Sustainable use of wood sawdust as a replacement for fine aggregate to improve the properties of concrete: a Peruvian case study

Currently, wood residues such as sawdust generated by local sawmills are shown as a sustainable alternative to be incorporated in the preparation of concrete. There is a complex environmental problem due to the inadequate management of industrial wastes; therefore, the objective of this study was to evaluate the mechanical properties of concrete using wood sawdust (WS) of the Pinus type obtained in Peru. WS was used in percentages of 0.5%, 1%, 1.5% and 2% substituting in weight the fine aggregate, elaborated for concrete control designs with w/c ratio 0.759 and 0.573, respectively; in addition, compressive strength, flexural strength, tensile strength and modulus of elasticity were analyzed in both cases, tested in cylindrical and prismatic specimens for 7, 14 and 28 days of curing. The results indicated that it is possible to reduce the workability up to 25% and 18.75%; the unit weight showed a slight insignificant reduction; however, the air content did increase up to 60 and 70%, as the dose of WS increases. Regarding the mechanical properties at 28 days, the results at 1% WS were better, i.e., the compressive strength increased by 12.60% and 5.21%, the flexural strength increased by 11.29% and 4.05%, the tensile strength increased by 20.89% and 9.48%, and the modulus of elasticity increased by 6.08% and 7.35%, respectively. It was concluded that up to a maximum of 1% WS is advisable to prepare non-structural concrete, and from an environmental point of view, it is a highly favorable result for its reuse and contribution to the Sustainable Development Goals (SDGs).