Effectiveness of fly ash, zeolite, and unburnt rice husk as a substitute of cement in concrete

This experimental study analyzed the impacts of unburnt rice husk, fly ash, and zeolite on the strength of glass powder added concrete. At the first stage of the study up to 30% mass of fine aggregates was replaced by glass powder to understand the impact of the glass powder on the strength of concrete. Study results show that increasing the concentration of glass powder tends to decrease the compressive strength of the concrete. The relative decrease in compressive strength with 10% and 30% content of glass powder was measured at 9.5% and 13.3%, respectively. Furthermore, at a 10% constant concentration of glass powder several concrete specimens were prepared using unburnt rice husk, fly ash, and zeolite powder as replacement of cement (up to 15%). Study results indicate that the use of unburnt rice husk, fly ash, and zeolite with the combination of glass powder decreases the compressive strength of concrete. The lowest reduction rate was observed for fly ash added concrete, while the addition of unburnt rice husk shows the highest reduction in compressive strength.