Influência dos diferentes teores de cal e aditivo incoporador de ar nas propriedades das argamassas de emboço

Abstract

This study aimed to investigate the influence of different lime and air-entraining admixture (AEA) contents in composite mortar mixtures, which were produced by blending two fine aggregates, 70% artificial sand and 30% natural sand. To evaluate the effects produced by different proportions of lime and air-entraining admixture, 9 mortar mixes were prepared with a cement-to-sand ratio of 1:6 and varying additions of lime (0.2, 0.4, and 0.6) and AEA (0.2%, 0.4%, and 0.6%), dosed to achieve a consistency of 260±10 mm (flow table). The results indicated the influence of AEA on the mortar properties. As the admixture content increased, the mortars required less water to achieve the desired workability. It was also observed that the increase in AEA content resulted in a higher amount of entrained air in the mortars, leading to a reduction in their strengths. Among the studied mixtures, five complied with the criteria of the ABNT NBR 13281 standard for external plaster mortars, while four only met the ]criteria for internal coating mortars.