带初始冻融损伤的混凝土材料受盐冻作用下性能劣化分析
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摘要
为探明早期受冻后引起的带有初始损伤的混凝土材料在冻融循环与硫酸盐侵蚀耦合作用下力学性能的损伤演变规律,在制备混凝土试件养护期内,分别在7 d与14 d时实施冻融1次,使其产生不同程度的初始损伤,进而研究早期冻融造成的不同程度初始损伤对试件宏观性能与内部结构的影响作用。基于损伤力学理论,分别将混凝土试件的动弹性模量与抗压强度定义为损伤变量,对变量的损伤过程进行回归拟合分析,构建了由早期冻融造成的不同初始损伤试件在腐蚀受冻环境中的损伤演变方程。结果表明:两种带有不同初始损伤度的混凝土试件其各项力学性能的衰变过程受早期冻融影响均出现了"超前效应",且该效应的出现幅度与初始损伤度有着极大联系;同时,通过对比分析混凝土超声脉冲传播速度与内部缺陷区的变化过程得知,早期冻融加速了空洞与裂缝的扩展速度,对混凝土综合性能的初始值与后期抗盐冻能力存在不利影响;动弹性模量与抗压强度损伤演变方程可作为相似损伤程度下混凝土力学性能衰减的通用公式,为相似环境下结构的服役状态评估和寿命预测提供理论依据,同时可以基于动弹性模量与抗压强度的损伤关系式对二者进行相互推导,降低了由于仪器不足等原因导致数据获取不足的局限性。
In order to find out the damage evolution rule of the concrete with initial damage caused by early freezing under the coupling of freezethaw cycle and sulfate erosion, initial damage to concrete specimens by freezing and thawing them at the 7 th and 14 th day during the preparation of concrete specimens was carried. Based on this, different initial damage degree on macro performance and internal structure was researched.Then according to the principle of damage mechanics, the dynamic modulus of elasticity and compressive strength were defined as damage variables, by regression fitting analysis of damage process of variable, and the damage evolution equation of different initial damage specimen caused by early freeze-thaw was established in corrosion and freezing environment. The results indicated that two kinds of concrete specimens with different initial damage are affected by early freeze-thaw in the decay process of their mechanical properties and their form are "lead effect", which is closely related to the degree of initial damage. At the same time, the comparison and analysis of the change process of ultrasonic pulse propagation velocity and internal defect zone of concrete inferred that early freeze-thaw accelerates the propagation speed of cavity and crack, and the initial value of macroscopic mechanical properties of concrete and the ability of resisting salt and freezing in later stage are affected. The dynamic modulus of elasticity and the damage evolution equation of compressive strength can be used as a general formula for the attenuation of mechanical properties of concrete with similar damage degree, which can provide a theoretical basis for evaluating the service status and predicting the life of structures in similar environments. At the same time, the damage relationship between dynamic modulus of elasticity and compressive strength can be deduced from each other, which can reduce the limitation of data acquisition due to the shortage of instruments.
In order to find out the damage evolution rule of the concrete with initial damage caused by early freezing under the coupling of freezethaw cycle and sulfate erosion, initial damage to concrete specimens by freezing and thawing them at the 7 th and 14 th day during the preparation of concrete specimens was carried. Based on this, different initial damage degree on macro performance and internal structure was researched.Then according to the principle of damage mechanics, the dynamic modulus of elasticity and compressive strength were defined as damage variables, by regression fitting analysis of damage process of variable, and the damage evolution equation of different initial damage specimen caused by early freeze-thaw was established in corrosion and freezing environment. The results indicated that two kinds of concrete specimens with different initial damage are affected by early freeze-thaw in the decay process of their mechanical properties and their form are "lead effect", which is closely related to the degree of initial damage. At the same time, the comparison and analysis of the change process of ultrasonic pulse propagation velocity and internal defect zone of concrete inferred that early freeze-thaw accelerates the propagation speed of cavity and crack, and the initial value of macroscopic mechanical properties of concrete and the ability of resisting salt and freezing in later stage are affected. The dynamic modulus of elasticity and the damage evolution equation of compressive strength can be used as a general formula for the attenuation of mechanical properties of concrete with similar damage degree, which can provide a theoretical basis for evaluating the service status and predicting the life of structures in similar environments. At the same time, the damage relationship between dynamic modulus of elasticity and compressive strength can be deduced from each other, which can reduce the limitation of data acquisition due to the shortage of instruments.
引文
[1]Li Z,Wang N,Zhang X,et al.High precipitation and low evaporation resulted in high lake levels of the Juyanze paleolake,Northwest China,during 34-26 cal kyr BP[J].Climate Research,2016,69(1/2/3):193-207.
[2]Suleiman A R,Nehdi M L.Exploring effects of supplementary cementitious materials in concrete exposed to physical salt attack[J].Magazine of Concrete Research,2017,69(11):576-585.
[3]Xu Cundong,Tian Zixun,Xie Jialin,et al.Study on the durability of concrete under the action of sulfate attack and freeze-thaw cycle[J].Concrete,2017(6):21-23.[徐存东,田子荀,谢佳琳,等.硫酸盐侵蚀-冻融循环复合作用下混凝土材料耐久性研究[J].混凝土,2017(6):21-23.]
[4]Shuldyakov K,Kramar L,Trofimov B,et al.Superplasticizer effect on cement paste structure and concrete freeze-thaw resistance[C].AIP Publishing LLC,2016:768-769.
[5]Piasta W.Analysis of carbonate and sulphate attack on concrete structures[J].Engineering Failure Analysis,2017,79(1):606-614.
[6]Hoppe F J,Souza D J,Medeiros M H F,et al.Concrete attack by sodium sulfate:Mineral additions as a mitigation tool[J].Ceramica,2015,61(358):168-177.
[7]Qiao Hongxia,Zhu Binrong,Chen Dingshan.Experimental study of the deterioration mechanism of concrete in xining saline soil area[J].Journal of Basic Science and Engineering,2017(4):805-815.[乔宏霞,朱彬荣,陈丁山.西宁盐渍土地区混凝土劣化机理试验研究[J].应用基础与工程科学学报,2017(4):805-815.]
[8]Siad H,Lachemi M,?ahmaran M,et al.Preconditioning method for accelerated testing of concrete under sulfate attack[J].Aci Materials Journal,2016,113(4):493-504.
[9]Yang Yonggan,Zhang Yunsheng,She Wei,et al.Deterioration mechanism of concrete with initial damage exposed to sulfate attack[J].Journal of Building Materials,2017,20(5):705-711.[杨永敢,张云升,佘伟,等.带初始损伤混凝土受硫酸盐侵蚀劣化的机理分析[J].建筑材料学报,2017,20(5):705-711.]
[10]Colombi P,Fava G,Sonzogni L.Effect of initial damage level and patch configuration on the fatigue behaviour of reinforced steel plates[J].Fatigue&Fracture of Engineering Materials&Structures,2015,38(3):368-378.
[11]Liu Juanhong,Zhao Li,Ji Hongguang.Influence of initial damage on degradation and deterioration of concrete under sulfate attack[J].Chinese Journal of Engineering,2017,39(8):1278-1287.[刘娟红,赵力,纪洪广.初始损伤对混凝土硫酸盐腐蚀劣化性能的影响[J].工程科学学报,2017,39(8):1278-1287.]
[12]Pang Sen,Diao Bo,Ye Yinghua,et al.Effect of seawater wetdry cycles on mechanical performance of RC beams with initial damage[J].Journal of Beijing University of Aeronautics and Astronautics,2017,43(5):1004-1012.[庞森,刁波,叶英华,等.海水干湿循环对初始损伤RC梁力学性能的影响[J].北京航空航天大学学报,2017,43(5):1004-1012.]
[13]Kim Y R,Khil B S,Jang S J,et al.Effect of barium-based phase change material(PCM)to control the heat of hydration on the mechanical properties of mass concrete[J].Thermochimica Acta,2015,613:100-107.
[14]Li Jingpei,Li Xianfeng Li Lin,et al.Axial bearing behavior of deteriorated foundation pile under sulfate attack[J].Journal of Shanghai Jiaotong University,2016,50(11):1761-1766.[李镜培,李险峰,李林,等.硫酸盐侵蚀损伤劣化基桩竖向承载特性[J].上海交通大学学报,2016,50(11):1761-1766.]
[15]Gouder C,Saravanan U.Modeling diffusion of sulfate through concrete using mixture theory[J].Acta Mechanica,2016,227(11):3123-3146.
[16]Siad H,Lachemi M,?ahmaran M,et al.Preconditioning method for accelerated testing of concrete under sulfate attack[J].ACI Materials Journal,2016,113(4):222-225.
[2]Suleiman A R,Nehdi M L.Exploring effects of supplementary cementitious materials in concrete exposed to physical salt attack[J].Magazine of Concrete Research,2017,69(11):576-585.
[3]Xu Cundong,Tian Zixun,Xie Jialin,et al.Study on the durability of concrete under the action of sulfate attack and freeze-thaw cycle[J].Concrete,2017(6):21-23.[徐存东,田子荀,谢佳琳,等.硫酸盐侵蚀-冻融循环复合作用下混凝土材料耐久性研究[J].混凝土,2017(6):21-23.]
[4]Shuldyakov K,Kramar L,Trofimov B,et al.Superplasticizer effect on cement paste structure and concrete freeze-thaw resistance[C].AIP Publishing LLC,2016:768-769.
[5]Piasta W.Analysis of carbonate and sulphate attack on concrete structures[J].Engineering Failure Analysis,2017,79(1):606-614.
[6]Hoppe F J,Souza D J,Medeiros M H F,et al.Concrete attack by sodium sulfate:Mineral additions as a mitigation tool[J].Ceramica,2015,61(358):168-177.
[7]Qiao Hongxia,Zhu Binrong,Chen Dingshan.Experimental study of the deterioration mechanism of concrete in xining saline soil area[J].Journal of Basic Science and Engineering,2017(4):805-815.[乔宏霞,朱彬荣,陈丁山.西宁盐渍土地区混凝土劣化机理试验研究[J].应用基础与工程科学学报,2017(4):805-815.]
[8]Siad H,Lachemi M,?ahmaran M,et al.Preconditioning method for accelerated testing of concrete under sulfate attack[J].Aci Materials Journal,2016,113(4):493-504.
[9]Yang Yonggan,Zhang Yunsheng,She Wei,et al.Deterioration mechanism of concrete with initial damage exposed to sulfate attack[J].Journal of Building Materials,2017,20(5):705-711.[杨永敢,张云升,佘伟,等.带初始损伤混凝土受硫酸盐侵蚀劣化的机理分析[J].建筑材料学报,2017,20(5):705-711.]
[10]Colombi P,Fava G,Sonzogni L.Effect of initial damage level and patch configuration on the fatigue behaviour of reinforced steel plates[J].Fatigue&Fracture of Engineering Materials&Structures,2015,38(3):368-378.
[11]Liu Juanhong,Zhao Li,Ji Hongguang.Influence of initial damage on degradation and deterioration of concrete under sulfate attack[J].Chinese Journal of Engineering,2017,39(8):1278-1287.[刘娟红,赵力,纪洪广.初始损伤对混凝土硫酸盐腐蚀劣化性能的影响[J].工程科学学报,2017,39(8):1278-1287.]
[12]Pang Sen,Diao Bo,Ye Yinghua,et al.Effect of seawater wetdry cycles on mechanical performance of RC beams with initial damage[J].Journal of Beijing University of Aeronautics and Astronautics,2017,43(5):1004-1012.[庞森,刁波,叶英华,等.海水干湿循环对初始损伤RC梁力学性能的影响[J].北京航空航天大学学报,2017,43(5):1004-1012.]
[13]Kim Y R,Khil B S,Jang S J,et al.Effect of barium-based phase change material(PCM)to control the heat of hydration on the mechanical properties of mass concrete[J].Thermochimica Acta,2015,613:100-107.
[14]Li Jingpei,Li Xianfeng Li Lin,et al.Axial bearing behavior of deteriorated foundation pile under sulfate attack[J].Journal of Shanghai Jiaotong University,2016,50(11):1761-1766.[李镜培,李险峰,李林,等.硫酸盐侵蚀损伤劣化基桩竖向承载特性[J].上海交通大学学报,2016,50(11):1761-1766.]
[15]Gouder C,Saravanan U.Modeling diffusion of sulfate through concrete using mixture theory[J].Acta Mechanica,2016,227(11):3123-3146.
[16]Siad H,Lachemi M,?ahmaran M,et al.Preconditioning method for accelerated testing of concrete under sulfate attack[J].ACI Materials Journal,2016,113(4):222-225.