Mechanical Properties and Durability of High Strength Concrete Containing Rice Husk Ash

摘要

This paper reports an investigation on the mechanical properties and durability of high strength concrete containing rice husk ash (RHA). Mixtures containing 10% RHA by weight of cement and w/cm of 0.27 were cast. RHA was incorporated either as an admixture or as cement replacement material. A superplasticizing admixture was used to provide flowing characteristics. Results on the workability, mechanical properties and initial surface absorption (ISA) test are reported. The specimens were subjected to water and air-drying conditions and tests on the specimens were carried out up to 180 days. By applying a superplasticizer based on polycarboxylic ether, workability of RHA concrete in the range of 200-250 mm slump can be attained. This type of concrete can achieve high strength of 80 N/mm~2 at 28 days, irrespective of method of inclusion of rice husk ash or curing conditions. Compared to condensed silica fume (CSF) concrete at similar w/cm and workability, the strength of RHA concrete is about 6% lower. In general, the mechanical properties of RHA concrete are higher than the control super-plasticized concrete but marginally lower than the CSF concrete. Durability of RHA concrete with regards to ISA is similar or better than CSF concrete.