Post Date:14,Oct,2024

(1) Polycarboxylate water reducer contains a large amount of nutrients for the survival of bacteria and other microorganisms. The higher the temperature, the easier it is for microorganisms to reproduce, and the faster the effective ingredients in polycarboxylate water reducer are consumed. In the absence of preservatives, when the ambient temperature is greater than 25℃ and stored for 7 days, and when the ambient temperature is around 10℃ and stored for 28 days, the bacterial content is at the level of 10cfu/ml. At this time, the concrete has a large loss over time and a short setting time.

(2) Professional preservatives or sodium metabisulfite in the market have good bactericidal and antiseptic effects, and 1‰ is added. The bacterial content of the water reducer with preservatives is <10cfu/ml after being stored at 9-15℃ for 28 days, and 5% is added. The bacterial content of the water reducer with sodium metabisulfite is 10-100cfu/ml after being stored at 9-15℃ for 28 days. The concrete has normal loss over time and setting time. Therefore, in order to prevent the polycarboxylate water reducer from spoiling during storage, adding preservatives is an effective method.

(3) According to the antiseptic challenge test of polycarboxylate water reducer, when the addition amount of the two preservatives was 2%, the bacterial content during the entire antiseptic challenge test was <10cfu/ml; when the addition amount of the preservative was 1‰, the bacterial count of the polycarboxylate water reducer with the addition of preservative E16 began to increase after 21 days, and the bacterial count of the polycarboxylate water reducer with the addition of preservative 02F began to increase after 7 days, indicating that the bactericidal and antiseptic abilities of different preservatives are different. Therefore, the actual type and amount of preservatives added need to be determined through experiments based on specific storage conditions and duration.