Bibliographic analysis of the use of pozzolanic additions and modified mixing methods in recycled aggregate concretes

Abstract

The growth in demand for natural aggregates, their diminishing reserves, the increased generation of construction waste and the disposal of this waste have become important economic and environmental matters. Recycling construction waste as coarse recycled aggregates in concretes is an alternative to mitigate the issues related to their disposal and the increasing pressure on natural aggregates. However, the use of recycled aggregates in concrete jeopardizes its performance. Modified concrete mixing approaches and the use of pozzolanic materials may lessen the issue, improving the performance of recycled aggregate concretes, contributing to a greater acceptance and use of the material. Using the ProKnow-C (Knowledge Development Process – Constructivist) methodology, a state-of-the-art research portfolio concerning modified mixing methods and pozzolanic additions to recycled aggregate concretes was assembled. A qualitative and quantitative analysis about pozzolanic additions and mixing methods was performed, identifying which are the most effective mixing methods and pozzolan additions. After the analysis, it was pointed that mixing methods with addition of silica fume enveloping the recycled aggregates improved the concrete’s compression performance the most.