Engineering Characteristics and Potential Increased Utilisation of Sawdust Composites in Construction—A Review

Many timber producing countries generate more than 2 million m3 of sawdust annually. In developing countries, sawdust is often disposed of by open dumping, open burning, or dumping in landfills. This poses huge environmental challenges related to air pollution, greenhouse gas emissions, and destruction of plant and aquatic life. Findings from this review article reveal that sawdust can be used to make sawdust construction composites with good modulus of elasticity, water absorption and strength characteristics that satisfy international specifications. These composites include particleboards, sawdust concrete blocks or bricks and sawdust concrete. The article concludes that partially replacing 5% to 17% of sand with sawdust, or replacing cement with sawdust ash in proportions of 5% to 15% in concrete mixes can produce structural concrete with compressive strengths greater than 20 MPa. Partially replacing 10% to 30% of sand used in the manufacture blocks and bricks with sawdust can also produce sawdust bricks and blocks with compressive strengths greater than 3 MPa. Sawdust composites are also attractive for their low thermal conductivity, high sound absorption and good sound insulation characteristics. These findings indicate that increased utilisation of sawdust composites in construction will mitigate against potential sawdust environmental pollution, conserve energy and reduce disposal costs.