STUDY OF MIX-DESING OF SELF-COMPACTING CONCRETE WITH CONSTRUCTION AND DEMOLITION WASTE

Abstract

The objective of this work was to perform a self-compacting concrete (SCC) dosage study using partial replacement of natural aggregates by recycled aggregates obtained from construction and demolition waste (CDW).The experimental program consisted in the production of CAA with three percentages of substitution (10%, 20%, 30%) of the natural fine aggregate (NFA) per recycled fine aggregate (RFA), characterizing it according to NBR 15823-1. Was used cement CP-II-E and silica fume as supplementary material. The natural fine aggregate used was sand. The coarse aggregate was the crushed gravel, and a superplasticizer additive. The applied methodology included an adaptation of the Gomes method for self-compacting concrete. The SCC in the fresh state was evaluated through the tests: slump flow; flow time at Funnel V and Box-L. Although reducing the properties in the fresh state, it was possible to conclude that the use of percentages of up to 30% of recycled fine aggregate from construction and demolition wastes in the production of SCC is technically feasible, considering the particularities and limitations of the recycled material.