摘要
为促进大宗固体废弃物煤矸石在结构工程中的资源化利用,以陕北矿区五个典型矿源煤矸石为研究对象,开展煤矸石放射性、化学组成、矿物组成、含碳量与发热量等基本理化特性试验与煤矸石混凝土立方体抗压强度、轴心抗压强度、劈裂抗拉强度等基本力学性能试验,分析煤矸石的理化特性,研究煤矸石粗骨料对混凝土力学性能的影响。结果表明:煤矸石化学组成主要为SiO2与Al2O3,矿物组成主要为石英与黏土矿物,含碳量为0.91%~2.09%,发热量为424.31~1869.34 kJ/kg,满足GB 50821—2012《煤炭工业环境保护设计规范》中一类煤矸石指标要求,可用作骨料使用。煤矸石的含碳量、吸水率、压碎指标、堆积密度及表观密度均是影响煤矸石混凝土立方体抗压强度的指标之一,但各指标间高度相关,均可以含碳量的函数表示,含碳量是影响煤矸石混凝土立方体抗压强度的主要因素。通过回归分析,建立以煤矸石含碳量为变量的煤矸石混凝土立方体抗压强度计算公式,所得计算值与试验值吻合较好。此外,煤矸石混凝土轴心抗压强度与立方体抗压强度换算可采用GB 50010—2010《混凝土结构设计规范》中公式,而劈裂强度与立方体抗压强度换算应在GB 50010—2010公式基础上进行折减,折减系数取0.9。
To promote the utilization of coal gangue in structural engineering,this paper presents a study on the coal gangue from five typical coal mines in the Northern Shaanxi mining area.The physicochemical properties of coal gangue were analyzed,and the influence of coal gangue coarse aggregate on the mechanical properties of concrete was studied.The results show that the chemical composition of coal gangue consists mainly of SiO2 and Al2O3,the mineral composition consists mainly of quartz and clay minerals,the carbon content is between 0.91%and 2.09%,and the calorific value is between 424.31-1869.34 kJ/kg.The coal gangue used in this study meet the requirements of Class 1 coal gangue in GB 50821—2012‘Code for design of environmental protection in coal industry',and can be used as aggregate for concrete.The carbon content,water absorption rate,crushing index,packing density and apparent density of coal gangue concrete(CGC)are among the indicators that affect the cubic compressive strength of CGC,but they are highly correlated and can be expressed as a function of carbon content.Therefore,the carbon content is the main factor affecting the cubic compressive strength of CGC.A formula for calculating the compressive strength of CGC cubes was established with the carbon content as a variable.In addition,it is recommended that the conversion between the axial compressive strength and cubic compressive strength of CGC can be done using the corresponding formula in GB 50010—2010‘Code for design of concrete structure',while the conversion between the splitting tensile strength and cubic compressive strength should be reduced on the basis of the corresponding formula in GB 50010—2010,with a reduction coefficient of 0.9.
作者
白国良
刘瀚卿
刘辉
陈菲
朱可凡
BAI Guoliang;LIU Hanqing;LIU Hui;CHEN Fei;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 EducationXAUAT,Xi'an 710055,China;Northern Shaanxi mining Co.,Ltd,Yulin 719000,China;Shaanxi Coal Group Shenmu Ningtiaota Mining Co.,Ltd,Yulin 719000,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2023年第10期243-254,共12页
Journal of Building Structures
基金
国家自然科学基金面上项目(52378191)
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)。
关键词
煤矸石
煤矸石混凝土
理化特性
抗压强度
劈裂抗拉强度
coal gangue
coal gangue concrete
physicochemical properties
compressive strength
spliting tensile strength
