摘要
通过对高延性水泥基复合材料(ECC)试样进行冻融循环试验、微观孔结构试验和单轴压缩试验,研究了冻融损伤ECC试样的抗压应力-应变关系及影响机制。在此基础上,将ECC受压构件等效为由无数根平行的单元杆件组成的受力模型,建立了考虑损伤层厚度的冻融损伤ECC抗压本构模型。结果表明:随着冻融循环次数增加,试样抗压峰值强度降低,峰值应变无明显变化,极限破坏时延性特征显著;试样二维切片中含气量、平均弦长、间距系数均随冻融循环次数的增加逐渐增大,气孔比表面积减小。建立的模型能够较好的描述冻融损伤ECC的抗压应力-应变关系,为寒冷地区服役的ECC提供了理论参考。
Through freeze-thaw cycle test,micro-pore structure test and uniaxial compression test of engineered cementitious composites(ECC)specimens,the compressive stress-strain relationship and its influencing mechanism of freeze-thaw damage ECC samples were studied.On this basis,the ECC compression member is equivalent to a stress model composed of countless parallel element members,and a freeze-thaw damage ECC compression constitutive model considering the thickness of damage layer is established.The results show that with the increase of freeze-thaw cycles,the peak compressive strength of the specimen decreases,the peak strain has no obvious change,and the ductility characteristics at ultimate failure are significant.The air content,average chord length and spacing factor in the two-dimensional section of the specimen increase gradually with the increase of freeze-thaw cycles,while the specific surface area of pores decreases.The established model can well describe the compressive stress-strain relationship of ECC damaged by freeze-thaw damage,which provides a theoretical reference for ECC serving in cold areas.
作者
刘曙光
鲁肃
闫敏
尹立强
闫长旺
LIU Shuguang;LU Su;YAN Min;YIN Liqiang;YAN Changwang(School of Civil Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;Institute of Mining Technology,Inner Mongolia University of Technology,Hohhot 010051,China;Department of Civil Engineering,Ordos Institute of Technology,Ordos 017000,China;Inner Mongolia Engineering Research Center of Ecological Building Materials and Prefabricated Construction,Hohhot 010051,China)
出处
《混凝土》
CAS
北大核心
2023年第6期84-90,共7页
Concrete
基金
国家自然科学基金(51968056,51768051)
内蒙古自治区自然科学基金(2021LHBS05003)
内蒙古自治区科技成果转化项目(2019CG072)
内蒙古工业大学科学研究项目(ZZ202003,BS2021048)。
