Synthesis and characterization of rice husk ash concrete

As a kind of waste, the rice husk ash can be applied in concrete for reducing energy and resource waste. In this paper, the rice husk ash concrete was prepared with a water to cement ratio of 0.40. For exploring the optimum concentration of rice husk ash, six specimens with different concentration of rice husk ash (5, 10, 15, 20, 25 and 30%) were prepared. The mechanical performance (flexural strength, compressive strength and splitting tensile strength) at 7 and 28 curing days, chloride penetration resistance, impermeability resistance were investigated. The results showed that the addition of rice husk ash improved the correspondingly mechanical and durability performance. The optimum concentration of rice husk ash in concrete was 20%, and the further tested improving of flexural strength, compressive strength, and splitting tensile strength values were higher by 24.3, 22.0 and 25.6%, respectively. The chloride penetration resistance performance trend was similar with that of the improving mechanical performance. The minimum electric flux of rice husk ash concrete specimen was obtained with 20% added rice husk ash. The microstructure, discerned by Scanning electron microscopy technique, was found that the addition of rice husk ash concentrated the matrix, which finally improved the correspondingly performances. Copyright © 2015 American Scientific Publishers.