固硫灰的膨胀及其控制

中文摘要: 研究了纯固硫灰的膨胀，固硫灰掺量、固硫灰细度、不同养护条件对固硫灰水泥净浆膨胀的影响，并对各龄期的水化产物进行XRD、SEM分析，得出了固硫灰的膨胀机理，在此基础上探讨了各种控制固硫灰膨胀的方法。结果表明：固硫灰硫、钙含量高，加水后7 d内钙矾石大量生成引起膨胀。而相对湿度对固硫灰的膨胀有很大影响，通过磨细可以提高固硫灰的活性和在早期释放固硫灰的膨胀，并且通过添加骨料和在早期使体系强度快速增加能有效的控制体系的膨胀。
Abstract:The expansion of circulating fluidized bed fly ash (CFA) and the effect of CFA content,fineness of CFA and curing regimes on the expansion properties of cement paste were investigated.Moreover,the mechanism of expansion of CFA was discussed by XRD and SEM,as well as the control measure.The results indicated that the formation of ettringite in 7 days after the hydration of CFA results in expansion and relative humidity has significant effect on the expansion of CFA.Mechanical grinding can improve activities of CFA and release the expansion in early stage,adding aggregate and improving early strength are effective ways to control expansion.