Assessment of properties variability of recycled construction and demolition aggregates

Abstract

The need to seek an environmentally appropriate destination for construction and demolition waste (WCD) makes recycling this material essential. The characteristics of the aggregates produced by the recycling process affect the performance of composites made with Portland cement, in addition to this, the quality of the recycled aggregate is strongly influenced by the production process. This work aim is to analyze and evaluate, through statistical tools, such as analysis of variance (ANOVA) and Scott-Knott test, the variability of the properties of fine and coarse recycled aggregates (RA) produced in four recycling plants in the state of São Paulo over a period of time one year. Fine (Фmax<4.8mm) and coarse (Фmax 9.5/25mm) recycled aggregate (RA) samples were collected in four recycling plants in the state of São Paulo, namely: Hortolândia, Limeira, Jundiaí and Várzea Paulista. Three collections were carried out for each plant, with a space of four months between collections. The physical properties tested for the characterization and analysis of the variability of the aggregates were: fineness modulus, water absorption, fines content and specific mass. The results obtained from the tests carried out indicate that characteristics variability of aggregates from different recycling plants exists. It can be said that this variability is due not only to the differences in the production process of each plant, but also to the quality of the debris received at each plant and the effectiveness of its sorting.