Views: 8 Author: su Publish Time: 2018-12-14 Origin: Site
In the past 40 years, the application of water reducing agent in concrete has been rapidly developed. Polycarboxylate water reducing agent has become an indispensable component for the preparation of high performance concrete as a new generation of water reducing agent. However, the problem of poor adaptability of polycarboxylate water reducer (PCE) to cement has been a technical problem for cement manufacturers, concrete construction units and admixture manufacturers. Grinding is the most energy-consuming part of the cement production process. Improving the mechanical structure of the grinding and adding grinding aids during the grinding process are effective measures to reduce energy consumption and improve grinding efficiency. With the implementation of the energy conservation and emission reduction strategy, the proportion of grinding aids used in China's cement grinding process has exceeded 50%.
Although the use of grinding aids greatly reduces the grinding energy consumption of the cement industry, it seriously affects the adaptability between cement and various admixtures. Triethanolamine is an important component of commonly used grinding aids in the industry. Domestic and foreign scholars have done a lot of research on triethanolamine and polycarboxylate water reducers, but most of the work focuses on the efficiency of triethanolamine (TEA) on cement grinding. Increased and early strength enhancement effects, while investing less in the adaptation of triethanolamine (TEA) to admixtures during application.
There is a big difference in particle dispersibility, fineness and particle size distribution between the cement and the ungrinded grinding aid. These differences will affect the cement hydration process and the cement to reduce water. The adsorption characteristics of the agent molecules have a certain influence on the adaptability of the cement and the water reducing agent. The fluidity of the cement paste and the change of the fluidity over time are indicative of the adaptability of the cement to the polycarboxylate superplasticizer (PCE). One of the important indicators, the degree of fluidity is related to the particle size distribution of cement particles, particle morphology and surface characteristics, particle surface area, cement hydration characteristics and molecular adsorption and dispersion of water reducer, and the addition of grinding aids makes The interaction of the above factors becomes more complicated.