Composite Mortars Produced with Wood Waste from Demolition: Assessment of New Compounds with Enhanced Thermal Properties

Abstract

In this study, wood waste from demolition was used by replacing natural aggregate for developing lightweight mortars. Many domestic buildings in the historical city centers of Spain have wooden floors and roof structures. Their rehabilitation process produces a large amount of waste, including wood waste. In this study, the wood waste, wood shavings, and sawdust were tested in ratios of 2.5, 5, 10, and 20% by weight of sand. Mortars containing wood were characterized in fresh and hardened states by means of their consistency and bulk density (fresh state) and mechanical tests, bulk density, water absorption by capillarity, vapor permeability, and thermal behavior (hardened state). The results showed that increasing the amount of waste hinders the workability of the sample and prolongs setting times. Furthermore, compounds with larger-sized particles, those based on wood shavings, showed a more pronounced decrease in density and produced the best thermal results. Finally, contrary to what one might expect, the wood-shavings compounds also presented better mechanical properties.