持续荷载对面板混凝土冻融性能和孔结构影响  

Effect of Sustained Load on Freeze-Thaw Performance and Pore Structure of Panel Concrete

作　　者：张小刚 李明付 田斌 李佳辉 熊勃勃 ZHANG Xiaogang;LI Mingfu;TIAN Bin;LI Jiahui;XIONG Bobo(China Electric Power Construction Group Kunming Survey and Design Institute Co.,Ltd.,Kunming 650000,China;College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China)

机构地区：[1]中国电建集团昆明勘测设计研究院有限公司,昆明650000 [2]三峡大学水利与环境学院,湖北宜昌443002

出　　处：《三峡大学学报（自然科学版）》2024年第6期18-24,共7页Journal of China Three Gorges University：Natural Sciences

基　　金：中国电建集团昆明勘测设计研究院有限公司重点研发项目(KD-ZDYF2022-001);国家自然科学基金项目(52009068);水利部水利科研项目(SKS-2022102)。

摘　　要：为研究持续荷载对面板混凝土冻融性能和和孔结构影响,开展了不同压应力水平(0.3、0.5)和拉应力水平(0.03、0.06)作用下的混凝土冻融循环实验.研究了不同应力水平下试件的相对动弹性模量、质量损失率、抗压强度损失率、超声波速损失率等参数随冻融循环次数的变化;其次研究了气泡个数和气泡间距系数等参数随荷载水平的变化规律;最后基于实验数据建立了持续荷载下混凝土冻融寿命预测模型.结果表明:0.3fc的压荷载增加了混凝土的抗冻能力,而0.5fc的压荷载降低了混凝土的抗冻能力.随着拉荷载的增大,混凝土的抗冻能力降低.气泡间距系数随压荷载的增加先减小后升高,随拉荷载的增加而增大.建立的寿命预测模型能够实现不同持续荷载水平下的混凝土冻融寿命预测.In order to study the effect of sustained load on the freeze-thaw performance and pore structure of panel concrete,concrete freeze-thaw cycle experiments under different compressive stress levels(0.3,0.5)and tensile stress levels(0.03,0.06)were carried out.Firstly,the changes of relative dynamic elastic modulus,mass loss rate,compressive strength loss rate,ultrasonic velocity loss rate and other parameters of specimens under different stress levels with the number of freeze-thaw cycles were studied.Secondly,the number of bubbles and bubble spacing coefficient were studied with the changes of load level.Finally,a prediction model for concrete freeze-thaw life under sustained load was established based on experimental data.The results show that a compressive load of 0.3fc increases the frost resistance of concrete,while a compressive load of 0.5fc reduces the frost resistance of concrete.As the tensile load increases,the frost resistance of concrete decreases.The bubble spacing coefficient first decreases and then increases with the increase of compressive load,and increases with the increase of tensile load.The established life prediction model can predict the freeze-thaw life of concrete under different sustained load levels.

关 键 词：混凝土 冻融循环 气泡间距系数 持续荷载 寿命预测 

分 类 号：TB641.4[一般工业技术—制冷工程] TV331[水利工程—水工结构工程]