Can desert sand be used in construction ?

Answer is both Yes and No.

let’s see why we should not use desert sand in construction?

Desert sand grains are finer and smoother so their surface chemistry would not be able to offer sufficient number of multi-directional chemical linkages. If their grain size is too small, the slurry slip and the concrete would have poor strength. Desert sands possess an open structure, and there is little interlock between sand grains. If this sand is kept dry, these bonding bridges provide considerable bearing strength. But if the sand becomes wet, the bridges soften and when overloaded, the bridges break and collapse.

Desert sand usually contains high amounts of salt, which is very bad for concrete as it will rust the steel reinforcement, and also severely affects the strength of the concrete. 

The strength of a mortar comes from the angular edges of the sand particle. River sand is broken quartz that retains the angular edges while the desert sand gets rounded off due to blasting effect of winds. The mortar made of it will have poor bonding. The smooth surface allows easy propagation of cracks. 

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We can use desert sand in the following cases

 There are some researchers focusing on this sand in China recently. 

  1. Where there are no other options and in areas where there is a lot of it, then desert sand may be used, but it will lead to concrete with poor strength. For some applications, this may not be a problem. 
  2. Yes you can use it in concrete provided it satisfies the requirements (standards and specifications). You should test for grading, fineness, absorption and deleterious substances.
  3. There are some high quality desert sands that can be used in construction. However, extra fineness may be a problem in the workability but advantageous in stability and cohesion
  4. You can use it if you mix it with other sizes to bring the mixture within the acceptable limits. You also need to wash it to remove dust and check its chloride and sulfate contents if the desert is close to the sea.
  5. The mortar made of it will have poor bonding. The smooth surface allows easy propagation of cracks. The salt in the sand aids this propagation by acting as a solid lubricant. When necessary, the bond strength can be improved by a richer mix i.e. more of cement. To illustrate: 4:1 of P sand, 3:1 of M -sand or 2:1 of desert sand will have comparable strength.

As far as I know literature have not said much on it. My suggestion is “Don’t use the desert sand in construction, Until it’s researches find a way to use it in construction.”

 

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