超塑化剂掺量对混凝土力学性能及耐久性的影响

在砼中，当超塑化剂掺量超过１．１％（相应砼坍落度大于２００ｍｍ）时，砼１ｄ、２８ｄ和９１ｄ的抗压强度和抗弯强度降低１５％～５０％，且空气渗透性提高。但含硅粉的砼的性能，不受超塑化剂掺量的影响。１．１％可能是水泥——超塑化剂掺量的饱和浓度。

EFFECT OF SUPERPLASTICIZER DOSAGE ON MECHANICAL PROPERTIES AND PERMEABILITY OF CONCRETE

When the dosage of superplasticizer in concrete exceeds 11% of cementitious by mass(concrete slump 200mm),the compressive strength(1d,28d and 91d)and flexural strength(28d) of concrete can be reduced by 15% to 50%,and the air permeability is increased. But the properties of concrete contained silica fume aren't effected by the dosage of superplasticizer.May be the dosage 11% of cementitious is the saturation concentration of the cement-superplasticizer mixture dosage.