固体硅酸钠激发粉煤灰-矿渣基地质聚合物抗压强度的试验研究  

Experimental Study on the Compressive Strength of Slag-fly Ash Based Geopolymer Activated by Solid Sodium Silicate

作　　者：高铭洁 户国[1] 吴俊[1] 闵一凡 李延波 Gao Mingjie;Hu Guo;Wu Jun;Min Yifan;Li Yanbo(College of Urban Railway Transportation,Shanghai University of Engineering Science,201620,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;School of Material Science and Engineering,Yancheng Institute of Technology,224051,China)

机构地区：[1]上海工程技术大学城市轨道交通学院,201620 [2]同济大学土木工程学院,上海200092 [3]盐城工学院材料科学与工程学院,224051

出　　处：《特种结构》2023年第2期100-105,共6页Special Structures

基　　金：国家自然科学基金项目(52078288)。

摘　　要：本文拟以高炉矿渣和粉煤灰为前驱体,固体硅酸钠为碱性激发剂,制备“一步法”粉煤灰-矿渣基地质聚合物。研究粉煤灰掺量、硅酸钠模数、碱激发剂摩尔浓度、龄期等因素对地质聚合物抗压强度、凝结时间、流动度和微观结构发育的影响。结果表明:掺入粉煤灰能提高地质聚合物的流动度及和易性,但其抗压强度随粉煤灰掺量增加而减小;随着硅酸钠模数和碱激发剂摩尔浓度提高,地质聚合物抗压强度呈先升后降的趋势。本研究中当前驱体为100%高炉矿渣(粉煤灰含量0%),固体硅酸钠模数为1且碱性激发剂浓度为5.0mol/L时,地质聚合物28d抗压强度可达9.19MPa。在地质聚合物中产生硅铝酸钠和水化硅(铝)酸钙等凝胶,随着龄期增长,形成致密结构,从而提高了其抗压强度,但过量粉煤灰使地质聚合物产生较多孔隙,使其强度降低。Using blast furnace slag and fly ash as precursors and solid sodium silicate as alkaline activator,a"single stage method"to prepare fly ash-slag based geopolymer was proposed in this paper.The influences of fly ash content,sodium silicate modulus,alkali activator molar concentration,aging and other factors on the compressive strength,setting time,fluidity,and microstructure development of geopolymers were investigated.The results show that adding fly ash in the precursor can improve the fluidity and workability of geopolymers,but the compressive strength decreases with the increase of fly ash content;With the increase of the sodium silicate modulus and alkali activator molar concentration,the compressive strength of the geopolymer increases first and then decreases.In this study,when the precursor is 100%blast furnace slag(0%fly ash content),solid sodium silicate modulus is 1 and the alkaline activator concentration is 5.0 mol/L,the 28-day compressive strength of geopolymer can be up to 9.19 MPa.The geopolymer is activated by solid sodium silicate,and the main hydration product in the later stage is aluminosilicate(N-A-S-H)gel,which continue to develop and form a dense structure as the curing age,thereby increasing the compressive strength.However,excessive fly ash can make the geopolymer more porous and reduce its strength.

关 键 词：地质聚合物 固体硅酸钠 无侧限抗压强度 微观结构 

分 类 号：TU526[建筑科学—建筑技术科学]