循环流化床固硫灰渣低收缩水泥的制备及性能

通过分别使用循环流化床(CFBC)固硫灰、渣代替部分原材料制备低收缩水泥熟料,加入质量分数为10%的石膏即得到CFBC固硫灰、渣低收缩水泥,然后利用X射线衍射、扫描电镜等方法研究水与水泥的质量比(简称水灰比)对CFBC固硫灰渣低收缩水泥水化程度、抗压强度和线性膨胀率的影响。结果表明,随着水灰比的增加,CFBC固硫灰渣低收缩水泥的主要水化产物钙矾石数量增多,未水化的硅酸二钙含量减少,水化程度增大;而该水泥线性膨胀率与水灰比呈正比关系,抗压强度与其呈反比关系;利用固硫灰制备的水泥早期膨胀率随着水化时间而增大,但后期由于石膏量的不足,膨胀率则随着水化时间而减小。

Preparation and Performance of CFBC Ash and Slag Low Shrinkage Cement

Low shrinkage cement clinker was prepared respectively by using circulating fluidized bed combustion(CFBC) ash and slag as raw materials,and 10% mass fraction of gypsum were added to prepare CFBC ash and slag low shrinkage cement.The effect of mass ratio of water and cement(mw/mc) on hydration extent,expansion rate and compressive strength of CFBC ash and slag low shrinkage cement were researched by X ray diffraction and scanning electron microscopy.The experimental results indicate that the expansion rate and compressive strength of CFBC ash and slag low shrinkage cement are strongly effected by mw/mc,the compressive strength raises and the expansion rate reduced with the raise of mw/mc.The content of main hydration products ettringite and unhydrated β-C2S are respectively raises and decreases as mw/mc increases.mw/mc is propitious to improve hydration extent of CFBC ash and slag low shrinkage cement.The expansion rate of cement prepared with CFBC ash raises with the curing period,while the 1,3 d expansion rate of cement prepared with CFBC slag increases with the curing period,but 7,28,56 d expansion rate decreases with the curing age due to the lack of gypsum.