Expansive concrete caisson pile and manufacturing method thereof, and concrete expanding agent

Abstract

The invention provides an expansive concrete caisson pile and a manufacturing method thereof, and a concrete expanding agent, and belongs to the technical field of engineering materials and construction of concrete pile foundation. The method comprises the following steps of: alternatively pouring common concrete and expansive concrete into a caisson pile hole sequentially so as to form bamboo joint type I-shaped pile; and pouring slurry at the pile end of the I-shaped pile or the expansive concrete pile so as to form a II-shaped pile or a III-shaped pile. The expanding agent is manufactured by pulverizing 40 to 80 percent of limestone and 20 to 60 percent of gypsum, calcining the powder in a rotary kiln at the high temperature of 1,300 to 1,500 DEG C, and pulverizing 20 to 80 weight percent of the calcined substance and 20 to 80 weight percent of calcium sulfoaluminate cement or alunite or calcium aluminate cement or a mixture of the calcium sulfoaluminate cement, the alunite and the calcium aluminate cement until the specific surface area is 150 to 400 square meters per kilogram. By the method, the manufacturing cost of the expansive concrete caisson pile can be reduced obviously; and compared with the common expansive concrete caisson pile, the expansive concrete caisson pile has the advantage of obviously increasing the bearing capacity of a single caisson pile.

Description

technical field [0001] The invention belongs to the technical field of concrete pile foundation engineering materials and construction, and relates to concrete pouring piles, concrete expansion agents and their manufacturing methods and applications. Background technique [0002] Concrete pouring pile is a structural measure often used in industrial and civil construction and foundation construction to improve the bearing capacity of the foundation. It is widely used in high-rise buildings, bridges and some areas with poor ground endurance. Adopting technical measures to improve the bearing capacity of a single pile is an important research content in the technical field of cast-in-situ piles. There have been many achievements in this regard, such as expanding the pile head (drilling the bottom), expanding the pile body (support plate) , Pile tip (side) post grouting technology, etc. These technologies can improve the bearing capacity of single piles of cast-in-place piles,...

AI Technical Summary

Problems solved by technology

[0009] Due to the large volume of cast-in-situ piles, the concrete in the pile holes is closer to the condition of moisture-absolute curing. The expansion cement or expansion agent used in the above-mentioned disclosed technology belongs to the ettringite type expansion agent. When the amount of such expansion agent is large, It will significantly reduce the strength of concrete, and the expansion rate is small when the dosage is small, and its expansion effect will be further reduced under the condition of absolute humidity, so the actual expansion is low, so the increase in the bearing capacity of the single pile of cast-in-place piles is small

In addition, these technologies all use expansive concrete for the pile body, and the addition of a large amount of expansion agent will also increase the cost of cast-in-place piles. This is also a factor that restricts the promotion of expansive concrete cast-in-place pile technology, so it is necessary to improve the above technologies

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