With the rapid development of economy and science and technology, the pace of development of construction industry is accelerating, and the requirement of concrete for construction projects is becoming higher and higher. Accordingly, the existing technology of concrete admixture products has been difficult to meet the current situation. As the third generation product of water reducing agent, polycarboxylic acid water reducing agent has been favored by all kinds of engineering because of its low content, high water reducing rate and strong molecular designability. At present, it has become one of the ideal additives for preparing new generation concrete. However, polycarboxylic water reducer products also have some limitations, especially its high sensitivity limits its wide application. The results show that temperature, sulfate concentration and other environmental conditions will affect the adsorption of Polycarboxylic Water reducer, resulting in high sensitivity in its application. In order to obtain Polycarboxylic Water Reducer with good performance and low sensitivity, many scholars have studied its synthesis technology and considered that silane modified polycarboxylic water reducer is ideal.
In this paper, the mechanism and properties of silane modified polycarboxylic water reducer are briefly introduced, which can be used as a reference for the development and application of Polycarboxylic Water reducer.


At present, the main explanation about the mechanism of polycarboxylic water reducer is that Polycarboxylic Water Reducer adsorbs to the surface of cement particles through carboxyl and sulfonic groups in the main chain, and then disperses through steric hindrance effect and electrostatic repulsion. It is generally believed that the adsorption of these groups on the surface of cement particles is achieved by anionic electrostatic adsorption and bridging with Ca2+ ions, which belongs to physical adsorption [3]. Compared with chemical adsorption, physical adsorption is more susceptible to various factors, which leads to the reduction of adsorption capacity. As far as polycarboxylic water reducer is concerned, when the concentration of sulfate in solution is too high, sulfate ion will compete with carboxyl group and other anions in the main chain of Polycarboxylic Water reducer, which reduces the amount of Polycarboxylic Water Reducer adsorbed on the surface of cement particles [4]. In addition, higher ambient temperature will also lead to desorption of Polycarboxylic Water Reducer and reduce the dispersibility of Polycarboxylic Water reducer.
All these indicate that polycarboxylic water reducer is very sensitive in practical application, and its application effect is affected by many factors.