Does the floor slab need to be reinforced before opening, and does it have an impact on the cast in

Hello, I come to your question, a situation like this is very common in the renovation of modern building structures, and the reinforcement treatment is also very simple:

The first step, unloading:

When dismantling the floor slab, in order to ensure safety, the live load on the floor slab is first unloaded;

The second step is to cut the floor slab

Use professional demolition and cutting tools (wall saws, rhinestone cutting machines, etc.) to cut along the edge of the beam and the red line of the floor slab, pay attention to the cutting of the floor slab must be cut in blocks, so that the manual can be moved or use the inverted chain and other hoisting tools to put down the divided floor plate safely, cut the floor slab along the red line direction to the left side of the red line less than 40cm, the 40cm concrete should be broken and removed with electric tools to retain the remaining 40cm of the original floor steel bar, and bend 90 degrees at 20cm of the steel bar;

The third step is to add a beam:

There is no floor slab red line direction to add a 250cm 220cm cast-in-place concrete beam, the upper and lower iron of the beam each 4 secondary national standard thread No. 16 steel bar, the new beam reinforcement to be implanted (i.e., planting reinforcement method) of the original beam 15d (that is, 15 deep (note: the contact part between the new beam and the original beam must be chiseled, the original beam plastering layer and the steel bar protective layer are removed), the beam stirrups are arranged with a national standard round steel bar No. 8 steel bar spacing of 15cm, and the two ends of the beam 1 3 are stirrups with a spacing of 10cm. Then insert the bent 40cm original floor reinforcement into the new beam to support the formwork;

The fourth step, pouring the concrete beam:

Rinse the contact parts of the new and old concrete with clean water and brush a layer of interface agent, and pour concrete after the interface agent is dry, pay attention to the later concrete curing and maintain sufficient moisture;

Concrete curing for 10-15 days, remove the formwork to make stairs.

It depends on how big it is, generally within 200mm can be used, and no matter how big it is, it has to be reinforced.

There is a possibility that the 200 will also break the rebar.

Look at the size of the hole. The small opening is about 500x500, which will not affect the stability of the floor structure. If it is large, it may need to be reinforced, such as an escalator, and the opening part is large and needs to be treated.

Reinforced concrete structures are structures made of concrete equipped with reinforcement of steel bars. The main load-bearing elements are built with reinforced concrete. It includes thin shell structures, cast-in-situ structures of large formwork, and reinforced concrete structures constructed using sliding formwork, rising plates, etc.

A structure made of steel and concrete.

The steel bar is subjected to tensile force, and the concrete is subjected to pressure. It has the advantages of being strong, durable, good fire performance, saving steel and low cost than steel structure. It is made of reinforced concrete elements that are pre-made in a factory or construction site and assembled on site.

The thickness of the reinforced plate is taken according to the value of 1 40 of the short span of the plate, and generally takes four sizes or three sizes. As far as possible, secondary steel including secondary steel with a diameter of 10 (less supplied at present), and a stressed steel bar with a diameter of 12, except for the hook, shall not use primary steel. The steel bar should have a large diameter and large spacing, but the spacing should not be greater than 200, and the spacing should be 200 as much as possible.

Generally, the cracks of the plate with a span of less than meters can meet the requirements). The upper part of the slab with a span of less than 2 meters does not have to be disconnected, and the steel bar can not be drawn, only indicating that the steel bar is a two-way double row 8@200. The spacing between the upper and lower steel bars of the plate should be equal, and the diameters can be different, but the diameter types of steel bars should not be too much.

Avoid the opening of the main reinforcement, which does not affect the structure, but do not use chiseling, use a drilling machine to punch holes!

Hello five-story building, I want to make a staircase on the second floor to dig a hole, mainly a floor house, can you open a hole.

Excuse me, will the toilet toilet diversion and opening 110 pipe holes affect the floor? Thank you for the expert advice!

If the hole is large, it belongs to the plane irregularity, and to this extent, it should not be possible to assume the rigidity in the plane, and the influence of the local deformation of the floor slab needs to be considered, and the result of the satwe calculation feels that it cannot be used directly.

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When the long side of the rectangular opening is greater than 1000 and the diameter of the circular opening is greater than 1000, the beam is generally set around the opening.

For the sake of prudence (because it is difficult to say the quality of the current project), some design institutes have an internal control of 800.

But it is not absolute, individual projects, need to open a larger hole, and can not set up beams, need to do special treatment, as long as the safety can be ensured, it is also feasible.

Your second layer is to do it according to the interlayer, and the plate thickness is 150 double-layer two-way reinforcement. In fact, it is one basement and two floors above ground.

I feel that the stiffness and displacement may not be enough, so let's add anti-sideshift members!

If you can make a beam on the edge of the board, it will strengthen the integrity.

Summary. First, how big is the opening of the floor slab needs to be reinforced, if the size of the opening has exceeded 30 30 cm, such a hole needs to be reinforced. If the construction standards are followed, reinforcement measures must generally be carried out.

Some may be built in private construction for the purpose of building houses, and the size is 50 50 or more, and reinforcement is required. Generally speaking, the floor opening is to be able to install the staircase, and the size is basically more than 20 20 cm, in fact, the opening size reaches such a large area, it is still relatively large, so it is necessary to take reinforcement measures. When it comes to specific reinforcement, you need to ask a professional reinforcement company to conduct an investigation according to the situation on the site and then carry out reinforcement.

How big is the opening of the floor slab that needs to be reinforced, and which one of these specifications.

1. How big is the opening of the floor slab that needs to be reinforcedIf the size of the hole has exceeded 30 30 cm, such a hole needs to be reinforced. If the construction standard is followed, reinforcement measures must generally be carried out. Some may be built in private construction for the purpose of building houses, and the size is 50 50 or more, and reinforcement is required.

Generally speaking, the floor opening is to be able to install the stairs, and the size is basically more than 20 20 cm, in fact, the size of the opening reaches such a large area, or it is relatively large, so it is necessary to take reinforcement measures. When it comes to specific reinforcement, you need to ask a professional reinforcement company to conduct an investigation according to the situation on the site and then carry out reinforcement.

2. Why should the letter oak be reinforced1. Some floor openings are not only for the installation of stairs, but also because of the renovation of the entire house. Because it is different in size and type, some pipes, air ducts or sliding pipe wells need to be installed in order to install equipment.

2. In this case, it will bring certain safety hazards, because once the hole is opened, the differential source grinding will lead to the reduction of the strength of the entire floor slab, which will affect the seismic effect of the house. In case of **, the floor slab will be greatly cracked and damaged, which will have a great destructive force on the equipment, facilities and personnel of the house. 3. What kind of reinforcement scheme should be adopted, according to the size of the opening, but also to choose appropriate reinforcement technology and excellent materials, in order to ensure the safety of the structure.

2. Do you need qualifications for reinforcement and renovation projects 1. In this industry, qualifications are very important, and relevant qualifications must be obtained to ensure that the quality of the reinforcement is guaranteed. First of all, you need to have been in this industry for more than 10 years, have relevant staff, and have to obtain a senior title. 2. Each single item engaged in reinforcement projects cannot be less than 300,000 yuan, and there must be relevant structural engineers, as well as the registered capital of the enterprise must also meet the standard.

In real production and life, it often involves the reinforcement and transformation of the structure, so that it is inevitable to open holes in the floor slab. After the floor slab is opened, the original force transmission path and reinforcement are partially cut off, on the one hand, the internal force of the surrounding slab of the hole is increased, which will cause stress concentration, on the other hand, the plate reinforcement is reduced, the bearing capacity is reduced, and effective reinforcement needs to be carried out according to the actual situation.

When the width of the hole b 300mm or the diameter of the hole d perpendicular to the stress direction of the plate is 300mm, and the number of cutting steel bars is 5%, it can not be treated. When B 1000mm or D 1000mm, the number of steel bars cut is 20%, and the force influence on the plate after the opening is small, and only according to the structure of reinforcement, the compensation reinforcement method can be used to lift the steel bar (ASFY) cut in the plate and be installed at the edge of the hole. In order to facilitate construction, generally use adhesive steel or carbon fiber cloth as the rear compensation rib, and its total amount should be.

When the above situation is exceeded, it is necessary to adopt a suitable steel side beam or cast-in-place concrete side beam for reinforcement method through design calculation.

Reinforced with bonded steel. When the opening position is located in the negative moment area of the plate, the adhesive steel should be reinforced on both sides when the adhesive steel is used as the compensation reinforcement. For the reinforcement method of pasting steel plates, it is advisable to paste on the outermost layer in the direction of greater force (the meaning is the last paste), and the steel plate and steel plate in the direction of less force should be pasted on the inner layer (pasted first).

At this time, the first bonded steel plate should be slotted rough at the concrete veneer, and the thickness of the slotted steel plate is +3mm, so as to ensure that the first bonded steel plate surface is flush with the floor floor. It can also be pasted flush in both directions, but the steel plate in the direction of less stress needs to be cut into three sections, welded on site, and locally poured with adhesive.

Relevant requirements a, the steel plate selection specifications should be 100mm wide 200mm, thickness 3mm The opening is small, and the structural reinforcement can be used to use this reinforcement method. c. The area of the compensating steel plate shall not be less than the times of the equivalent cross-sectional area of the truncated steel bar.

Carbon fiber reinforcement.

When the opening position is located in the negative moment area of the plate, when the adhesive carbon cloth is used to reinforce, double-sided reinforcement should also be carried out, and the sequence of vertical and horizontal fiber cloth pasting can not be restricted.

Relevant requirements a, the carbon cloth selection specifications are 200mm wide 300mm, the mass is 200g The opening is small, and the structure can be strengthened before this reinforcement method can be used. c. The maximum tensile value of the compensating carbon cloth shall not be less than the multiple of the equivalent tensile value of the truncated steel bar. d. When the carbon cloth is in contact with the steel plate, a layer of adhesive should be applied, and no direct contact should be made.

Floor slab is one of the building materials in construction projects, and it has strong compressive resistance. How to reinforce the floor opening? In this article, I mainly introduce to you the specific construction steps and construction precautions for the opening and reinforcement of the floor slab.

One. The construction steps of the floor slab opening and reinforcement.

The first step, unloading:

When dismantling the floor slab, in order to ensure safety, the live load on the floor slab is first removed;

The second step is to cut the floor slab

Use professional demolition and cutting tools (wall saws, rhinestone cutting machines, etc.) to cut along the edge of the beam and the red line of the floor slab, pay attention to the cutting of the floor slab must be cut in blocks, so that the manual can be moved or use the inverted chain and other hoisting tools to put down the divided floor plate safely, cut the floor slab along the red line direction to the left side of the red line less than 40cm, the 40cm concrete should be broken and removed with electric tools to retain the remaining 40cm of the original floor steel bar, and bend 90 degrees at 20cm of the steel bar;

The third step is to add a beam:

There is no floor slab red line direction to add a 250cm 220cm cast-in-place concrete beam, the upper and lower iron of the beam each 4 secondary national standard thread No. 16 steel bar, the new beam reinforcement to be implanted (i.e., planting reinforcement method) of the original beam 15d (that is, 15 deep (note: the contact part between the new beam and the original beam must be chiseled, the original beam plastering layer and the steel bar protective layer are removed), the beam stirrups are arranged with a national standard round steel bar No. 8 steel bar spacing of 15cm, and the two ends of the beam 1 3 are stirrups with a spacing of 10cm. Then insert the bent 40cm original floor reinforcement into the new beam to support the template; The fourth step, pouring the concrete beam:

Rinse the contact parts of the new and old concrete with clean water and brush a layer of interface agent, and pour concrete after the interface agent is dry, pay attention to the later concrete curing and maintain sufficient moisture;

Concrete curing for 10-15 days, remove the template and make stairs.

2. Precautions for floor slab opening and reinforcement.

1. When carrying out the reinforcement of the floor slab, first of all, the operation of the floor opening can not have a problem, if you are not right when the floor opening operation, there is a problem, then the subsequent reinforcement operation will be adversely affected, you will feel very troubled in the process of reinforcement, and the reinforcement work may not be carried out smoothly. Therefore, when carrying out the reinforcement operation of floor slab opening, first of all, there must be no problem in the process of floor slab opening.

2. When you reinforce the floor slab, your reinforcement technology should arrive at home, and this so-called technology should mean that you need to pay full attention to the operation or process and precautions when you reinforce, and only in this way can you ensure that you will not be affected by adverse factors when you reinforce, and the final reinforcement effect can have the best guarantee.

3. If you are not professional when the floor slab is reinforced, it is best to ask professional construction personnel to help, they usually have more rich technical experience for these.