Impact of Wood Bio-aggregate Content on the Thermo-physical and Mechanical Properties of Bio-based Cementitious Composites

Abstract

Wood bio-based cementitious composite (WBBC) is a promising and eco-friendly construction material which can offer enhanced thermal insulation and reduced environmental impact. This study investigates the influence of wood bio-aggregate content on the thermo-physical and mechanical properties of WBBC. The mixtures were prepared using varying wood shaving contents (i.e., 40 %, 50 %, and 60 % by volume) and a cementitious matrix comprised of a cement-fly ash-metakaolin blend. Thermal conductivity, bulk density, and scanning electron microscopy (SEM) tests were performed on samples at 28 days of age. In addition, uniaxial compressive strength tests were performed to characterize the composites mechanically. Results indicate that thermal conductivity decreased with increasing biomass content. Specifically, WBBC60 exhibited a thermal conductivity value approximately 40 % lower (0.29 W/m × K) than WBBC40 (0.51 W/m × K). The bio-aggregate content significantly influences the mechanical behavior of the composites, leading to a noticeable reduction in compressive strength values, ranging from 8.18 MPa for WBBC40 to 0.53 MPa for WBBC60. SEM analysis revealed the detailed porosity of wood aggregates and the cementitious matrix, along with the interfacial interactions between them. These findings demonstrate the potential of WBBC as an effective thermal insulator, particularly those with higher bio-aggregate content.