Abrasion resistance of ultra-high performance concrete with coarse aggregate

Abrasion resistance is a critical property for concrete structures subjected to abrasion deterioration, such as industry floors, pavement, or hydraulic structures. Studies on abrasion resistance of normal concrete have been well established, whereas there is limited research on the abrasion behavior of ultra-high performance concrete (UHPC). This study developed lower-cement UHPC incorporating basalt and calcined bauxite coarse aggregate, and a normal concrete was prepared for comparison. The abrasion resistance was evaluated based on the mass loss and abraded depth of concrete. A nanoindentation test was also conducted to investigate the underlying mechanisms that determine the macro-behavior. The UHPC with calcined bauxite aggregate showed 28% higher compressive strength than UHPC with basalt aggregate due to the rough surface texture and super high stiffness of the calcined bauxite. The evaluated UHPCs with coarse aggregate show good mechanical strength as well as excellent abrasion resistance than normal concrete that their abraded depth or mass loss was only approximately one-third of that of the normal concrete. The high strength and densified paste matrix of UHPC has a relatively bigger effect on the abrasion resistance of UHPC than the effect of coarse aggregate type, ITZ properties, or steel fiber which contribute more to the strength of UHPC.