A comprehensive assessment of concrete with recycled coarse aggregate treated by a combination of heating, grinding, and acid-soaking process

Abstract

Waste generated after a concrete construction demolition causes environmental problems. Utilization of recycled aggregates extracted from concrete waste has been recommended to overcome these problems. Aggregates occupy about 70-80% of concrete volume; therefore, using recycled aggregate from waste concrete can potentially prevent the landfill problem. So far, the conventional recycling method is processed by crushing the concrete rubble into smaller sizes according to fine and coarse aggregate sizes. However, the product still needs to achieve an adequate quality recycled aggregate. Several methods have been attempted to obtain better quality; though, they demand a reasonably high cost. Recycled aggregates produced from a combination of thermal, mechanical, and chemical processes are proposed in this study. This production process is relatively easy, especially for developing countries. In addition, the results obtained significantly improve the quality of recycled aggregates compared to the conventional method. This paper comprehensively discusses the recycled aggregate produced by a combination of thermal, mechanical, and chemical processes. The reviews involve the recycled aggregate's physical properties, the concrete's mechanical and microstructural properties, and the production costs of concrete made from these recycled aggregates. As a comparison above, concrete made from natural aggregates is also analyzed.