High-performance concrete with fine recycled concrete aggregate: Experimental assessment

摘要

High-performance concrete (HPC) is a cement-based material with excellent properties and durability which determines high-level structural utilization. However, the necessity of high-quality natural resources such as quartz powder and sand and a high amount of cement and silica fume and reinforcement by fibers causes a high environmental footprint and costs. One of the possible ways to reduce the environmental footprint and cost of the HPC/UHPC is to replace the powder or sand with secondary raw materials. In this study, the two types and three fractions of fine recycled concrete aggregate (fRCA) are used as supplementary materials in HPC. The reference mixture is based on the UHPC mixture without reinforcement to find out the influence of aggregate replacement. The properties of fresh and hardened concrete are examined. The results show a slight decline of mechanical properties however the autogenous shrinkage decrease with the replacement of natural aggregate by fRCA, which shows the possibilities of natural resources savings and thus leads to a lower environmental footprint of concrete structures as a contribution to the solution of sustainable development goals set by the United Nations in 2015 as an action plan up to 2030.