SULFATE RESISTANCE OF MORTAR INCORPORATED WITH RICE STRAW ASH

Abstract

Due to environmental hazards, cementitious materials are chemically attacked and degraded causing a reduction in service life. In this context, use of supplementary cementitious materials (SCM) got prominence in the recent past, which can improve the durability property of cement-based materials. Further, use of SCM is important for sustainable development. In our previous research, it is found that Rice Straw Ash (RSA) contains very high silica content, thus it can also act as pozzolanic material. In this paper, an experimental study is made on cement mortar samples with different percentage replacements of cement with RSA to evaluate its sulfate resistance in sodium and magnesium sulfate solutions. Sulfate reactivity tests are conducted on the control specimen and mortar containing RSA and it is found that both sodium and magnesium sulfate cause deterioration in the samples and the former causes more expansions in the samples. Very effective sulfate resistance is found with higher volume replacement of cement with RSA. Though there is a wide difference in volume expansion of controlled specimens soaked in sodium sulfate and magnesium sulfate, this difference is diminished with 15% cement replacement with RSA.