Influência do uso de aditivo incorporador de ar na resistência mecânica do concreto

Abstract

The main purpose of this paper is to analyze the interaction between the air-entraining admixtures (AEA) and concrete, particularly about chances in concrete compressive strength. Through this research, the influence of the air-entraining admixture on concrete properties is discussed. To do so, an experimental analysis was done, evaluating the characteristics of fresh and hardened concrete mixtures, such as their consistency, density and compressive strength. In order to reach this goal, a number of tests were chosen: the slump test, compressive strength tests by using cylindrical samples, and measuring dimensions of these samples, as well as taking their weight, so that their densities could be calculated. A number of mix designs was made, and, for each one of them, two samples were tested. The first sample had no air-entraining admixture in it, whereas the second one had. The first chapter of this paper gathers some relevant information concerning concrete technology, as the history of concrete, its properties, tests, supplementary cementing materials and admixtures. After that, in the second part, the air-entraining admixture was carefully discussed. Therefore, its creation, operating principle, use, advantages and precautions were detailed. Lastly, the final chapter showed the experimental procedures used in this research, describing its results and taking conclusions about them