Influência do módulo de finura nas proprieades de argamassas com aditivo incorporador de ar

Abstract

The characteristics of the fine aggregate that are present in mortar composition significantly influence the properties of the mortars, and may change the application yield and performance in the hardened state. Using standardized sands provided by the Institute of Technological Research, four particle size compositions were determined with each one having different fineness modules. The use of these 04 compositions, in an initial proportion with a ratio of 1:1:6 that are given by volume of CPII-F 40 cement, CH-II slaked lime, sand and two levels of air-incorporating additive, with water/dry materials constant ratio were able to generate eight types of mixtures. Each of these tests was performed to evaluate the properties in both fresh and hardened state, also aiming to evaluate the influence of the variation of the fineness module on the properties. Related to the fresh state, the increase of the fineness module caused the increase in the entrained air content, decrease in water retention, higher consistency index and lower energy needed for spreading. Related to the hardened state, the observed effects regarding to the compressive strength and adhesion were more influenced by a better particle size distribution rather than by a variation of the fineness module. Permeability attributed to water and steam was higher in mortars composed of sand with larger fineness modules. Shrinkage indicators showed a decreasing trend as the fineness module increased.