THE EFFECTS OF TYPES OF RICE HUSK ASH ON THE POROSITY OF CONCRETE

Controlled burning can produce amorphous rice husk ash (RHA) with high silica content and this can significantly enhance the porosity of concrete. This study has been undertaken to investigate the effects of replacing 5%, 10%, 15% and 20% of cement in concrete by both RHA and microwave incinerated rice husk ash (MIRHA) burnt at 800°C, 700°C and 600°C. The porosity of concrete mixes was determined at 28 days and in general showed that 5% replacement of MIRHA-800 provided the lowest percentage of porosity compared to all mixes. X-Ray Fluorescence (XRF) analysis was performed to determine the content of various chemical oxides in RHA and MIRHA.