水泥粉体流动行为及其与不同材质库壁粘附性研究

Research on Flowability of Cement Powder and Its Adhesion with Different Wall Materials

水泥粉体流动性与其储存、输送、给料、混合等操作密切相关。通过休止角、内摩擦角、粘聚力和无侧限抗压强度测试方法,研究了含水率对水泥粉体流动性的影响,对比了水泥粉体与砂浆、钢、涂料、防腐卷材四种壁面材料的壁摩擦角和附着力。结果表明:随着水泥粉体含水率增加,休止角、粘聚力和无侧限抗压强度增加,水泥粉体流动性变差。松散堆积水泥粉体随着放置时间增加,由于水泥水化引起颗粒尺寸增加造成流动性变好。固结应力增加,无侧限抗压强度明显增大,导致水泥粉体流动性变差。水泥粉体在不同壁面材料的粘聚力均随着含水率的增加而增大,在水泥库内表面涂覆涂料和防腐卷材均可以起到降低水泥粉体与壁面的摩擦力和附着力的作用。

The flowability of cement powders is closely related to the storage,transportation,feeding,mixing and other operations.The effect of moisture content on the flowability of cement powders was investigated by the repose angle,inner friction angle,adhesion and unconfined compressive strength.The wall friction angle and adhesion of cement powder with mortar,steel,coating and anticorrosive coiled material were compared.The results show that as the moisture content of cement powder increases,the repose angle,cohesion and unconfined compressive strength increase,and the flowability of cement powder decreases.With the increase of storage time,the flowability of cement powder becomes better with the increase in particle size caused by the hydration of cement.The unconfined compressive strength increases obviously with the increase in consolidation stress,resulting in the poor flowability of cement powder.The adhesion of cement powder on different wall materials increases with the increase of moisture content.The friction force and adhesion between cement powder and wall reduce by covering the inner surface of cement silo with coating or anticorrosive coiled material.