Effect of metallic aggregate and cement content on abrasion resistance behaviour of concrete

Abstract

Many concrete structures are required to have sufficient abrasion resistance, such as dams, canals, roads and floors. The abrasion resistance of concrete may be defined as its ability to resist being worn away by rubbing. Compressive strength and aggregate type are also important factors affecting the abrasive behaviour of concrete. However, very little information on the properties of haematite containing concrete has been reported. The authors report on the abrasion resistance of concrete with four different cement contents (300, 350, 400 and 450 kg m(-3)) and with haematite as a metallic aggregate with replacement ratios of 15, 30, 45 and 60% under 5, 10 and 15 kg loads. The water/cement ratio was kept constant at 0.40 to evaluate the effects of haematite and cement content. Slump tests were conducted to evaluate the workability of fresh concretes. For hardened concrete samples, mechanical tests such as compressive strength, splitting tensile strength, unit weight and wear resistance were performed. Along with the physical and mechanical properties of concretes, haematite was studied as a mineral. Increasing both cement and haematite content has substantial effects on the strength of the concrete. Polarising microscopy views of the interfaces show that haematite aggregates exhibit greatly improved bond strength. Wear loss of concrete decreases with increasing concentration of haematite, while it increases with increasing cement content. An equation representing wear as a function of cement content, compressive strength and also applied load provides virtually perfect agreement with the experimental results.