Compounding Technology Of Polycarboxylate Superplasticizer And The Application In Engineering

Polycarboxylate Superplasticizer is the third generation high performance water reducing admixture which follows Lignin sulfonate water reducing admixture and Naphthalene water reducing admixture, In recent years, it begins to be widely used for concrete engineering. The development process period of Polycarboxylate Superplasticizer is short, after Twenty-first Century, accompanied by the emergence and development of high performance concrete, people put forward higher requirements for concrete admixtures, Polycarboxylate Superplasticizer entered a rapid development period, People began to concern and study effects of the compound technology of Polycarboxylate Superplasticizer on the properties of concrete, at present, Polycarboxylate Superplasticizer is still in continuously perfect development. Polycarboxylate Superplasticizer has a lot of advantages, such as high water reducing rate, excellent slump retaining performance, air entraining is controllable, without retarding seriously, High economic benefit, but many problems also appeared in the Polycarboxylate Superplasticizer engineering applications,such as, the adaptability of Water reducing admixture and cement is bad, it is also sensitive to mud content on the sand and stone aggregate, the workability of fresh concrete is bad, they are challenges to thelarge scale engineering application of polycarboxylate superplasticizer.This paper mainly used the method of improving the technique of Polycarboxylate Superplasticizer compounding,the purpose is to overcome the shortcomings of Polycarboxylate Superplasticizer,in order to plays a more important role in the engineering application of concrete.Improvement of Polycarboxylate Superplasticizer compound technology which is mainly determined by three components:(1)The adaptability of the mother liquor of Polycarboxylate Superplasticizer is based on the control variate method,through the observation of the workability of the fresh concrete(The new-built Baolan passenger dedicated line BLTJ-7 C40 pumping concrete), namely the initial slump and the slump retaining, the mother liquor NO.8 25 g and NO.7 23 g of Shandong are suitable(per 100 g PCA);(2)The determination of retarder is based on the comparative experiments, The time of initial setting and final setting are tested by concrete penetration resistance instrument, the Sodium gluconate is suitable;(3)The method of air entraining is the elimination of gas before air elimination, the Defoaming agent and Air entraining agent are Evonik Degussa, while the Defoaming agent and Air entraining agent are 0.1 g and 0.15 g(per 100 g PCA) finally Air content of concrete is 3.6%。This paper,for the application problems of Polycarboxylate Superplasticizer in the practical engineering which new-built Baolan passenger dedicated line,some niche targeting attempt has been completed.In the summer, adding Guangdong Hualixin preservative to the Polycarboxylate Superplasticizer in case that goes bad and smelly.For the problem of poor cohesiveness of fresh concrete with the reason of bad aggregate, by appropriately increasing the water reducing rate, Mixing thickener agent HPMC with PAC, high workability concrete is reazliable, Improving the compounding technique of Polycarboxylate Superplasticizer can fatherly expand itsengineering adaptability.