ANÁLISE DA ABSORÇÃO DE ÁGUA EM CONCRETOS CONVENCIONAIS E EM CONCRETOS PRODUZIDOS COM ADITIVOS HIDROFUGANTES: Levantamento de informações pela ótica dos mecanismos de transporte no concreto

Abstract

The objective of this work was to study concrete and concrete with waterproofing additives that act by waterproofing, observing the ability of fluid transport to the interior of the concrete through the absorption by capillarity, in order to understand its microstructural behavior to interfere in the durability of structures, absorption is one of the most frequent mass transport mechanisms. Three different types of concretes were analyzed, with dry mortar contents of approximately α ≅ 46.5%, α ≅ 50% and α ≅ 53.5%; and fix the water / cement ratios and the cement consumption for the different concretes analyzed, in order to obtain reliable comparative parameters. Subsequently, the materials were characterized and the concretes produced in the laboratory. After the molding and curing of the specimens of the different concretes produced, tests of compressive strength, tensile strength by diametrical compression and water absorption by capillarity were carried out, following the parameters established by norm. The results, for the analyzed ages, indicated that the concretes, in general, presented a height of infiltration above the limits of cover established by norm, being necessary a more in depth verification in each case, mainly of elements buried or in contact with the soil, in order to obtain concretes with characteristics of lower permeability and consequently more durable. Another point observed was that the additives used in the study caused negative interferences in the concretes, affecting their mechanical strengths, where these presented reduction in comparison with the concretes that were molded without the use of additives. The application of mass hydrophobics, especially in concrete for structural purposes, was not feasible at first, and further studies are recommended to understand, from the microstructural point of view, its interaction with concrete.