NOTE This standard governs the work of filling the space between a leveled steel base plate or bearing plate and its concrete support with cementitious or epoxy non-shrink grout so that bearing loads transfer uniformly from steel to concrete. The grout bed is a structural, load-bearing element that carries the full base plate bearing reaction into the concrete pedestal; voids, low strength, or delamination in the grout are bearing defects, not cosmetic ones, and the work is inspected and tested on that basis. (1.1.1)

NOTE This standard applies wherever the structural drawings show a grouted base plate or bearing plate condition, regardless of project type or occupancy. (1.1.2)

NOTE Base plate fabrication, column erection, and anchor rod setting are performed under their own standards and are coordinated with, but not governed by, this section. (1.1.3)

NOTE The split of work between the steel erector who sets and levels the plate and the concrete trade who places the grout is a frequent source of gaps; clear assignment in the Contract Documents closes the gap. (1.1.8)

NOTE ASTM C1107 is the controlling material standard for packaged cementitious non-shrink grout and defines the Grade A, B, and C volume-change classes referenced throughout this standard. (2.3)

NOTE AISC 360 Section J8 establishes the bearing strength of concrete under the plate, and AISC Design Guide 1 is the primary engineering reference for plate thickness, grout-space thickness, and grout hole sizing. (2.4)

NOTE ACI PRC-351.1 is the most widely cited guidance on grout consistency, minimum thickness relative to flow length, substrate preparation, and anchor bolt torquing sequence; although it is written around equipment bases, its placement guidance is directly applicable to structural building base plates. (2.5)

NOTE Because the grout bed is load-bearing, the absence of test specimens leaves no basis to accept or reject the work; specimens are required for every placement, not sampled across the project. (4.1.5)

NOTE Special inspection of base plate grouting, where required by the building code or the Contract Documents, shall verify substrate condition, grout consistency, fill completeness, and curing. (4.1.9)

NOTE Epoxy grout cure is strongly temperature dependent: cold placement retards cure and may prevent bond, while hot placement accelerates set and shortens working time, so epoxy is never placed outside its range without a temperature plan. (5.1.3)

NOTE Epoxy grout is selected for high chemical exposure, vibration, or very high bearing demand, reaching compressive strengths well above cementitious grout but at higher cost and with strict temperature control; it is not the default for ordinary column bases. (6.1.5)

NOTE Selecting a low grade where high bearing stress is present is a common error; the Engineer of Record confirms that the grade and minimum strength match the design bearing demand, not just the volume-change requirement. (6.2.2)

NOTE Dry-pack consistency is a stiff, hand-rammed mix used for small plates with limited access; flowable and fluid consistencies are pumped or poured under larger plates and are the common choice for column bases. (6.3.1)

NOTE Adding water beyond the published maximum to improve flow reduces compressive strength and increases bleed; consistency is controlled by selecting the right mix, not by overwatering. (6.3.5)

NOTE A typical grout space is 1 to 2 in., with 1.5 in. the common case; the minimum is 1 in. and a single lift of standard cementitious grout without aggregate extension is generally limited to 3 in. (7.1.2)

NOTE ACI PRC-351.1 relates minimum grout thickness to flow length, recommending at least 1 in. for a 1 ft flow length plus 0.5 in. for each additional foot the grout must travel under the plate. (7.1.3)

NOTE When the grout thickness is not coordinated before fabrication, the fabricator cuts the plate and the anchor rods are set to the wrong elevation, leaving the plate too high or too low; the thickness is therefore fixed on the drawings before fabrication begins. (7.1.6)

NOTE Grout cannot reliably reach the center of a plate wider than about 24 in. by side flow alone; fill and vent holes through the plate are required so grout rises through the plate and air escapes. (7.2.1)

NOTE A smooth, troweled concrete top provides inadequate bond; roughening the pedestal top is a construction requirement, not a recommendation, and is verified before grouting. (8.1.1)

NOTE Dry concrete wicks mixing water out of the grout, lowering strength and causing delamination at the interface; the inspector verifies the SSD condition before placement begins. (8.1.5)

NOTE Leveling nuts thread on the anchor rods below the plate and remain in place permanently; steel shims and wedges are set between the plate and concrete and may or may not be removed after grouting, depending on the design. (9.1.1)

NOTE Leaving steel shims in place without full grout encapsulation creates corrosion paths and interrupts uniform bearing; the Contract Documents shall state whether shims are removed or left permanently in place. (9.1.7)

NOTE Grout leaking through gaps between the form and the concrete drains the grout space and leaves voids under the plate; forms are sealed and inspected before placement begins. (10.1.1)

NOTE Placing grout from a single side, or through fill holes, drives the air across and out the far side; placing from opposing sides simultaneously traps air and leaves voids. (10.2.1)

NOTE Torquing anchor rods against a fresh grout bed can crack or delaminate the grout; final torque is applied only after the grout has gained enough strength to resist it. (11.1.1)

NOTE For cementitious grout, the strength required for torquing is typically reached in 3 to 5 days, and for epoxy grout in about 24 hours at 70°F; the actual time depends on temperature and the manufacturer's strength data. (11.1.3)