Ecological mortars produced from sustainable hydrated lime obtained from biomass ash

Abstract

Sustainable hydrated lime is produced from biomass ash rich in calcium carbonate, with properties similar to industrial hydrated lime. However, there is a lack of current and relevant research on sustainability related to the use of alternative limestone, derived from waste such as biomass ash. In this sense, the present research aims to study the behavior of cementitious coating mortars with partial and total replacement of industrial hydrated lime by sustainable hydrated lime, through microstructural, macrostructural, physical and chemical tests. Microstructural analyses performed by SEM demonstrated the presence of cement hydration products (CSH and ettringite) in all mortars evaluated. Chemical analyses through XRF and XRD showed similarity in chemical composition and crystallographic phases between the mortar with industrial hydrated lime and the ecological mortars. The FTIR showed chemical bonds characteristic of cement mortars in all ecological mortars, ratified by TG/DTG, which shows the decomposition of products such as CSH, ettringite, portlandite and calcite in all ecological mortars. Through the results found, the viability of replacing sustainable hydrated lime with industrial hydrated lime in the preparation of ecological mortars stands out, at the optimum percentage of 50 %, with possible total replacement (100 %) without significant losses in resistance.

Keywords

• Cement-based mortars
• Biomass ash
• Chemical properties
• Mechanical properties
• ANOVA