Life cycle assessment, mechanical properties, and durability of roller compacted concrete pavement containing recycled waste materials

Abstract

This study focused on the environmental life cycle assessment of roller compacted concrete pavement (RCCP) containing ceramic waste aggregate and coal waste powder. Also, the mechanical and durability properties of RCCP were tested. 10, 15, 20, and 25% ceramic waste aggregates, by the weight of coarse aggregates, were used as replacements for natural aggregates. Moreover, coal waste powder was used in the mixture at the replacement levels of 4 and 8% by the weight of cement. The results showed that the use of ceramic waste as aggregates increased the vibrating compaction time of fresh mixtures while decreasing their density. Furthermore, coal waste powder reduced the vibrating compaction time of RCCP mixtures. The life cycle assessment method showed that using these materials reduced greenhouses gases, and 15% of ceramic waste aggregate and 8% of coal waste powder declined greenhouses gases by 10%. Also, this combination of ceramic waste aggregate and coal waste powder showed the highest positive impact on the global warming index, reducing by 9 %. Moreover, the microstructural analysis of concrete was performed by SEM images, and the durability of RCCP was measured. The results showed that after replacing 15% natural aggregates with ceramic waste, 90-d compressive, splitting tensile and flexural strengths were increased by 14, 39, and 20%, respectively. Also, using ceramic waste aggregate increased the durability of concrete after 90-d curing time. Overall, using these waste materials in RCCP can not only reduce emissions and global warming issues but can enhance the mechanical properties of RCCP and recycle plenty of waste materials.