Evaluation of the characteristics of recycled aggregates produced in campinas-SP/Brazil

Abstract

To use the aggregate generated by recycling plants in the production of concrete, it is essential to know its characteristics. This paper aims to evaluate samples of recycled aggregates, both small and large, produced at two recycling plants located in the city of Campinas, SP, Brazil, comparing the results with parameters established by NBR 15116:2004 and with the characteristics of the natural aggregates used in the production of concrete. For the development of the study, samples of aggregates, small and large, both natural and recycled were collected, which had their characteristics determined and evaluated according to the specifications of NBRs 7211:2009 and 15116:2004. The results indicate that even the recycled aggregates showing some variability throughout the tests and unfulfilled with some normative specifications, it is concluded that their use in concrete is close to becoming feasible. It was verified that simple corrections in the recycling plants or additions of a certain amount of natural aggregate, would probably already be enough for the total standardization of the recycled aggregate. Comparing the recycled aggregates with the natural ones it was verified that the recycled ones present a higher index of fines and mainly greater absorption of water, which reflects in smaller values of specific mass, apparent specific mass and crushing resistance. However, these are not limiting factors in the use of recycled materials in concretes without structural function, since they will not be so mechanically required.