certified test data showing compliance with ASTM C1107 (cementitious) or ASTM C579 (epoxy)
- Substrate preparation and placement procedure, including forming, mixing, lift depth, and curing method
- Hot-weather and cold-weather placement procedures where ambient conditions outside 45-90 °F are anticipated
- Safety Data Sheets for grout and any admixtures
☑ Product data sheet (grade, consistency, water limits)
☑ Certified compliance test data (C1107 or C579)
☑ Substrate prep and placement procedure
☐ Hot/cold weather placement procedures
☐ Safety Data Sheets
3.2The Contractor shall submit the following informational submittals:
- Manufacturer's qualification statement and reference projects for equipment and crane-rail grouting
- Field test reports for compressive strength specimens cast during placement
- Placement records noting ambient and substrate temperature, batch water, and time of placement
☐ Manufacturer qualification statement
☑ Field compressive strength test reports
☑ Placement records (temperature, water, time)
3.3The Contractor shall submit the following closeout submittals:
- Certified test results confirming the placed grout met the specified compressive strength
- Manufacturer's warranty documentation where a product warranty is offered
☑ Certified compressive strength results
☐ Manufacturer warranty documentation
4 Quality Assurance
4.1Grout shall be installed by personnel experienced in precision grouting of the specified type and consistency.
NOTE Cementitious and epoxy grout differ substantially in mixing, placement window, and exotherm behavior; crews trained on one are not automatically competent on the other. (4.1.1)
4.2A single manufacturer's grout system shall be used for each application.
4.3Products from different manufacturers shall not be combined within one placement.
4.4Each grout type and lot shall be sampled and tested for compressive strength at the frequency specified in the Testing section.
4.5The Contractor shall not begin grouting until the Engineer of Record has confirmed that the grout compressive strength specified meets or exceeds the bearing strength assumed in the structural design.
NOTE ACI 318-19 Section 26.11 ties the grout bearing capacity to the design assumptions for the base plate connection; a grout weaker than the assumed value undermines the connection regardless of the plate or anchor design. (4.5.1)
4.6Grout consistency, lift depth, and access geometry shall be verified against the manufacturer's data sheet before placement.
NOTE Fluid-grade grout poured into a deep or one-sided pocket may bridge and leave voids; matching consistency to access is a quality control checkpoint, not a field convenience. (4.6.1)
5 Environmental and Service Conditions
5.1The Contractor shall record ambient air temperature and substrate temperature at the time of placement and throughout the initial cure.
5.2Grout shall be placed and cured within the temperature range specified on the manufacturer's data sheet, and in no case shall placement proceed with a substrate below 40 °F.
NOTE ASTM C1107 grout and typical manufacturer data assume a placement and cure window of roughly 45-90 °F; outside that window, strength gain, set time, and nonshrink behavior all drift from the qualified values. (5.2.1)
NOTE Below 45 °F, hydration slows and the grout may not reach its leveling-nut load before being disturbed; above 90 °F, accelerated set shortens the working window and increases the risk of plastic shrinkage. (5.2.2)
5.3Epoxy grout shall not be specified for sustained service temperatures above the manufacturer's heat-deflection limit.
NOTE Two-component epoxy grout softens under prolonged heat (commonly above about 120 °F) and generates significant exotherm in deep pours; matching the product to the service temperature is essential for heavy equipment near hot processes. (5.3.1)
● No (placement within 45-90 °F)
○ Yes (heated enclosure and insulating blankets)
Interior dry (typical building structure)
Exterior or intermittently wet
Chemical exposure (process, containment)
Elevated or cyclic temperature
Dynamic or vibratory load (rotating equipment)
6 Grout Type and Composition
6.1The grout type shall be selected to match the load magnitude, chemical exposure, thermal exposure, and dynamic service of the application.
NOTE Cementitious non-shrink grout is the default for static structural base plates and most equipment; epoxy grout is reserved for heavy dynamic loads, aggressive chemical exposure, or where the highest strength and impact resistance are required. (6.1.1)
6.2Cementitious grout shall be a packaged, dry, hydraulic-cement non-shrink grout complying with ASTM C1107, requiring only the addition of water at the site.
NOTE Field-blended sand-cement mixes are not non-shrink grout; the nonshrink performance is a property of the proprietary packaged product, verified by the manufacturer to ASTM C827 and C157. (6.2.1)
6.3Cementitious grout shall use a nonmetallic (silica or natural mineral) aggregate.
NOTE Metallic, iron-based aggregate grout oxidizes when exposed to moisture, causing rust staining and surface spalling; nonmetallic aggregate is preferred for nearly all modern applications, including all exterior and wet exposures. (6.3.1)
6.4Epoxy grout, where specified, shall be a two-component or three-component thermosetting system qualified by the manufacturer to ASTM C579 for compressive strength and ASTM C413 for absorption.
NOTE There is no single ASTM product standard for two-component epoxy grout equivalent to ASTM C1107; epoxy grout is governed by manufacturer qualification testing to the relevant ASTM test methods. (6.4.1)
6.5Admixtures shall not be added to packaged grout except those expressly permitted by the manufacturer's published data sheet.
NOTE Adding water or unapproved admixtures to improve flow raises the water-cement ratio, lowers strength, and can void the nonshrink performance; consistency is adjusted only by the manufacturer-approved method. (6.5.1)
● Cementitious non-shrink (ASTM C1107, nonmetallic)
○ High-early-strength cementitious non-shrink
○ High-strength precision cementitious (10,000+ psi)
○ Two-component epoxy (heavy/dynamic/chemical)
● Nonmetallic (silica / natural mineral)
7 Consistency and Grade
7.1The grout consistency shall be selected to match the clearance depth under the plate and the access available for placement.
NOTE ASTM C1107 defines Grades A, B, and C by the time period over which the nonshrink requirement applies; in practice these correspond to fluid, flowable, and plastic (dry-pack) consistencies respectively. (7.1.1)
NOTE Fluid grout is self-leveling and poured, flowable grout is poured with a slight head and rodded, and plastic grout is rodded or hand-packed into deep or one-sided pockets where a poured grout would bridge. (7.1.2)
7.2Fluid or flowable consistency shall be used for placements with through-access or a head box where the grout can flow fully beneath the plate.
7.3Plastic (dry-pack) consistency shall be used where access is restricted to one side or where the pocket is too deep for a poured grout to consolidate without voids.
7.4The selected consistency shall achieve a minimum effective bearing area of 95 percent of the base plate area in contact with cured grout.
NOTE Effective bearing area is the fraction of the plate that actually bears on solid grout; voids and unfilled zones reduce it and concentrate load on the contact points, which is the failure this standard exists to prevent. (7.4.1)
○ Fluid (Grade A) - self-leveling, poured
● Flowable (Grade B) - poured with head, rodded
○ Plastic / dry-pack (Grade C) - rodded or hand-packed
8 Compressive Strength
8.1Cementitious grout shall meet or exceed the ASTM C1107 minimum compressive strengths for the specified grade, tested to ASTM C109.
NOTE The ASTM C1107 standard-grade minimums are 1,000 psi at 1 day, 2,500 psi at 3 days, 3,500 psi at 7 days, and 5,000 psi at 28 days; higher classes reach 8,000 psi (Grade C) and 10,000 psi or more for precision and crane-rail products. (8.1.1)
8.2The 28-day compressive strength shall equal or exceed the value assumed for the grout in the structural base plate design.
8.3High-early-strength grout shall be specified where the structure or equipment must be loaded before the standard grout reaches its design strength.
8.4Epoxy grout, where specified, shall develop the manufacturer's published compressive strength tested to ASTM C579.
NOTE Two-component epoxy grout typically develops 12,000-14,000 psi at 7 days per ASTM C579, well above cementitious grout, which is why it is selected for the heaviest and most impact-prone bases. (8.4.1)
5,000 (ASTM C1107 standard)
8,000 (Grade C / high-strength)
10,000 (precision / crane rail)
14,000 (epoxy, 7-day per C579)
● Standard cure (load at 28 days)
○ High-early (load before 28 days)
9.1Cementitious grout shall exhibit zero or positive height change in the plastic state when tested to ASTM C827.
9.2Cementitious grout shall exhibit no net length reduction in the hardened state when tested to ASTM C157.
NOTE "Nonshrink" does not mean "no volume change"; ASTM C1107 permits controlled expansion in the plastic state to compensate for settlement and bleed, while preventing net shrinkage that would break bearing contact after the plate is in place. (9.2.1)
9.3Grout expansion shall not be so large as to crack the grout shoulder or lift the base plate off its leveling supports.
NOTE Excessive expansion is as harmful as shrinkage: it can crack the exposed grout edge or jack the plate against its anchors; this is why expansion is required to be controlled, not maximized. (9.3.1)
10 Substrate Preparation
10.1The concrete substrate shall have reached a minimum compressive strength of 3,000 psi before grouting unless the structural drawings require a higher value.
NOTE ACI PRC-351.1R guidance is that the substrate be substantially mature before grouting so the bearing concrete does not become the weak link beneath a high-strength grout. (10.1.1)
10.2The bearing surface shall be roughened to remove laitance and expose sound aggregate, achieving an ICRI concrete surface profile of CSP 5 to CSP 7.
NOTE Laitance is the weak surface skin left by bleed water; grout bonded to laitance delaminates under load. Roughening to a CSP 5-7 profile removes it and creates mechanical key for the grout. (10.2.1)
10.3All oil, grease, curing compound, paint, dust, and other bond-breaking contamination shall be removed from the bearing surface and anchor pockets before grouting.
10.4For cementitious grout, the prepared concrete shall be brought to a saturated surface-dry (SSD) condition immediately before placement, with no free standing water in the pocket.
NOTE A dry substrate draws mixing water out of fresh cementitious grout, causing plastic shrinkage and a weak, dusty interface; SSD means the concrete is saturated but the surface holds no puddles that would dilute the grout. (10.4.1)
10.5For epoxy grout, the prepared concrete shall be clean and dry.
10.6Epoxy grout shall not be placed on a wet or saturated substrate.
NOTE Epoxy chemistry is the opposite of cementitious: water on the surface interferes with the bond and cure, so epoxy substrates are dried, not pre-soaked. (10.6.1)
● Saturated surface-dry, no free water (cementitious)
○ Clean and dry (epoxy)
30005000
Default: 3000 psi
11 Clearance Depth and Lift Limits
11.1The clearance between the underside of the base plate and the concrete bearing surface shall be set within the range specified for the selected grout and consistency.
NOTE Clearance is set by leveling nuts, shim packs, or wedges; too little clearance prevents the grout from flowing and consolidating beneath the plate, while too much may demand a higher-strength or epoxy grout. (11.1.1)
11.2Cementitious fluid and flowable grout shall be placed in clearances of not less than 3/4 in.
11.3Cementitious fluid and flowable grout shall be built up in lifts not exceeding the manufacturer's maximum, typically 3 in. to 4 in. per lift.
11.4Epoxy grout shall be placed in lifts of not less than 1 in. and not more than 3 in. to limit exotherm.
NOTE Deep epoxy pours generate enough internal heat to crack or discolor the grout and accelerate the cure uncontrollably; limiting lift depth keeps the exotherm manageable. (11.4.1)
11.5Deep pockets exceeding the single-lift maximum shall be filled in successive lifts, each allowed to set per the manufacturer's instructions before the next is placed.
Per drawings — base plate / equipment grouting detail
12.1Forms shall be liquid-tight and constructed to retain fluid grout at the placement head without leakage.
NOTE Fluid and flowable grout will find any gap; a leaking form bleeds out paste, lowers the head, and leaves voids at the plate edge. (12.1.1)
12.2A head box or extended form shall be provided on the pour side where a hydraulic head is needed to drive grout fully beneath the plate.
12.3Wood and other absorptive forms shall be thoroughly wetted (for cementitious grout) or coated with form-release (for epoxy grout) before placement.
NOTE Dry wood forms draw water from fresh cementitious grout, causing plastic shrinkage and voids at the grout-form interface; pre-wetting prevents this. For epoxy, a release coat lets the form strip cleanly without bonding. (12.3.1)
12.4Forms shall provide a chamfer or shoulder at the exposed grout edge to relieve the feather edge and resist chipping.
Wood forms (pre-wetted / release-coated)
Steel forms
Foam dam / expanding gasket
● Yes (fluid/flowable poured placement)
○ No (plastic / dry-pack placement)
13 Placement
13.1The base plate or equipment base shall be set, plumbed, and leveled on leveling nuts, shims, or wedges, and accepted before any grout is placed.
NOTE Grout is not adjustable after it sets; the plate must be at its final elevation and level, and the leveling stack verified, before grouting begins. Grouting first and adjusting later is not possible. (13.1.1)
13.2Mixing water shall be measured and held strictly within the range published on the manufacturer's data sheet.
NOTE Field addition of water beyond the published range is the single most common cause of low-strength, shrinking grout; the water-cement ratio is a controlled quantity, not a flowability dial. (13.2.1)
13.3Grout shall be placed continuously from one side so that it advances across the pocket and pushes air ahead of it, venting from the far side.
NOTE Placing from one side and letting the grout chase the air out is what produces a void-free bearing surface; pouring from multiple sides at once traps air pockets under the plate. (13.3.1)
13.4Grout shall be worked under the plate by gravity head, strapping, chaining, or rodding as appropriate to the consistency, without adding water to ease placement.
13.5Plastic and dry-pack grout shall be rodded or hand-packed in restricted-access pockets to ensure full consolidation and contact.
13.6The placement shall be completed within the working time of the mixed grout; partially set grout shall not be retempered with water or reused.
Poured with gravity head (fluid)
Poured with head box and rodding (flowable)
Rodded / hand-packed (plastic, dry-pack)
Pumped (large equipment bases)
☑ Leveling nuts set and plate plumb
☐ Shim packs / wedges in final position
☑ Plate elevation and level accepted
14 Curing
14.1Cementitious grout shall be wet-cured or cured with a manufacturer-approved curing compound for a minimum of 3 days, and 7 days where practical, at an ambient temperature of 50 °F or above.
NOTE Cementitious grout depends on retained moisture to gain strength; premature drying at the exposed edges causes surface shrinkage cracking and a weak skin even when the core is sound. (14.1.1)
14.2A curing compound shall not be applied to any concrete surface that will receive grout, nor to the grout bearing surface itself.
NOTE A curing compound left on the bearing concrete is a bond breaker; that is why curing compound is excluded from the grouted contact area, even though it is acceptable on the exposed grout shoulder. (14.2.1)
14.3Exposed grout edges shall be protected with wet burlap, insulating blankets, or an approved curing compound immediately after the forms permit.
14.4Epoxy grout shall be cured per the manufacturer's instructions and shall not require wet curing.
NOTE Epoxy grout cures by chemical reaction rather than hydration, so it is not wet-cured; its cure schedule and minimum temperature are governed entirely by the manufacturer's data sheet. (14.4.1)
Wet cure (burlap / soaker, kept continuously moist)
Approved curing compound on exposed edges
Insulating blanket (cold weather)
15 Testing
15.1Compressive strength specimens shall be cast during each grouting operation at the frequency specified for the project.
NOTE Specimens are cast from the grout actually placed, cured alongside the work where possible, and tested to confirm the in-place grout met the specified strength before the structure or equipment is loaded. (15.1.1)
15.2Cementitious grout specimens shall be cube specimens tested to ASTM C109; epoxy grout specimens shall be tested to ASTM C579.
15.3A set of specimens shall be tested at the age at which the grout is to carry load and again at 28 days for record.
15.4Grout that fails to meet the specified compressive strength shall be removed and replaced, or evaluated by the Engineer of Record before the affected bases are loaded.
One set per placement
One set per day of grouting
One set per 10 base plates
One set per equipment base
☐ Load age (early, per schedule)
☑ 7 days
☑ 28 days (record)
16 Installation Sequencing and Coordination
16.1The grouting operation shall be coordinated with the steel erector and the equipment installer so that base plates are leveled and accepted before grout is ordered.
NOTE Grout has a short working life and is sensitive to substrate and ambient conditions, so it is placed only after the plate is final; coordinating the sequence avoids placing grout against a plate that still needs adjustment. (16.1.1)
16.2Anchor bolt pockets and sleeves shall be cleaned of debris and standing water before the leveling and grouting sequence.
16.3The grout bearing strength assumed in the structural design shall be coordinated with the structural drawings and confirmed by the Engineer of Record prior to placement.
NOTE AISC 360-22 Commentary J8 and ACI 318-19 Section 26.11 both tie the base plate bearing check to the grout strength; the specified grout must match the design assumption, which is a coordination item between the spec and the structural drawings. (16.3.1)
17 Delivery, Storage, and Handling
17.1Packaged grout shall be delivered in the manufacturer's original, unopened, labeled packaging.
17.2Grout shall be stored off the ground in a dry, covered location and protected from moisture, freezing, and temperature extremes.
NOTE Cementitious grout that has absorbed moisture in storage partially hydrates and loses strength and flow; epoxy components are temperature-sensitive and must be conditioned to the manufacturer's range before mixing. (17.2.1)
17.3Grout that has exceeded its shelf life, shows signs of moisture damage, or has lumped or hardened in the bag shall not be used.
17.4Epoxy components shall be conditioned to the manufacturer's specified temperature range before mixing.
18 Warranty
18.1The Contractor shall warrant the grout installation against voids, cracking, loss of bearing, and strength deficiency for the project's specified warranty period.
18.2Where the grout manufacturer offers a product warranty, it shall be transferred to the Owner at closeout.
19 Spare Materials
19.1The Contractor shall deliver to the Owner unopened spare grout where field re-grouting or future equipment mounting is anticipated.
NOTE Keeping a small stock of the exact grout used lets the Owner re-grout a relocated piece of equipment or repair a damaged edge with the same qualified product rather than an unmatched substitute. (19.1.1)
● None
○ 1 bag per grout type
○ 2 bags per grout type