What is prestressed steel bar The difference between prestressed steel bar and ordinary steel bar

Prestressed reinforcement is the compressive stress applied to the concrete of the structural component in advance by the pre-tensioning method or the post-tensioning method before the structural component is used.

In reinforced concrete structures, there will be cracks in the components under tension, although it does not affect safety, but the feeling is not good. The use of first to apply tensile force to the steel bar, and then pour concrete, to reach the strength of the requirements to loosen the steel bar, so that the steel bar retracts, and the normal use of the load of the tensile force offset (first tension method) after the law is to pour the concrete reserved hole, after forming the steel bar under tension, and then anchor at both ends of the component with instruments.

In the structure of ordinary reinforced concrete, due to the low ultimate tensile strain of concrete, the strain of the steel bar in the component greatly exceeds the ultimate tensile strain of the concrete under the action of the use load. The strength of the reinforcement in reinforced concrete elements is not fully utilized. Therefore, it is unreasonable to use high-strength steel bars for ordinary reinforced concrete structures.

In order to make full use of high-strength materials and make up for the gap between concrete and steel tensile strain, people apply prestressing to reinforced concrete structures. That is, before the external load is applied to the member, a certain method is used in advance to apply pressure on the member (mainly in the tension zone) to form a prestressed reinforced concrete structure. When the component bears the tensile force generated by the external load, the existing pre-pressure in the concrete is first counteracted, and then with the increase of the load, the concrete can be tensile and then cracks appear, thus delaying the appearance and development of the cracks of the component.

1. The concepts of the two are different, the so-called prestress.

That is to say, it has the effect of bearing stress, and when it is used, it is necessary to apply tensile force to the steel bar before it can be poured. When the strength reaches the standard requirements, the steel bar will be loosened, and then it will be retracted, and the tensile force can be added after forming, which belongs to this type of steel bar. The ordinary steel bar is in the pouring concrete structure, which does not bear any stress, so that the concrete and steel bar are better combined to achieve a more solidified effect.

2. The performance characteristics will also be different. If the former type of steel bar is used, then correspondingly, its crack resistance and impermeability will be more prominent, which can effectively save steel and reduce the generation of cracks in concrete structures. If it is an ordinary type, in comparison, its corrosion resistance and crack resistance are not as good as the prestressed type.

1. The difference in production methods, the prestressed steel bar is used to apply compressive stress to the concrete by the pre-tensioning method or the post-tensioning method, and the ordinary steel bar itself does not need to bear any stress, but only needs to bear external stress. 2. The difference in performance characteristics, prestressed steel bar crack resistance, stiffness and permeability resistance, can save steel, while ordinary steel bar only has some durability and corrosion resistance.

1. Principle, the prestressed steel bar, as the name suggests, is to apply prestress to the steel bar, so that the bending resistance and bearing capacity of the steel bar touch the tung dust concrete are stronger, and the concrete structure composed of prestressed reinforced concrete components is the prestressed reinforced concrete structure. It improves the tensile strength of reinforced concrete at a certain level, so that our reinforced concrete structure will become more stable, and we will be safer when we use it.

2. The appearance of prestressed steel bars is to make full use of this high-strength material to solve the relationship between concrete and steel bar tensile strain, so the prestressed steel is applied to the reinforced concrete structure. That is, before the external load acts on the member, a certain method is used in advance, the pressure is applied on the reinforcement member, when the member bears the tensile force generated by the external load, the pre-pressure in the concrete is offset at first, and then with the increase of the load, the concrete can be tensile and then cracks appear, thus delaying the appearance and development of the crack of the component.

3. Characteristics, in our prestressed reinforced concrete structure, the strength grade of concrete should be high, and the strength of steel bars should also be high; The quality will also be more reliable, and the prestressed concrete structure with a higher degree of stress will perform like a homogeneous elastic material and will not be broken suddenly; The stiffness of the prestressed concrete structure is large, the deflection is small, and the crack width is small, so the web of the prestressed concrete beam can be made thinner, and the self-weight is greatly reduced.

1. The principle, as the name suggests, is to apply prestress to the steel bar, so that the bending resistance and bearing capacity of the reinforced concrete are stronger, and the concrete structure composed of prestressed reinforced concrete components is the prestressed reinforced concrete structure. It improves the tensile strength of reinforced concrete to a certain extent, so that our reinforced concrete structure will become more stable, and it will be safer when we use it.

2. The appearance of prestressed steel bars is to make full use of this high-strength material and solve the relationship between concrete and steel bar tensile strain, so it is late to apply prestress to reinforced concrete structures. That is, before the external load acts on the member, a certain method is used in advance to apply pressure on the reinforcement member, when the member bears the tensile force generated by the external load, the existing pre-pressure in the concrete is first offset, and then with the increase of the load, the concrete can be tensile and then cracks appear, so that the denier delays the appearance and development of the cracks of the component.

3. Characteristics, in our prestressed reinforced concrete structure, the strength grade of concrete should be high, and the strength of steel bars should also be high; The quality will also be more reliable, and the prestressed concrete structure with a higher degree of stress will perform like a homogeneous elastic material and will not be broken suddenly; The stiffness of the prestressed concrete structure is large, the deflection is small, and the crack width is small, so the web of the prestressed concrete beam can be made thinner, and the self-weight is greatly reduced.

Summary. Hello, I found out that the prestressed reinforced concrete is to apply pressure to the ground before the structural components are subjected to external loads, and the resulting prestressed state is used to reduce or offset the tensile stress caused by the external load, that is, with the help of the higher compressive strength of the concrete to make up for the lack of tensile strength, so as to achieve the purpose of delaying the cracking of the concrete in the tensile area.

What is prestressed reinforced concrete.

Hello, I found out that the prestressed reinforced concrete is to apply pressure to the ground before the structural components are subjected to external loads, and the resulting prestressed state is used to reduce or offset the tensile stress caused by the external load, that is, with the help of the higher compressive strength of the concrete to make up for the lack of tensile strength, so as to achieve the purpose of delaying the cracking of the concrete in the tensile area.

The structure made of prestressed concrete is also called a prestressed reinforced concrete structure because the precompressive stress is achieved by the method of tensile reinforcement.

Prestressed concrete [Definition] In order to avoid the premature appearance of cracks in reinforced concrete structures, make full use of high-strength steel bars and high-strength concrete, and try to apply pressure to the concrete in the tension zone before the concrete structure or component bears the use load.

Objective] Precompressive stress is used to reduce or offset the tensile stress of concrete caused by load, so as to control the tensile stress of structural components in a small range, or even in a compressive state, so as to delay the emergence and development of concrete cracks, so as to improve the crack resistance and stiffness of components.

1. The principle, as the name suggests, is that the bending resistance and bearing capacity of the reinforced concrete are stronger by applying prestress to the steel bar, and the concrete structure composed of prestressed reinforced concrete components is a prestressed reinforced concrete structure. It improves the tensile strength of reinforced concrete to a certain extent, so that our reinforced concrete structure will become more stable, and we will be safer when we use it.

2. Construction technology, the emergence of prestressed steel bars is to make full use of this high-strength material and solve the relationship between concrete and steel bar tensile strain, so the prestressing is applied to the reinforced concrete structure. That is, before the external load acts on the member, a certain method is used in advance, the pressure is applied on the reinforcement member, when the member bears the tensile force generated by the external load, the pre-pressure in the concrete is offset at first, and then with the increase of the load, the concrete can be tensile and then cracks appear, thus delaying the appearance and development of the crack of the component.

3. Characteristics, in our prestressed reinforced concrete structure, the strength grade of concrete should be high, and the strength of steel bars should also be high; The quality will also be more reliable, and the prestressed concrete structure with a higher degree of stress when it is delayed, the performance is like a homogeneous elastic material, and it will not be suddenly broken; The stiffness of the prestressed concrete structure is large, the deflection is small, and the crack width is small, so the web of the prestressed concrete beam can be made thinner, and the self-weight is greatly reduced.