Experimental and environmental investigations of the impacts of wood sawdust on the performance of reinforced concrete composite beams

The majority of sawdust is produced by various lumber industries located all over the world. It has been established that using recycled materials to replace some of the fine aggregates is a viable solution. Most researchers focused on the durability aspect of wood sawdust concrete, while less information is available on its structural performance. Therefore, this article aimed to investigate the performance of reinforced concrete beams fabricated from concrete with a partially replaced fine aggregate (FA) by wood sawdust (WS) in the range of 5% to 45% (by weight). Six beams underwent 4-point bending tests till collapse. The beams' slump, density, compressive strength, cracking and failure mode, energy absorption, and economic and environmental aspects were studied. The findings showed that the failure region of sawdust concrete was more significant than the reference samples. Despite the compressive strength of the concrete containing different ratios of sawdust being reduced by about 7% - 30%, the target compressive strength still has a limit of low to normal concrete grade. The results show that the increase in sawdust percentages decreased the acquired absorbed energy of the subjected load to reach failure. A cost reduction of 9% and a cost index of 61% is achieved using wooden sawdust-based concrete. By substituting sawdust for fine aggregate, the sustainability of sawdust concrete in terms of cost and environmental advantages may be improved. In addition, it is well-known that harnessing the transformative potential of industrial waste in concrete production not only minimizes landfill usage, but also promotes resource efficiency, reduces carbon emissions, and advances the circular economy, propelling designers, engineering and builders towards a greener and more sustainable future in the construction industry. According to the test findings, wood sawdust may be utilized to produce normal and low-strength structural concrete.