Utilization of microwave incinerated rice husk ash (MIRHA) in ductile self-compacting concrete

Global annual rice production is estimated to be equivalent to 500 million tonnes. This gives around 100 million tonnes of husk available in the form of waste. While some husk is used as fuel in the rice mills to generate steam others are often left to disintegrate slowly in the field or burnt in the open for disposal. These practices clearly pose serious environmental pollution and health problems. Control burning using a microwave incinerator was used in this study to produce rice husk ash with a high silica content. The benefits of microwave incinerated rice husk ash (MIRHA) as a partial cement replacement material in ultra-high strength high performance concrete known as ductile self-compacting concrete (DSCC) has led to the research on the possibilities of combining both MIRHA and fly ash as an addition in DSCC replacing up to 20 of cement volume whilst improving its mechanical properties. The additions of these supplementary cementitious materials are expected to give positive effects on the hardened concrete properties. The test results showed that MIRHA and fly ash combination in DSCC improved compressive, tensile and flexural strength by average of 7 while maintaining its self-compacting abilities. © 2014 WIT Press.