Study of the Ecological Interest of a Rice Husk Ash Mortar

Abstract

To comply with the requirements of sustainable development, several organizations are studying the possibility of using renewable and ecological materials. This work aims to determine in what context it is ecological to replace cement with rice husk ash partially. To do this, on the one hand, we determined the CO2 mass emitted during the production of cement from the limestone decarbonation equation. On the other hand, we determined the CO2 mass emitted during the production of RHA (rice husk ash) using the complete rice husk combustion equation and Steven's realistic decomposition model. We then compared the quantity of CO2 emitted during the production of cement to that emitted during the combustion of the rice husk. Finally, we partially replaced cement with ground RHA to evaluate the effect of this substitution on the porosity and compressive strength of mortars. According to the findings of this study, cement production emits 0.94 kg of CO2 per kilogram of clinker, compared to 1.72 kg for RHA production, per kilogram of clinker and per kilogram of RHA, respectively. Also, these results show that using RHA leads to an improvement of the porosity up to 10.14%, and 15.59% for the improvement of the compressive strength. It is, therefore not more ecological to produce rice husk ash and replace it with cement. However, using rice husk ashes from energy production furnaces has a double advantage. The first concerns the environmental aspect, and the second concerns the improvement of mortars' durability and compressive strength.