橡胶-钢纤维混凝土的劈裂应力-应变曲线特征及破坏机理研究  

Splitting stress-strain curves and failure mechanism of rubber-steel fiber concrete

作　　者：徐颖[1,2] 丁进甫 刘家兴 杨荣周 顾柯柯 XU Ying;DING Jinfu;LIU Jiaxing;YANG Rongzhou;GU Keke(School of Civil Engineering and Architectrue,Anhui University of Science and Technology,Huainan 232001,China;State Key Laboratory of Mining Response and Disaster Prevention andControl in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学土木与建筑学院,安徽淮南232001 [2]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南232001

出　　处：《混凝土》2023年第8期72-76,86,共6页Concrete

基　　金：国家自然科学基金面上项目(52074009);国家自然科学基金青年项目(52008003)。

摘　　要：为探究橡胶掺量及其粒径对橡胶-钢纤维混凝土(R-SFC)应力-应变曲线特征和破坏机理的影响,利用电液伺服万能试验机对R-SFC试件进行静载劈裂抗拉试验。结果表明:随着橡胶掺量的增加,R-SFC的应力-应变曲线均位于钢纤维混凝土(SFC)的上方,且峰后延/韧性显著地增加。随着橡胶粒径的增大,R-SFC的弹性段先减小后增大,且各粒径下峰后曲线近似平行。劈裂抗拉强度和峰值应变随橡胶掺量的增加均逐渐降低。在SFC中加入橡胶颗粒可以明显地改善其低应力劈裂脆性并提高其峰后变形能力。根据材料特性和破坏形态建立了橡胶和钢纤维协同作用的桥接模型,并基于该模型推导了协同作用的力学简化计算表达式。最后,结合纤维间距理论和断裂力学推导了劈裂抗拉强度式。To explore the influence of rubber contents and its particle sizes on the stress-strain curves and failure mechanism of rubber-steel fiber concrete(R-SFC),an electro-hydraulic servo universal testing machine was used to carry out static load splitting tensile test on R-SFC specimens.The results show that with the increase of rubber content,the stress-strain curves of R-SFC were all located above the steel fiber concrete(SFC),and the post-peak delay/toughness increased significantly.With the increase of the rubber particle sizes,the elastic segment of R-SFC first decreased and then increased,and the curves after the peak of each particle sizes were approximately parallel.The splitting tensile strength and peak strain gradually decreased with the increase of rubber content.Adding rubber particles into SFC can obviously improved its low stress splitting brittleness and increased post-peak deformation ability.A synergistic bridging model of rubber and steel fibers was established according to the material properties and failure morphology,and a simplified mechanical expression for synergistic interaction was derived based on the model.Finally,the formula of splitting tensile strength was derived by combining the fiber spacing theory and fracture mechanics.

关 键 词：橡胶-钢纤维混凝土(R-SFC) 应力-应变曲线 劈裂抗拉 破坏机理 桥接模型 强度公式 

分 类 号：TU528.572[建筑科学—建筑技术科学]