摘要
用外掺煅烧无水石膏方法模拟固硫灰渣中的SO3，研究了SO3对固硫灰渣一硅酸盐水泥熟料（质量比为30：70）系统凝结时间、抗压强度、线性膨胀率、化学结合水量及水化产物的影响规律．结果显示，当系统中SO3含量（质量分数，下同）为2．5％～3．5％时，其初、终凝时间均可达到普通硅酸盐水泥所要求的标准，说明固硫灰渣中无水石膏有一定调凝作用，但无水石膏的调凝效果明显不如二水石膏。此外，系统SO3含量增加，化学结合水量也随之增加，说明SO3对烧黏土质矿物的火山灰活性有一定激发作用．当SO3含量小于3．5％时，系统强度会随之增高；S03含量超过3．5％时，钙矾石生成量较多，系统线性膨胀率增加，导致系统强度有一定程度降低．研究表明，固硫灰渣作掺和料使用时，如果胶凝系统中不掺入二水石膏，则需要控制胶凝系统S03含量为2．5％～3．5％．
The high SO3 content of circulating fluidized bed combustion（CFBC） ash as compared to other coal ashes has significant effect on the hydration and performance of CFBC ash cementitious system. Cal cined anhydrite was used to control the SOa content of the CFBC ash-Portland cement clinker（30 ： 70, by mass） system, and the influence of SO3 on the setting time, compressive strength, linear expansion ratio, chemically combined water content and hydration products was investigated. The results show that the ini tial and final setting time of the system can meet the standard for ordinary Portland cement if the SO3 content of the system ranges from 2.5% to 3.5% 1 indicating that the anhydrite of CFBC ash plays a role in the control of setting time; however, the efficiency of anhydrite is obviously inferior to that of gypsum. Moreover, the chemically combined water content of the system increases with the SOa content due to the exciting effect of SOa on the combusted clay minerals of CFBC ash. If the SOa content of the system is low er than 3.5%, the system strength will increase with the SOa content; however, if the content exceeds 3.5 %, the production of ettringite and the resulting expansion will inevitably lead to the reduction of the strength. It is suggested that it is necessary to control the SOa content of CFBC ash-Portland cement clink- er system within the range of 2.5% to 3.5%, if no gypsum is added to the system.
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2013年第4期688-693,共6页
Journal of Building Materials
基金
国家自然科学基金资助项目(51132010
51272222)
山东省科技发展计划资助项目(2011GGX10705)
烟台市科技发展计划资助项目(2012ZH249)
关键词
固硫灰渣
SO3
水化
性能
无水石膏
circulating fluidized bed combustion（CFBC） ash
S03
hydration
performance
anhydrite
