Self-healing concrete pile preventing frost heaving and bonding weakening

Abstract

The invention discloses a self-healing concrete pile preventing frost heaving and bonding weakening. In order to improve the bonding performance between steel bars and concrete, a steel capsule string formed by connecting steel capsules through strip-shaped polypropylene fabrics in series is twined on each steel bar. By adopting the self-healing concrete pile, the tensile strength and shear strength of concrete can be remarkably improved, roughness of the concrete can be greatly enhanced, and accordingly the anti-seismic performance of the concrete is improved. The critical bonding stress between the steel bars and the concrete can be remarkably increased. As polypropylene has good plasticity, roughness and temperature adaptability, the polypropylene can have extremely strong resisting capacity on heaving stripping and degradation between the steel bars and the concrete in the freezing-thawing process. Because the positions and orientations of the steel capsules are distributed randomly in the concrete, the steel capsules can break to conduct repairing and heeling on cracks in all directions. Self-compacting concrete is adopted as the concrete in the pile, and accordingly the steel capsules in the concrete can be prevented from breaking during vibrating.

Description

technical field [0001] The invention belongs to the technical field of anti-freezing and pull-out damage, in particular to a self-healing concrete pile with bond-weakening anti-freeze and pull-out. Background technique [0002] In cold regions, since the expansion deformation caused by freezing of soil is limited by the pile foundation, tangential frost heave force will be generated on the pile foundation surface. As the freezing depth of the seasonal freeze-thaw layer increases, the tangential frost heaving force around the pile will gradually increase. When the pile foundation is buried deep or bottom expansion piles are used, under the action of tangential frost heaving force, the concrete cracks, and the steel bars inside the pile foundation and the concrete produce bond slippage. [0003] At present, the main method is to replace non-frost-heaving materials on the side of the pile, generally using non-frost-heaving coarse-grained materials such as coarse sand, pebbles,...

AI Technical Summary

Problems solved by technology

However, reducing the size of the pile section will reduce the critical bearing capacity of the pile; increasing the diameter of the reinforcement increases the cost, and there may be a situation of over-reinforcement; therefore, this method is not practical

[0006] What is more noteworthy is that none of the above methods consider the large mechanical property difference between concrete and steel bars during the freeze-thaw process, which is manifested in the deterioration of the bond performance between concrete and steel bars during the freeze-thaw process, and even the occurrence of The falling off between the two is an extremely serious potential hazard to the long-term operation of the pile foundation

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