Life cycle analysis (LCA) for the incorporation of rice husk ash in mortar coating

Abstract

Considering that the civil construction segment is responsible for a significant amount of the environmental impact, once it consumes a large amount of natural resources and energy, the incorporation of waste in the process brings sustainable benefits for the companies as well as for society. In addition, the reduction of the useful life of mortar coating related to the lack of adherence to the substrate provokes a large generation of waste, increasing the environmental liability of the respective industry. This study aimed to determine the technical and environmental viability of the incorporation of rice husk ash (RHA) waste in mortar coatings, in order to reduce the consumption of natural resources and improve the conditions of adherence of the cementitious matrix. For this evaluation, mechanical tests were carried out to test the adherence to the substrate, besides a survey of all the processes related to mortar coating production, from natural resources extraction till the application of the product and its consequent impact. Finally it was used the life cycle analysis (LCA) tool to evaluate the environmental issue. The results showed an increase of 100% of bond strength for the mortars with 5% addition of RHA, and it was identified, among the processes surveyed, a smaller number of significant impacts in relation to the mortar with no addition. It is noticed that, for the conditions of this study, the mortars with RHA addition present better technical and environmental performance compared to the usual mortars.