煤矸石粉对UHPC力学及收缩性能的影响及收缩计算方法  

Influence of coal gangue powder on mechanical and shrinkage behaviors of UHPC with calculation method of autogenous shrinkage

作　　者：黄书才[1] 喻鹏 汤志军[1] 周佳乐 牛建东[3] 孙喜波 HUANG Shucai;YU Peng;TANG Zhijun;ZHOU Jiale;NIU Jiandong;SUN Xibo(China Railway 15th Bureau Group Corporation Limited,Shanghai 200040,China;School of Environment and Civil Engineering,Dongguan University of Technology,Dongguan 523803,China;School of Civil Engineering,Central South University,Changsha 410083,China;Guangdong Changhong Construction Group Corporation Limited,Guangzhou 511316,China)

机构地区：[1]中铁十五局集团有限公司,上海200040 [2]东莞理工学院生态环境与建筑工程学院,广东东莞523803 [3]中南大学土木工程学院,湖南长沙410083 [4]广东长宏建设集团有限公司,广东广州511316

出　　处：《混凝土》2024年第11期67-73,共7页Concrete

基　　金：国家自然科学基金(52008106);中铁十五局集团有限公司企业委托课题(11001202301001);中铁隧道局企业委托课题(738012490);中铁隧道局企业委托课题(738012491)。

摘　　要：为配制出适用于实际工程的“低碳、绿色、环保、经济”且各项性能均佳的煤矸石UHPC,实现固废资源再利用,对不同煤矸石粉末质量代替率(20%、40%和60%)的UHPC抗拉强度、抗压强度、弹性模量和自收缩应变进行了试验测试;揭示了煤矸石粉配制UHPC的内在机理,并评估了已有混凝土自收缩理论计算方法对煤矸石UHPC的适用性。结果表明:可通过掺入大量煤矸石粉末来配制UHPC,其棱柱体抗压强度达到130 MPa,抗拉强度达到6.7 MPa;掺入60%煤矸石粉末的UHPC初凝收缩应变占总收缩的比例提高了12.2%,自收缩总应变减小了12.5%;增加煤矸石粉末掺量,可有效缩短UHPC初凝时间,加速UHPC自收缩过程,减小UHPC自收缩应变;已有的混凝土自收缩计算方法未体现煤矸石掺量对UHPC自收缩应变和初凝时间的影响。最后,基于试验结果修正并提出了煤矸石UHPC收缩应力计算方法,该计算方法可有效预测煤矸石UHPC自收缩性能。It aims to fabricate a low carbon,green,environmental,and economical coal gangue ultra-high performance concrete(UHPC)with excellent mechanical properties used in practical engineering,realizing a reutilization of solid waste.The tensile and compressive strengths,elastic modulus,and autogenous shrinkage stain of the UHPC with various mass substitution ratios(20%,40%,and 60%)were experimentally measured.In addition,the mechanism of coal gangue in producing UHPC was revealed,and the applicability of existing theoretical calculations for concrete autogenous shrinkage was assessed.The results indicate that high content of coal gangue powder can be used in the production of UHPC.The prism compressive strength of the UHPC with 1.5%steel fiber content exceeded 130 MPa,and its tensile strength reached 6.7 MPa.The autogenous shrinkage strain at initial setting time and finial shrinkage strain of the UHPC with 60%coal gangue powder content were reduced by 12.2%and 12.5%,respectively.The increase in volume of coal gangue powder effectively reduced the initial setting time of UHPC,accelerated the UHPC autogenous shrinkage process,and decreased the UHPC autogenous shrinkage strain.The existing concrete autogenous shrinkage calculation methods fail to reflect the effect of coal gangue powder content on the UHPC autogenous shrinkage strain and its initial setting time.Finally,based on the experimental results,a calculation method for coal gangue UHPC autogenous shrinkage was modified and proposed,and this method was effective in predicting the autogenous shrinkage behavior of coal gangue UHPC.

关 键 词：超高性能混凝土 煤矸石粉末 力学性能 收缩性能 计算方法 

分 类 号：TU528.31[建筑科学—建筑技术科学]