Improving the abrasion resistance of hydraulic-concrete containing surface crack by adding silica fume

Abrasion damage generally results from constant friction and impact of waterborne silt, sand, gravel, rocks, ice, and other debris on concrete surfaces during the operation of a hydraulic structure. In this study, a waterborne abrasion over a large area of the test slab was developed to investigate the influence of surface cracks on the abrasion–erosion resistance of concretes, with variable surface crack type and silica fume content. The test results concluded that: (1) the abrasion rate is higher for water flow impinging directly on the crack than that above the crack; (2) increased crack width reduces the abrasion resistance of the tested concrete; (3) the abrasion rate increased with the angle of the crack to the water flow; and (4) the abrasion resistance increased with the addition of silica fume for concrete having a surface crack. These findings and may be of interest to engineers designing concrete hydraulic structures.