Chloride permeability and impact resistance of polypropylene-fiber-reinforced silica fume concrete

Permeability and imp act resistance of polypropylene-fiber-reinforced concrete mixtures containing silica fume with variable design proportions were studied. Two fiber lengths were considered, 12.5 and 19 mm, and four fiber volume fractions, 0, 0.1%, 0.3%, and 0.5%. Silica fume was used as a replacement by weight of cement. Two silica fume contents were used, 5% and 10%. Results showed that the incorporation of polypropylene fibers increased the permeability of conventional concrete. The addition of silica fume improved fiber dispersion in the cementitious matrix, causing a significant reduction in the permeability of the polypropylene fiber reinforced concrete. Moreover, the addition of silica fume was noted to significantly enhance the polypropylene fiber effectiveness in improving the impact resistance of concrete. (C) 1998 Elsevier Science Ltd.