掺加聚羧酸减水剂的混凝土微观结构表征

Microstructure characterization of concrete with polycarboxylate superplasticizer

通过扫描电镜和压汞试验，表征和分析了聚羧酸减水剂对混凝土硬化水泥浆体、界面结构和水泥石孔结构的影响。结果表明，早龄期的混凝土硬化水泥浆体和界面结构裂纹较宽，裂缝较多，龄期长，结构较密实；相同龄期掺有聚羧酸减水剂的混凝土硬化水泥浆体和界面过渡区结构裂缝数量和裂纹宽度均小于萘系减水剂；掺有聚羧酸减水剂少害孔和无害孔含量多，而有害孔和多害孔含量少。聚羧酸减水剂对混凝土结构优于萘系减水剂。

The effects of polycarboxylate superplasticizer on hardened cement paste structure,interface structure and pore structure of concrete were analyzed by scanning electron microscopy and mercury test.The results showed that the early age hardened cement paste structure and interface structures of concrete become wider and more cracks and accordingly become more dense to longer age hardened cement paste and interface structure of coocrete.For the same age of hardened cement paste and interface structure of concrete,polycarboxylate superplasticizer showed clearly narrower and less cracks than that of naphthalene superplasticizer. Polycarboxylate superplasticizer greatly had higher content of less harmful and harmless hole and reduced the Probability of forming harmful hole.It was concluded that polycarboxylate superplasticizer is much superior to naphthalene superplasticizer.