基于NMR技术的自然腐蚀环境下混凝土强度劣化分析  

Analysis of concrete strength deterioration in freeze-thaw corrosion environment based on NMR technology

作　　者：张文静 李波[1] 张戎令[1] 安康乐 王先龙 张富奎 王玉林 ZHANG Wenjing;LI Bo;ZHANG Rongling;AN Kangle;WANG Xianlong;ZHANG Fukui;WANG Yulin(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Gansu Province Planning Survey&Design Institute Co.,Ltd.,Lanzhou 730030,China;Gansu Province Highway Construction Group Co.,Ltd.,Lanzhou 730030,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]甘肃省交通规划勘察设计院股份有限公司,甘肃兰州730030 [3]甘肃省公路交通建设集团有限公司,甘肃兰州730030

出　　处：《混凝土与水泥制品》2023年第12期17-22,共6页China Concrete and Cement Products

基　　金：交通运输行业重点科技项目(2021-ZD2-073);甘肃省科技重点研发计划项目(21YF11GA011);甘肃省交通运输厅科技计划项目。

摘　　要：为探究自然盐冻腐蚀环境下混凝土强度的劣化机理,通过抗压强度、微观孔结构(基于NMR技术)等试验,研究了不同水胶比的混凝土试件(A0>A1>A2>A3)标准养护28 d和自然盐冻腐蚀5年的抗压强度和微观孔结构时变规律,并分析了孔结构与抗压强度的关系。结果表明:与标养试件相比,自然腐蚀试件A0~A2的抗压强度较低,A3的抗压强度略有提高;试件的抗压强度损失率与水胶比基本呈正相关;经历自然腐蚀试件内部孔隙率均显著增加,A0~A2中小孔向大孔过渡明显,多害孔体积比均显著增加,试件的孔隙率与抗压强度呈负相关;自然腐蚀试件的抗压强度变化不仅与自身孔结构存在一定关系,还与结构所处位置有关。In order to explore the deterioration mechanism of concrete strength under natural salt freezing corrosion environment,the strength and time-varying law of micropore structure of concrete specimens with different water-binder ratios(A0>A1>A2>A3)for 28 d standard curing and natural salt freezing corrosion for 5 years were studied through compressive strength and micropore structure(based on NMR technology)tests,and the relationship between pore structure and compressive strength was analyzed.The results show that compared with the standard curing specimens,the compressive strength of natural corrosion specimens A0~A2 is lower and the compressive strength of A3 is slightly improved.The compressive strength loss rate of the specimen is basically positively correlated with the water-binder ratio.The internal porosity of natural corrosion specimens increases significantly,the transition from small holes to large pores in A0~A2 is obvious,the volume ratio of harmful pores increases significantly,and the porosity of the specimens is negatively correlated with compressive strength.The change of compressive strength of natural corrosion specimens is not only related to its own pore structure,but also related to the position of the structure.

关 键 词：混凝土 冻融循环 腐蚀 核磁共振波谱法 抗压强度 

分 类 号：TU528.1[建筑科学—建筑技术科学]