Abrasion Resistance of Fine Aggregate-Replaced Silica Fume Concrete

Abstract

This investigation evaluated the resistance to abrasion of concrete proportioned to have four levels of fine aggregate replacement (5%, 10%, 15%, and 20%) with silica fume. Control mixtures containing no silica fume were also used for comparison purposes. Three cement factors, namely, 500 lb/cu yd (900 kg/cu m), 650 lb/cu yd (1,157 kg/cu m), and 800 lb/cu yd (1,424 kg/cu m), and two water-to-cementitious materials ratios (w/cm)--0.325 and 0.40)--were employed. The fresh and bulk characteristics, such as slump, air content, time of setting, bleeding, unit weight, and compressive strength, were examined to characterize the selected matrixes. The standard testing method--American Society for Testing and Materials (ASTM) C 779, Procedure C, Ball Bearing--was used to ascertain the resistance to wear. The influence of silica fume addition, cement factor, w/cm, and curing were studied. The relationship between depth of wear and compressive strength was also presented. Finally, the fresh properties, compressive strength (and strength development), and abrasion resistance of the fine aggregate-replaced silica fume concretes were compared with those of the reference mixtures. Laboratory test results concluded that the resistance to wear of concrete containing silica fume as a fine aggregate replacement was consistently better with increasing amounts of silica fume up to 10%. The abrasion resistance and compressive strength decreased with increases in w/cm and improved with increases in cement factor and curing age. Both compressive strength and resistance to wear of fine aggregate-replaced silica fume concretes were better than those exhibited by the equivalent control matrixes. A significant correlation was found between the depth of wear and compressive strength.