Estudo da argamassa estabilizada para assentamento com adição mineral de metacaulim.

Abstract

The construction industry, over the years, has undergone great technological advances, in the search for the rationalization of construction. To achieve this goal, new constructive techniques and new materials have appeared in the market. Among these materials it is possible to highlight the appearance of stabilized mortars. This presents several applications such as laying, wall covering, flooring, ceiling and facades. And it has as main advantage, compared to ordinary mortars, the fact of remaining workable and preserve its properties for up to 72 hours. However, the studies on this type of mortar in Brazil have still been underdeveloped, since it is a type of product still not very widespread in the country, mainly because of the paradigms created on its costs of production. In this sense, the present study has as objective to evaluate the properties in the fresh and hardened conditions of the mortars stabilized for 36 hours, with different contents of metakaolin (MK) mineral addition in the partial replacement of the cement, 0, 10 and 20%, with the purpose of improving the properties of these mortars through the use of these additions, which can contribute to reduce its cost. Initially, the physical, chemical and mineralogical characterization of the constituent materials of the mortars studied was performed. A mass trait used commercially for its production was adopted and its properties were studied in the fresh and hardened state. In the fresh state, the workability (consistency), mass density and air content were evaluated. In the hardened state, the compressive strength, bulk density and capillary absorption were analyzed for cylindrical specimens (5 x 10 cm) at the age of 28 days. It was observed that the mortar with 10% MK had consistency similar to 36 hours, and at 48 hours had better performance. The fresh mass density and the incorporated air content increased up to 4.20% and decreased up to 45%, respectively, with the highest MK content. In the hardened state, there was a gain of compressive strength with the increase of MK content, where the sample with 10% presented satisfactory results throughout its stabilization time.