聚丙烯纤维珊瑚海水混凝土循环受压试验及应力-应变本构关系  

Cyclic compression test and stress-strain constitutive relationship of polypropylene fiber coral seawater concrete

作　　者：陈宗平[1,2] 覃钦泉 梁莹 周济 CHEN Zongping;QIN Qinquan;LIANG Ying;ZHOU Ji(School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;School of Architecture and Civil Engineering,Nanning University,Nanning 530200,China)

机构地区：[1]广西大学土木建筑工程学院,南宁530004 [2]南宁学院土木与建筑工程学院,南宁530200

出　　处：《复合材料学报》2024年第8期4259-4271,共13页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51578163);中央引导地方科技发展资金项目(桂科ZY21195010);八桂学者专项研究经费项目([2019]79号);广西科技基地和人才专项(AD210750031);广西大学对口支援学科建设项目(2023N01)。

摘　　要：为研究聚丙烯纤维珊瑚海水混凝土(PPF/CAC)在循环受压荷载作用下的力学行为,以聚丙烯纤维体积分数和加载方式为变化参数,设计了20个圆柱体试件进行单轴受压及单轴循环受压试验。试验观察了PPF/CAC的破坏形态,获取了应力-应变全曲线及峰值应力-应变、塑性应变等重要指标,深入分析了PPF/CAC在单轴循环受压作用下的应力-应变行为和损伤演化。结果表明:与单调加载相比,循环加载试件的强度退化了1.21%~3.67%,聚丙烯纤维能有效延缓强度退化;聚丙烯纤维体积分数为0.15vol%时珊瑚混凝土的峰值应力和峰值应变增幅最大,分别为10.45%和6.45%,改性效果最好;此外,聚丙烯纤维体积分数的增加可显著降低塑性应变的积累,提高弹性刚度比。本文根据试验结果定义了滞回曲线的4个特征点:卸载点、公共点、残余点和终点,并建立了残余应变、公共点应变和终点应变与卸载应变的关系。最后,提出了PPF/CAC在循环荷载作用下的应力-应变本构方程和损伤本构模型,且基于损伤演化规律简化后的应力-应变本构方程可以有效地预测其在循环荷载作用下的应力-应变行为。The stress-strain characteristics and damage evolution of polypropylene fiber coral seawater concrete(PPF/CAC)under uniaxial cyclic compression were studied.A total of 20 samples with different fiber volume fractions were tested.The failure form of PPF/CAC was observed in the test,and the stress-strain curve,peak stress-strain,plastic strain and other important indexes were obtained.The results show that the strength of specimens under cyclic loading is reduces by 1.21%-3.67%compared with that under monochrome loading,and the degradation can be slowed down with the increase of fiber content.The peak stress and peak strain increases are the largest when the polypropylene fiber volume fraction is 0.15vol%,which are 10.45%and 6.45%,respectively.In addition,the increase of PPF volume fraction can significantly reduce the accumulation of plastic strain and increase the elastic stiffness ratio.According to the test results,four characteristic points of hysteresis curve are defined:Unloading point,common point,residual point and end point.And the relationship between residual strain,common point strain and end point strain and unloading strain is established.Finally,the stress-strain constitutive equation and damage constitutive model of PPF/CAC under cyclic load are proposed,and the simplified stress-strain constitutive equation based on the damage evolution law can effectively predict the stress-strain behavior of PPF/CAC under cyclic load.

关 键 词：聚丙烯纤维 珊瑚海水混凝土 循环受压 应力-应变 本构方程 

分 类 号：TU528[建筑科学—建筑技术科学] TB332[一般工业技术—材料科学与工程]