Desempenho termomecânico de argamassas com adição de resíduos de vermiculita para construções rurais.

Abstract

In the state of Paraíba there is a significant concentration of the vermiculite mineral that, through its extraction, generates raw materials for civil construction. During its processing, tons of waste are generated and deposited in the environment in an inadequate way, causing great environmental impacts. The objective of this work was to analyze the feasibility of the use of the vermiculite residue in substitution for the portion of natural fine sand in the elaboration of coating mortars with improved properties. Samples of vermiculite residue were collected at Pedra Lavrada, Santa Luzia / PB, to perform characterization tests, in order to evaluate their application in mortars. Mortars with 1: 4 traces (cement: sand) were prepared, with substitution contents of 0%, 30%, 60% and 100% fine sand. Portland cement CP II-Z 32, with water / cement factor between 0.65 and 0.85, was used. The mortars were analyzed in the hardened state through the tests of resistance to compression, immersion absorption and capillarity. Considering the best result found, plates were prepared for the thermal behavior test. The characterization of the vermiculite residue showed a great amount of fines, which led to an improvement in the compressive strength, water absorption by immersion and capillarity in the mortar, when compared to the reference mortar (0%). The results of the thermal behavior analysis, obtained by means of the thermal gradient between the faces of the plates, showed a variation in the thermal gradient of up to 40% higher for the plates containing vermiculite residue when compared to the results obtained in the reference mortar (0% ). Thus, it is possible to conclude that the vermiculite residue is suitable for the production of coating mortar and guarantees improved properties, mainly in terms of its thermal behavior compared to the reference mortar.