Why, although desert sand is rich in resources, it can not be used as building materials instead of river sand and artificial sand?
1. Severe Weathering
Desert sand is mainly formed by wind. In the arid area, the stone slowly collapses under the weathering action, the larger stone remains in place to form the Gobi and other landforms, and the small stone particles are accumulated together by the wind to form the desert.
Desert sand is mostly made of stone weathering. After years of storm erosion, it becomes thin and scattered, without viscosity.
2. Too Small Fineness
The sand diameter that used for construction is basically greater than 1mm, and different diameters are needed to meet the grading requirements. Desert sand is produced by wind transport and deposition, with a much smaller diameter (generally less than 0.25mm), it’s too fine fineness.
3. Poor Plasticity
The cross section of sand particles for construction is generally circular, so that the stress is uniform. The sand at the bottom of the river is transported by the river, and the particles roll along the river. The sand selected is relatively round, while the sand in the desert is very smooth, and has certain oil property, which does not have the plasticity as ordinary construction sand.
4. High Alkali Content
Desert sand is formed by long-term weathering in the dry environment of wind and sun, with high alkali content. It will react with some substances in building materials, which will affect the quality of sand and stone mixture, thus affecting the strength and safety of buildings.
5. Poor Grading
Desert sand is mostly weathered in situ, without long-distance transportation and sorting, and various particle sizes are mixed with each other, so the grading isn’t suitable for construction sand.
Construction sand is stricted with mud content. The impurities in the desert sand are not filtered and the clay content is high. If it is used in concrete, the concrete strength will be greatly reduced. In contrast, river sand is deposited by water flow from a long distance. After a long period of cleaning and erosion, it becomes very clean.
7. High Transportation & Mining Costs
Desert is usually far away from urban. Considering the transportation cost and labor price, desert sand is not cheap.