非自燃煤矸石混凝土的基本力学性能及其影响因素研究
Research on the Fundamental Mechanical Properties of Raw Coal Gangue Concrete and Its Influencing Factors
贡强 1马海兵 1寇栩霆 2沈玲华2
作者信息
- 1. 山西平榆高速公路有限责任公司,山西晋中 030002
- 2. 太原理工大学土木工程学院,太原 030024
- 折叠
摘要
为提高煤矸石的资源化利用,将非自燃煤矸石进行部分或全部取代天然骨料制备混凝土,并分析了水灰比、取代率、外掺硅灰及搅拌方式等因素对非自燃煤矸石混凝土试件立方体抗压强度、劈裂强度、应力-应变关系曲线、弹性模量、峰值荷载和峰值应变等的影响规律,并采用微观电镜扫描观察试件破坏断面的微观结构特征.结果表明:采用二次搅拌工艺及外掺硅灰+二次搅拌等方式均可提高非自燃煤矸石混凝土的基本力学性能,前者的提高幅度大于后者;增大取代率和水灰比不利于非自燃煤矸石混凝土试件的力学性能,且后者的降低幅度更大.此外,通过微观电镜扫描的观察可见,采用二次搅拌工艺的试件界面过渡区孔隙较少,且更为致密,从而能更有效地提高试件的宏观力学性能.
Abstract
To enhance the resource utilization of raw coal gangue,this study partially or fully replaced raw coal gangue with natural aggregates to prepare concrete.The effects of factors such as water-cement ratios,replacement rates,the addition of silica fume and mixing methods on the compressive strength,splitting strength,stress-strain relationship curve,elastic modulus,peak load and peak strain of specimens were analyzed.Additionally,the microstructure charac-teristics of the specimens'failure surfaces were observed using scanning electron microscopy.The results show that the mechanical properties of raw coal gangue concrete were improved by using a secondary mixing process,and the combination of the secondary mixing process with the addition of silica fume.The former method exhibited greater improvement than the latter.An increase in replacement rate and water-cement ratio is detrimental to the mechanical performance of non-self-igniting coal gangue concrete specimens,with the latter experiencing a greater reduction in magnitude.Furthermore,scanning electron microscopy observations reveal that the interfacial transition zones of the specimens using the secondary mixing process exhibited fewer pores and a denser structure,which effectively im-proved the macroscopic mechanical properties of the specimens.
关键词
二次搅拌工艺/非自燃煤矸石/基本力学性能/混凝土/微观结构Key words
secondary mixing process/raw coal gangue/basic mechanical properties/concrete/microstructure引用本文复制引用
基金项目
山西省自然科学基金(202203021211131)
出版年
2024
NETL
NSTL
万方数据