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 proporti ons were studied. Two fiber lengths were considered, 12.5 and 19 mm, a nd four fiber volume fractions, 0, 0.1%, 0.3%, and 0.5%. Silica fume w as used as a replacement by weight of cement. Two silica fume contents were used, 5% and 10%. Results showed that the incorporation of polyp ropylene fibers increased the permeability of conventional concrete. T he addition of silica fume improved fiber dispersion in the cementitio us matrix, causing a significant reduction in the permeability of the polypropylene fiber reinforced concrete. Moreover, the addition of sil ica fume was noted to significantly enhance the polypropylene fiber ef fectiveness in improving the impact resistance of concrete. (C) 1998 E lsevier Science Ltd.