The effect of silica fume and steel fiber on the dynamic mechanical performance of high-strength concrete

The impact and fatigue performance of high-strength concrete (HSC), silica fume high-strength concrete (SIFUHSC), steel fiber high-strength concrete (SFRHSC), and steel fiber silica fume high-strength concrete (SSFHSC) under the action of repeated dynamic loading were studied. The mechanisms by which silica fume and steel fiber reduce damage were also investigated. The results indicate that steel fiber effectively restrained the initiation and propagation of cracks during the failure of an HSC structure, mitigated the stress concentrations at the tips of cracks, and delayed the damage process under impact and fatigue. Silica fume effectively improved the structure of the interface, eliminated the weakness of the interfacial zone, reduced the number and size of cracks, and enhanced the ability of steel fibers to resist cracking and restrain damage. As a result, the corporation of steel fibers and sifica fume can increase greatly the performance of HSC subjected to impact and fatigue. (C) 1999 Elsevier Science Ltd. All rights reserved.