Waste wood ash and fly ash as partial cement replacement in producing concrete hollow blocks

Abstract

Wood charcoal from roasted chicken branches produces wood ash that most people consider as waste. This paper used wood ash and fly ash to partially replace cement in producing concrete hollow block. It aims to investigate the effects of partial replacement of cement on the density, water absorption, compressive, and fire resistance in the concrete hollow blocks. The weight percentage of replaced cement is 45%. Ratio 2, which has 15% wood ash, and 30% fly ash is required to be used for partial cement replacement. The CHB with partial cement replacement demonstrated a lighter weight but higher water absorption. Also, its fire resistance shows that all ratio samples have higher weight loss percentage than the control sample. Finally, the compressive strength of the CHB with partial cement replacement (ratio 2) showed a small difference compared to the control sample made.