Estudo das matérias-primas utilizadas na construção dos conjuntos habitacionais localizados na cidade de Campina Grande.

Abstract

Lately the housing complexes of social interest built in the city of Campina Grande in Paraíba are being focus of criticisms regarding the performance of the buildings, especially as to the emergence of diseases originating from their raw materiais. The quality of the materiais used such as aggregates, reboncal (plasticizers for plaster and masonry), cement, mortars, blocks and tiles are of fundamental importance in the construction of these housing complexes and their poor performance can have as consequences serious defects in the structure and finishing work. This study aims to analyze the raw materiais used in the construction of these housings, as well as compare the obtained results of these analysis with the standard recommendations of ABNT, for the analysis of the studied materiais the following tests were made: for the cements tests of chemical analyses, specific mass, loss on ignition, setting time, fineness, X-ray diffraction (XRD), and compressive strength were made; for the aggregates tests of particle size, specific mass, pulverulent materiais; for the reboncal, X-ray diffraction (XRD), thermal analyses, chemical analyses, specific mass, stability and fineness; for the mortars tests of compressive strength, index void, specific gravity in the hardened state, water retention, air entrained content, specific gravity in the fresh stage, water absorption, dry density, specific mass and tension strength by diametrical compression; for the ceramic blocks tests of water absorption and compression and for the tiles water absorption and flexural strength. The results showed that the cements used in the construction of the housing complexes did not meet the requirements of compressive strength and the cement used in the housing complex Três Irmãs, did not meet the specifications required by the ABNT standard NBR 11578/1991; the reboncal used in the construction as lime, through the chemical analysis, was found that it was not hydrated lime, the aggregates did not meet the requirements of the ABNT standard NBR 7214/1982 for the leveis of pulverulent materiais; the mortars used in the housing complexes met the limits established by ABNT NBR 13281/2005; the ceramic blocks used in the housing complexes Novo Cruzeiro and Três Irmãs presented maximum water absorption within the limit allowed by the ABNT standard NBR 15270/2005, but for the compression test it did not meet the respective standard, presenting strength lower than 1/3 of the allowed strength of 1.5 MPa; less than half of the tiles from the Três Irmãs housing presented flexural strength as established by the standard and for the Novo Cruzeiro housing most of the tested pieces presented flexural strength superior to the standard requirement.