Optimisation of hybrid eco-efficient mortars with aggregates from construction and demolition waste and olive biomass ash

Abstract

Materials considered as waste, such as Construction and Demolition Wastes (C&DW) and Biomass Bottom Ash (BBA) are the subject of this study to implement them in cement-based materials. After basic and advanced characterization, as well as leaching studies to assess the environmental impact, they are implemented in mortars as a replacement for standard silica sand. In this way, their mechanical behaviour, durability and micro-properties in hardened state are tested. The feasibility of implementing Mixed Recycled Aggregates (MRA) from C&DW and BBA to replace natural sand in high substitution rates is studied by substituting the wastes alone and in combination. Mortar mixes in which 50% of the aggregate is replaced, reaching more than 80% of the standard mortar strength. Mixtures in which 10% of the aggregate is replaced reaching more than 95% of the standard mortar strength.