纳米二氧化硅改性硫酸铝无碱液体速凝剂的制备及其性能研究  

Preparation and properties of nano-SiO2 modified aluminum sulfate alkali-free liquid accelerator

作　　者：刘孝通 刘远 杨林[1] 杨安旭 曹建新[1] LIU Xiaotong;LIU Yuan;YANG Lin;YANG Anxu;CAI Jianxin(School of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,China;Guizhou Tianwei Building Materials Technology Co.,Ltd.,Guiyang 550009,China)

机构地区：[1]贵州大学化学与化工学院,贵州贵阳550025 [2]贵州天威建材科技有限公司,贵州贵阳550009

出　　处：《混凝土》2024年第11期117-121,共5页Concrete

基　　金：国家重点研发计划(2018YFC1900206-2);贵州省科技计划项目(黔科合平台人才[2019]5409号);贵州大学实验室开放项目(SYSKF2023-008)。

摘　　要：采用硫酸铝、氟硅酸、氢氧化铝等原料制备无碱液体速凝剂母液,使用纳米SiO_(2)对其进行改性处理,用基准水泥检测了改性无碱速凝剂的性能指标,并采用XRD、SEM、TG-DTG等手段对掺有速凝剂水泥样品进行检测,结果表明:随着纳米SiO_(2)掺量的增加,掺有速凝剂的水泥抗压强度逐渐增加,凝结时间先降低后增加,当速凝剂中掺入3%纳米SiO_(2)时,凝结时间最短。添加含有3%纳米SiO_(2)的速凝剂,水泥初凝时间为195 s,终凝时间为345 s。1 d抗压强度可以达到10.2 MPa,28 d抗压强度为50.5 MPa。在速凝剂中引入纳米SiO_(2)可以促进水泥的水化,但当速凝剂中纳米SiO_(2)掺量较高时,会使钙矾石变为细针状导致速凝效果变差。Aluminum sulfate,fluosilicic acid,aluminum hydroxide and other raw materials were used to prepare alkali-free liquid accelerator mother liquor,and nano-SiO_(2)was used to modify it.The performance index of the modified alkali-free accelerator was tested with the reference cement,and XRD,SEM,TG-DTG and other means were used to test the cement samples mixed with accelerator.The results show that with the increase of nano-SiO_(2)content,the compressive strength of cement mixed with accelerator gradually increases,and the setting time first decreases and then increases.When the accelerator is mixed with 3%nano-SiO_(2),the setting time is the shortest.Adding accelerator containing 3%nano-SiO_(2),the initial setting time of cement is 195 s,and the final setting time is 345 s.The 1 d compressive strength can reach 10.2 MPa,and the 28 d compressive strength is 50.5 MPa.The introduction of nano-SiO_(2)in the accelerator can promote the hydration of cement,but when the content of nano-SiO_(2)in the accelerator is high,it will make the ettringite become fine needle-like and lead to the deterioration of the accelerator effect.

关 键 词：无碱液体速凝剂 纳米SIO2 凝结时间 抗压强度 作用机理 

分 类 号：TU528.042[建筑科学—建筑技术科学]