Evaluation of the influence of lightweight aggregates based on wood charcoal waste (wcw) in mortars

Abstract This study investigates the effect of wood charcoal waste (WCW) as a lightweight aggregate on the properties of cement-based mortars. Mortars were formulated with WCW incorporated at replacement levels of 0%, 5%, 10%, 15%, 20%, and 30% by sand volume. WCW additions between 10% and 30% led to compressive strength reductions ranging from 20% to 60% and increased water absorption from 14% to 76%. XRD analysis of samples with 15% WCW revealed a reduction in the relative intensity of primary crystalline peaks of ettringite and portlandite. This reduction is not attributed to a decrease in the concentration of these compounds within the cement matrix but is likely due to the encapsulation of Portland cement hydration products within the alveolar structure of the WCW, as confirmed by SEM micrographs.