自燃煤矸石粗骨料特性及其对混凝土性能的影响  

Properties of Spontaneous Combustion Coal Gangue Coarse Aggregate and Its Influence on Concrete

作　　者：李少伟 周梅[1] 张莉敏 LI Shaowei;ZHOU Mei;ZHANG Limin(College of Civil Engineering,Liaoning Technical University,Fuxin 123000,China;Fujian Provincial Key Laboratory of Green Building Technology,Fujian Building Research Institute Co.,Ltd.,Fuzhou 350108,China;Yunneng Water Conservancy&Electric Power Co.,Ltd.of Sichuan Province,Chengdu 610000,China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000 [2]福建省建筑科学研究院有限责任公司福建省绿色建筑技术重点实验室,福建福州350108 [3]四川云能水利电力工程咨询有限公司,四川成都610000

出　　处：《建筑材料学报》2020年第2期334-340,380,共8页Journal of Building Materials

基　　金：国家自然科学基金委员会与神华集团有限公司联合资助项目(U1261122);国家自然科学基金资助项目(51808352)。

摘　　要：在系统掌握自燃煤矸石粗骨料基本特性的基础上,研究了不同取代率下自燃煤矸石粗骨料混凝土的拌和物和易性,以及混凝土强度、弹性模量、破坏特征和应力-应变曲线,并通过界面过渡区微观表征了自燃煤矸石粗骨料混凝土的微结构特征.结果表明:与天然碎石相比,自燃煤矸石粗骨料的表观密度小、吸水率高、压碎和坚固性指标大;随着自燃煤矸石粗骨料取代率递增,混凝土拌和物的坍落度和混凝土的表观密度、弹性模量递减,塑性有一定程度改善,轴压纵向劈裂破坏形态越发明显;取代率小于50%的自燃煤矸石粗骨料对混凝土的内养护作用比其自身强度低的影响更为显著,使混凝土界面过渡区更为密实,抗压强度有一定幅度的提高;当取代率大于50%后,因自燃煤矸石粗骨料自身缺陷增多而导致混凝土强度有所下降.Based on systematically knowing the basic features of spontaneous combustion coal gangue coarse aggregate(SGCA), concrete with different replacement rates of SGCA were investigated in workability of concrete mixture, strength, elastic modulus, failure characteristics and stress-strain curve of concrete. The microstructure characteristics of spontaneous combustion coal gangue coarse aggregate concrete(SGC) and its macroscopic behavior in damage and constitutive relation were analyzed by the interfacial transition zone(ITZ) microscopic characterization. The results show that, compared with natural gravel, SGCA has smaller apparent density, higher water absorption rate, larger crushing value and firmness index. When the replacement rate of SGCA increases, the slump of concrete mixture, the apparent density and elastic modulus of concrete decrease, and the plasticity improves in some extent. SGCA has internal curing effect, which can significantly improve the ITZ in concrete and increase the compressive strength in a certain extent when the replacement rate is lower than 50%, while more than 50%, the strength of concrete decreases.

关 键 词：自燃煤矸石粗骨料 自燃煤矸石粗骨料混凝土 和易性 力学性能 微观结构 

分 类 号：TU528.01[建筑科学—建筑技术科学]