EFFECTS OF DESERT SAND SUBSTITUTION ON CONCRETE PROPERTIES USING DESERT SAND-DOPED ARTIFICIAL SAND AS THE FINE AGGREGATE

As governments are increasingly attaching more importance to environmental protection, many policies and regulations are being promulgated to restrict or prohibit river sand extraction. Thus, there is a growing tendency for concrete production to use desert sand-doped artificial sand as the fine aggregate. This paper investigated the microstructure, mechanical properties, durability, and volume stability of concrete with desert sand and artificial sand. In the study, the strength grades of concrete ranged from C30 to C100, while the substitution ratios of the desert sand for the artificial sand ranged from 0 % to 100 %. The results showed that a high substitution ratio of desert sand increased the concrete porosity and extended the interface zone width. The concrete strength generally decreased as the desert sand substitution ratio increased, however, for the C50 and C60 strength grades, concrete with 20 % desert sand had minor positive effects. Basically, as the desert sand substitution ratio increased, the Cl- penetration resistance and frost resistance tended to be weaker, although there were a few exceptions. High substitution ratios of desert sand were also not good for the sulfate attack resistance of concrete. In most cases, concrete with 20 % desert sand shrank more slowly than concrete without desert sand. These conclusions provide the experimental support for the promotion of desert sand applications in the concrete industry.