摘要
高贝利特硫铝酸盐水泥(High belite calcium sulphoaluminate cement,HBCSA)是一种新开发的具有低收缩特性的新型胶凝材料,具有强度发展均衡、不易析碱泛白、体积稳定性高和耐久性好等优异性能。但实际应用中发现HBCSA凝结硬化快,常用缓凝剂都难以有效延缓其快速水化的问题,这成为制约其广泛应用的瓶颈。为有效控制HBCSA的凝结时间,扩大其应用范围,本工作将探讨适用于HBCSA的化学外加剂,并揭示HBCSA的水化硬化作用控制机理,提出有效的调控措施。研究发现,将聚羧酸减水剂(Polycarboxylate superplasticizer,PCE)与缓凝组分β-环糊精(β-cyclodextrin,β-CD)复掺到HBCSA净浆或胶砂试件中具有较好的缓凝效果。同时测试了掺加复合外加剂的HBCSA浆体的流动度、凝结时间和各龄期胶砂试件强度,并利用扫描电子显微镜(Scanning electron microscope,SEM)、X射线衍射分析仪(X-ray diffraction,XRD)、总有机碳(Total organic carbon,TOC)分析仪和八通道热导式等温量热仪深入研究复合外加剂对HBCSA性能的影响。研究结果表明:PCE复掺β-CD的加入减缓了HBCSA水化产物中钙矾石的生成速度,从而有效延长了水泥凝结时间,且两者复配对改善HBCSA的流动性和中后期胶砂强度有积极作用。
High belite calcium sulphoaluminate cement （HBCSA） is a newly developed cementing material with broad application prospects for its excellent mechanical properties, high volume stability, good durability and anti efflorescence property. Howe- ver, it is difficult for common retarders to delay its rapid hydration effectively due to the rapid setting and hardening of HBCSA, which has become the bottleneck restricting the wide application of this kind of new cement. In order to control the setting time of HBCSA and extend its application scope, the retarding material suited for HBCSA was explored and discussed in this paper, and the mechanism of hydration hardening of HBCSA was revealed, as well as the effective control measures were put forward. It was found that the combination of polycarboxylate superplasticizer （PCE） and β-cyclodextrin（β-CD） had good retarding effect to HBCSA paste or mortar. The fluidity, setting time and strength of HBCSA mortar with the admixture were tested. Scanning electron microscope （SEM）, X-ray diffraction （XRD） analyzer, total organic carbon （TOC） analyzer and hydration heat evolution of cement were carried out. The results showed that the adding of PCE and β-CD could slow down the crystallization rate of ettringite, the setting time of HBCSA cement paste was significantly prolonged, and the cement setting time was increased with the increment of retarder content. Adding PCE and β-CD had a positive effect on improving the fluidity of HBCSA and the strength of rubber in the middle and late stages.
作者
唐芮枫
王子明
何欢
张琳
蔡扬扬
王杰
TANG Ruifeng;WANG Ziming;HE Huan;ZHANG Lin;CAI Yangyang;WANG Jie(School of Materials Science and Engineering,Beijing University of Technology,Beijing 100124)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第22期4000-4005,共6页
Materials Reports
基金
"十三五"国家重点研发计划(2016YFB0303504)
关键词
高贝利特硫铝酸盐水泥
聚羧酸减水剂
Β-环糊精
缓凝
凝结时间
high belite calcium sulphoaluminate cement
polycarboxylate superplasticizer
β-cyclodextrin
retardation
setting time
