木质素、聚羧酸及其复配型和共聚型减水剂性能比较研究

将共聚型木质素-聚羧酸系高效减水剂、未聚合木质素磺酸钙的聚羧酸系高效减水剂、木质素磺酸钙和复配型木质素-聚羧酸系高效减水剂的性能进行比较,探讨了四种不同减水剂对水泥水化的影响。结果表明:共聚型木质素磺酸钙-聚羧酸系高效减水剂可以使木钙中含有使水泥净浆产生闪凝现象的杂质得以减少或消除,使聚羧酸系高效减水剂的保水性提高,且成本远低于聚羧酸系高效减水剂。复配型木质素磺酸钙-聚羧酸系高效减水剂随掺量增加,水泥净浆强度下降,产生负面叠加效果,共聚型木质素磺酸钙-聚羧酸系高效减水剂随掺量增加,水泥净浆强度提高,改善了木钙造成水泥净浆强度降低的缺陷。共聚型的木质素磺酸钙-聚羧酸系高效减水剂相对于复配型对硅酸三钙水化有一定的促进作用。

Comparison Research on Properties of Lignin,Polycarboxlate Superplasticizer,Compound and Copolymer Lignin-polycarboxylate Superplastczer

The properties of copolymer lignin-polycarboxylate superplasticizer,polycarboxylate superplasticizer,calcium lingosulphonate and compound lignin-polycarboxylate superplasticizer are compared.The influences of four kinds of water reducers on hydration of cement are discussed.The results show that the copolymer lignin-polycarboxylate superplasticizer could reduce or eliminate the impurities of calcium lignosulphonate which will cause the cement paste flash condensate.The water retention of polycarboxylate superplasticizer is improved,and the cost of copolymer lignin-polycarboxylate superplasticizer is far less than polycarboxylate superplasticizer.With the dosage of compound lignin-polycarboxylate superplasticizer increasing,the compressive strength of net cement slurry is decreased,and moreover,the negative superimposed effects will carry out.With the dosage of copolymer lignin-polycarboxylate superplasticizer increasing,the compressive strength of net cement slurry is increased,and the defects of calcium lignosulphonate that cause the compressive strength of net cement slurry reduced is improved.Compared to compound lignin-polycarboxylate superplasticizer,the copolymer lignin-polycarboxylate superplasticizer can promote the hydration of C3S.