Ceramic and mixed construction and demolition wastes (CDW): a technically viable and environmentally friendly source of coarse aggregates for the concrete manufacture

摘要

Nowadays, it is widely recognized that construction and demolition wastes (CDW) pose a significant environmental problem. However, in spite of the interest that the topic of their reutilization in the construction industry has aroused among worldwide researchers, the actual practice regarding the use of recycled aggregates from CDW is limited to low level applications (mostly as unbound materials). This fact is especially true for recycled aggregates containing ceramic materials, which are commonly regarded as impurities.The aim of this study was to move towards a high value recycling of CDW. Thus, the objective of the PhD thesis was twofold; first, the analysis of the engineering properties of recycled aggregates from CDW with varying percentages of ceramic waste and, secondly, the performance assessment of four recycled concrete mixtures made with a 50% substitution of the natural coarse aggregates by means of a comprehensive set of tests, both in fresh and hardened state.Overall, the results of this doctoral research demonstrated the feasibility of using recycled aggregates from CDW with significant content of ceramic wastes as a partial replacement of the natural gravel in the manufacture of recycled concrete. Therefore, constituting a suitable high-level application for this type of residues that, in countries such Spain, represents around the 70% of the produced material at the CDW management plants.