Effect of Recycled Glass Powder and Nano-Silica on the Strength and Permeability of Concrete

In Lima, many concrete structures experience accelerated deterioration due to physical and chemical factors, limiting their durability. This study evaluates the effect of recycled glass powder (RGP) and a nanosilica additive (1.5 %) on concrete with f’c = 27.5 MPa (280 kg/cm²), focusing on optimizing its mechanical properties, durability, and economic feasibility. Mixtures with 10 %, 15 %, and 20 % cement replacement by RGP were prepared, assessing compressive, tensile, and flexural strength, as well as permeability and water absorption. The mixture with 10 % RGP (RGP-10) showed the best early age mechanical performance, increasing compressive strength by 39.1 %, tensile strength by 12.7 %, and flexural strength by 26.2 % compared to the concrete control. Mixtures with 15 % and 20 % RGP showed lower initial strength, although future gains are expected due to delayed pozzolanic reactions. Regarding durability, RGP-10 reduced permeability by 9.02 % and water absorption by 6.45 %, while RGP-15 and RGP-20 achieved even greater reductions, with permeability decreasing by 11.48 % and 9.84 %, and water absorption by 8.68 % and 10.56 %, respectively. Although the nanosilica additive increases the initial cost, its combination with RGP produces significant improvements in mechanical properties and durability, contributing to a reduction in maintenance related costs, resulting in a durable, sustainable, and economically viable material.