Suitable For Precast Concrete Experimental Study Of Early-strength Polycarboxylate Water Reducing Agent

Polycarboxylic acid water reducer is the latest generation of concrete admixtures water reducer products,but also in the emerging domestic concrete admixtures in an increasingly important position.Water reducing agent is one of the most important admixtures in concrete.Polycarboxylic acid water reducer has a large market capacity,a high degree of industry segmentation and a higher professional requirement for chemical industry.Compared with traditional inorganic salt early strength polycarboxylic acid superplasticizer,early strength polycarboxylic acid superplasticizer not only has lower dosage and higher water reduction rate,but also has the advantages of good fluidity and slump protection of fresh concrete,green and pollution-free environment.The industrial production of precast concrete components can make use of slag and fly ash in large quantities,so that natural resources can be reused.The early strength of concrete determines the turnover efficiency of the mold,and improving the early strength of precast concrete components can greatly improve the production efficiency.Steam curing,as the most commonly used curing method for precast concrete components,has the disadvantages of harmful gas emission and large energy consumption.The development of early-strength water-reducing agent suitable for low-temperature curing can reduce the curing temperature of concrete and even avoid steaming,which is of great significance for cost saving and environmental protection.Test using ontology polymerization in this paper,the big monomer for lab homemade polyether type monomer HD-5000,polymerization monomer acrylic acid(AA),N,N-dimethyl acrylamide(DMAA),thioglycolic acid(TGA)as chain transfer agent,through high temperature decomposition azo 2 isobutyric acid dimethyl(AIBME)provides free radical polymerization reaction,the preparation of synthetic a super early strength PC-Z type poly carboxylic acid water reducing agent powder.The effects of various factors on the properties of early strength polycarboxylic acid superplasticizer were studied by single factoranalysis.The best synthetic solution was confirmed by orthogonal test.The best synthetic solution was determined as: reaction temperature is 85℃,dosage of chain transfer agent is 0.45% of the large molar ratio of monomer,initiator using secondary feeding,dosage of 0.05% of the large amount of monomer substance.This test type synthesis of the early strength of poly carboxylic acid water reducing agent powder PC-Z type and two kinds of early strength poly carboxylic acid water reducing agent and PC PC-1-2 contrast experiment was carried out,through the water reducing performance,early strength property and temperature sensitivity test contrast,jianshuiji molecular adsorption quantity analysis and USES the HDGM grouting material to test it,determine the type of super early strength poly carboxylic acid water reducing agent powder PC-Z good water reducing performance and temperature adaptability.Through the VCCTL virtual experiment platform of the national institute of standards and technology of the United States,the performance of the polycarboxylic acid superplasticizer synthesized in different cement and different mineral admixtures was simulated and analyzed,and the optimal mixture ratio of mineral admixtures was obtained through the experiment.In order to study the early strength effect of pc-z in the low-temperature curing environment,this test tested the performance of concrete at low temperature.