拉应力作用下早龄期混凝土相对湿度响应试验研究  

Experimental Investigation of Relative Humidity Response in Early-Age Concrete Under Tensile Stress

作　　者：赵海涛[1,3] 丁健 杨果 相宇 徐文 陈育志[5] ZHAO Haitao;DING Jian;YANG Guo;XIANG Yu;XU Wen;CHEN Yuzhi(College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;School of Civil Engineering,Southeast University,Nanjing 211189,China;School of Materials Science and Engineering,Southeast University,Nanjing 211189,China;Sobute New Materials Co.,Ltd.,Nanjing 211103,China;School of Architectural Engineering,Jinling Institute of Technology,Nanjing 211169,China)

机构地区：[1]河海大学土木与交通学院,江苏南京210098 [2]东南大学土木工程学院,江苏南京211189 [3]东南大学材料科学与工程学院,江苏南京211189 [4]江苏苏博特新材料有限公司,江苏南京211103 [5]金陵科技学院建筑工程学院,江苏南京211169

出　　处：《西南交通大学学报》2024年第5期1104-1112,共9页Journal of Southwest Jiaotong University

基　　金：国家重点研发计划(2021YFF0500800);国家自然科学基金项目(U1965105,51878245)。

摘　　要：为系统研究早龄期混凝土内部相对湿度对不同水平拉应力的响应规律,设计恒定轴拉下混凝土内部相对湿度测试方法,试验研究了不同拉应力下的相对湿度响应规律,并基于试验结果和理论分析,给出早龄期混凝土单面干燥条件下相对湿度与拉应力的线性模型.研究结果表明:拉应力施加会造成混凝土内部相对湿度瞬时下降,当拉应力从0.8 MPa增加到3.2 MPa时,混凝土深度分别为50、75、100 mm处的相对湿度变化值从0.5%、0.4%和0.3%增加到0.8%、0.7%和0.6%;随着拉应力逐渐增大,相对湿度下降值逐渐增大;在相同拉应力下,距离混凝土暴露面近的相对湿度对拉应力的响应更为显著;拉应力持荷状态下相对湿度会逐渐恢复,恢复时间约2.5 h,在压应力持荷状态下也出现了类似现象,恢复时间约20.0 h,拉应力持荷状态下相对湿度恢复时间更短.In order to systematically investigate the response law of the internal relative humidity of concrete at an early age to different tensile stress levels,a test method of the internal relative humidity of the concrete under constant axial tension was developed in this paper,and the response law of the relative humidity under different tensile stresses was studied experimentally.According to the experimental results and theoretical analysis,a linear model of the relative humidity and tensile stress of early-age concrete under one-side drying conditions was presented.The results show that the tensile stress causes the instantaneous decrease in the internal relative humidity of the concrete.When the tensile stress increases from 0.8 MPa to 3.2 MPa,the relative humidity change at the depth of 50,75,and 100 mm of the concrete increases from 0.5%,0.4%,and 0.3% to 0.8%,0.7%,and 0.6%,respectively.At the same time,with the increase in tensile stress,the decrease in the relative humidity gradually increases.Under the same tensile stress,the response of relative humidity of the concrete,close to the exposed surface,to tensile stress which is is more obvious.The relative humidity gradually recovers during the tensile stress loading,and the time is about 2.5 h.A similar phenomenon also occurs during the compressive stress loading,and the time is about 20.0 h.Therefore,the relative humidity recovery time is shorter during the tensile stress loading.

关 键 词：早龄期 混凝土 相对湿度 拉应力 线性模型 

分 类 号：TU528.1[建筑科学—建筑技术科学]