Reseach And Preparation Of Slow-Release Polycarboxylic Acid Based Superplasticizer

The requriment of the superplasticizer applied in construction increases with the development of construction industry, new superplasticizers was studied to meet various construction requirements and application characteristics. The slow-release polycarboxylic acid based superplasticizer offers a slow release of it's dispersion actions to achieve the effect that the flowability of the concretee increases gradually. It can both prevent the bleeding of the fresh concrete, ensure the operating property and avoid the evaporation of the mixing water caused by transport in hot weather. So the concrete may have a good workability, mechanics performance and durability. Therefore, the slow-release polycarboxylic acid based superplasticizer is a new type product that applys to special construction requirement.The study preparaed a basic polycarboxylic acid based superplasticizer reaction system with good dispersion and flowability retain properties first. Through the study and experiments on the protection and releasing mechanisms for carboxylic acid ions, it selected dimethyl itaonate as the releasing component, And then optimized the system to get the objective slow-release polycarboxylic acid based superplasticizer.The study characterized the structure and performance by adopting the method of inftared spectrum, total organic carbon adsorpt and laser multi-angle scattering etc.. The test results make the adsorption process clear, and analysised relationship between the molecular weight, molecular weight distribution of the objective slow-release superplasticizers.The test for different cement adaptability, saturated content and concrete slump and mechanical property show the addition, workability and mechanical strength. The objective slow-release superplasticizers perform good slow-release function in application.