聚丙烯纤维混凝土高温后单轴受压应力应变全曲线  

Complete Stress-strain Curve of Polypropylene Fiber Reinforced Concrete under Uniaxial Compression after High Temperatures

作　　者：李兵[1] 张刚 林煜期 谢卓衡 秦培成 LI Bing;ZHANG Gang;LIN Yuqi;XIE Zhuoheng;QIN Peicheng(College of Civil Engineering and Architecture,Haikou University,Haikou 570228,China;Hainan Provincial Fire and Rescue Brigade,Haikou 570228,China)

机构地区：[1]海南大学土木建筑工程学院,海南海口570228 [2]海南省消防救援总队,海南海口570228

出　　处：《材料科学与工程学报》2022年第4期608-614,共7页Journal of Materials Science and Engineering

基　　金：海南省自然科学基金创新研究团队资助项目(520CXTD433);国家自然科学基金资助项目(51768017);海南大学自科类横向课题资助项目(HD-KYH-2020039)。

摘　　要：本研究共设计制作了60组聚丙烯纤维(PPF)混凝土棱柱体试件,并进行了6种温度作用后的单轴受压应力-应变全曲线试验。结果表明:常温下,PPF混凝土的峰值应力、弹性模量均高于基准混凝土;其峰值应变和泊松比的大小与PPF掺量和长度相关,当PPF长度为3mm、掺量为1.0kg/m^(3)时峰值应力最大;高温后,PPF混凝土的应力-应变全曲线相似,其质量损失率、峰值应力、峰值应变、弹性模量及泊松比的变化主要取决于PPF高温融化、气化对混凝土截面的削弱和温度应力释放两个方面。随经历温度升高,峰值应力和弹性模量减小,峰值应变与泊松比先降后增。当PPF长度为9mm,掺量为0.5kg/m^(3)时,高温后性能最优。研究基于回归分析,建立了高温后PPF混凝土单轴受压应力-应变的分段式本构方程。In this study,a total of 60 groups of polypropylene fiber(PPF)concrete prismatic specimens were fabricated and uniaxial compressive stress-strain tests after 6 different temperatures.Relevant test results indicate that the peak stresses and elastic modulus of PPF concrete are higher compared to the reference concrete,but their peak strains and Poisson’s ratios are directly relevant to PPF lengths and contents.When the PPF length is 3 mm and the PPF admixture is 1.0 kg/m^(3),the peak stress reaches the maximum value at ambient temperature.After high temperatures,the stress-strain curves of PPF concrete are similar,and their concrete mass loss rates,peak stresses,peak strains,elastic modulus,Poisson’s ratios are mainly related to the weakened concrete section and stress release due to the melting and gasification of PPF.As the subjected elevate temperatures continue to rise,the peak stresses and elastic modulus decrease gradually,and the peak strains and Poisson’s ratios firstly decrease slowly and then increase remarkably.At last,through regression analysis,the uniaxial compression stress-strain piecewise constitutive equations of PPF concrete after high temperatures are established.

关 键 词：PPF混凝土 单轴受压试验 高温后 应力-应变全曲线 本构方程 

分 类 号：TU502[建筑科学—建筑技术科学]