Recycling of cement stabilised gravel base material in a highway into aggregates for concrete

摘要

This paper presents a case study on the recycling of highway base material into aggregates and the further use of the recycled concrete aggregates (RCAs) for manufacturing new concrete. The highway was damaged due to non-uniform settlement of the subgrade. The base material in this highway was lean concrete, or cement stabilised gravel. In this work, the lean concrete base material of the damaged highway was firstly demolished and then crushed into aggregates, i.e., RCAs. The physical and mechanical properties of the coarse fraction of the RCAs were examined. The results indicated that the RCAs exhibit a fairly satisfactory performance. The RCAs were then utilised to substitute natural coarse aggregate in producing new concrete. It was found that the concrete with the RCAs can achieve the desired workability and compressive strength. Finally, the concrete with RCAs was successfully used in the repair of the damaged highway.