Non-Shrink Grout Volume Under a Base Plate
Non-shrink grout under a column base plate - the gap volume minus the steel footprint, and the bags: grout = (plate length x plate width - column area) x thickness; bags = ceil(grout / bag yield). An 18 x 18 in plate over an 8 x 8 in column on a 1.5 in grout bed is 390 in^3 - 1 bag with waste; a big 24 x 24 in plate at 2 in takes 2. Plate area and bed thickness both drive it. Distinct from the pipe-casing annular-grout-volume.
Formula and source
grout_in3 = (plate_length_in x plate_width_in - column_area_in2) x grout_thickness_in; grout_ft3 = grout_in3 / 1728 x (1 + waste_pct/100); bags = ceil(grout_ft3 / bag_yield_ft3).
Base-plate grout-volume identity by name (net plate area x bed thickness, plus waste; bags over the bag yield); first-principles volume arithmetic.
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