Comparação da resistência do concreto com variação do agregado graúdo a partir do ensaio esclerométrico

Abstract

This paper presents a study about the spatial variation of the hardness of a concrete surface and its relationship with the compressive strength. For the research will be used the same trace in two concrete mixtures, one using a coarse aggregate with maximum dimension of 12.5 mm and the other with 25 mm aggregate. The objective is to identify if the variation in coarse aggregate size exerts influence on the analysed properties of concrete. Cylindrical specimens were made for the axial compression test and prisms to be subjected to the non-destructive test. The detection of surface hardness is made by the reflection sclerometer test. The bounce points were located with aproximity of up to 10 mm, allowing to map the hardness in the surface of the specimens. From the sclerometric index is made a correlation with the compressive strength, based on the correlation equations developed in previous research. The concrete with a trace corresponding to the gravel of greater granulometry presented greater heterogeneity and surface hardness. Thus, the obtained results are evaluated and related to the results of destructive tests of rupture of standard specimens. Than the distribuition are adjusted by statistical distribution curves. Analyzing the effect of the variation of the maximum dimension of the coarse aggregate the concrete producing with the smaller coarse aggregate presented results similar to those of axial compression, where as the larger gravel presented greater divergence in the hardness and correlation results between the different faces of the prism.