Beijing Dongke United Technologies Co.,Ltd.

Polycarboxylate Superplasticizer

Concrete additives

The first generation of superplasticizers

naphthalene-based superplasticizers and melamine resin-based superplasticizers were developed in the early 1960s. Because of their performance compared to ordinary water-reducing agents, they were developed in the late 1930s. Lignosulfonate is a representative-it has a significant improvement, so it is also called a superplasticizer. The second-generation superplasticizer is sulfamate, although it is after the third-generation superplasticizer—polycarboxylic acid in chronological order. The graft copolymer with both sulfonic acid group and carboxylic acid group is the most important of the third-generation superplasticizers, and the performance is also the most excellent high-performance superplasticizer.

The water reduction rate of the superplasticizer can reach more than 20%.

Mainly naphthalene series, melamine series and water reducers made from them, of which naphthalene series are the main ones, accounting for 67%. Especially in my country, most of the superplasticizers are naphthalene series superplasticizers with naphthalene as the main raw material. Naphthalene-based superplasticizers can be divided into high-concentration products (Na2SO4 content <3%), medium-concentration products (Na2SO4 content 3%-10%) and low-concentration products (Na2SO4 Content>10%). Most naphthalene-based superplasticizer synthesis plants have the ability to control the content of Na2SO4 below 3%, and some advanced companies can even control it below 0.4%.

The superplasticizer has a strong dispersing effect on the cement, which can greatly improve the fluidity of the cement mixture and the slump of the concrete, and at the same time greatly reduce the water consumption and significantly improve the workability of the concrete. However, some superplasticizers will accelerate the loss of concrete slump, and excessive mixing will cause bleeding. The superplasticizer basically does not change the setting time of concrete. When the amount is large (overdose incorporation), it has a slight retardation effect, but it does not delay the growth of the early strength of hardened concrete.

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