What are the requirements for breaking broken pile heads

Broken pile (also known as broken pile head): when pouring the cast-in-place pile, the elevation of the cast-in-place pile top shall be 0
5 ~ 1
0m higher than the planned pile top elevation to ensure the concrete strength of the pile head
However, the pile head part higher than the planned elevation of the pile top must be chiseled during the construction of subsequent processes
The operation of chiseling this part of pile head concrete is called & ldquo; broken pile head & rdquo;

During the construction of pile foundation, in order to ensure the quality of pile head, the elevation of pile top shall generally be higher than the planned elevation, such as cast-in-place pile: when pouring concrete, the sediment at the pile bottom and the impurities precipitated in the mud during the pouring process will form a certain thickness on the concrete surface, which is generally called laitance, so when the concrete solidifies, the over poured part shall be chiseled out, Expose the main reinforcement (reinforcement) above the pile top elevation, and carry out the construction of bearing platform after the pile foundation is tested to be qualified

1、 Requirements for breaking pile head:
1
The pile head can be broken only when the concrete strength of the cast-in-place pile reaches more than 80% of the planned strength
It is prohibited to use scouring instead of breaking, soft breaking and blasting to break the pile head

2
Be careful not to damage the reinforcement during ring cutting, and the bending of reinforcement shall not exceed 15 & deg;
After the pile head is broken, the pile top is slightly convex (the pile center is slightly higher and the periphery is slightly lower)

3
In the process of breaking the pile head, protect the pile head reinforcement and acoustic pipe (when there is an acoustic pipe), and do not bend the pile head reinforcement at will

4
The length of anchorage reinforcement embedded in the bearing platform (or tie beam and pile extension) shall not be less than the minimum anchorage length requirements of planning specifications and rules

5
After the pile head is broken, there shall be no residual loose concrete on the pile top; After surveying and setting out the center of the pile position, snap two ink lines on the broken pile top to clearly mark the pile center and pile number, and keep photos for archiving

The tools for breaking the pile head are mainly divided into manual and mechanical
The mechanical name of the pile head is pile breaking machine, pile cutting machine, etc
, which is many times faster than manual
If the construction period is tight, mechanical breaking is advocated

Pile breaking machine is required for pile breaking
In order to better connect the foundation pile with the above ground concrete structure, the foundation pile will generally extend 1 to 2 meters above the ground to keep the reinforcement intact on the ground
Pile breaking machine is a special equipment for breaking the above ground pile head concrete of the foundation pile

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