复配缓凝剂提升低掺量聚羧酸减水剂水泥净浆塑化效果研究

Improve the plasticizing effect of cement paste with low content of polycarboxylate superplasticizer by retarder compound

研究了柠檬酸钠为主的复合缓凝体系对净浆辅助塑化的改进作用。结果表明:低掺量减水剂情况下,缓凝剂复掺对浆体辅助塑化的改进效果与复合组分有关,其中酒石酸或柠檬酸复合柠檬酸钠对浆体辅助塑化效果最好,酒石酸钾钠或三聚磷酸钠次之,六偏磷酸钠无效。凝结时间测试结果表明,缓凝剂复合延缓浆体凝结,但是延缓程度取决于参与柠檬酸钠复配所用缓凝剂的缓凝效果及用量;与辅助塑化提升效果相比,复配对凝结时间的影响相对较小。

In this paper, the effect of retarder compounded with sodium citrate on improving auxiliary plasticizing was studied. The results showed that in the case of low content of polycarboxylate superplasticizer,the effect of the addition of retarder compounded with sodium citrate on auxiliary plasticizing of paste is related to the composite components. Among them,the retarder of tartaric acid/citric acid compounded with sodium citrate has the best auxiliary plasticizing effect on paste,followed by potassium sodium tartrate/sedium tripolyphosphate compounded with sodium citrate,sodium hexametaphosphate invalid. The test results of setting time show that the compounded retarder delays the setting time of paste. However, the retardation degree depends on the retarding effect and the content of retarder used to compound with sodium citrate. Compared with the promotion effect of auxiliary plasticization effect,retarders compound has a relatively small influence on the setting time of paste.