补偿收缩复合胶凝材料的水化与膨胀性能

研究了补偿收缩复合胶凝材料的膨胀性能以及水化过程、水化产物及微观结构等.结果表明:硫铝酸钙-氧化钙类膨胀剂早期膨胀量大、膨胀速度快,更适用于配制高强度等级的补偿收缩混凝土;用水量充足时,该类膨胀剂与水泥在水化早期相互促进,用水量不足时,两者的水化转变为相互抑制;膨胀剂的水化速度快于水泥,在低水胶比情况下也能生成大量膨胀性产物钙矾石,产生理想的膨胀量;在膨胀剂掺量一定的情况下,膨胀剂膨胀效能的发挥与材料内部微观结构的致密程度密切相关.

Hydration and Expansion Properties of Shrinkage Compensating Composite Cementitious Materials

Hydration and expansion properties of shrinkage compensating composite cementitious materials were studied. The results show that sulfoaluminate as calcium expansive agent will result in a larger expansion and a greater expansion speed in early ages, so it is more suitable for the preparation of high strength shrinkage compensating concrete. During the hydration process, when the water is sufficient, expansive agent and cement promote the hydration in early ages. While the water is in shortage, promotion changes to restraint. The effect of expansive agent for the hydration process is greater than the cement, so it grabbed the water firstly. In the case of the low water cement ratio, expansive agent will also generate many ettringite and produce appropriate expansion. When the content of expansive agent is fixed, the eff ectiveness of expansion performance is closely related to the microstructure of hardened binder pastes.