Matters needing attention in the use of polycarboxylate superplasticizer

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New Earth Group


Matters needing attention in the use of polycarboxylate superplasticizer

    Polycarboxylate superplasticizerFor the aggregate mud content is particularly sensitive, mud content is too large to reduce the performance of polycarboxylic acid pumping agent (soil will absorb part of the pumping agent, resulting in polycarboxylic acid pumping agent water reduction rate decreased significantly). Therefore, the use of polycarboxylic acid pumping agent should strictly control the quality of aggregate. When the mud content of aggregate increases, the dosage of polycarboxylic acid pumping agent should be increased. During the apparent inspection of incoming sand and gravel, carefully observe whether there is any obvious difference in mud content. When there is obvious difference, sample and test shall be taken immediately. If the mud content exceeds 1% of the mud content of the sand and gravel imported before, the newly pulled sand and gravel must be stored separately and used after adjusting the mixing ratio. Otherwise, the factory slump of concrete will be large and sometimes small, and sometimes the concrete mixture arriving at the construction site will collapse too fast. Sometimes there will be serious segregation of concrete, even causing blockage of the pump pipe; Cause great trouble to the demander.
Polycarboxylic acid pumping agent can not be mixed with naphthalene water reducing agent, the use of polycarboxylic acid pumping agent must be used naphthalene water reducing agent mixer and mixer clean, otherwise it may lead to polycarboxylic acid pumping agent reduce water reducing effect, and significantly reduce the strength of concrete. Polycarboxylic acid pumping agent and other series of pumping agent adaptability should be determined by test.
Polycarboxylic acid pumping agent should avoid long-term contact with iron materials. Due to the polycarboxylic acid pumping agent products are often acidic, long-term contact with iron products will occur slow reaction, and even make its color dark, black, resulting in product performance decline. It is recommended to use polyethylene plastic drums or stainless steel drums for storage to ensure its performance stability.
For concrete above C45, high-efficiency special polycarboxylic acid pumping agent should be prepared. If you also use a common type of polycarboxylic acid pumping agent, it will lead to concrete mixture too sticky, not easy to pump. During the mix proportion test for C50 and above concrete, the backflow time of the mixture in the slump cone can be increased (I. e., place the slump cone on the iron plate with its large mouth upward, fill it with concrete, tap and scrape it, and start the stopwatch when lifting the slump cone); The backflow time should not be more than 20 seconds. Otherwise, the phenomenon of pumping difficulties will occur.

Key words:

Polycarboxylate superplasticizer