Material Design and Quality Control System of Materials for Fluidity of Concrete

为了发展自密实混凝土、高强混凝土和高强度混凝土，有必要用梳型高效减水剂控制混凝土的流动性。研究了梳型高效减水剂的接枝链长和用量对吸附分散机理的影响，以及它们对浓缩石灰石悬浮液流动性的影响。此外，还观察到了影响CaCO_3悬浮液中Ca~(2+)和Gt~(2+)浓度的某些可溶盐的加入，降低了梳状聚合物在CaCO_3上的吸附。因此，某些类型的离子可以选择性地影响聚合物在固体表面的吸附过程。在C3A-CaSO4体系中加入梳状高效减水剂可加速C3A的早期水化。对于梳状高效减水剂，C_3A周围形成的凝胶中SO_4~(2-)含量减少。为了控制梳状高效减水剂水泥的流动性，必须控制铝酸盐相的早期水化反应。

For the development of self compacting concrete, high strength concrete and high duarable concrete, it is necessary to control the fluidity of concrete with comb-type superplasticizers. This study discusses the influence of graft chain length and dosage of comb-type superplasticizers on adsorption and dispersion mechanisms, and their subsequent effect on the fluidity of concentrated limestone suspensions. Furthermore, the addition of certain soluble salts, which can effect the concentration of Ca^<2+> in liquid phase of CaCO_3 suspensions, has been observed to decrease the adsorption of comb-type polymers on CaCO_3. Thus, the polymer adsorption process on solid surfaces can be selectively influenced by certain types of ions. Early hydration of C_3A is accelerated by adding of comb-type superplasticizers in C_3A-calcium sulfates systems. In the case of comb-type superplasticizers, SO_4^<2-> contents in gel formed around C_3A is decreased. It is necessary to control the early hydration reaction of aluminate phase in order to control the fluidity of the cement with comb-type superplasticizers.