Evaluation of reinforced concrete structural durability in the post-occupation phase – A case study in Novo Hamburgo/RS

Abstract

Researches on building performance have been developed over time. The Brazilian Performance Standard-NBR 15575-deals with the issues of durability applied to residential buildings, establishing criteria and parameters to classify the systems into minimum, intermediate and higher performance levels. In relation to the service life, studies are also associated with the building’s structural durability, in which the technical specifications and quality of materials, construction systems, building process, use and maintenance of the building are important factors for better performance. In order to evaluate the structural durability over the years, a case study was conducted in a building designed to meet the higher level established in the Brazilian Performance Standard, with service life of 75 years in the structural project, through the non-de-structive surface hardness of concrete test by using a Schmidt hammer and semi-de-structive carbonation tests. The superficial hardness test was conducted on a concrete column following the procedures of NBR 7584, while the carbonation samples were collected in 3 concrete columns in which a phenolphthalein solution was sprayed to observe the alkalinity of the samples. For all tests, three different heights were considered. The concrete testing hammer indicated an average surface hardness of approximately 50 MPa, and for carbonation tests, it was noted that the concrete was not carbonated at a depth of 5mm. So, the criteria of service life could be considered attended.