Whether the column reinforcement cover is calculated in terms of main reinforcement or stirrups

Answer: 1. The minimum thickness (mm) of the concrete protective layer is table.

Environmental Category Plates, Wall Beams, Columns.

A 15 20

II a 20 25

II b 25 35

III A 30 40

III B 40 50

2. In different environmental categories, the thickness of the concrete protective layer refers to the distance from the outer edge of the outermost steel bar to the concrete surface, which is suitable for concrete structures with a design life of 50 years.

3. The thickness of the protective layer of the stressed steel bar in the component should not be less than the nominal diameter of the steel bar.

4. For concrete structures with a design service life of 100 years, the thickness of the protective layer of the outermost steel bar should not be less than the multiple of the value in the table in a first-class environment; In the second and third types of environments, special and effective measures should be taken.

5. When the concrete strength grade is not greater than C25, the thickness of the protective layer in the table is increased by 5.

6. The thickness of the protective layer of the steel bar on the bottom surface of the foundation should be calculated from the top surface of the cushion when there is a concrete cushion, and should not be less than 40mm. Answer: From the above analysis, the rebar protective layer should be calculated from the nominal diameter of stirrups or reinforcing bars (when the diameter is greater than the specified rebar protective layer).

According to the provisions of GB50010-2010 "Code for the Design of Concrete Structures", the 3rd floor is correct and should be used. This is a provision of the new norm and a modification of the old norm. Please pay attention!

After the implementation of this specification, the new requirement was changed to be calculated according to stirrups.

Concrete reinforcementThickness of the protective layerYesCount from stirrups

The thickness of the concrete protective layer refers to the distance from the outer edge of the outermost steel bar (such as the outermost steel bar of the beam is naturally stirrups) to the concrete surface, so the thickness of the concrete steel reinforcement protective layer is calculated from the stirrups.

Reference: 16G101-1 (replaces 11G101-1) Drawing rules and structural details of concrete structure construction drawings plan overall representation method (cast-in-place concrete frame, shear wall, beam, slab).

The outermost reinforcement is counted.

So it should be the outside of the stirrups to the outer surface of the concrete member.

It is clearly stated in the GB50010 concrete structure design code.

The protective layer of steel reinforcement is generally two and a half centimeters, that is. Of course, it is from the most surface of the steel bar, that is, from the stirrups or gluten to start the amount, hope, thank you.

The distance from the outside of the main reinforcement to the outside of the concrete is the thickness of the protective layer.

The thickness of the concrete reinforcement protective layer is the thickness from the outer edge of the main reinforcement to the outside of the concrete, that is to say, the size of the stirrups should measure the inside of the stirrups rather than the outer edge.

The thickness of the concrete reinforcement protective layer is calculated from the stirrups, not from the main reinforcement.

The GB50010-2010 edition revised the definition of the concrete cover in the 2002 version, from "the distance from the outer edge of the longitudinal stressed steel bar to the concrete surface" to "the range from the outer edge of the steel bar in the structural component to the surface of the component", that is, the thickness of the protective layer is calculated from the stirrup skin.

The reinforcement cover in concrete is used to protect the reinforcement. From the perspective of the durability of concrete carbonization, blunting and steel corrosion, the thickness of the concrete protective layer is calculated by the outer edge of the outermost steel bar (including stirrups, structural reinforcement, distribution reinforcement, etc.) instead of the outer edge of the longitudinally stressed reinforcement.

We used to teach that we were counting from the main tendon.

According to the current "Code for the Design of Concrete Structures" GB50010-2010 (2015 Edition), the definition is as follows:

Note 1 on page 56 of the 16G101-1 atlas provides greater clarity on the distance from the outside of the stirrups to the concrete surface.

It is shown below. <>Thank you.

According to the relevant regulations, the concrete reinforcement protective layer should be calculated from the edge of the stirrups. Because the protective layer is defined from the outermost edge of the rebar. The vertical distance to the outer edge of the concrete. The thickness of the protective layer is related to the environment in which the concrete reinforcement is exposed.

Previously it was from the main reinforcement.

Now from the stirrups.

However, if it is a distribution rib that is not subject to force, it does not count.

The protective layer is calculated from the outermost layer of the outermost reinforcement.

Summary. The reinforcement cover is calculated from the outer skin of the main reinforcement.

The rebar cover is the distance from the outer edge of the outermost rebar to the concrete surface.

The distance from the outer edge of the outermost reinforcement to the concrete surface (from the latest atlas 11G101, the original old atlas 03G101 is: the distance from the outer edge of the main reinforcement or longitudinal reinforcement to the concrete surface).

Function. The reinforcement cover is counted from **.

The reinforcement cover is calculated from the outer skin of the main reinforcement. The steel bar protects the empty hall layer, which is the distance from the outer edge of the outermost steel bar to the hidden surface of the concrete ruler. The distance from the outer edge of the outermost reinforcement to the concrete surface (from the current latest atlas 11G101, the original old atlas 03G101 is:

The hidden distance from the outer edge of the main reinforcement or longitudinal bar to the concrete surface). Function.

Protect the steel bars from rust (the air is wide and the moisture content is wide, and the higher the carbon dioxide content in the air, the thicker the protective layer is needed). 2.Bonding and anchoring (the steel bar should be transmitted to the concrete through the protective layer, if the thickness of the protective layer is not enough, cracks will appear prematurely, the steel bar can not be fully stressed, and at the same time, water and carbon dioxide can invade a lot and corrode the steel bar).

3.The inside of the steel bar is made up of numerous triangular precoons, not a straight plate, designed to withstand the protective effect of the vehicle.

Counted from stirrups, i.e. from the outermost reinforcement.

The old atlas (03G101-1) protective layer is the protective layer of the stressed steel bar, and the protective layer of the new atlas (11G101-1) is the protective layer of the outermost reinforcement, and the value of the protective layer in the atlas should be increased by 5 when the concrete strength grade is not greater than C25.

From the perspective of the durability of concrete carbonization, ravioli and steel corrosion, the thickness of the concrete protective layer is calculated by the outer edge of the outermost steel bar (including stirrups, structural reinforcement, distribution reinforcement, etc.) instead of the outer edge of the longitudinally stressed reinforcement.

Summary. Hello dear, it is generally between twenty-five mm and forty-five mm, and the specific thickness is how much it depends on the size of the beam and column, the concrete grade, etc., as follows:

1. If C20 concrete is used, the thickness of the protective layer should be more than 45 mm.

2. If C30 or C25 concrete is used, the thickness of the protective layer should be more than 35 mm.

What is the thickness of the protective layer for column and beam stirrups?

This question is up to me, it takes a little time to type, please be patient

Hello dear, it is generally between 25 mm and 45 mm, how much is the specific thickness, generally need to look at the size of the beam and the column, the concrete level air macro and other aspects, as follows: 1. If C20 concrete is used, then the thickness of the protective layer should be more than 45 mm. 2. If C30 or C25 concrete is used, the thickness of the protective layer should be more than 35 mm.

3. If C35 concrete is used to make the mold disturbance, then the thickness of the protective layer should be more than 25 mm. Note: When you set up the protective layer of beams and columns, it is best to make reasonable arrangements according to the actual construction drawings, although the thickness of the protective layer can have a little type error, but the error can not be destroyed too much, it should be within the specified range, otherwise it will affect the structure and strength of the beam and column.

Hello, there is no fixed calculation formula, the thickness standard of concrete protective layer is as follows: 1. When the tensile reinforcement of beams and columns is arranged in one row: when the thickness of the protective layer of reinforcement is arranged in two rows of tensile reinforcement of beams and columns: the thickness of the protective layer of the reinforcement is 20mm for the general plate and wall reinforcement.

The thickness of the reinforcement protective layer is stipulated: (to calculate the number of reinforcement roots, the protective layer on both sides of the component length is generally 5-6 cm, and when calculating the length of the steel limb sail rib, the protective layer at the end of the reinforcement is 2-3 cm.) ）