Crack evolution mechanism and CT scale damage characteristics in concrete under hydraulic impacting
LIU Jialiang1,2,3, ZHANG Di1, WANG Mengjin1
1.School of Civil Engineering, Chongqing Jiaotong University, Chongqing 400074, China;
2. State and Local Joint Engineering Lab of Traffic Civil Engineering Materials, Chongqing Jiaotong University, Chongqing 400074, China;
3. MOE Engineering Research Center of Bridge Structure and Materials in Mountain Area, Chongqing Jiaotong University, Chongqing 400074, China
Abstract：Using the CT scanning technology, concrete’s meso fracture state was detected in all directions under hydraulic impacting. The mechanical processes of "V" shaped taper crushing core, surface cracks and circumferential cracks in concrete under hydraulic impacting were illustrated based on the CT scanning results and the liquid-solid collision theory. Then concrete failure mechanisms under hydraulic impacting in stages of cracking, expanding, and rupturing were explored and 5 typical hydraulic impact induced cracks evolution characteristics and mechanical mechanisms were revealed. Furthermore, the CT scanning images were processed with the histogram equalization and the threshold segmentation. A damage characterization method based on image gray value was proposed to study the CT scale damage distribution characteristics in concrete under hydraulic impacting. It was quantitatively shown that strong hydraulic impacting can cause obvious damage in aggregate and mortar basic transition zone of the unbroken area in concrete; the closer the distance to induced cracks, the more serious the damage deterioration degree.
[1] 李万莉, 徐宝富, 申燚. 水射流破碎水泥路面的微结构损伤模型及仿真[J]. 同济大学学报(自然科学版), 2005, 33(1):42-46.
LI Wanli, XU Baofu, SHEN Yi. The cement pavement broken water jet micro structure model and Simulation of damage [J]. Journal of Tongji University (Natural Science Edition), 2005, 33 (1): 42-46.
[2] 穆朝民, 王海露. 煤体在高压水射流作用下的损伤机制[J]. 岩土力学, 2013(5):1515-1520.
MU Zhaomin, WANG Hailu. The damage mechanism of coal body under the action of high pressure water jet [J]. Rock and Soil Mechanics, 2013 (5): 1515-1520.
[3] JIANG H, LIU Z, GAO K. Numerical simulation on rock fragmentation by discontinuous water-jet using coupled SPH/FEA method [J]. Powder Technology, 2017, 312:248-259.
[4] 卢义玉, 黄飞, 王景川, 等. 超高压水射流破岩过程中的应力波效应分析[J]. 中国矿业大学学报, 2013, 42(4):519-525.
LU Yiyu, HUANG Fei, WANG Jingchuan, et al. Analysis of stress wave effect during rock breaking by ultra-high pressure water jets [J]. Journal of China University of Mining and Technology, 2013, 42 (4): 519-529.
[5] 司鹄, 薛永志, 周维. 自激振荡脉冲射流破岩效率数值模拟[J]. 振动与冲击, 2016, 35(20):149-153.
SI Hu, XUE Yongzhi, ZHOU Wei. Numerical simulation of rock breaking efficiency of self excited oscillation pulsed jet [J]. Vibration and Shock, 2016, 35(20): 149-153.
[6] 司鹄, 薛永志. 基于SPH算法的脉冲射流破岩应力波效应数值分析[J]. 振动与冲击, 2016, 35(5):146-152.
SI Hu, XUE Yongzhi. Numerical analysis of stress wave effect of pulsed jet rock breaking based on SPH algorithm [J]. Vibration and Shock, 2016, 35(5):146-152.
[7] 陆朝晖, 卢义玉, Michael Hood, 等. 截断式脉冲射流流场结构模拟与冲蚀硬岩能力分析[J]. 振动与冲击, 2017, 36(19):180-185.
LU Zhaohui, LU Yiyu, Michael Hood, et al. Structure simulation of truncated pulsed jet flow field and analysis of erosion hard rock capacity [J]. Vibration and Shock, 2017, 36(19):180-185.
[8] 陈厚群, 丁卫华, 党发宁, 等. 混凝土CT图像中等效裂纹区域的定量分析[J]. 中国水利水电科学研究院学报, 2006, 4(1):1-7.
CHEN Houqun, DING Weihua, DANG FaNing, et al. Quantitative analysis of equivalent crack area in concrete CT images [J]. Journal of China Water Resources and Hydropower Research Institute, 2006, 4 (1): 1-7.
[9] 党发宁, 刘彦文, 丁卫华, 等. 基于破损演化理论的混凝土CT图像定量分析[J]. 岩石力学与工程学报, 2007, 26(8):1588-1593.
DANG Faning, LIU Yanwen, DING Weihua, et al. Quantitative analysis of concrete CT images based on the theory of breakage evolution [J]. Journal of Rock Mechanics and Engineering, 2007, 26 (8): 1588-1593.
[10] HE N, LU K, BAO H. An Improved Geometric Active Contour Model for Concrete CT Image Segmentation Based on Edge Flow [J]. Chinese Journal of Electronics, 2010, 19(4):687-690.
[11] 赵亮, 李昌华, 徐胜军, 等. 基于多尺度信念传播的混凝土CT图像分割[J]. 计算机工程, 2012, 38(8):195-197.
ZHAO Liang, LI Changhua, XU Shengjun, et al. Concrete CT image segmentation based on multi-scale belief propagation [J]. Computer Engineering, 2012, 38 (8): 195-197.
[12] 汤积仁, 卢义玉, 孙惠娟, 等. 基于CT方法的磨料射流冲蚀损伤岩石特性研究[J]. 岩石力学与工程学报, 2016(2):297-302.
TANG Jiren, LU Yiyu, SUN Huijuan, et al. Study on the characteristics of erosion and damage of abrasive water jet based on CT method [J]. Journal of Rock Mechanics and Engineering, 2016 (2): 297-302.
[13] 黄飞, 卢义玉, 刘小川, 等. 高压水射流冲击作用下横观各向同性岩石破碎机制[J]. 岩石力学与工程学报, 2014, 33(7):1329-1335.
HUANG Fei, LU Yiyu, LIU Xiaochuan, et al. Cross-isotropic rock fragmentation mechanism under the impact of high-pressure water jet [J]. Chinese Journal of Rock Mechanics and Engineering, 2014,33 (7): 1329-1335.
[14] 武利强, 王良, 章晓桦, 等. 沥青混凝土水力劈裂的细观机理研究[J]. 水力发电, 2017, 43(2):47-50.
WU Liqiang, WANG Liang, ZhANG Xiaohua, et al. Meso-mechanism study of hydraulic fracturing of asphalt concrete [J]. Power System, 2017,43 (2): 47-50.
[15] 施惠生, 孙丹丹, 吴凯. 混凝土界面过渡区微观结构及其数值模拟方法的研究进展[J]. 硅酸盐学报, 2016, 44(5):678-685.
SHI HuiSheng, SUN Dandan, WU Kai. Review on the Microstructure of Transitional Zone in Concrete Interface and Its Numerical Simulation [J]. Chinese Journal of Silicommunity, 2016, 44 (5): 678-685.
[16] 张志呈. 岩石爆破裂纹的起裂, 扩展, 分岔与止裂[J]. 爆破, 1999(4):21-24.
ZHANG Zhicheng. The initiation, propagation, bifurcation and crack arrest of rock burst [J] . Blast, 1999 (4): 21-24.
[17] 徐世烺, 赵国藩. 混凝土裂缝的稳定扩展过程与临界裂缝尖端张开位移[J]. 水利学报, 1989(4):33-44.
XU Shijie, ZHAO Guofan. Stable propagation of concrete cracks and open crack tip displacement [J]. Journal of Hydraulic Engineering, 1989 (4): 33-44.
[18] 郝景宏, 姜袁, 梅世强, 等. 基于X射线CT的混凝土内部裂纹识别研究[J]. 混凝土, 2010(10):44-47.
HAO Jinghong, JIANG Yuan, MEI Shiqiang, et al. Research on internal crack identification of concrete based on X-ray CT [J]. Customs, 2010 (10): 44-47.
