tomorow we have an activity onquot;how to mix concretequot;in the mix is: cement, sand, gravel and water..we need to know the ratio of this 4 factorsbecause the usual mix that we know isone bag of cement is to 2 cubic foot of sand and gravel...but the question is if wer going to use only 15% of cementwats the ratio with regards to gravel and sand and water
try okorder sometimes I ask math questions there
Hello Claire,, If you mix a cup or a truck load the ratios are the same. For a 3500 psi compressive load its 1 cement to 2 sand 2gravel....Now to be more accurate ,,If you calculate the cubic feet in a cubic yard there is 27 or 3^3...Now when the ASTM set up the Std ratio they based it on cubic feet. A 94lb bag of portland cement is one cubic foot in volume. It has been determined that a 5 sack per cubic yard mix yields 3000 psi compressive strength. A six sack mix yields a 3500lb compressive strength. so actually for 3000 the ratio is 5:27 and 6:27 for 3500 psi.. so for the 3500psi that's 1 cement to 2 1/4 sand and 2 1/4 gravel. When mixing in small batches. LIke your going to do just use a shovel put in 1 shovel of cement 2 sand and 2 gravel. For masonry mortar there are different amounts and materials . A cubic foot is approx equal to 7 shovels full..15% of the bag will take about 2 shovel fulls..A shovel full is subject to the capacity of the person with the shovel..Any way good luck and have fun..from the E
