A special defoamer for phc pipe pile concrete

Abstract

The invention relates to a defoaming agent special for PHC pipe pile concrete. The defoaming agent is characterized by being prepared from, by mass, 20%-26% of amide phosphate, 10%-16% of polysiloxane, 5%-8% of polyether, 2%-12% of an emulsifying agent, 4%-14% of modified nano-silicon dioxide and 42%-59% of water. The defoaming agent is prepared by mixing the raw materials according to the mass percent and then stirring the raw materials for 1 h to 5 h at the temperature of 50 DEG C to 65 DEG C. According to the defoaming agent, the stability is high, the inhibition time is long, bubbles with the diameter larger than 30 nm in the PHC pipe pile concrete with the strength grade of C60 or above can be quickly eliminated, therefore, micro bubbles can be uniformly distributed, the gas content of the concrete is effectively decreased, the pipe pile concrete is smooth in surface after being subjected to centrifugal shaping, and the mechanical property and the durability of the concrete are improved.

Description

technical field [0001] The invention relates to the application field of concrete admixtures, in particular to a special defoamer for PHC pipe pile concrete. Background technique [0002] Due to the water reducing agent and other admixtures often mixed in the concrete proportioning, the cement material itself, etc., it is easy to generate air bubbles during the mixing and pouring process, and the liquid film of the air bubbles in the concrete slurry adheres to a large number of solid particles such as cement. Finally, the air bubbles change from the original liquid film to a liquid-solid composite film, the liquid film becomes thicker, the elasticity is enhanced, and it can exist stably in the concrete. By vibrating the concrete, some air bubbles can be directly discharged, but some air bubbles move, and the gas in the small air bubbles squeezes into the large air bubbles. After repeated interactions, many large-scale air bubbles can be formed. In concrete, air bubbles large...

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Problems solved by technology

[0003] CN 103691163A discloses an environmentally friendly defoamer, which is prepared by using polyether modified siloxane, emulsifier, and nano-silica as a carrier, but the nano-silica has not been modified, the specific surface area is limited, and the dispersed The effect is low, it is difficult to quickly eliminate the air bubbles in the concrete

CN 105293990 A discloses a self-emulsifying concrete defoamer and a preparation method thereof, which consists of low-hydrogen-containing siloxane or siloxane derivatives, glycosyl-containing acrylate compounds or derivatives thereof through addition reaction It is prepared and has self-emulsifying properties. It can eliminate large bubbles with a diameter greater than 50nm in concrete when used in concrete. However, toluene is used as a solvent in the preparation process, which is harmful.

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