Experimental study on rockfall impact resistance of high ductile concrete slabs
KOU Jialiang1,2, WANG Huacheng1
1.School of Civil Engineering & Architecture,Xi’an University of Technology, Xi’an 710048, China;
2.State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048, China
Abstract:In order to study the rockfall impact resistance of high ductile concrete (HDC) slabs under impact load, the hammer drop test is conducted from14m height and include 6 block of HDC slabs and 2 regular concrete (RC) slabs. The fiber contents of HDC are 0.5%, 1% and 2%. The difference of impact resistance between HDC and RC as well as the effects of different fiber content on the impact resistance of the HDC slabs were analyzed. The test process of each specimen was recorded by high speed camera, and the destruction form of the specimen, the maximum displacement of the impact center and the maximum impact and impulse of the drop Hammer were analyzed. The results show that under the same impact load, the regular concrete slabs are penetrated, the bottom of the slabs are sprayed with a large amount of concrete fragments, the damage surface is neat and smooth, the crack is wide and in cross shape, and the steel bar does not yield, which belongs to local through destruction. The HDC slabs produces several cracks that are gradually developed from the center, and shown radiation-like distribution, the bottom of the slab has a small amount of concrete debris spalling. Due to the HDC and steel bar has a good bonding capacity, the steel bar yield or broke eventually, but the whole slabs only cracked and not broke, the minimum instantaneous acceleration of the falling hammer directly impacting the RC plate is 933.01g, maximum impact force 914.35kN, maximum impact time 0.0278s, the large strain rate reaches the order of 1011s-1. In contrast, the minimum instantaneous acceleration of the HDC board drop hammer 28.1% less than RC board, maximum impact force reduced by 28.1%, maximum impact time is extended by 0.006s, large strain rate is reduced by 106s-1, indicating that the HDC slab has good impact resistance performance, and the fiber volume content of 1% of HDC impact resistance is the strongest.
寇佳亮1,2,王华丞1. 高延性混凝土板抗落石冲击性能试验研究[J]. 振动与冲击, 2020, 39(11): 239-247.
KOU Jialiang1,2, WANG Huacheng1. Experimental study on rockfall impact resistance of high ductile concrete slabs. JOURNAL OF VIBRATION AND SHOCK, 2020, 39(11): 239-247.
[1] 陈宇龙. 滚石运动过程中关键参数的影响分析[J]. 岩土工程学报, 2013,35(s2):191-196.(Che Yulong. Influence of key factors on trajectories of rockfalls [J]. Chinese Journal of Rock Mechanics and Engineering,2013,35(s2):191-196.)
[2] 赵旭, 刘汉东. 水电站高边坡滚石防护计算研究[J]. 岩石力学与工程学报,2005,24(20):3742-3748. (Zhao Xu, Liu Handong. Research on protective structures for high slopes rockfall around a- hydropower station [J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(20):3742-3748.)
[3] 肖柏军, 胡晓波, 宁明哲,等. 纤维增强混凝土抗冲击性能试验结果的统计分析[J]. 铁道科学与工程学报,2007,4(2):44-47.(Xiao Baijun, Hu Xiaobo, Ning Mingzhe, et al. Statistical analysis of impact properties on a fiber-reinforced concrete[J]. Journal of Railway Science and Engineering,2007,4(2):44-47.)
[4] Hwang S, Song P S, Sheu B C. Impact resistance of polypropylene fiber-reinforced concrete[J]. Chungcheng Institute of Technology,2003,32(1):1-14.
[5] Fujikake K, Li B, Soeun S. Impact Response of Reinforced Concrete Beam and Its Analytical Evaluation[J]. Journal of Structural Engineering, 2009, 135(8):938-950.
[6] Schellenberg K, Volkwein A, Roth A, et al. Large-scale impact tests on rockfall galleries[C] Proceedings of the 7th International Conference on Shock & Impact Loads on Structures. CI-Premier Pte Ltd, 2007: 497-504.
[7] 何思明, 吴永, 李新坡. 滚石冲击碰撞恢复系数研究[J]. 岩土力学,2009,30(3):623-627.(He Siming, Wu Yong, Li Xinpo. Research on restitution coefficient of rock fall[J]. Rock and Soil Mechanics, 2009, 30(3): 623-627.)
[8] 何思明, 吴永, 杨雪莲. 滚石坡面冲击回弹规律研究[J]. 岩石力学与工程学报, 2008,27(s1):2793-2798.(He Siming,Wu Yong,Yang Xuelian. Study of rock - fall motion on slope[J]. Chinese Journal of Rock Mechanics and Engineering, 2008,27(s1):2793-2798.)
[9] 曾翔, 许斌. 无腹筋钢筋混凝土梁抗冲击行为试验研究[J]. 土木工程学报,2012(9):63-73.(Zeng Xiang,Xu Bin.Experimental study on the impact-resistant behavior of RC beams without shear-resistant rebar [J].China Civil Engineering Journal,2012,45(9):63-73)
[10] Li V C. From Micromechanics to Structural Engineering The Design of Cementitious Composites for Civil Engineering Applications[J].Proceedings of the Japan Society of Civil Engineers,1993,10(471):1-12.
[11] 李为民, 许金余. 玄武岩纤维对混凝土的增强和增韧效应[J].硅酸盐学报, 2008,36(4):476-481.(Li Weimin,Xu Jinyu. Strengthening and toughening in basalt fiber-reinforced concrete[J]. Journal of the Chinese Ceramic Society,2008,36(4):476-481.)
[12] 张山, 张俊发, 陶磊, 等. S形钢龙骨-夹芯板防护层的落石冲击缓冲性能试验研究[J]. 振动与冲击, 2017,36(24):148-155.(Zhang Shan, Zhang Junfa, Tao Lei, et al. Tsets for cushion performance of a protective layer with S-shaped steel joist and sandwich slab under rockfall impact [J]. Journal of Vibration and Shock, 2017,36(24):148-155.)