The amount of cement and slag required for laying 100 super, yd. of floor, lin. thick, in the proportion of 1 to 1, is as follows: - The cubic contents of the concrete when laid will be 900 super, ft. x 1/12ft. = 75 cub. ft. There will be required about 2 cub. yd. of slag, broken small enough to pass through a 3/4-in. ring, and 51 cub. ft. of cement (at 90 lb. to the cubic foot) = 45 cwt. This 108 cub. ft. of cement and slag will shrink to about 75 ft. when mixed and wetted.