Análise de concretos de pós reativos a base de carbonato extra leve, mica e carbonato de cálcio

Abstract

The constant search and need for stronger concrete resulted in new techniques and studies where improved mechanical properties through the elimination of coarse aggregates and the betterment of granulometric composition of the mixture. Through surveys conducted since 1990 in France and Canada, was developed Reactive Powder Concrete (RPC), to replace the High Performance Concrete (HPC). It is basically composed of powders - quartz sand, cement common, quartz powder and silica fume, steel fibers small, superplasticizer and water, and solids with sizes less than 2 mm, and its compressive strength is in around 150MPa. Este study aims to examine the compressive strength and moisture absorption from three types of concrete run with different powders materials. Were used in place of the quartz powder substances extra light carbonate, mica and calcium carbonate, of these components being used in each concrete. The samples were cured at temperatures of 20 ° C and 90 ° C and tested aged 7 and 28 days. The results indicated that the curing temperature and time of subjection to heat treatment became stronger material. The concrete had developed high resistance to compression to excellent average to moisture absorption when compared to conventional concrete, but can not yet be classified as RPC, because the resistances obtained were less than 150MPa. The mica was found to be not suitable for this type of concrete to present the worst results. The extra light carbonate and calcite, despite its low for a RPC also showed to possess the same potential by means of further studies with improved techniques.