Análise experimental da resistência à compressão de concretos de pós reativos com e sem adição de fibras

Abstract

The requirement of materials with performance superior to the current materials available in the Civil Engineering market is the motor force behind researches that aim at the development of new technologies. In this context, Reactive Powder Concrete (RPC) emerged, which stands out in questions of quality control, since the optimization in the selection of the materials used for its preparation associated with a detailed and rigorous process of cure treatment, ensure high compressive and tensile strengths, which are higher than a conventional concrete. The present research had as main objective to perform an experimental analysis of the compressive strength of RPCs with different types and dosages of fibers, using materials available in the Brazilian market. Initially, a study of RPC traces obtained from researches of publications found in the literature was performed, and the trace that obtained the best compressive strengths at 28 days was used for this research. With the trace, CPR test specimens with fiber dosages were made in the proportions of: 0%, 0.5% and 1%. The fibers used were steel and polyethylene. In addition, a trace of conventional concrete was prepared according to the Brazilian Portland Cement Association (BPCA) method. The RCP models were vapor cured for 72 hours and continued to cure submerged in water up to the test ages. Conventional concrete samples were directly cured in water up to the test ages. The test was the uniaxial compression strength, according to Brazilian norm NBR 5739/2007, at the ages of 3, 14 and 28 days. With the results, it has been found that reactive dusts have a better compressive strength performance than conventional concrete. Furthermore, it is possible to verify the influence of the fiber dosage on the rupture of the concrete according to the rupture planes observed, such as the behavior of each fiber and residual resistances conferred by them after collapse.