循环流化床固硫灰渣低收缩水泥的制备及性能

Preparation and Performance of CFBC Ash and Slag Low Shrinkage Cement

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。

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.