甘蔗渣灰对磷酸钾镁水泥性能与水化的影响  

Effects of Sugar Cane Bagasse Ash on the Properties and Hydration of Magnesium Potassium Phosphate Cement

作　　者：蒋增贵 王欣 刘剑辉 刘乐平 陈正[1] 莫耀鸿 赖创林 史才军[2] JIANG Zenggui;WANG Xin;LIU Jianhui;LIU Leping;CHEN Zheng;MO Yaohong;LAI Chuanglin;SHI Caijun(College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;College of Civil Engineering,Hunan University,Changsha 410082,China;College of Chemistry and Materials,Nanning Normal University,Nanning 530001,China)

机构地区：[1]广西大学土木建筑工程学院,南宁530004 [2]湖南大学土木工程学院,长沙410082 [3]南宁师范大学化学与材料学院,南宁530001

出　　处：《材料导报》2024年第18期102-109,共8页Materials Reports

摘　　要：甘蔗渣灰(SCBA)是蔗糖生产过程中产生的废弃物。由于SCBA产量丰富且具有火山灰活性,已被逐渐应用于建筑材料。本工作研究了不同掺量及粒径的SCBA对磷酸钾镁水泥(MKPC)凝结时间、流动度、抗压强度、体积稳定性、质量损失、水化进程、水化产物和微观结构的影响。结果表明,由于SCBA的稀释效应延缓了MKPC的pH值上升,从而延缓了MKPC的早期水化,延长了其凝结时间,降低了其早期(24 h之前)强度。但随着中后期pH值的上升,SCBA发挥填充作用和成核效应,MKPC的水化产物生成量增多且SCBA中的元素会渗入K-鸟粪石晶体中或形成一些新的无定形磷酸铝、硅酸钾和钙质类的胶凝水化产物,致使结构更致密,从而提升了试件中长期的强度。MKPC的早期水化速率随着SCBA掺量的增加逐渐降低,早期水化产物K-鸟粪石的生成量减少,导致早期收缩减小;中后期50~100 nm与小于50 nm的连通孔的比例增加,加快了自由水的蒸发和迁移,使得质量损失和干燥收缩增大。小粒径SCBA的掺入量为20%时MKPC的综合性能较好。本研究为SCBA作为MKPC替代胶凝材料提供了理论基础,并进一步促进了农副产品在新型胶凝材料中的应用。Sugar cane bagasse ash(SCBA)is a waste produced in the process of sucrose production.Because SCBA is rich in yield and has pozzolanic activity,it has been gradually used for building materials.In this work,the effects of SCBA with different content and particle size on the setting time,fluidity,compressive strength,volume stability,mass loss,hydration process and products and microstructure of magnesium potassium phosphate cement(MKPC)were studied.The results showed that the dilution effect of SCBA slowed down the increase of pH of MKPC,which can delay the early hydration and increase the setting time and early strength(before 24 hours)of MKPC.However,with the increase of pH value in the middle and later stages,SCBA played a filling role and nucleating effect.The amount of hydration products of MKPC increased,and some new amorphous aluminum phosphate,potassium silicate,and calcium gelled hydration products were formed.It can result in a denser structure and higher strength in the medium and long term.Because the hydration rate of early MKPC gradually decreased with the increase of SCBA content,the formation of early hydration product K-struvite decreased,and the early shrinkage decreased.The proportion of connected pores with the size of 50—100 nm and less than 50 nm increased in the middle and late stage,which accelerated the evaporation and migration of free water,and increased the mass loss and drying shrinkage.When the content of SCBA with small particle size is 20%,the comprehensive performance of MKPC is better.This study can provide a theoretical basis for SCBA as a substitute for MKPC cementitious material,and further promote the application of agricultural by-products in new cementitious materials.

关 键 词：磷酸钾镁水泥 甘蔗渣灰 宏观性能 微观结构 水化机理 

分 类 号：TU525[建筑科学—建筑技术科学]