摘要
为探究煤矸石对混凝土性能的影响,以不同煤矸石粉(Coal gangue powder,CGP)掺量和煤矸石粗骨料(Coal gangue coarse aggregate,CGA)取代率制备C30混凝土,对煤矸石混凝土抗折性能及抗氯离子渗透性能进行试验研究,并通过压汞法及扫描电镜进一步分析其影响规律和改善机理。结果表明,随着掺量的增加,煤矸石混凝土抗折强度先增大后减小,15%CGP为抗折强度最优掺量。抗氯离子渗透性能随CGP掺量的增加而提高。煤矸石粗骨料取代率为100%时,CGP的掺入对其抗折强度的优化更为显著。CGP的加入使凝胶孔和过渡孔等无害孔增加,毛细孔和大孔等有害孔减小,进而优化混凝土颗粒级配,提高结构密实度。一方面CGP在二次水化中产生大量C-S-H凝胶,使煤矸石混凝土微观结构更加密实,另一方面未反应的CGP可填充至煤矸石混凝土孔隙和裂缝中,提高界面过渡区强度,进而提高煤矸石混凝土抗折强度和抗氯离子渗透性能。
In order to explore the influence of coal gangue on the performance of concrete,C30 concrete was prepared with different contents of coal gangue powder(CGP)and different substitution rates of coal gangue coarse aggregate(CGA).The flexural properties and chloride ion penetration resistance of coal gangue concrete were studied.The influence law and improvement mechanism were further analyzed by mercury intrusion method and scanning electron microscope.The results showed that with the increase of dosage,the flexural strength of coal gangue concrete increased first and then decreased,and 15%CGP was the optimal dosage of flexural strength.The resistance to chloride ion penetration increased with the increase of CGP content.When the substitution rate of coal gangue coarse aggregate was 100%,the incorporation of CGP had a more significant optimization of its flexural strength.The addition of CGP increased the harmless pores such as gel pores and transition pores,and decreased the harmful pores such as capillary pores and macropores,thus optimizing the particle size distribution of concrete and improving the structural compactness.On the one hand,CGP produced a large amount of C-S-H gel in the secondary hydration,which made the microstructure of coal gangue concrete more dense.On the other hand,the unreacted CGP can be filled into the pores and cracks of coal gangue concrete to improve the strength of the interfacial transition zone,and then improve the flexural strength and chloride ion penetration resistance of coal gangue concrete.
作者
阎杰
邢国斌
左军鹏
李敬如
翁维素
YAN Jie;XING Guobin;ZUO Junpeng;LI Jingru;WENG Weisu(College of Civil Engineering,Hebei Institute of Architecture Civil Engineering,Zhangjiakou 075000,China;Research and Development Center for Application Technology of Green Building Materials and Building Renovation in Hebei Universities,Zhangjiakou 075000,China)
出处
《森林工程》
北大核心
2023年第5期190-196,共7页
Forest Engineering
基金
河北省教育厅自然科学重点项目(ZD2022066)
河北省科技厅科技支撑计划项目(20373802D)
河北省住房和城乡建设厅建设科技研究项目(120)
2022年河北省建设科技研究指导性计划项目(2022-2017)。
关键词
活化煤矸石粉
煤矸石粗骨料
微观结构
抗折强度
抗氯离子渗透
Activated coal gangue powder
coal gangue coarse aggregate
microstructure
flexural strength
resistant to chloride ion penetration
