Evaluation of Impact Resistance of Steel Fiber and Organic Fiber Reinforced Concrete and Mortar

Abstract

In this study, the Impact resistance of steel fiber and organic fiber reinforced concrete and mortar was evaluated and the improvement in toughness resulting from an increase in compressive strength and mixing fiber for impact resistance on performance was examined. The types of fiber were steel fiber, PP and PVA, and these were mixed in at 0.1, 0.5 and 1.0 vol.%, respectively. Impact resistance is evaluated with an apparatus for testing impact resistance performance by high-speed projectile crash by gas-pressure. For the experimental conditions, Specimen size was 100×100×20, 30mm (width×height×thickness). Projectile diameter was 7 and 10 mm and impact speed is 350m/s. After impact test, destruction grade, penetration depth, spalling thickness and crater area were evaluated. Through this evaluation, it was found that as compressive strength is increased, penetration is suppressed. In addition, as the mixing ratio of fiber is increased, the spalling thickness and crater area are suppressed. Organic fibers have lower density than the steel fiber, and population number per unit area is bigger. As a result, the improvement of impact resistance is more significant thanks to dispersion and degraded attachment performance.

A Study on the Penetration Resistance and Spalling Properties of High Strength Concrete by Impact of High Velocity Projectile

“…1에 [1][2][3] 콘크리트의 내충격 성능을 확보하기 위한 방법으로 기 존에는 시험체 두께의 증가 및 콘크리트 외부를 흙으로 덮는 등 기초적인 방법이 주로 이루어지고 있었지만, 최 근 콘크리트의 내충격 성능을 극대화시키는 방안으로 콘 크리트의 압축강도, 휨 ․ 인장강도 및 파괴에너지 등 역학 적 특성의 향상을 통하여 충격에 대한 저항성을 향상시 키는 방안 등이 모색되고 있으며, 콘크리트의 역학적 특 성과 내충격 성능과의 상관성 구명 및 내충격 성능의 예 측에 관한 연구가 활발히 진행되고 있다. [1][2][3][4][5][6][7] 이에 대한 기존 연구자들의 문헌에 따르면 콘크리트 의 압축강도 증가는 고속 충격을 받은 콘크리트의 표면 관입깊이를 억제하고, 휨 ․ 인장강도 및 파괴에너지 등 인 성의 향상은 배면박리를 억제하는 것으로 나타나고 있다.…”

A modeling strategy for the shear and flexural performance prediction of SFRC beams without stirrups accounting for the variability of properties

“…Therefore, selecting the appropriate mix components, optimizing their dosage, and understanding their benefits are critical for achieving desirable performance in SFRC. [3][4][5][6] In this sense, the random distribution of steel fibers in concrete can effectively inhibit the propagation of microcracks and facilitate load transfer, improving the composite tensile behavior. 7 Furthermore, the presence of an appropriate volume percentage of fibers significantly enhances the shear and flexural strengths and ductility of SFRC.…”