Background technology

Adopt normal concrete directly to be cast under water, owing to be subjected to the effect of current scour, cement slurry seriously separates with gathering materials in the concrete mix, grout can be broken up loss by current, not only cement slurry is few in the pour mass, and water/glue ratio increase greatly, concrete structure homogeneity extreme difference, intensity and weather resistance seriously descend.Adopt normal concrete to carry out pollution that underwater pouring causes near water environment and the destruction of organism in water is difficult to the imagination.

For many years, in order to improve quality with normal concrete cast underwater structures, engineering unit also adopted multiple special construction method, constructed as adopting cofferdam drainage, folded bag method, pre-packed method or service tools such as employing conduit, bottom opening container, but facts have proved, adopt these traditional constructional methods, the shortcoming that exists is still a lot, and not only quantities is big, and careless slightly, accident resulting from poor quality of projects is difficult to avoid, and the example of failure is also more.

Since former West Germany in 1974 carried out the anti-concrete development research of dispersion first under water and is applied to actual engineering, many countries all actively dropped into the research of this respect, have obtained successful effect.But, take a broad view of over and resist the research and the application achievements of disperseing the concrete aspect under water, because the anti-dispersant that adopts and the anti-under water limitation of disperseing concrete performance of preparing, the anti-under water concrete strength grade generally lower (C30 is following) that disperses of pouring into a mould disperses concrete erosion resistance, frost resistance, anti-Cl to resisting under water ^-The research of weather resistance aspects such as perviousness is also less, and more and more incompatible actual engineering is to the anti-new demand that disperses concrete at aspects such as mechanical property and weather resistance under water.In addition, traditional anti-dispersant volume is big, and the cost height has also limited the use of actual engineering.

In relevant patent, also have by plain class of simple adding of fiber or the concrete report of the anti-under water dispersion of polypropylene-base tackifier (water-holding agent) material preparation, but the concrete land and water strength ratio of being prepared has only 65%-70% (7 days) and 70%-75% (28 days), and concrete slump-loss is bigger, is not suitable for remote transportation and pumping construction.