一种聚羧酸高性能缓凝减水剂的制备与性能测试

Preparation for a Kind of High Performance Retarding Polycarboxylate Water Reducer and Performance Testing

以顺丁烯二酸酐(MA),α-甲基丙烯酸(MAA),烯丙基聚氧乙烯醚-1000(APEG-1000)为单体,过硫酸铵(NH4S2O8)为引发剂,合成一种聚羧酸高性能缓凝减水剂。通过红外光谱对减水剂分子共聚反应进行表征,扫描电镜观察水化物微观结构,X射线衍射观察对水化物的影响,进行水泥净浆性能测定。结果表明,在水灰比0.29,减水剂掺量为水泥质量0.3%的情况下,水泥净浆流动度达到340mm,减水率达到30.4%,具有较强的缓凝效果,初凝和终凝时间达到483min和1320min。硬化水泥浆体抗压强度得到提高,与空白样对比,7d和28d抗压强度比达到了121.6%、138.2%。

A novel retarding high performance polycarboxylate water reducer is synthesized with maleic anhydride （MA）, mathacrylic acid （MAA） and allyl alcohol polyoxyethylene-1000 （APEG-1000） initiated by ammonium persulfate. Fourier transform infrared spectroscopy is used to indicate grafting process, SEM is used to observe microstructure of the hydration of cement, XRD is used to observe the influence of the hydration of cement, and the influence of polycarboxylic superplasticizer on the performance of cement paste is investigated. The results show that when the superplasticizer dosage is 0.3% of cement mass, together with 0.29 of water cement ratio, the fluidity of cement paste can reach 340mm, the water-reducing rate is 30.4%, the retarding effect is distinct, and its initial setting time is 483 min and its final setting time is 1320 rain. The compressive strength of hardened cement paste is improved, and the compressive strength ratios of 7d and 28d are 121.6% and 138.2% compared with blank samples.