The precautions of polycarboxylic acid water reducing agent mainly include the following six points:1. There is a problem with the adaptability of cement. For some cements, the water reduction rate is low and the slump is large. Therefore, when the cement adaptability is not good, the concrete trial
As a new generation of water reducing agent, polycarboxylic acid water reducing agent is widely used in concrete engineering, but there are still some problems in the process of use that are difficult and difficult to solve. Therefore, some matters should be brought to our attention during use.
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%.
Polycarboxylate superplasticizer can produce ideal water reduction and reinforcement effect when the dosage is low, less influence on concrete setting time, better slump retention, and adaptability to cement/mixture It is relatively good, has little influence on the shrinkage of concrete (refers to usually does not excessively increase dry shrinkage), does not use formaldehyde in the production process and does not discharge waste liquid, low content of sulfonate and chloride ion, etc. A new generation of water reducing agent after melamine, aliphatic and sulfamate water reducing agents. The polycarboxylic acid-based water reducing agent has a high water-reducing rate, excellent moisture retention performance, and good adaptability to cement, but its application range is limited due to its high price. By compounding, the price of the water reducing agent can be reduced, and some aspects of its performance, such as early strength, retardation, deflation, and defoaming, can be enhanced.