醇胺类和C-S-H-PCE纳米种子多元体系协同效应对高掺粉煤灰-水泥浆体早期强度的影响  

Enhancement of early-age strength of the high content fly ash blended cement paste by synergistic effect of polysystem of alcamines and C-S-H-PCE nanocomposite seeds

作　　者：王方刚 陆加越 张英杰 于诚 刘建忠 WANG Fanggang;LU Jiayue;ZHANG Yingjie;YU Cheng;LIU Jianzhong(Jiangsu Bote New Materials Limited Company,Nanjing 211103,China;State Key Laboratory of High Performance Civil Engineering Materials,Jiangsu Research Institute of Building Science,Nanjing 210008,China)

机构地区：[1]江苏苏博特新材料股份有限公司,江苏南京211103 [2]江苏省建科院高性能土木工程材料国家重点实验室,江苏南京210008

出　　处：《混凝土》2024年第11期138-144,154,共8页Concrete

基　　金：国家自然科学基金(52178215)。

摘　　要：粉煤灰虽然降低成本,降低碳排放等诸多优点,但在高掺量(>30%)下其火山灰反应缓慢会降低整个体系的水化程度,导致早期强度发展缓慢。如何高效、环保的提高高掺量粉煤灰-水泥浆体早期强度是十分必要的。从抗压强度、水化热、凝结时间、XRD、TG-DTG、ICP和SEM等方面研究了不同剂量醇胺类(三乙醇胺,TEA、三异丙醇胺,TIPA)和/或C-S-H-PCE组合对水泥(55%)和高掺量粉煤灰(45%)浆体和粉煤灰自身早期水化的影响和作用机理。结果表明:C-S-H-PCE与醇胺类(TEA、TIPA)的协同作用,显著提高水泥的水化程度和粉煤灰的反应程度。二者联合使用更能促进AFt的生成,对早期抗压强度的提高起协同作用,且显著优于二者单独加入效果之和。揭示了协同效应的内在机理:C-S-H-PCE提供成核点位,促进水泥水化,加速AFt形成;醇胺类(TEA、TIPA)一方面促进AFt转化成AFm,产生更多的CH,加速FA在孔隙溶液中的溶解,另一方面与Al和Fe发生络合,加速FA玻璃相中活性氧化铝和二氧化硅溶解到孔隙溶液中参与火山灰反应,形成额外的C-S-H凝胶。Although fly ash has many advantages such as reducing hydration heat and carbon emission,However,the slow reaction of volcanic ash will reduce the hydration degree of the whole system at high dosage(typically>30%in mass),resulting in slow development of early-age strength.Therefore,it is necessary to develop the highly-effificient and environmental-friendly method for the enhancement of the early-age strength of cement and fly ash paste.The mechanism and effect of alcamines(TEA,TIPA)and C-S-H-PCE on the early hydration of cement(55%)and high content fly ash(45%)and fly ash itself were assessed in terms of compressive strength,hydration heat,setting time,XRD,TG-DTG,ICP and SEM.The results show that alcamines(TEA,TIPA)and C-S-H-PCE exhibit a synergistic enhancement effect on the hydration degree of cement and the reaction degree of fly ash.The combination of C-S-H-PCE and alcamines(TEA,TIPA)could promote the formation of AFt,and played a synergistic effect on the improvement of early compressive strength,which is much higher than the sum of individual effects of alcamines(TEA,TIPA)and C-S-H-PCE.Moreover,the underlying mechanism of the synergistic effect is revealed through this study.C-S-H-PCE provides nucleation sites to promote cement hydration and accelerate AFt formation.On the one hand,alcohol amines(TEA,TIPA)promote the conversion of AFt into AFm,produce more CH,and accelerate the dissolution of FA in pore solution.On the other hand,they complexate with Al and Fe,and accelerate the dissolution of activated alumina and silica in FA glass phase into pore solution to participate in pore-ash reaction,and form additional C-S-H gel.

关 键 词：高掺量粉煤灰 三乙醇胺 三异丙醇胺 C-S-H-PCE 早期强度 协同效应 

分 类 号：TU528.01[建筑科学—建筑技术科学]