【摘要】 系统研究了聚羧酸减水剂(PC)对陶瓷模具石膏工作性能、强度、吸水及耐溶蚀性能的影响,并采用电导率、水化温升、SEM形貌分析及BET孔结构测试方法进行机理研究.结果表明:陶瓷模具石膏减水率(质量分数)随PC掺量(质量分数)增加而逐渐增加,掺0.30%PC时,陶瓷模具石膏减水率高达18.7%;陶瓷模具石膏浆体流动度经时损失明显降低,有效工作时间延长4min,凝结时间稍有延缓;PC对提高陶瓷模具石膏强度及耐溶蚀效果显著,掺0.30%PC时,其抗折、抗压强度分别为4.38,15.9MPa,增幅高达22%,57%,溶蚀率(质量分数)由-0.93%降至-0.15%,降幅达16.1%;掺入PC可降低陶瓷模具石膏的吸水性能;PC在石膏颗粒表面的吸附可延缓石膏的水化进程,使二水石膏晶体细化,长径比增加,晶体搭接密实度提高,可降低硬化体孔隙率、细化孔径,有效提高石膏抵抗浆体电解侵蚀破坏的能力.更多还原

【Abstract】 The effects of polycarboxylate-type water reducer(PC)on working performance,strength,water absorption and corrosion rate of model-gypsum were presented.The mechanism was analyzed by measurement of electric conductivity,the temperature rise of hydration,SEM and BET.The result shows that PC content of 0.30%(by mass)had a high reduction rate of 18.7%(by mass)to improve the workability of gypsum which made the working time extended for 4min and the setting time lengthened slightly.The strength and corrosion properties of gypsum were significantly increased.Flexural strength and compressive strength were improved by 22% and 57% at 0.30% of PC content,and the corrosion rate decreased from-0.93%to-0.15%.Water absorption rate decreased with the increase of PC content.The mechanisms show that the adsorption on the surface of gypsum is the base for PC to the function.The hydration process of gypsum delayed to some extent.The dimension of dehydrate crystal is fined.The amount of pore in gypsum is lessened and the sizes become smaller.The corrosion was remarkably diminished.更多还原