等强度下化学外加剂对混凝土内部相对湿度和徐变的影响

Influences of Chemical Admixtures on Internal Concrete Relative Humidity and Creep Effects Under the Same Strength

以自制的徐变加载装置,探究了萘系减水剂、聚羧酸减水剂及缓凝组分、减缩组分对混凝土基本徐变和干燥徐变的影响规律。结果表明:相比萘系减水剂,聚羧酸减水剂能显著降低混凝土的干燥徐变,对基本徐变的降低效果稍低;复掺缓凝组分的混凝土的干燥徐变明显高于基准组,基本徐变仍比基准组略有提高;复掺减缩组分对混凝土的基本徐变和干燥徐变均有较好的降低效果;预应力加载不会加速内部水分向外界扩散;聚羧酸减水剂和减缩组分通过降低内部水分传输来降低干燥徐变,在密封状态下,也会削弱混凝土内部水分传输的强度,延长其传输时间,同样会较低程度降低基本徐变。

Using homemade creep loading device to research the influence rules ot naphthalene superpiasucmer, polyccuboxylate and retarding component, reduction component working on basic concrete creep and drying creep. The result shows that compared with naphthalene superplasticizer, polycarboxylate can significantly reduce concrete drying creep, while the creep of the basic reducing effect is slightly lower; the concrete dry creep of the retarding component mixed con- crete is obviously higher than the benchmark group and the basic creep is still slightly higher than the reference group the reduction component mixed concrete has good reducing effect on the basic creep and drying creep, especially its effect on the drying creep is more obvious; loading prestressed concrete does not accelerate the diffusion of the internal moisture to the outside; polycarboxylate and the reduction component by reducing the internal moisture transfer to reduce the drying creep,in a sealed state, will weaken the strength of the concrete internal moisture transport, extending its transmission time, it will also reduce the basic creep in lesser degree.