Concreções lateríticas: propriedades básicas e sua utilização em vigas isostáticas submetidas à flexão simples.

Abstract

This dissertation presents the results of an investigation carried out to assess the physical, chemical and mechanical properties of lateritic concretions from Sape-Pb and Mosqueiro-Pa, as well as evaluates the mechanical properties of lateritic concrete when used instructural beams. The results obtained allowed it to be concluded that the lateritic concretions contained a considerable amount of sesquioxides and were composed of quartz, goethite and hematite, kaolinite being the only clay mineral. The absorption and durabitily values for the concretions were beyond the normal level. The lateritic concrete revealed a ratio tensile: compressive strength similar to normal concrete, although the compressive strength values were on average, 50% of those for normal concrete. The structural beams presented a behaviour, in terms of strength, similar to normal concrete, but the deflexion values were slightly superior to the values for normal concrete, besides the fact that the elasticity modulus, determined by ultra-sound, being inferior to the normal concrete. The results from the laboratory tests with the beams showed that there were no problems of interaction between steel and the lateritic concrete. Also the development of cracks and failure were in the same mode as for normal concrete. In overall it can be concluded that the lateritic concretions are an alternative aggregate to fabricate concrete of low cost where there is an occurrence of lateritic concretions.