低引气缓凝型聚羧酸减水剂的性能研究

Study on the performance of low air entraining and set retarding polycarboxylate superplasticizer

经分子设计并合成低引气缓凝型聚羧酸减水剂。试验表明低引气缓凝型聚羧酸减水剂在较小的掺量下,具有较好的分散性,保塑性好,减水率高,有一定的低引气作用,缓凝效果明显,对混凝土抗压强度有较好的影响,并且具有较强的适应性。掺入低引气缓凝型聚羧酸减水剂的水泥试样,水泥水化温度峰有明显的推迟现象,峰值也有明显的降低。扫描电镜可以观察到硬化水泥净浆的孔隙小、孔隙分布比较均匀,表明低引气缓凝型聚羧酸减水剂的分子结构、性能和微观形貌有着紧密的联系。

Through the molecular design theory,the low air entraining and set retarding polycarboxylate superplasticizer was synthetized.The result showed that the low air entraining and set retarding polycarboxylate superplastieize had better dispersity,better maintain plasticity,high wa- ter reducing rate,having good low air entraining effect,obvious set retarding effect,good effect of compressive strength of concrete and strong adaptability in the smaller content of the low air entraining and set retarding polycarboxylate superplasticize.Adding the low air entraining and set retarding polycarboxylate superplasticizer in the cement sample,hydration temperature of cement has obvious delay phenomenon and reduce Through the testing of SEM, the compact relation of molecular structure of the low air entraining and set retarding polycarboxylate superplasticize on its performance and micro morphology of cement.