Question

V. (8 points) Consider casting a concrete driveway 40 feet long, 12 feet wide and 6 in. thick. The proportions of the mix by weight are given as 1:2:3 for cement, sand, and gravel with w/c of 0.50. The specific gravities of sand and gravel are 2.60 and 2.70 respectively. Entrained air content is 7.5%. How many pounds of cement, water, sand, and gravel are needed for the driveway?

Answer 1

sol S volume of Concesete? v= 40 x12x6 = 240ff l Required J = 210 Cutt: W, 2005 » W=0.56 wswatex ; C = Cement: W= weight of water per Cabic foot of volume of Concoreta C= weight of Cement per cubic foot of volume of Concrete Szweight of sand per cubic foot of volume of concrete. ga weight of gravel per cubic foot of volume of concrete. Specific graniting of sand = 2.60 Specific gravity of gravel = 2.70. Assuming Specific gravity of Cement = 3.15. entrained air content is 27.5% =0.075 C:S:9=1:2:3... ) cos. 822. i. g=30 Volume of water = 0.5€ Per 1x 62:43 Volume of Cement a s - 3.15x62043 volume of sand = 20 2160X62043 gravel = 36 2.70x62.43 Total volume of Mix = 1 volume at

z> or 5c +2c +32 . 2060x62.43 2.70x62.48. 62.43 3.15*62.43 + 0.075=1 . St. Ċ - 210405; w=10.70273 5:4281 ;9 -64.215; Now for a volume of chocuft is Cement = 21.405x840 =.5137.2 lb. water=10.7027x240 = 2568.64816 sand=42.81 X 240 2.10274.4 lb. gravel = 84.215x240 z 1541106 lb...