Application of Granite Fines to Substitute Sand in Concrete Production

Nowadays, sustainable construction by using alternative concrete materials has been advocated around the globe due to the exhaustion of major sources of natural sand (NS), compounded with environmental and ecological considerations. In the meantime, a huge amount of granite fines (GF) as a by-product of crushing and sizing of granite in production of building stone for masonry industry, tile, coarse aggregate for the concrete industry, etc. are produced every year which generally treated as waste. And the landfilling of them causes serious environmental problems. Considering the stable source and sand-like physical properties of GF, it can serve as an ideal alternative material to substitute sand as the fine aggregate component in the production of concrete, which not only minimizes environmental issues but also provides economic benefits, especially in small countries such as Singapore with limited or almost zero sources of sand. The technical feasibility is conducted for three classes of concrete, i.e., C32/40, C40/50, and C50/60 produced with GF with varying fines content which is defined as the percentage of particle size finer than 62.5 μm (10%, 16%, and 22%) and percentage substitution (0%, 30%, 50%, 75%, and 100%). The technical feasibility of producing concrete with GF substitution is then evaluated based on performance comparisons between specimens with GF and NS (0% substitution) with regards to fresh concrete properties (workability through slump test, and setting time) and durability of hardened concrete properties (water absorption, water penetration, and rapid chlorine penetration).