For ordinary reinforced concrete structures, it is unreasonable to use high strength steel bars.

First, it is not economical, ordinary reinforced concrete is lower than high-strength reinforced concrete, which is very important for the construction unit. In addition, in the ordinary reinforced concrete structure, the use of high-strength steel bar can not exert its own material strength, can only be used as low-strength steel bar, ignore the significance of adopting high-strength steel bar, secondly, in the ordinary reinforced concrete structure, another important reason that does not adopt high-strength steel bar is that the deformation and cracks of structural components can not meet the requirements. Due to the high strength of the steel bar, the required cross-sectional area is small, which leads to the increase of the stress of the steel bar under the standard load, which makes the crack width of the member increase. To put it simply, high-strength concrete has high strength, high brittleness, and the probability of cracks increases, and high-strength steel bars must be configured to withstand tensile stress, resulting in construction difficulties.

There is no strict definition.

What kind of steel bar is more reasonable, it is necessary to analyze it from several aspects.

1. The amount of material is saved, and the higher the strength, the more saving. However, if the stress of the component is small, and the reinforcement calculated by using the high-strength reinforcement is less than the minimum reinforcement required by the structure, it is unreasonable and does not save.

2. To meet the mechanical performance requirements of the component, this mainly refers to ductility, which should have good ductility and damage (suitable reinforcement beam).

Considering the above two points comprehensively, there is no absolute statement that high-strength steel bars are unreasonable, such as C35-C40 concrete, prestressed steel bars can be used in places with large stress.

Generally, it refers to the steel bar above HRB400 as a high-strength steel bar, and HRB400 is a dividing line.

Answer]: C In the reinforced concrete structure family, HRB400 hot-rolled steel bar is the leading steel bar, and HRB335 hot-rolled steel bar is used as auxiliary steel bar; The prestressed concrete structure is dominated by high-strength steel wire and steel strand.

Answer]: C Benchun did not fight the question to check the concrete strength of the reinforced concrete grinding structure. The concrete strength of reinforced concrete structures should not be lower than C20.

What are the principle requirements for the performance of steel reinforcement base used in reinforced concrete structures?

Correct answer: 1) Steel bars for construction are required to have a certain strength (yield strength and tensile strength).Higher strength steel bars should be appropriately used to obtain better economic benefits.

2) The steel bar is required to have sufficient plasticity (elongation and cold bending properties).In order to make the structure obtain better destructive properties.

3) It should have good welding performance to ensure that there are no cracks and excessive deformation after welding.

4) There should be enough adhesion between the steel bar and the concrete to ensure that the two work together.

Answer]: A The stiffness of reinforced concrete components can be improved by applying prestress to the tension zone to reduce the development of cracks in the tension zone, while applying the pre-tension stress in the compression zone is ineffective.

8-2 Why is it unreasonable to use high-strength steel bars for ordinary reinforced concrete components, while high-strength materials must be used for prestressed concrete?

Hello, Xiaohai, a home expert, is happy to answer for you. First of all, the relaxation loss of low-strength ordinary steel bars is large, and because the strength is very low, the prestress loss will be exhausted soon, which is not conducive to structural safety. This is the reason for the use of high-strength steel bars.

The reasons for the use of high-strength concrete are as follows: 1. The prestressed steel bar or mega strength is high, which produces a large axial compressive stress on the concrete, and the use of low-strength concrete is easy to produce a large shrinkage creep loss. 2. Prestressed concrete components are generally equipped with more prestressed steel bars in the tension zone of the section, which will make the bending member produce a larger relative compression zone height, which is not conducive to ensuring the ductility of the component.

3. The prestressed components are more sensitive to cracking, and the tensile strength of high-strength concrete is higher, which is easier to meet the requirements of the code for cracks. 4. High-strength steel bars should be matched with high-strength concrete to better play the role of high-strength steel bars. If my answer is helpful to you, please give a thumbs up (in the lower left corner), I look forward to your like, your efforts are very important to me, and your support is also the motivation for my progress.

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Summary. Reasonable reinforcement reinforcement in the concrete component can improve the deformation and bearing capacity of the concrete component, hello. We are glad to answer for you: the bearing capacity of concrete structures is significantly improved after the rational allocation of steel bars.

Reasonable reinforcement bar can improve the deformation and bearing capacity of concrete member in concrete member with reasonable configuration.

Reasonable reinforcement reinforcement in the concrete component can improve the pin deformation and bearing capacity of the concrete component, hello. Shouqingyou is happy to answer for you: after the reasonable allocation of steel bars, the bearing capacity of the concrete structure is significantly improved.

Dear, is it convenient to express it in words?

For mild steel, the "Code for Highway Reinforced Concrete and Prestressed Concrete Bridge and Culvert Section (JTGD62-2018)" takes Qunian crack strength collapse reputation as the value of steel design strength.

Dear, I said that I expressed it in words, can't you copy it?

Words express it.

Hello dear. Glad to answer for you :b