Procedimentos e resultados de ensaios de caracterização física e mecânica de blocos cerâmicos estruturais e de vedação

Abstract

In Brazil ceramic blocks are widely used in masonry constructions and their quality is guaranteed by the Brazilian standard ABNT NBR 15270. This standard went through a revision process in the year 2017 and this research took advantage of this moment to evaluate some of the current Brazilian standard tests, such as wa-ter absorption index determination, initial absorption index and compressive strength tests, and to perform non-standard tests such as density, durability, adhesion strength and efflorescence tests in order to validade the code review and contribute for its future update. The tests were performed in blocks donated by manufacturers from the states of São Paulo, Minas Gerais, Rio de Janeiro, Rio Grande do Norte and Pará. The research showed that the tests of total absorption indices carried out in hot and cold water present similar results in Brazilian ceramic blocks. The abra-sion resistance test was related to the compressive strength test, where blocks with higher resistance to abrasion presented higher resistance to compression. In the test of adhesion with and without roughcast, the blocks without roughcast had poor ad-hesion levels and the blocks with roughcast showed acceptable adhesion levels. As for the efflorescence tests, the Franco test (2012) and the American standard ASTM C67 were evaluated, where the methodology of the American standard presented procedures was concluded more appropriate. From the density tests with and with-out paraffin, the values indicate that there a difference in each procedure result.