Some test results using rice husk charcoal as aggregate for foam concrete

Abstract

Rice husk charcoal, when burned under natural conditions, has a SiO2 content of approximately 40%. Its activity level only reaches about 70% at 7 days old. When rice husk charcoal is mixed into foamed concrete, it helps reduce the bulk density, water absorption, and shrinkage of the foamed concrete. If approximately 54 kg of rice husk charcoal is added to 1m³ of foamed concrete, the shrinkage can be reduced by about 17% compared to the original. The above level of rice husk does not reduce the compressive and flexural strength of foamed concrete with a strength grade B5.