煤矸石混凝土单轴受压应力-应变曲线试验研究  

Experimental study on stress-strain curve of coal gangue concrete under uniaxial compression

作　　者：刘瀚卿 白国良[1,2] 王建文 代沐容 朱可凡 LIU Hanqing;BAI Guoliang;WANG Jianwen;DAI Murong;ZHU Kefan(School of Civil Engineering,Xi’an University of Architecture&Technology,Xi’an 710055,China;Key Lab of Structural Engineering and Earthquake Resistance,Ministry of Education(XAUAT),Xi’an 710055,China;Shaanxi Coal Group Shenmu Ningtiaota Mining Co.,Ltd,Yulin 719000,China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055 [2]西安建筑科技大学结构工程与抗震教育部重点实验室,陕西西安710055 [3]陕煤集团神木柠条塔矿业有限公司,陕西榆林719000

出　　处：《建筑结构学报》2023年第7期236-245,254,共11页Journal of Building Structures

基　　金：国家自然科学基金项目(52078410);陕西省科技计划成果推广项目(2020CGHJ-017);陕西省教育厅重点实验室项目(20JS071)。

摘　　要：为研究煤矸石粗骨料的掺入对混凝土受压应力-应变曲线的影响,完成了96个不同矿源、取代率的煤矸石混凝土棱柱体试块单轴受压试验。研究结果表明:有别于普通混凝土的剪切破坏形态,受煤矸石粗骨料影响,煤矸石混凝土均为劈裂破坏;不同矿源的煤矸石混凝土应力-应变曲线大致相似,但煤矸石取代率越高,上升段曲线斜率越小,而下降段曲线斜率越大;随煤矸石取代率的增加,煤矸石混凝土的峰值应变与极限应变虽不断增大,但极限应变与峰值应变之比却不断降低,表明煤矸石混凝土延性较差。考虑煤矸石粗骨料的影响,分别建立了煤矸石混凝土弹性模量、峰值应变与极限应变的计算公式。基于GB 50010—2010《混凝土结构设计规范》中给出的普通混凝土分段式应力-应变曲线公式,提出了适用于煤矸石混凝土的本构模型,由模型计算得到的理论曲线与试验曲线总体吻合较好,可用于煤矸石混凝土结构非线性分析。In order to investigate the effect of incorporating coal gangue coarse aggregate(CGCA)on the compressive stress-strain behavior of concrete,96 prismatic specimens of coal gangue concrete(CGC)with different mineral sources and different replacement ratios were tested under uniaxial compression.The results indicate that,in contrast to ordinary concrete,CGC exhibits a splitting failure mode due to the influence of the CGCA.The stress-strain curves of CGC from different mineral sources are roughly similar,but as the replacement ratio of coal gangue increases,the slope of the ascending segment of the curve decreases while that of the descending segment increases.With the increase of coal gangue replacement ratio,although the peak and ultimate strain of CGC increase,the ratio of ultimate strain to peak strain decreases continuously,indicating poor ductility of CGC.Considering the influence of the CGCA,the calculation formulas of elastic modulus,peak strain and ultimate strain of CGC were established respectively.Based on the segmented concrete constitutive model given in GB 50010—2010“Code for design of concrete structure”,the stress-strain curve model suitable for CGC was proposed.The theoretical curves obtained from the model show good agreement with the experimental curves and can be used for the nonlinear analysis of CGC structure.

关 键 词：煤矸石混凝土 单轴受压试验 应力-应变曲线 峰值应变 极限应变 

分 类 号：TU528.01[建筑科学—建筑技术科学] TU317.1