In the daily construction process of acceptance, we often encounter the problem of super-thick steel protective layer, the thickness is not good. Here are some methods to deal with the problem of super-thick steel protective layer, hoping to be useful to us.
Super Thickness of Reinforcement Protective Layer
I. Reasons for Over Thickness of Reinforcement Protective Layer
In the process of concrete pouring and vibration, construction workers trampled down the floor gluten and did not straighten it and recover, which resulted in the protection layer of the floor steel bar (negative moment steel bar) exceeding the standard allowable deviation.
II. Processing Methods
1. Firstly, the scaffolding support frame is set up at the bottom of the floor, and then the floor slab is picked out and chiseled, and the floor concrete is picked and chiseled manually. In order to avoid disturbing the original reinforcement and concrete, small hammers and chips should be used for chiseling construction instead of heavy hammers.
2. When removing slab concrete, the construction organization of removing the slab concrete is two people. The depth of removing is less than 30mm, so it can't be more removing. First, along the wall and the center of the beam, the two ends of the slab concrete can be gouged to ensure the safety of the structure and reduce the influence of the construction on the surrounding structure.
3. Remove the original reinforcement of the concrete slab without disturbance, and place the reinforcement on the slab from scratch. The reinforcement is the same as the negative moment reinforcement equipment of the planned slab.
4. The new bonded steel bars in the upper layer and the reinforced concrete in the base layer are tied with the 6 @ 600 bonded steel bars (planted steel bars).
5. After picking and chipping, we should ensure the integrity of reinforcing bars on the original slab surface. If there are twists and turns, they should be straightened out.
6. After the concrete is cleaned up, the next working procedure shall be carried out after the supervision and inspection meets the requirements.
7. After finishing and removing the concrete, use ink bucket to bounce the orientation and distance line of the quasi-planted reinforcement on the slab surface. The specification distance of the square planted reinforcement with walls and columns is the same as the negative bending moment reinforcement planned by the original floor panel. The square reinforcement without walls and columns (negative bending moment reinforcement) is anchored and tied according to the standard length. Colligation.
8. According to the elastic distance line, the long-direction steel bar (negative bending moment bar at the base) is planted first, and the short-direction steel bar (negative bending moment bar at the top) is replaced. The steel bar is bound at the beginning after the glue is solidified.
III. Quality Requirements
1. Main control project:
(1) The specifications, shapes, sizes, quantities, anchorage lengths and joints of reinforcing bars must conform to the planning requirements and construction standard rules.
(2) It is necessary for the steel bar to have a certificate of qualification and a statement of re-examination, and the re-examination is qualified.
2. General items:
(1) The binding of reinforcing bars requires full binding and no missing buckles are allowed.
(2) The direction of the hook is correct. The binding joints shall conform to the rules of construction standards, and the lap length shall not be less than the planning requirements and standard rules.