​Prevention And Treatment Of Mildew Of Polycarboxylate Superplasticizer

(1) polycarboxylic acid superplasticizers contain a large number of nutrients that bacteria and other microorganisms rely on to survive. The higher the temperature, the easier it is for microorganisms to reproduce, and the faster the consumption of active ingredients in polycarboxylic acid superplasticizers. In the case of no preservatives, the ambient temperature is greater than 25℃ for 7 days, the ambient temperature is about 10℃ for 28 days, and the bacterial content is at the level of 10cfu/ml. At this time, the concrete loss with time is large, and the setting time is short.

(2) The professional preservative or sodium metabisulfite on the market has good sterilization and anti-corrosion effect, and 1‰ is added. After the preservative added water reducer is stored at 9-15℃ for 28 days, the bacterial content is <10cfu/ml, and 5% is added. Sodium pyrosulfite superplasticizer was stored at 9-15℃ for 28 days, and the bacterial content was 10-100cfu/ml. Concrete has normal losses with time and setting time. Therefore, in order to prevent the deterioration of polycarboxylic acid superplasticizer during storage, adding preservatives is an effective method.

(3) According to the anticorrosive attack test of polycarboxylic acid superplasticizer, when the amount of two preservatives added is 2%, the bacterial content during the entire anticorrosive attack test is <10cfu/ml; When the amount of preservative added was 1‰, the number of bacteria of polycarboxylate superplasticizer added with preservative E16 began to increase after 21 days, and the number of bacteria of polycarboxylate superplasticizer added with preservative 02F began to increase after 7 days, indicating that different preservatives had different bactericide and preservative abilities. Therefore, the actual type and amount of added preservatives need to be determined by experiment according to the specific storage conditions and storage time.

Hydroxypropyl Methyl Cellulose HPMC

Redispersible Polymer Powder (RDP JF2)

Calcium Lignosulfonate (CF-4)