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

Kim, Gyu-Yong,Hwang, Heon-Kyu,Nam, Jeong-Soo,Kim, Hong-Seop,Park, Jong-Ho,Kim, Jeong-Jin The Korean Institute of Building Construction 2012 한국건축시공학회지 Vol.12 No.4

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 $100{\times}100{\times}20$, 30mm ($width{\times}height{\times}thickness$). 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.

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

김규용,황헌규,남정수,김홍섭,박종호,김정진 한국건축시공학회 2012 한국건축시공학회지 Vol.12 No.4

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.

Engineering Properties of Steel Fiber Reinforced High Performance Concrete

Kim Young Ik,Sung Chan Yong The Korean Society of Agricultural Engineers 2004 한국농공학회논문집 Vol.46 No.7

In this paper, the flowability, strengths, impact resistance and sulfuric acid resistance of steel fiber reinforced high performance concrete (SFHPC) for the steel fiber content and fly ash and blast furnace slag as admixtures were presented. For evaluating flowability particularly, tests of slump flow, box-type passing ability and L-type filling ability were performed. The slump flow of SFHPC was some decreased with increase of the steel fiber content. At the box-type passing ability, the difference of box height of SFHPC is greatly increased with increasing the fiber content. The L-type filling ability of SFHPC was not excellent above $0.75\% of the steel fiber content. Also, the compressive strength of SFHPC was decreased with increase of the steel fiber content, but the flexural strength of SFHPC was much higher than that of the concrete without the steel fiber. At the impact resistance, drop number of SFHPC for reaching final fracture was increased with increase of the fiber content. Also, the drop number for reaching initial fracture of lmm was increased with increase of the fiber content. At the sulfuric acid resistance, 4-week weight change of SFHPC with the steel fiber was almost similarity that of HPC without the steel fiber and was in the range of 73.6 to 81.5.

고속 비상체의 충돌을 받은 섬유보강 모르타르의 내충격 성능 평가

김규용(Kim Gyu-Yong),남정수(Nam Jeong-Soo),미야우치 히로유키(Miyauchi Hiroyuki) 대한건축학회 2011 大韓建築學會論文集 : 構造系 Vol.27 No.9

Recently, the damaged building and loss of life have been increasing by man-made disasters. In this study, the impact resistance performance of fiber reinforced concrete against high-velocity projectile was evaluated by using high pressure gas apparatus and AUTODYN. Plain mortar specimen was penetrated by steel projectile at 350 m/s and was fractured heavily at the backside. On the other hand, the PVA, PE and STF specimens reinforced with fiber have higher impact resistance than plain mortar, and were analyzed by Hughes equation. Finally, the impact resistance of specimens was calculated from viewpoint of fracture mode by AUTODYN and it was concluded that fiber reinforced concrete improve the impact resistance performance.

고속 비상체의 충돌을 받은 섬유보강 모르타르의 내충격 성능 평가

김규용,남정수,미야우치 히로유키,Kim, Gyu-Yong,Nam, Jeong-Soo,Miyauchi, Hiroyuki 대한건축학회 2011 대한건축학회논문집 Vol.27 No.9

Recently, the damaged building and loss of life have been increasing by man-made disasters. In this study, the impact resistance performance of fiber reinforced concrete against high-velocity projectile was evaluated by using high pressure gas apparatus and AUTODYN. Plain mortar specimen was penetrated by steel projectile at 350 m/s and was fractured heavily at the backside. On the other hand, the PVA, PE and STF specimens reinforced with fiber have higher impact resistance than plain mortar, and were analyzed by Hughes equation. Finally, the impact resistance of specimens was calculated from viewpoint of fracture mode by AUTODYN and it was concluded that fiber reinforced concrete improve the impact resistance performance.

Steel단섬유보강 시멘트복합체의 내충격성능

남정수 ( Nam Jeong-soo ),김홍섭 ( Kim Hong-seop ),최경철 ( Choe Gyeong-cheol ),이상규 ( Lee Sang-kyu ),손민재 ( Son Min-jae ),김규용 ( Kim Gyu-yong ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.1

The aim of this study is to investigate the impact resistant performance of steel short fiber-reinforced cement based composites (SFRCCs) containing 1.0, 1.5, 2.0 and 3.0% volume fraction of steel short fibers subjected to high velocity impact of steel projectile (the diameter of 19.05mm and the mass of 28.13g). The gunpowder impact facility was used for impact tests, and the impact velocity was from about 350 to 700m/s. The specimens were damaged in various failure modes, which are penetration, scabbing, and perforation. Comparing with Plain specimen, SFRCCs have superior capacity on the scabbing limit, and slightly bulged in the back side under the impact velocity of 700m/s. In addition, the impact resistant performance of SFRCCs improved with increase of steel short fiber volume ratio. The fibers play an important role in controlling the local damage of SFRCCs.

Performance and modeling of high-performance steel fiber reinforced concrete under impact loads

Ramadoss Perumal 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.13 No.2

Impact performance of high-performance concrete (HPC) and SFRC at 28-day and 56-day under the action of repeated dynamic loading was studied. Silica fume replacement at 10% and 15% by mass and crimped steel fiber (Vf = 0.5%- 1.5%) with aspect ratios of 80 and 53 were used in the concrete mixes. Results indicated that addition of fibers in HPC can effectively restrain the initiation and propagation of cracks under stress, and enhance the impact strengths and toughness of HPC. Variation of fiber aspect ratio has minor effect on improvement in impact strength. Based on the experimental data, failure resistance prediction models were developed with correlation coefficient (R) = 0.96 and the estimated absolute variation is 1.82% and on validation, the integral absolute error (IAE) determined is 10.49%. On analyzing the data collected, linear relationship for the prediction of failure resistance with R= 0.99 was obtained. IAE value of 10.26% for the model indicates better the reliability of model. Multiple linear regression model was developed to predict the ultimate failure resistance with multiple R= 0.96 and absolute variation obtained is 4.9%.

Preparation and Properties of HUHPC with Low Shrinkage and High Impact Resistance

Qingjun Ding,Jinhua Gong,Gaozhan Zhang,Yang Liu,Jun Yang,Yongyuan Zhang,Peng Zhou 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.8

At present, nuclear energy is widely used to reduce pollution and clean energy. However, the radiation-proof concrete currently used to prepare nuclear shields cannot meet the protection requirements of nuclear safety. Therefore, there is an urgent need to develop radiation-proof concrete materials with high impact resistance and ultra-high strength. In this paper, the low-shrinkage, high-impact Heavy Ultra-High-Performance Concrete (HUHPC) was designed by the following innovative methods: Porous high titanium heavy slag sand (HTHS) (industrial solid waste) with “slow-water release” effect and expansion agent were synergistically used to improve volume stability; Irregular HTHS with “embedded lock” effect and steel fibers were synergistically utilized to enhance impact resistance; Heavy ilmenite sand was used to lift volume weight. The workability, mechanical properties, volume stability, impact resistance, and microstructure were studied. The results show that the designed HUHPC volume weight is more than 2,800 kg/m3 which can enhance the radiation protection performance greatly. The 180 d shrinkage of HUHPC is less than 400 με, which volume stability is improved by more than 30%. The addition of lithium carbonate slightly decreased the 28 d strength of HUHPC, but the appropriate admixture amount (0.9%) could improve the impact resistance of HUHPC by 33%.

420 MPa급 내진내화 복합성능 H형강의 소재 및 용접에 대한 연구

최종열,여동진,김희동,정준호,양재근 한국강구조학회 2023 韓國鋼構造學會 論文集 Vol.35 No.5

1906년 샌프란시스코 대지진, 1955년 고베 대지진 등 큰 규모의 지진이 발생하였을 때 많은 화재사고가 접수되었다. 이와같은 재해로 인한 최악의 사태를 대비하고자 국내에서는 내진내화 복합성능 H형강을 개발 중이며, 본 연구에서는 건축구조용으로서사용가능 여부를 확인하기 위해 소재성능과 용접 적합성에 대한 시험을 진행하였다. 소재성능의 경우 평판 인장시험, 샤르피 충격시험 등 4종류의 시험을 진행하였으며, 동일 강도 건축구조용 강재의 KS기준을 만족하는 것으로 확인된다. 또한 강재의 두께에 따라강도 및 충격에너지 등 기계적 특성이 차이 나는 것으로 확인된다. 용접적합성의 경우 각종 인장시험, 샤르피 충격시험 등 6종류의시험을 진행하였다. 이에 따르면 개발된 매칭 용접봉과의 적합성에는 큰 이상이 없는 것으로 나타나며, 강재의 두께가 용접성능에 영향을 미치는 것으로 확인된다. 따라서 본 연구를 통해 내진내화 복합성능 H형강이 건축구조용으로 사용될 수 있을 것으로 기대된다. Numerous fire accidents were received during the massive earthquake strikes of 1906-San Francisco and 1955- Kobe. In South Korea, Seismic and Fire Resistance H-Shape Steel Beam Section is in development in order to prevent struc tural failures due to such disasters. This paper presents experimental results conducted on material performance and welding suitability to analyze the applicability of such steels. For analyzing the material performance, four experiments including flat tensile test and Charpy impact test were conducted. The results suggest that the Seismic and Fire Resistance H-Shape Steel Beam Section satisfies the Korean Industrial Standard (KS) of other steel that is generally used for domestic construction projects. It was also analyzed that the strength and impact energy is highly related to the thickness of the Seismic and Fire Resistance H-Shape Steel Beam Section. For analyzing the welding suitability, six experiments including tensile test and Charpy impact test were conducted. The results suggest that the welding rod and the experiment steel were well matched and the thickness also affected the welding suitability. Therefore, it was concluded that the Seismic and Fire Resistance H-Shape Steel Beam Section can be used appropriately in construction structures.

대용량 전동기 내충격 성능평가

이승규(S. K. Lee),이성욱(S. W. Lee),최소해(S. H. Choi),박영수(Y. S. Park),공영경(Y. K. Kong) 한국정밀공학회 2010 한국정밀공학회 학술발표대회 논문집 Vol.2010 No.11월