Wang Huan, Zhao Weixun, Wang Siqi, Wang Chao, Du Qifei, Yan Yan, Yang Xianke, Lv Sa, Hu Hongliang, Jin Yujie, Kong Lingwei, Wang Ping, Chi Yaodan, Yang Xiaotian
Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China.
Department of Materials Science, Jilin Jianzhu University, Changchun 130118, China.
Materials (Basel). 2023 Dec 5;16(24):7515. doi: 10.3390/ma16247515.
At present, it is known that when there is clay in concrete, polycarboxylates (PCE) will preferably adsorb in the clay, so that PCE cannot be fully combined with cement particles, which reduces the workability of the cement slurry. In this paper, a new type of maltitol-ammonium salt cationic (KN-lm) sacrificial agent (SA) has been successfully developed via a simple method, which makes PCE easier to bond with cement particles in the cement slurry containing clay. The effect of KN-lm on the fluidity of clay-containing cement paste is studied, and the experimental results show that KN-lm, as an efficient SA of cement slurry, makes PCE more compatible with clay-containing cement slurry, and increases the initial fluidity of cement slurry by about 19%. Further investigations of TOC, XRD, and zeta potential measurements reveal that a KN-lm ion is only preferably adsorbed into clay compared to PCE through electrostatic adsorption but without having any crystal structure change, thus resulting in good dispersion of cement particles. The addition of KN-lm plays an important role in hindering the hydration expansion of the clay by preferential electrostatic adsorption, which means PCE cannot easily insert into the interlayer of the clay.
目前已知，当混凝土中存在黏土时，聚羧酸系高效减水剂（PCE）会优先吸附在黏土中，导致PCE无法与水泥颗粒充分结合，从而降低水泥浆的工作性。本文通过一种简单方法成功研制出一种新型麦芽糖醇铵盐阳离子型（KN-lm）牺牲剂（SA），该牺牲剂能使PCE在含黏土的水泥浆中更易与水泥颗粒结合。研究了KN-lm对含黏土水泥浆流动性的影响，实验结果表明，KN-lm作为水泥浆的高效牺牲剂，能使PCE与含黏土水泥浆更具相容性，使水泥浆的初始流动性提高约19%。对总有机碳（TOC）、X射线衍射（XRD）和ζ电位测量的进一步研究表明，与PCE相比，KN-lm离子仅通过静电吸附优先吸附到黏土中，且不会引起任何晶体结构变化，从而使水泥颗粒具有良好的分散性。KN-lm的加入通过优先静电吸附在阻碍黏土水化膨胀方面发挥了重要作用，这意味着PCE不易插入黏土的层间。
