减水剂对水泥净浆早期自收缩性能的影响

Influence of Water Reducer Admixture on Early Autogenous Shrinkage of Cement Paste

以水泥净浆为研究对象,研究了萘磺酸盐系、聚羧酸盐系和氨基磺酸盐系3种高效减水剂对混凝土早期自收缩性能的影响。研究发现,减水剂对水泥石的毛细孔细化作用、缓凝作用以及抑制水化作用使其早期自收缩增大。此外,水泥的水化初期,水泥石的自收缩随着减水剂掺量的增加而降低;而随着水化的不断进行,其自收缩随着减水剂掺量的增加而增大。

The influence of three type water reducer admixtures on autogenous shrinkage of cement paste was researched. The results indicated that water reducer admixture can refine the cement paste＇s capillary pores, slow setting and retard hydration, which increases the early autogenous shrinkage of cement paste. Further more, the autogenous shrinkage of cement paste decreases along with dosage increase of water reducer admixture at the early stage of hydration, but increased along with dosage increases later.