摘要
【目的】在我国严寒地区,冻融损伤会使再生混凝土(RAC)结构提前达到耐久性极限甚至导致构件失效,为了延长再生混凝土(RAC)结构在严寒地区的使用寿命,【方法】对再生混凝土(RAC)、天然混凝土(NC)、普通钢纤维再生混凝土(PFRAC)和不锈钢纤维再生混凝土(SFRAC)进行冻融循环试验。经过冻融循环后,测得RAC、NC、PFRAC、SFRAC的质量损失及相对动弹性模量,分析冻融循环过程中混凝土内部的损伤机理及劣化规律。以相对动弹性模量为损伤变量,基于响应面模型(RSM)和Weibull分布建立了钢纤维再生混凝土冻融损伤模型,研究冻融循环次数、PF和SF的掺量对再生混凝土抗冻性的影响。【结果】结果表明,SF的掺入能有效延缓RAC质量的损失和相对动弹性模量的降低。冻融循环150次时,掺量为2%的SFRAC质量损失和相对动弹性模量分别下降3.01%和19.57%。SFRAC与RAC相比,质量损失率降低了0.4%,相对动弹性模量提高了14.17%。【结论】Weibull分布和响应面模型(RSM)的预测结果 基本一致,但RSM预测值的相对误差要低于Weibull分布的预测值。两种模型的相关系数R2均在0.94以上,预测结果较为准确,可为钢纤维再生混凝土在寒冷地区的使用提供理论参考。
[Objective]In the severe cold region of China,freeze-thaw damage can cause recycled concrete(RAC)structures to reach the durability limit earlier or even lead to component failure,to prolong the service life of recycled concrete(RAC)structures in severe cold region,[Methods]freeze-thaw cycling tests were conducted on recycled concrete(RAC),natural concrete(NC),plain steel fiber recycled concrete(PFRAC)and stainless steel fiber recycled concrete(SFRAC)were subjected to freeze-thaw cycle tests.After freeze-thaw cycles,the mass loss and relative dynamic elastic modulus of RAC,NC,PFRAC,and SFRAC were measured to analyze the internal damage mechanism and deterioration law of concrete during freeze-thaw cycles.The relative dynamic elastic modulus was used as the damage variable,and a freeze-thaw damage model for steel fiber recycled concrete was established based on the Response Surface Model(RSM)and the Weibull distribution to study the effects of the number of freeze-thaw cycles and the admixture of PF and SF on the frost resistance of recycled concrete.[Results]The result show that SF incorporation can effectively delay the loss of mass and the decrease of the relative dynamic elastic modulus of RAC.At 150 freeze-thaw cycles,the mass loss and relative dynamic elastic modulus of SFRAC with 2%dosage decreased by 3.01%and 19.57%,respectively.The mass loss rate of SFRAC was reduced by 0.4%and the relative dynamic elastic modulus increased by 14.17%compared with that of RAC.[Conclusion]The prediction result of Weibull distribution and Response Surface Modeling(RSM)are basically the same,but the relative error of the predicted value of RSM is lower than that of Weibull distribution.The correlation coefficients R2 of the two models are above 0.94,and the prediction result are more accurate,which can provide theoretical references for the use of steel fiber recycled concrete in cold regions.
作者
钟楚珩
范祖伟
周金枝
施佳楠
ZHONG Chuheng;FAN Zuwei;ZHOU Jinzhi;SHI Jianan(College of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan430068,Hubei,China;China State Key Laboratory of Bridge Structure Health and Safety,Wuhan430034,Hubei,China)
出处
《水利水电技术（中英文）》
北大核心
2024年第2期50-61,共12页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(52208340)
湖北省高等学校优秀中青年科技创新团队项目(T2022010)
湖北工业大学博士启动基金(BSQD2020051)。
关键词
再生混凝土
不锈钢纤维
相对动弹性模量
冻融循环
WEIBULL分布
响应曲面(RSM)
力学性能
影响因素
recycled concrete
stainless steel fibers
relative dynamic modulus of elasticity
Weibull distribution
freeze-thaw cycle
Response Surface Method(RSM)
mechanical properties
influence factor
作者简介
钟楚珩(1989—),男,讲师,博士,主要从事土木工程材料的研究。E-mail:zhongchuheng@gmail.com;通信作者:周金枝(1964—),女,教授,博士,主要从事土木工程材料的研究。E-mail:zhoujinzhi@hbut.edu.cn。
