聚醚型减缩剂延缓水泥水化的机理分析  

Mechanism Analysis of Polyether Shrinkage Reducing Admixture(SRA)Delaying Cement Hydration

作　　者：黄正峰 欧忠文 罗伟 王飞 王廷福 HUANG Zhengfeng;OU Zhongwen;LUO Wei;WANG Fei;WANG Tingfu(Army Logistics Academy of PLA,Chongqing 401311,China)

机构地区：[1]中国人民解放军陆军勤务学院,重庆401311

出　　处：《材料导报》2024年第10期70-74,共5页Materials Reports

基　　金：军队后勤科研计划项目(BLJ17J008);军委后保部科研项目(CLJ19J020);国家自然科学基金(11702324)。

摘　　要：减缩剂在抑制混凝土收缩上的应用十分广泛,但对水泥水化进程会产生阻碍,探究产生这种负面影响的原因具有一定的现实意义。聚醚型减缩剂是目前应用极为广泛的一类减缩剂,以此类减缩剂作为研究对象,通过测试水泥的水化热和水化程度、液体的表面张力、砂浆的抗压强度和凝结时间、浆体孔隙溶液中的离子浓度、硫酸盐的最大溶解度和溶解速度,探讨了聚醚型减缩剂延缓水泥水化进程的机理。结果表明:加入减缩剂会显著降低砂浆前期的力学性能和水泥的水化程度,但随着龄期的延长这种负面影响会逐渐减弱;减缩剂还会延长砂浆的凝结时间,降低水泥的水化热,孔隙溶液中氢氧根浓度和硫酸盐的最大溶解度、溶解速度降低是导致这一现象的原因;含有减缩剂的孔隙溶液、去离子水溶液的表面张力与减缩剂浓度呈双线性关系,拐点之后减缩剂浓度的增加对表面张力无明显作用;延迟掺入减缩剂可以降低其对水泥水化的不利影响,减少砂浆强度降幅。Shrinkage reducing admixture is widely used to restrain the shrinkage of concrete,but it will hinder the hydration process of cement.It is of practical significance to explore the source of this negative effect.Polyether type shrinkage reducing admixture is the most widely used shrinkage reducing admixture at present.Taking this kind of shrinkage reducing admixture as the research object.By testing the hydration heat and hydration degree of cement,the surface tension of liquid,the compressive strength and setting time of mortar,the ion concentration in paste pore solution,the maximum solubility and dissolution rate of sulfate,the interaction mechanism between shrinkage reducing admixture and cement was discussed.The results show that the addition of shrinkage reducing admixture can significantly reduce the mechanical properties of mortar and the hydration degree of cement,but the negative effect will gradually decrease with the increase of age,and the setting time of mortar and the hydration heat of cement will also be reduced by adding shrinkage reducing admixture.The decrease of hydroxyl radical concentration,maximum solubility and dissolution rate of sulfate in pore solution is the reason for this phenomenon.There is a bilinear relationship between the surface tension of pore solution and deionized aqueous solution containing shrinkage reducing admixture and the concentration of shrinkage reducing admixture.After the inflection point,the increase of the concentration of shrinkage reducing admixture has no obvious effect on the surface tension,and the delayed addition of shrinkage reducing admixture alleviates its adverse effect on cement hydration and reduces the decrease of mortar strength.

关 键 词：减缩剂 抗压强度 水化程度 水化热 离子浓度 表面张力 机理分析 

分 类 号：TU528.01[建筑科学—建筑技术科学]