How to arrange the reinforcement of the raft when it meets the cushion cap, and how to arrange the r

For the arrangement of raft reinforcement, for the lower reinforcement, if it is a two-way plate, generally which reinforcement is below and which is below, is not particularly restricted. For one-way plates, the stressed ribs are at the bottom and the attached ribs are at the top. For the upper layer of reinforcement, it is the opposite of the lower layer.

It should be noted that the thickness of the protective layer, the overlap of the reinforcement and the anchoring of the end reinforcement.

Supplement: raft foundation, also known as slab foundation, full hall foundation. It is an independent foundation under the column.

Or a strip foundation.

All of them are connected with contact beams, and the bottom plate is poured as a whole below. It is composed of a base plate, beams, etc. as a whole. The building load is larger, the bearing capacity of the foundation is weak, the concrete bottom plate is often used, the building load is beared, the raft foundation is formed, its integrity is good, and the uneven settlement of the foundation can be well resisted.

Raft foundations. It is divided into flat raft base and beam plate raft base, and the flat raft base supports local thickened raft type; The beam-plate raft base supports two forms: upper flat and lower flat rib beam. Generally speaking, when the bearing capacity of the foundation is uneven or the foundation is weak, a raft type foundation is used. Flat raft foundation due to the simplicity of construction in high-rise buildings.

has been widely used.

Each has its own use, the raft meets the side cushion cap and the cushion cap reinforcement is a double-layer raft bottom reinforcement and the surface reinforcement should still be full,

To be full, the raft has the steel bars of the raft slabs, and the bearing caps are in the steel bars of the cushion caps, so it is reasonable to be full.

The elevation of the cushion cap is usually lower than the elevation bottom of the cushion cap, and the place where the cushion cap and the cushion plate are handed over, the steel bars of the cushion cap are all covered regardless of the surface reinforcement or the bottom reinforcement, because they have their own force transmission system, and it is also the place where the force is concentrated, and the reinforcement reinforcement is indispensable, and if necessary, individual nodes also have reinforcement encryption requirements. The country has a basket atlas, so stay tuned! I hope you're happy with this answer, thank you!

The top surface of the foundation floor is in the upper layer, and the long reinforcement is in the lower layer; The short-facing reinforcement on the bottom surface of the foundation slab is in the lower layer, and the long-facing reinforcement is in the upper layer; It is easy to remember, and it is remembered that the raft-shaped foundation plate reinforcement is "short reinforcement clamping long reinforcement", like a sandwich cake, the long one is in the middle, and the short one is on both sides.

The reinforcement of the raft foundation is usually double-layer two-way reinforcement, and for the epithelial reinforcement, the long reinforcement is generally the bottom reinforcement, and the short reinforcement is the surface reinforcement; The lower steel bar is the opposite, with the long bar on top and the short bar on the bottom. Double-layered two-way reinforcement crosses and vertically places bottom gluten and gluten.

The spacing of the reinforcement of the raft foundation should not be less than 150mm, it should be 200 300mm, and the diameter of the stressed steel bar should not be less than 12mm. Two-way reinforcement mesh pieces are arranged on the top and bottom surfaces of the slab.

When the thickness of the raft is greater than 2m, it is advisable to set up a structural steel mesh parallel to the plate surface at a distance of no more than 1m along the thickness of the plate, and its diameter should not be less than 12mm, and the spacing in the vertical and horizontal directions should not be greater than 200mm.

For beam-plate raft foundations, the longitudinal reinforcement of the wall column should be inserted into the raft plate through the foundation beam, and should meet the requirements of anchorage length from the beam epithelium.

1. Analysis of the temperature crack mechanism of raft foundation concrete.

a) Temperature shrinkage due to exothermic cement hydration.

Cement hydration and exothermic is the main cause of cracks in the bulk concrete of raft foundations. A large amount of heat will be generated when cement is hydrated, and the section of large-volume concrete structures is generally thicker, and the heat is not easy to dissipate heat inside the structure, and the concrete will produce a large volume expansion due to heating. In the subsequent cooling phase, the volume of the concrete gradually shrinks as its temperature decreases.

In this case, the raft is constrained by the foundation or other structural objects, which creates a large temperature shrinkage stress inside the concrete raft. Once the temperature shrinkage stress in the concrete raft exceeds the tensile stress strength of the concrete at that age, cracks will be generated in the concrete that run through the entire cross-section, which will seriously reduce the impermeability, integrity, durability and other properties of the structure, bringing serious consequences. In addition, the raft foundation concrete will also be high because of the slow internal heat dissipation, and the surface part of the heat dissipation is fast and the temperature is low, so that the shrinkage value difference between the concrete inside and the surface is too large, and the surface tensile stress is excessive, so that the concrete surface cracks are produced.

2) The impact of changes in the outside temperature.

The higher the outside temperature, the higher the pouring temperature of the concrete, and the outside temperature drops, and increases the cooling range of the concrete, especially the sudden drop in temperature, which will greatly increase the temperature gradient between the outer layer of concrete and the internal concrete, which is extremely unfavorable to the large volume of concrete of the raft foundation.

The temperature inside the concrete is the adiabatic temperature of the heat of hydration, the pouring temperature and the heat dissipation and cooling of the structure lead to the superposition of various temperatures, and the temperature stress is caused by the temperature deformation caused by the temperature difference. The greater the temperature difference, the greater the temperature stress. At the same time, under high temperature conditions, large-volume concrete is not easy to dissipate heat, in this case, it is more important to study reasonable temperature control measures to prevent temperature stress caused by the temperature difference between the inside and outside of concrete.

To fully understand the arrangement of the raft foundation reinforcement, it is best to familiarize yourself with the national standard atlas. There are more detailed illustrations and requirements in it.

Generally speaking, the arrangement of the raft reinforcement and the floor reinforcement is just the opposite, it should be the long reinforcement below, the short reinforcement on the top, the floor slab is the short reinforcement at the bottom, and the long reinforcement at the top, (you think from the perspective of force, it should be easy to figure it out, right?) In your case, you should first look at whether your x-direction is long or short, and depending on this.

I'm not quite sure if your illustrated box is the entire raft, if yes, then here it should be 25 bars underneath.

Summary. Kiss! Hello, happy to answer your <>

How to arrange the additional reinforcement of the pro-raft foundation is as follows: There are 4 kinds of additional reinforcement of the raft:

First, the stool bar, after the lower raft reinforcement is completed, in order to control the spacing between the lower reinforcement and the upper reinforcement, a stool-shaped additional reinforcement is arranged, which is usually laid at intervals of 5m in the horizontal and longitudinal directions; Second, the side additional reinforcement, the spacing between the upper and lower layers of the raft is greater than 30cm, it is necessary to set up the side additional reinforcement, usually using 14 rebar; 3. Additional reinforcement at the yin corner, usually 12 20 steel bars are set up at the position of the upper and lower steel bars with the yin corner, with a length of 3m; Fourth, the yang angle additional reinforcement, usually the upper and lower layers of steel bars with the yang angle position each set 10 22 steel bars, length 3m, I hope mine can help you <>

Do you have any other questions?

How to arrange the additional reinforcement of the raft foundation.

Kiss! Hello, happy to answer your <>

How to arrange the additional reinforcement of the pro-raft foundation is as follows: There are 4 kinds of additional reinforcement of the raft:

First, the stool bar, after the lower raft reinforcement is completed, in order to control the spacing between the lower reinforcement and the upper reinforcement, a stool-shaped additional reinforcement is arranged, which is usually laid at intervals of 5m in the horizontal and longitudinal directions; Second, the side additional reinforcement, the spacing between the upper and lower layers of the raft is greater than 30cm, it is necessary to set up the side additional reinforcement, usually using 14 rebar; 3. Additional reinforcement at the yin corner, usually 12 20 steel bars are set up at the position of the upper and lower steel bars with the yin corner, with a length of 3m; Fourth, the yang angle additional reinforcement, usually the upper and lower layers of steel bars with the yang angle position each set 10 22 steel bars, length 3m, I hope mine can help you <>

Do you have any other questions?

I'm talking about the additional reinforcement at the bottom of the slab.

How to arrange the additional reinforcement at the bottom of the pro-plate is as follows: it is usually attached to the position where the force is more concentrated, such as the corner and the production place, and it will be separated from the main reinforcement, and the spacing between the two main reinforcements needs to be ensured to be 200 mm. Placed in the second row, the side should be the main reinforcement.

Summary. Hello, the cap foundation raft gluten should be placed below the foundation beam cap or the last reinforcement of the cap beam. The foundation plate reinforcement is mainly considered to be the foundation (soil layer) return under the upper load, so the construction should be disposed of in the opposite direction with the placement direction and joint position of the upper reinforcement, and there is no relevant normative basis, but it should belong to the mature experience of the construction agreement.

FYI. The teacher knows whether the reinforcement of the cushion cap foundation raft surface is placed above or below the cushion cap gluten, is there a normative basis, you Yu You's trembling, the cushion cap foundation raft reinforcement should be placed below the foundation beam cushion cap or the last reinforcement of the cushion cap beam. The foundation plate reinforcement is mainly to consider the foundation (soil layer) return force under the upper load, so the placement direction and joint position of the vertical core and the upper reinforcement should be disposed of in opposite directions during construction, and there is no relevant normative basis, but it should belong to the mature experience of the construction agreement. FYI.

Thank you. Hello, how should the raft gluten and cushion table gluten be placed, and whether the raft gluten should be placed under the cushion table gluten.

The raft gluten should be placed below the last reinforcement of the foundation beam, cap and cap beam.

Question 1: What is the relationship between the cushion cap and the raft foundation The felling foundation is also called the felling foundation, which is crisscrossed by many beams, and then the bottom plate is tied with steel bars on the beam, and the foundation is a whole formed by the cushion cap, beam and bottom plate after pouring concrete. The cap foundation is to directly seedling the column reinforcement in the independent cap for the upper main body felling, or to connect the caps with beams (foundation beams), but there is no bottom plate.

Question 2: Is there a cushion platform for the raft foundation? Yes, there will be a cushion cap if there is a pile under the raft.

Question 3: What is the difference between the pile cap and the raft foundation The pile cap bears the upper load, and the cap mainly bears the punching stress. The raft foundation is mainly based on the raft to bear the upper load, or to bear the bending and shear load.

Problem 4: I don't understand the structure of the foundation (raft foundation + cushion cap)! 50 points Between the floor of the first floor and the raft foundation is a reinforced concrete shear wall, and the third picture is.

Question 5: Can the basement floor floor with pile foundation cushion cap also be used as a raft foundation? Yes, the name doesn't have to be so strict.

In fact, the difference between the water-resistant plate and the raft plate is the thickness, the raft is directly used as a construction to carry the upper load, so it is thicker than the water-resistant plate. But if there is a cap on the bottom plate, there will generally be walls or columns on the cap. At this time, the cap is used as the construction of the main bearing upper load.

The bottom plate is generally called a water-resistant plate.

Question 6: What is the foundation of the pile cap with raft plate Pile foundation [can be]].

Question 7: Which is more cost-effective pile foundation or raft foundation is not simple and can be compared. If the foundation bearing layer that can be used for raft is not buried deeply, it must be suitable for raft foundation, and the construction is convenient; The construction period is very short; Basement waterproofing and reliable; There is no need for pile foundation testing, and the quality is intuitive.

It is definitely that the raft foundation has much better overall benefits. The pile foundation is suitable for sites where the hard bearing layer is buried deeply.

Question 9: Is the foundation in the figure below a raft foundation, and why should the column cap be dug separately? This is called a pier under the column.

Question 10: The raft foundation refers to the layer of steel bars placed under the cap and cap beams. The general situation is like this, the construction of the raft foundation is on top of the steel bar of the foundation class, that is, the general floor slab is reversed. Unless there is a specific design description.