건설재료시공학연구실

Building material & construction lab.

Abstract : In this study, Impact resistance of steel fiber and organic fiber reinforced concrete and mortar were evaluated and the effect of toughness improvement due to an increase in compressive strength and mixing fiber for impact resistance on performance was examined. Type of fiber is steel fiber, PP and PVA and they were respectively mixed in 0.1, 0.5 and 1.0 vol.%. Evaluation performance of impact resistance is tested by an apparatus for testing impact resistance performance by high-speed projectile crash by gas-pressure. As the experimental conditions, Specimen size is 100×100×20, 30mm(width×height×thickness). Diameter of projectile is 7 and 10 mm and impact speed is 350m/s. After impact test, destruction grade, penetration depth, spalling thickness and crater area were evaluated as evaluation criteria. As a result, it was found that the more compressive strength is increased, the penetration is suppressed. And the more mixing ratio of fiber is increased, the spalling thickness and crater area are suppressed. In case of organic fiber's, it has more low density than the steel fiber, population number per unit area is bigger. Consequently improvement effect of impact resistance is more effective by dispersion and degradated attach performance.