辅助胶凝材料（SCM）的协同效应对砼收缩开裂的影响

采用改进的椭圆环收缩开裂试验、自由收缩及强度试验,综合评价辅助胶凝材料双掺和三掺对混凝土收缩开裂的影响。试验结果表明,粉煤灰、矿渣和硅粉三掺,表现出互相紧密填充的物理效应和水化进程互补的化学效应,具有很好的协同效应,使胶砂初始开裂时间明显延长,混凝土自由收缩减小,早期收缩开裂性能显著改善,抗压强度达到最高。

Influence of Synergetic Effect of SCM on Cracking due to Shrinkage of Concrete

The effect of multiple adding of suplementary cementing materials (SCM) on shrinkage cracking of concrete was studied by means of modified ellipse ring shrinkage cracking test, non-restrained shrinkage, flexural strength. The results show that ternary addition of FA, GGBFS and SF exhibit physical action of compactive filling and chemical faction of suplementary hydration process. Ternary sample has good Synergetic effect. Initial cracking time of mortar increases markedly and non-restrained shrinkage of concrete decreases apparently. Properties of initial cracking due to shrinkage are obviously improved. Compressive strength of concrete achieves the maximum.