摘要
研究了浓度为6.4%的搅拌站回收浆液放置时间对混凝土性能的影响规律,采用XRD、SEM分析了不同放置时间回收浆液在水泥净浆中水化产物及微观形貌的变化过程。研究表明,回收浆液替代拌合用水掺入会显著降低C30混凝土拌合物的流动性,随着浆液放置时间越长,拌合物初始坍落度和扩展度逐渐降低,经时损失显著增大;当浆液放置在24 h之内时,混凝土各龄期抗压强度随放置时间的延长逐渐提高,超过24 h抗压强度趋于稳定。XRD和SEM结果显示,回收浆液在24 h之内随着浆液放置时间的延长,Ca(OH)_(2)衍射峰值逐渐增大,说明浆液活性增强,导致水化速率逐渐加快,水泥浆体孔隙减少,微观结构不断改善;在72 h之内有动态活性。
The effect of the placement time of the recycled slurry with a concentration of 6.4%in the mixing plant on the concrete properties was investigated.XRD and SEM were used to analyze the change process of hydration products and microscopic morphology of the recycled slurry in the net cement slurry at different placement times.The study shows that the recycled slurry replacing the mixing water will significantly reduce the fluidity of C30 concrete mixes,and the initial slump and expansion of the mixes gradually decrease with the longer placement time of the slurry,and the time loss increases significantly;when the slurry is placed within 24 h,the compressive strength of concrete at each age gradually increases with the extension of placement time,and the compressive strength tends to stabilize after 24 h.The XRD and SEM results show that the recycled slurry at 72 h has a significant effect on the concrete properties.The results showed that the recovered slurry was dynamically active within 72 h.The Ca(OH)_(2)diffraction peak increased gradually with the extension of slurry placement time within 24 h,indicating that the enhanced activity of slurry led to the gradual acceleration of hydration rate,the reduction of cement slurry pores and the continuous improvement of microstructure.
作者
刘品红
廖国胜
胡思达
廖宜顺
梅军鹏
舒德辉
LIU Pinhong;LIAO Guosheng;HU Sida;LIAO Yishun;MEI Junpeng;SHU Dehui(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China;Institute of High Performance Engineering Structure,Wuhan University of Science and Technology,Wuhan 430065,China;Hunan Shengjian Construction Materials Co.Ltd.,Miluo 414499,China)
出处
《新型建筑材料》
2023年第11期70-74,共5页
New Building Materials
关键词
混凝土
回收浆液
放置时间
活性
水化产物
concrete
recycled slurry
placement time
activity
hydration products
