超高性能混凝土三轴受压力学性能及破坏准则  

Mechanical properties and failure criterion of ultra-high performance concrete under tri-axial compression

作　　者：王淑楠 徐礼华[1] 李彪 池寅[1] 曾彦钦 WANG Shunan;XU Lihua;LI Biao;CHI Yin;ZENG Yanqin(School of Civil Engineering,Wuhan University,Wuhan 430072,China;School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430074,China;School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430068,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]武汉工程大学土木工程与建筑学院,湖北武汉430074 [3]湖北工业大学土木建筑与环境学院,湖北武汉430068

出　　处：《建筑结构学报》2024年第1期230-242,共13页Journal of Building Structures

基　　金：国家自然科学基金重点项目(51738011)。

摘　　要：为研究超高性能混凝土(UHPC)三轴受压力学性能及破坏准则,考虑围压、钢纤维体积掺量和长径比、聚丙烯纤维体积掺量等主要因素,设计制作39个超高性能混凝土圆柱体试件。通过常规三轴受压试验,考察UHPC三轴破坏形态,分析三轴应力-应变关系全曲线,揭示强度和变形性能指标变化规律,提出考虑纤维特征参数的UHPC多轴破坏准则。结果表明:三轴应力状态下UHPC的破坏形态均呈剪切型,围压对裂缝形成与分布影响显著;UHPC三轴受压全过程曲线分为线弹性段、非线性硬化段和应变软化段三部分;施加围压和掺入钢纤维均能显著改善UHPC三轴受压力学性能,当围压从0 MPa增至40 MPa时,峰值应力和峰值应变分别最大增加161.7%和224.7%,当钢纤维体积掺量由0%增至3%以及长径比由30增至80时,峰值应力和峰值应变分别最大增加24.6%和68.6%;聚丙烯纤维可有效提升UHPC的变形能力;围压对UHPC三轴受压力学性能的影响最大,钢纤维的影响次之,聚丙烯纤维的影响最小。基于Willam-Warnke五参数模型建立了UHPC破坏准则,模型预测结果与试验结果吻合较好。To study the tri-axial compressive mechanical properties and failure criteria of ultra-high performance concrete(UHPC),considering influence factors in terms of confining pressure,volume fraction of steel fiber(SF),aspect ratio of SF and volume fraction of polypropylene fiber(PF),a total of 39 UHPC cylinder specimens were fabricated.Through the conventional tri-axial compression tests,the tri-axial failure mode of UHPC was investigated,the tri-axial stress-strain curve was analyzed,the change law of strength and deformation performance indexes was revealed,and a multiaxial failure criterion of UHPC considering fiber parameters was proposed.Test results indicated that all specimens exhibit shear failure under tri-axial stress,and confining pressure has great effect on the formation and distribution of cracks.The whole tri-axial compression process includes linear elastic section,nonlinear hardening section,and strain softening section.The application of confining pressure and the inclusion of SF can significantly improve the mechanical properties of UHPC under tri-axial compression.As confining pressure increases from 0 MPa to 40 MPa,peak stress and strain increase by up to 161.7% and 224.7%,respectively.As the volume fraction of SF increases from 0% to 3% and the aspect ratio increases from 30 to 80,peak stress and strain increase by up to 24.6% and 68.6%,respectively.Meanwhile,the addition of PF contributes to the deformation capacity of UHPC.The confining pressure has the greatest influence on the mechanical properties of tri-axial compression,followed by the SF and then the PF.The failure criterion for UHPC was established based on Willam-Warnke five-parameter model.The model predictions are in good agreement with existing experimental results.

关 键 词：超高性能混凝土 三轴受压 混杂纤维 应力-应变关系 破坏准则 

分 类 号：TU528.572[建筑科学—建筑技术科学]