Green concrete - Recycling construction waste

Abstract

Within the European Union, the construction and demolition wastes come to at least 180 million tons per year. Roughly 75% of the waste is disposed to landfill, despite its major recycling potential. The bulk constituents of demolition debris are concrete (50-55%) and masonry (30-40%) with only small percentages of other materials such as metals, glass and timber. In Cyprus, at present, recycling of waste materials is practically inexistent and almost the entire demolition waste products are disposed off in landfill sites. This research paper presents the evaluation and the effective reuse of waste construction materials disposed to landfill sites in Cyprus, due to the lack of a lucid recycling policy and knowledge. The following materials were investigated: (a) recycled concrete aggregates (RCA), as natural aggregate replacements and (b) lime filler from the crushing process of calcareous aggregates used in the production of asphalt concrete, as a partial cement replacement. The study investigates how the waste materials affect workability, as well as mechanical properties and durability indicators. A series of mechanical and durability tests are compared with corresponding values from concrete mixtures being currently utilized in the local construction industry.