基于随机骨料模型的混凝土抗压强度尺寸效应研究
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摘要
将混凝土视为砂浆、骨料及过渡界面组成的三相复合材料,采用随机骨料模型从细观角度对混凝土轴压破坏过程及抗压强度尺寸效应进行数值分析。该模型中考虑了混凝土级配以及骨料分布的影响,通过赋予各相材料塑性损伤本构关系并引入初始缺陷来模拟混凝土破坏过程中裂缝的产生与扩展。通过与试验数据进行对比,认为所建立随机骨料细观模型能够较好地反映混凝土抗压强度尺寸效应规律。分析结果表明:初始缺陷大小对混凝土抗压强度尺寸效应影响显著,而混凝土强度等级与缺陷位置对尺寸效应影响较小。通过对混凝土轴压破坏机理进行分析,发现基于能量释放的尺寸效应模型能够较好地解释混凝土的破坏过程和预测模拟结果。
Concrete is composed of cement,aggregates,and the interface. A three-phase mesoscale model is adopted to analyze the size effect of concrete compressive strength and failure mechanism. The random distribution of coarse aggregate is considered during the establishment of the model. By assigning each phase its own damaged plasticity property and introducing initial defects,this mesoscale model can successfully simulate the propagation of the blunt crack band. Comparing with experimental data,the simulation makes a well prediction in the size effect of concrete compressive strength. The research results show that the size of the defect exerts a significant influence on the ultimate compressive capacity of concrete columns,while the strength grade of concrete and the location of defect present weak impacts. Finally,it is found through the analysis of failure mechanism that the size effect theory based on energy dissipation can perfectly account for the failure process and the simulation results.
Concrete is composed of cement,aggregates,and the interface. A three-phase mesoscale model is adopted to analyze the size effect of concrete compressive strength and failure mechanism. The random distribution of coarse aggregate is considered during the establishment of the model. By assigning each phase its own damaged plasticity property and introducing initial defects,this mesoscale model can successfully simulate the propagation of the blunt crack band. Comparing with experimental data,the simulation makes a well prediction in the size effect of concrete compressive strength. The research results show that the size of the defect exerts a significant influence on the ultimate compressive capacity of concrete columns,while the strength grade of concrete and the location of defect present weak impacts. Finally,it is found through the analysis of failure mechanism that the size effect theory based on energy dissipation can perfectly account for the failure process and the simulation results.
引文
[1]朱尔玉,杨威,王建海,等.不同形状尺寸C20混凝土试件抗压强度的关系[J].北京交通大学学报,2005,29(1):1-4.(ZHU Eryu,YANG Wei,WANG Jianhai,et al.Relationship of compressive strength of specimens with various shapes and sizes for C20 grade concrete[J].Journal of Beijing Jiaotong University,2005,29(1):1-4.(in Chinese))
[2]李家康.高强混凝土立方体抗压强度的尺寸效应[J].建筑材料学报,2004,7(3):81-84.(LI Jiakang.Dimensional effect of cubic compressive strength of high strength concrete[J].Journal of Building Materials,2004,7(3):81-84.(in Chinese))
[3]曾伟,石云兴,彭小芹,等.透水混凝土尺寸效应的试验研究[J].混凝土,2007(5):15-18.(ZENG Wei,SHI Yunxing,PENG Xiaoqin,et al.Experimental study on size effect of pervious concrete[J].Concrete,2007(5):15-18.(in Chinese))
[4]钱觉时,杨再富,黄煜镔,等.高强混凝土强度尺寸效应的试验研究[J].华中科技大学学报(城市科学版),2004,21(1):1-4.(QIAN Jueshi,YANG Zaifu,HUANG Yubin,et al.Experimental study of the size effect on the strength of high-strength concrete[J].Journal of HUST(Urban Science Edition),2004,21(1):1-4.(in Chinese))
[5]苏捷,方志.骨料组分和强度等级对混凝土单轴受压性能尺寸效应的影响[J].建筑结构学报,2014,35(5):120-127.(SU Jie,FANG Zhi.Influence of aggregate mixture and strength grade on dimensional effect of concrete uniaxial compressive behavior[J].Journal of Building Structures,2014,35(5):120-127.(in Chinese))
[6]ERIK Schlangen.Experimental and numerical analysis of fracture process in concrete[D].Delft:Delft University of Technology,1993:62-99.
[7]CUSATIS G,PELESSONE D,MENCARELLI A.Lattice discrete particle model(LDPM)for failure behavior of concrete:I:theory[J].Cement and Concrete Composite,2011(33):881-890.
[8]KOHEI Nagai,YASUHIKO Sato,TAMON Ueda.Mesoscopic simulation of failure of mortar and concrete by 2D rbsm[J].Journal of Advanced Concrete Technology,2004,3(3):385-402.
[9]GRIFFITH A A.Phenomena of rupture and flow in solids[M].New York:Phil Trans Press,1921:179-180.
[10]WEIBULL W.A statistical theory of the strength of materials[M].Stockholm:Generalstabens Litografiska Anstalts Fo9rlag,1939:1-45.
[11]BAZANT Z P.Size effect in blunt fracture:concrete,rock,metal[J].Journal of Engineering Mechanics,1984,110(4):518-535.
[12]CARPINTERI A.Scaling laws and renormalization groups for strength and toughness of disordered materials[J].International Journal of Solids and Structures,1994(31):291-302.
[13]KIM J K,EO S H.Size effect in concrete specimens with dissimilar initial cracks[J].Magazine of Concrete Research,1990,42(153):233-238.
[14]BAZANT Z P,XIANG Y.Size effect in compression fracture:splitting crack band propagation[J].Journal of Engineering Mechanics,1997,123(2):167-172.
[15]SIM J I,YANG K H,KIM H Y,et al.Size and shape effects on compressive strength of lightweight concrete[J].Construction&Building Materials,2013,38(2):854-864.
[16]SIM J I,YANG K H,JEON J K.Influence of aggregate size on the compressive size effect according to different concrete types[J].Construction&Building Materials,2013,44(7):716-725.
[17]MANSUR M A,ISLAM M M.Interpretation of concrete strength for nonstandard specimens[J].Journal of Material in Civil Engineering,2002,14(2):151-155.
[18]WITTMANN F H.Simulation and analysis of composite structure[J].Material Science and Engineering,1985,6(8):239-248.
[19]苏捷.混凝土受压与受拉性能的尺寸效应研究[D].长沙:湖南大学,2012:22-76.(SU Jie.The research on the size effect of concrete behavior in compression and tension[D].Changsha:Hunan University,2012:22-76.(in Chinese))
[2]李家康.高强混凝土立方体抗压强度的尺寸效应[J].建筑材料学报,2004,7(3):81-84.(LI Jiakang.Dimensional effect of cubic compressive strength of high strength concrete[J].Journal of Building Materials,2004,7(3):81-84.(in Chinese))
[3]曾伟,石云兴,彭小芹,等.透水混凝土尺寸效应的试验研究[J].混凝土,2007(5):15-18.(ZENG Wei,SHI Yunxing,PENG Xiaoqin,et al.Experimental study on size effect of pervious concrete[J].Concrete,2007(5):15-18.(in Chinese))
[4]钱觉时,杨再富,黄煜镔,等.高强混凝土强度尺寸效应的试验研究[J].华中科技大学学报(城市科学版),2004,21(1):1-4.(QIAN Jueshi,YANG Zaifu,HUANG Yubin,et al.Experimental study of the size effect on the strength of high-strength concrete[J].Journal of HUST(Urban Science Edition),2004,21(1):1-4.(in Chinese))
[5]苏捷,方志.骨料组分和强度等级对混凝土单轴受压性能尺寸效应的影响[J].建筑结构学报,2014,35(5):120-127.(SU Jie,FANG Zhi.Influence of aggregate mixture and strength grade on dimensional effect of concrete uniaxial compressive behavior[J].Journal of Building Structures,2014,35(5):120-127.(in Chinese))
[6]ERIK Schlangen.Experimental and numerical analysis of fracture process in concrete[D].Delft:Delft University of Technology,1993:62-99.
[7]CUSATIS G,PELESSONE D,MENCARELLI A.Lattice discrete particle model(LDPM)for failure behavior of concrete:I:theory[J].Cement and Concrete Composite,2011(33):881-890.
[8]KOHEI Nagai,YASUHIKO Sato,TAMON Ueda.Mesoscopic simulation of failure of mortar and concrete by 2D rbsm[J].Journal of Advanced Concrete Technology,2004,3(3):385-402.
[9]GRIFFITH A A.Phenomena of rupture and flow in solids[M].New York:Phil Trans Press,1921:179-180.
[10]WEIBULL W.A statistical theory of the strength of materials[M].Stockholm:Generalstabens Litografiska Anstalts Fo9rlag,1939:1-45.
[11]BAZANT Z P.Size effect in blunt fracture:concrete,rock,metal[J].Journal of Engineering Mechanics,1984,110(4):518-535.
[12]CARPINTERI A.Scaling laws and renormalization groups for strength and toughness of disordered materials[J].International Journal of Solids and Structures,1994(31):291-302.
[13]KIM J K,EO S H.Size effect in concrete specimens with dissimilar initial cracks[J].Magazine of Concrete Research,1990,42(153):233-238.
[14]BAZANT Z P,XIANG Y.Size effect in compression fracture:splitting crack band propagation[J].Journal of Engineering Mechanics,1997,123(2):167-172.
[15]SIM J I,YANG K H,KIM H Y,et al.Size and shape effects on compressive strength of lightweight concrete[J].Construction&Building Materials,2013,38(2):854-864.
[16]SIM J I,YANG K H,JEON J K.Influence of aggregate size on the compressive size effect according to different concrete types[J].Construction&Building Materials,2013,44(7):716-725.
[17]MANSUR M A,ISLAM M M.Interpretation of concrete strength for nonstandard specimens[J].Journal of Material in Civil Engineering,2002,14(2):151-155.
[18]WITTMANN F H.Simulation and analysis of composite structure[J].Material Science and Engineering,1985,6(8):239-248.
[19]苏捷.混凝土受压与受拉性能的尺寸效应研究[D].长沙:湖南大学,2012:22-76.(SU Jie.The research on the size effect of concrete behavior in compression and tension[D].Changsha:Hunan University,2012:22-76.(in Chinese))