Pesquisa de viabilidade da utilização da argamassa estabilizada modificada para revestimento sem a necessidade de aplicação do chapisco

Abstract

In Brazil, the construction industry has shown significant growth in recent years. Thus some problems existing in the area ended up being maximized. The lack of skilled labor, for example, is one of the main problems encountered. Moreover, traditional products and services are being replaced by new and better performance. Within this context, this paper presents the study of technical and economic feasibility of the application directly on the masonry ceramic bricks in "bone" stabilized mortar modified with adhesion promoter additive, the base copolymers. The objective is to evaluate the feasibility of applying plaster mortar, without conducting layer roughcast. Therefore, it was necessary to enhance the properties of the mortar holding steady focus upon satisfying the requirements established by the Brazilian Association of Technical Standards, described in NBR 13281 - Mortar for laying and covering walls and ceilings - requirements (ASSOCIAÇÃO. .. 2005d). Consequently, it was necessary to study the behavior of this "new" mortar both in fresh and hardened state. On the other hand, there was the need to compare its performance with the mortar stabilized commonly used. During the study of the properties of this "new" mortar in the fresh state it was first necessary to determine the quantity of mixing water can promote scattering around 250 mm employing cement and sand only in trace 1: 5.75. With the initial stroke, it was found that the behavior of mortar with addition of air-entraining additive and stabilizer. The percentages of these additions that provided the best consistency and workability over time, were used to compose the first reference mortar (Ref.1). The next step was to determine the optimum percentage of additive to be added to the adhesive mortar, along with decreasing increment of entraining air, and thus obtain a "new" mortar (Ref.2). To validate the proposal were made in reference mortars, several essays, including, consistency index, loss of firmness, absorption, water retention, bulk density, air content embedded, tensile and compression. The results show that, compared to the amount of incorporated air and scattering, both the mortars had results within the limits defined in the standard and used regionally. The water retention and compressive strength of the mortar with reference polymer, (Ref.2) gave the best result. Regarding the results of bond strength was evaluated mortars Ref.1 and Ref.2 applied to the roughcast and directly on the substrate. The results show that both can be applied in the ways outlined subject to adhesion, and the tensile stresses encountered in all cases were greater than the minimum established norm. Comparing the mixtures were applied to the roughcast and directly on the masonry, the Ref.2 showed greater resistance than Ref.1 in both cases, and the direct application there was a greater difference between the grip provided by Ref.2 compared the Ref.1