1 What measures can be taken when the deflection calculation of reinforced concrete beams and slabs

ImproveConcrete marking, increasing the height of the beam, selecting steel bars with small diameters and increasing the amount of steel bars can reduce the crack width. The selection of steel bars with small diameters or the increase in column cross-section can solve the width reduction of beam supportsThickness of the protective layer

Deflection. It is the linear displacement of the member axis perpendicular to the axis direction or the linear displacement of the middle surface of the plate and shell in the direction perpendicular to the midsurface when the force or non-uniform temperature changes.

The deflection of an elongated object, such as a beam or column, is the amount of displacement within the normal plane of the axis at each point on its axis when it is deformed. Thin plates or shells.

The deflection of is the mid-face normal at each point on the midface.

The amount of displacement on . The law of the deflection of each point on an object as a function of position and time is called the deflection function or displacement function. Calculating strain and stress by finding the deflection function is a research method in solid mechanics.

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Detection method

Traditionally, bridge deflection measurements are mostly measured using dial gauges.

or direct measurement by displacement meter, which is still widely used in bridge maintenance, safety assessment of old bridges or acceptance of new bridges in China. The advantage of this method is that the equipment is simple, multi-point detection can be carried out, and the deflection value of each measurement point can be directly obtained, and the measurement results are stable and reliable.

However, there are many shortcomings in the direct measurement method, which needs to pull the steel wire or set up a frame at each measurement point, so the direct measurement cannot be carried out when there is water under the bridge; For cross-line bridges, this method is also not available due to the influence of railway or road traffic restrictions.

High bridges crossing canyons, etc., cannot be measured by direct methods; In addition, the direct method of deflection measurement is more complicated and time-consuming, whether it is to lay out or cancel the instrument.

The above content refers to Encyclopedia - Deflection.

Reinforcement procurement. Construction projects should use qualified steel bars in strict accordance with the design requirements. At present, there are various steel brands on the market, and they are far from the same, if the construction unit does not specify the brand, the construction unit can purchase the steel bars of the large steel mill in accordance with the design requirements and understand the local steel channels, which can ensure the quality of raw materials.

Rebar approaches. When the raw materials of steel bars enter the site, the construction and supervision (construction) unit must carry out a re-inspection. All quality checks should be carried out on the steel bars first, and the steel bars entering the site should be straight and without damage, and there should be no cracks, oil stains, granular or flake rust on the surface; The surface mark (rolled trademark), signage, batch number, factory quality certificate, etc. of the product shall be consistent with the purchase contract (plan), and the supervision (construction) unit shall be jointly accepted and the acceptance record shall be formed.

Rebar substitution. When the construction site is affected by the supply of goods, design defects, local reinforcement binding or concrete pouring difficulties and needs to replace the reinforcement, the construction unit shall be confirmed by the design unit and handle the relevant design change documents.

Rebar rust removal. The surface of the steel bar used in the component should be clean to ensure that there is a good grip between the steel bar 1 and the concrete.

When the deflection check of reinforced concrete beam and slab is not satisfied, the cross-section height is increased.

The fire resistance limit of reinforced concrete components is related to the fire resistance level of the building and the minimum size of the component cross-section.

When the calculated deflection of the beam is greater than the deflection specified in the code, what measures can be taken to reduce the deflection.

When the calculated deflection of the beam is greater than the deflection specified in the code, the measures to reduce the deflection are as follows: 1. Increase the bending stiffness (increase the height of the cross-section, the most effective) 2. Arch, which can reduce the deflection and be more beautiful. 3. Reduce the load.

The use load cannot be reduced, but the dead load can be reduced. Such as hollow floor slabs, hollow beams, lightweight walls and other methods. 4. Construction prestress, prestressing first gives the structure a reverse deflection.

After reloading, the deflection is naturally smaller.

Summary. <>

Hello, dear, very happy with your question, when the calculated deflection of the beam is greater than the deflection specified in the specification, what measures can be taken to help you find out, when the calculated deflection of the beam is greater than the deflection specified in the specification, what measures can be taken: 1 If possible, the beam plus the column plate and the beam to reduce the span. 2.

Reinforcement is increased, but the effect is not obvious. 3.Using the pre-arching construction method, the deflection can be calculated according to the deduction of the arching value.

This method is more commonly used. If the deflection of the cantilever plate exceeds the limit, the secondary beam can be arranged in the plate to reduce the span of the plate. Hope mine can help you.

Wishing you good health and a happy mood!

What can be done when the calculated deflection of the beam is greater than the deflection specified in the code.

Hello, dear, very happy with your question, when the beam of the deflection is greater than the deflection specified in the specification, what measures can be taken to help you find out, when the calculated deflection of the beam is greater than the deflection specified in the specification, what measures can be taken: 1 If possible, the beam plus the column plate and the beam, the span is lowered. 2.

Reinforcement is increased, but the effect is not obvious. 3.Using the pre-arching construction method, the deflection can be calculated according to the deduction of the arching value.

This method is more commonly used. The deflection of the cantilever plate exceeds the excavation impulse limit, and the secondary beam can be arranged in the plate to reduce the span of the plate. Hope mine can help you.

Wishing you good health and a happy mood!

1 If it is possible, Liang Qiaoshen adds pillars and slabs to add beams to lower the degree of cross-lettering. 2.Reinforcement is increased, but the effect is not obvious.

3.Using the pre-arching construction method, the deflection can be calculated according to the deduction of the arching value. This square slip wide celery method is more commonly used.

If the deflection of the cantilever plate exceeds the limit, the secondary beam can be arranged in the plate to reduce the span of the plate.

Pro-provisions emphasize the pre-registration (i.e., before the act takes place) and the effect of the law, so as to make decisions that are confused in the text of the law. Stipulating as a verb means making a binding decision about the quantity, quality, manner and method of things, such as: quality standards of productsShall not exceed the date of the other brother slippery macro.

Summary. Hello dear, I'm glad to answer your questions<>

Reinforced concrete beam deflection limit: according to the "Code for Design of Concrete Structures" GB50010-2002, the test beam span ML70, its deflection limit = LO 250 = 10mm. The measured mid-span deflection is; In addition, during the whole test, no cracks were found, and the residual deflection after unloading was.

I hope the above is helpful to you, if you have any questions, please feel free to consult me<>

Reinforced concrete beam deflection limits.

Hello dear, I'm glad to answer your questions<>

Reinforced concrete beam deflection limit: according to the "Code for Design of Concrete Structures" GB50010-2002, the test beam span ML70, its deflection limit = LO 250 = 10mm. The measured mid-span deflection is; In addition, during the whole test, no cracks were found, and the residual deflection after unloading was.

I hope the above is helpful to you, if you have any questions, please feel free to consult me<>

What does af} II 1o 250 mean.

This is the calculation formula.

From what you said, it should be the reinforced concrete beams built by the house. If it is a reinforced concrete beam that has been used, it means that the bearing capacity of the beam is insufficient. The reason for this may be design, construction, or use.

Therefore, it is necessary to first analyze the cause of excessive deflection, and then formulate a remedial reinforcement plan through the design department. Commonly used reinforcement methods include steel plate reinforcement, carbon fiber reinforcement, in vitro prestressing, etc.

If it is a reinforced concrete beam that has just been constructed, this situation occurs, it is caused by the sinking of the formwork support. At this time, in addition to the refurbishment of the shape, it is also necessary to check whether the position of the reinforcement is correct. If the position of the reinforcement is offset too much, it is also necessary to check and take appropriate remedial measures.

If it is a beam design problem that causes excessive deflection, reinforcement measures can be taken, such as carbon fiber and steel plate reinforcement.

Have you been demoulded?

Tick and smooth it and you're good to go.

The bending stiffness of the cross-section close to the support is greater than that of the pure bending section, but there is shear deformation in the shear span, which will increase the deflection of the beam.