Estudo comparativo do efeito da substituição parcial do cimento Portland por vidro moído

Abstract

Cement is one of the materials that most generate CO2 in its production and, considering that the reuse of solid waste as raw material to produce other products is an environmentally correct solution. The objective of this work was to evaluate the effect, on the physical and mechanical properties, of the partial replacement of Portland cement (CP V-ARI) by glass powder in mortars in different proportions. Therefore, the results obtained in the mortar tests in the fresh and hardened states, developed in the laboratory, following established norms and standards, served as a basis for physically and mechanically characterizing whether the replacement proportions adopted (15, 25, 35 and 50%) presented equivalent or statistically satisfactory results in relation to the reference mortar (0% replacement), it was also verified whether the different colors adopted in the analyzes had a significant influence on the presented results. The mortars were prepared with Portland cement, fine aggregate, glass powder and a water/cement ratio of 0,7. The glass powder waste used had the following colors: green, blue, colorless, amber and colored. Except for green glass, all other colors had a diametral characteristic of approximately 44,87 μm. Values below 75 µm make it difficult for the alkali-silica reaction to occur because it acquires the behavior and characteristics of natural pozzolan. In flexural tensile strength, there was an increase in resistance from 28 to 90 days, there was also an increase in resistance from 90 to 365 days. At 28 to 90 days, with 15% replacement content, the results with the highest gains in flexural tensile strength in relation to the reference were obtained in the green color (33,3%) and blue color (17,7%), while in the 25% content the best results with resistance gains were in green color (21,4%) and colored color (12,0%). In terms of compressive strength, the best result obtained for the 15% content at 28 days was for blue color (94,7% of the reference) and green color (85,1% of the reference), and at 90 days, also for the 15%, the best result obtained was in blue color (85,9% of the reference) and green color (83,4% of the reference). Alkali-silica reactivity in mortars with 50% replacement of CP V-ARI by glass powder did not occur in any mortar because the diameters of the glasses powder had low granulometry, according to the expansions evidenced at 30 days. The solubility analysis indicated that glass powder colors do not influence the conductivity analysis. The mortars that showed the highest immersion absorption value and open porosity were those that contained the highest glass powder content in their composition (50% and 35%). The most adequate proportions, identified in this study, were in the partial substitutions of 15 and 25% of CP V-ARI by glass powder because they were closer to the reference value when compared to the other substitution percentages.