I've read that desert sand is too round for concrete mixes. But, I'm not building a dam, I'm building a 3 foot landscaping wall. I'm interested in using desert sand for the color, so this is an aesthetic choice. How will using desert sand affect the strength of my mix? Are there ways to counteract the effect? I've been reading everything. Is desert sand ok to use, just uneconomical for large projects?
You can use desert sand ( or use the approved concrete coloring admixtures which will give the tint you need) with the following considerations:
- Wash the sand thoroughly to remove any possible dirt or clay mixed with it, roundness is not a big issue.
- Add more cement to compensate for possible reduction in strength.
- Add concrete acrylic glue as per manufacturer's recommendation.
- Generally the following is recommended proportion of concrete materials:
Add 6 bags of 94lbs of cement, water not more than 40% of cement weight, to a cubic yard of sand and gravel. The more water the weaker your concrete. so consider the moisture of your sand as part of water ratio.
The aggregate should be roughly half less than 3/8" and half between 3/8 to 1.25" for your application and lack of slump tests.
Don't forget curing the wall, watering it for at least a week.
One could seek advice from local trades-people as to the ways to make your concrete stronger and as far as plasticity workable.