冻融-硫酸盐腐蚀耦合作用下早龄期混凝土强度演变及预测模型研究  

Research on Strength Evolution and Prediction Model of Early-age Concrete Under the Coupling Action of Freeze-Thaw and Sulfate Corrosion

作　　者：张学鹏 张戎令[1,2] 杨斌 肖鹏震 王小平 龙朝飞 ZHANG Xuepeng;ZHANG Rongling;YANG Bin;XIAO Pengzhen;WANG Xiaoping;LONG Zhaofei(College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Bridge Engineering National Local Joint Engineering Laboratory of Disaster Prevention and Contral Technology,Lanzhou Jiaotong University,Lanzhou 730070,China;China Railway Construction Management Co.,Ltd.,Beijing 100161,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]兰州交通大学道桥工程灾害防治技术国家地方联合工程实验室,兰州730070 [3]中国铁路建设管理有限公司,北京100161

出　　处：《材料导报》2024年第5期205-213,共9页Materials Reports

基　　金：国家自然科学基金(52068042,U2368209);中国国家铁路集团有限公司科技研究开发计划(K2021G025);甘肃省优秀博士生项目(23JRRA144)。

摘　　要：为了研究冻融-硫酸盐腐蚀耦合作用对早龄期混凝土力学性能的影响,基于新疆若羌地区实际环境条件,对三种水胶比的早龄期混凝土分别进行冻融循环、硫酸盐腐蚀、冻融-硫酸盐腐蚀耦合作用工况下的耐久性试验,分析不同环境作用工况与水胶比交互作用下早龄期混凝土强度经时演变规律和作用机制。同时,基于灰色系统理论与遗传算法,建立早龄期混凝土强度的变权缓冲GM(1,1)模型。研究结果表明:同环境作用工况下,随冻融循环次数增加,早龄期混凝土抗蚀系数均出现先增大后减小的变化规律,并且在腐蚀终期,水胶比与早龄期混凝土抗蚀系数呈负相关。在同水胶比条件下,相较于单一冻融循环工况,冻融-硫酸盐腐蚀耦合作用工况对早龄期混凝土抗蚀系数终值的影响程度更高。早龄期混凝土强度预测模型的最大平均预测误差仅为1.893%,具有较好的预测精度,可为寒冷、盐渍土地区混凝土结构服役状态评估提供参考;通过预测模型对不同环境作用工况下早龄期混凝土进行耐久性评估,可知:冻融循环作用下,0.26、0.32、0.38水胶比的早龄期混凝土预测服役寿命分别是75.3 a、24.6 a、15.3 a,而在冻融-硫酸盐腐蚀耦合作用工况下,同水胶比下早龄期混凝土预测服役寿命缩短至30.7 a、22 a、12.7 a。In order to study the coupling action of freeze-thaw and sulfate corrosion on the mechanical properties of early-age concrete, in this study, three early-age concrete tests with water-binder ratios based on the actual environmental conditions in Ruoqiang area of Xinjiang Province were carried out, namely, freeze-thaw cycle, sulfate corrosion and freeze-thawing sulfate corrosion coupling test, therefore the time evolution law and action mechanism of early-age concrete strength under different environmental action conditions and water-binder ratio interaction were analyzed. Meanwhile, this study based on grey system theory and genetic algorithm, the variable weight buffer GM (1, 1) model of early-age concrete strength was established. The results show that the corrosion resistance coefficient of early-aged concrete increases first and then decreases with the increase of the number of freeze-thaw cycles under the same environmental working conditions, and the water-binder ratio is negatively correlated with the corrosion resistance coefficient of early-aged concrete in the final corrosion period. Under the condition of the same water-binder ratio, compared with the single freeze-thaw cycle condition, the freeze-thaw-sulfate corrosion coupling condition has a higher impact on the final value of corrosion resistance coefficient of early-age concrete. The maximum average prediction error of the early-age concrete strength prediction model is only 1.893%, which has a good prediction accuracy, and would provide a reference for the evaluation of the service state of concrete structures in cold and saline soil areas. By evaluating the durability of early-age concrete under different environmental working conditions with the prediction model, the study concluded that: the predicted service life of early-age concrete with water-binder ratio of 0.26, 0.32 and 0.38 is respectively 75.3 a, 24.6 a and 15.3 a under the freeze-thaw cycle, while the predicted service life of early-age concrete with water-bin- der ratio is reduced t

关 键 词：冻融-硫酸盐腐蚀耦合 早龄期混凝土 强度演变规律 遗传算法 变权缓冲GM(1 1) 

分 类 号：TU528.4[建筑科学—建筑技术科学]