摘要
为研究硫酸盐-干湿循环与冻融复合作用下混凝土的力学性能退化规律,采用试验室加速腐蚀的方法,对混凝土试件进行轴心抗压试验,得到了不同干湿循环次数、混凝土强度和冻融循环次数下混凝土峰值应力、峰值应变及受压应力-应变曲线的变化规律,并对腐蚀后混凝土表观形态和微观形貌进行分析。结果表明:3∶1的干湿循环制度下硫酸钠主要发生物理结晶侵蚀;随着干湿循环次数增加,应力-应变曲线上升段斜率逐渐减小,峰值应力不断下降,峰值应变呈增大趋势;硫酸钠-干湿循环大大加快了冻融循环后试件的劣化速度,随着冻融循环次数增加,混凝土峰值应力逐渐减小,峰值应变逐渐增大。通过回归分析,建立了硫酸盐-干湿循环和冻融环境下混凝土应力-应变曲线方程,模型可为西部地区混凝土结构剩余寿命预测提供理论基础。
In order to study the degradation of the mechanical properties of concrete under the combined action of sulfate dry-wet cycles and freeze-thaw,the laboratory accelerated corrosion method was used to perform axial compression tests on concrete specimens,and different numbers of dry-wet cycles and concrete strength were obtained.The change law of the peak stress,peak strain and compressive stress-strain curve of concrete under the number of freeze-thaw cycles and the number of cycles.The appearance and microscopic morphology of the concrete after corrosion are analyzed.The results show that sodium sulfate mainly undergoes physical crystal erosion under the 3∶1 dry-wet cycle system.As the number of dry-wet cycles increases,the slope of the rising section of the stress-strain curves gradually decreases,the peak stress continues to decrease,and the peak strain increases.Sodium sulfate dry-wet cycle greatly accelerates the deterioration rate of the specimen after the freeze-thaw cycle.As the number of freeze-thaw cycles increases,the peak stress of concrete gradually decreases and the peak strain gradually increases.Through regression analysis,the concrete stress-strain curve equations under sulfate dry-wet cycles and freeze-thaw environments are established.The model can provide a theoretical basis for the prediction of the remaining life of concrete structures in the western region.
作者
韩敏
杨淑雁
陈小龙
孔骏
宋俊杰
徐盼盼
HAN Min;YANG Shuyan;CHEN Xiaolong;KONG Jun;SONG Junjie;XU Panpan(School of Civil Engineering and Water Conservancy,Ningxia University,Yinchuan 750021,China;School of Civil Engineering,Guangxi University,Nanning 530004,China)
出处
《混凝土》
CAS
北大核心
2023年第8期66-71,81,共7页
Concrete
基金
国家自然科学地区基金项目(51868065)。
