Rice Husk Ash in Concrete : The use of rice husk ash as a pozzolanic admixture in concrete

Different levels of cement replacement with RHA were investigated in terms of compression strength and workabiliy. Mixes with 20% and 40% cement replacement with RHA (the latter contained a WR) were selected for further testing. These tests included shrinkage, tensile strength, permeability and carbonation. Mixes with added lime were produced for the permeability and carbonation tests. Due to the encouraging results further concrete mixes for compression testing were produced that contained additional lime. Bleeding tests were also carried out on selected mix designs.HSC mixes containing RHA and Condensed Silica Fume (CSF) were investigated. The effect of RHA on a superplasticiser was examined. The temperature profiles of mixes containing RHA with a design strength of 50 MPa were monitored. Generally, the performance of RHA in 25 MPa and HSC has been assessed with conclusions made on the potential of this product in the construction industry.