蒸养条件下两性聚羧酸减水剂对胶砂及混凝土强度的影响

Effect of Amphoteric Polycarboxylate Superplasticizer on Strength of Mortar and Concrete at the Steam Curing

合成了阴离子型和两性型聚羧酸减水剂,研究了两类聚羧酸减水剂对水泥水化热、蒸养胶砂和蒸养混凝土强度的影响。结果表明:在蒸养条件下,与阴离子型聚羧酸减水剂相比,掺两性型聚羧酸减水剂的水泥水化温峰更高;在相同水灰比时,掺两性聚羧酸减水剂的蒸养胶砂和蒸养混凝土的强度也更高。XRD分析可知,掺入两性聚羧酸减水剂在蒸养条件下生成更多的AFm和氢氧化钙,促进了C_3S和C_2S的水化。

The anionic polycarboxylate and amphoteric polycarboxylate superplasticizers were synthesized.And the effect of two types of polycarboxylate superplasticizers on the hydration heat of cement,the strength of cement mortar as well as the concrete under the steaming curing were studied. The results show that under the steam curing,the cement with amphoteric polycarboxylate superplasticizer obtaines the higher peak temperature values than that produced by the cement with anionic polycarboxylate superplasticizer. The cement mortar as well as the concrete under the condition of steam curing have higher early compressive strength when the amphoteric polycarboxylate superplasticizer is mixed under the same water cement ratio. XRD analysis indicates that the early hydration of C3S and C2S were promoted and more monosulphate ettringite and calcium hydroxide are generated under the condition of steam curing when the amphoteric polycarboxylate superplasticizer is added in the mortar and concrete.