Concrete rectangular column with circular arc chamfer and manufacturing method

Abstract

This invention discloses a concrete rectangular column with rounded chamfers and its manufacturing method. The method includes designing a right-angled concrete rectangular column with right angles, determining the design diameter of the stirrups, the design diameter of a single corner longitudinal reinforcement, and the design cross-sectional area of ​​a single corner longitudinal reinforcement in the right-angled concrete rectangular column. The side lengths of the two sides of the cross-section of the right-angled concrete rectangular column are consistent with the side lengths of the cross-section of the concrete rectangular column with rounded chamfers. The influence of missing concrete at the rounded chamfer on the bearing capacity, axial stiffness, and bending stiffness of the right-angled concrete rectangular column is considered. The maximum value of the area increase required for a single corner longitudinal reinforcement is calculated. Based on the calculation results, a reinforcing cage and formwork are fabricated. After pouring concrete, the concrete rectangular column with rounded chamfers is completed. This invention ensures that the bearing capacity, stiffness, and other parameters of the designed concrete rectangular column with rounded chamfers are consistent with those of concrete rectangular columns designed using conventional methods.

Description

Technical Field

[0001] This invention relates to the field of architectural structural design, specifically to a concrete rectangular column with rounded chamfers and its manufacturing method. Background Technology

[0002] In the field of architecture, traditional reinforced concrete rectangular columns usually have four sharp edges. Such an appearance not only looks rigid, but the material is also prone to falling off when the edges of the column are bumped. At the same time, it is easy to be injured when foreign objects or people collide with the edges of the column. Therefore, in the process of modern architectural design, in order to make the structure of the interior space of the building safer and the environment softer, designers have tried to design rounded structures at the four corners of the rectangular column.

[0003] To achieve a smooth transition at the four corners of a rectangular column, a common practice in engineering is to surround the reinforced concrete rectangular column with a thin wooden panel during the later stages of decoration, with rounded wooden boards used for transition at the four corners. While this approach solves the problem of the traditional rigid lines of reinforced concrete rectangular columns, it significantly increases the size of the column, occupies more space, and the extensive use of decorative materials significantly increases construction costs. Furthermore, in actual projects, the wooden panel is usually connected to the reinforced concrete column using nails. The instantaneous impact force from nailing is extremely high, which can easily damage the surface concrete of the column, causing structural safety issues.

[0004] To ensure the overall stability of rectangular columns and reduce the use of decorative materials, designers have begun to explore the use of one-piece molding to manufacture reinforced concrete rectangular columns with rounded corners. However, current standards and calculation software primarily base the load-bearing capacity design of rectangular reinforced concrete columns on the basic premise that all four corners of the column are right angles. This overlooks the fact that the rounded corners reduce the cross-sectional area of ​​the concrete rectangular column compared to a conventional concrete rectangular column with right angles. If the design is still based on the conventional concrete rectangular column, it will lead to insufficient load-bearing capacity and stiffness, thereby causing structural safety issues. Summary of the Invention

[0005] This invention addresses the issue that using conventional manufacturing methods to design rounded corner concrete rectangular columns can lead to insufficient load-bearing capacity and stiffness, potentially causing safety problems. It proposes a rounded corner concrete rectangular column and its manufacturing method. By optimizing the parameters of the rounded corner concrete rectangular column, the invention ensures that the load-bearing capacity, stiffness, and other parameters of the designed and manufactured rounded corner concrete rectangular column are consistent with those of conventional concrete rectangular columns.

[0006] This invention is achieved through the following technical solutions:

[0007] A method for manufacturing a concrete rectangular column with rounded chamfers, specifically including the following steps:

[0008] S1. Based on the design objective of the rounded-corner concrete rectangular column, design a right-angled concrete rectangular column with right angles at all four corners. The side lengths L1 and L2 of the cross-section of the right-angled concrete rectangular column are consistent with the side lengths of the cross-section of the rounded-corner concrete rectangular column. The right-angled concrete rectangular column and the rounded-corner concrete rectangular column have the same concrete cover thickness c. The diameter of the stirrups in the right-angled concrete rectangular column is d1, the diameter of a single corner longitudinal reinforcement is d2, and the cross-sectional area of ​​a single corner longitudinal reinforcement is A. s ;

[0009] S2. Determine the rounding radius r of the concrete rectangular column with rounded chamfers, and determine the design value f of the concrete compressive strength based on the concrete strength grade and steel reinforcement grade. c and the design value of tensile strength f of the corner longitudinal reinforcement y Under the ultimate limit state of bearing capacity, the stress level of the concrete in a right-angled rectangular concrete column within a square region with side length r at the corner reaches the design value f. c Furthermore, the stress component σ1 generated by axial pressure and the stress component σ2 generated by bending moment are both related to f. c The relationship satisfies the formula: σ1 + σ2 = f c ;

[0010] S3. Considering the impact of missing concrete at the rounded corner on the bearing capacity of the right-angled concrete rectangular column, calculate the increased area △A required for a single corner longitudinal reinforcement. sc ;

[0011] S4. Considering the impact of missing concrete at the rounded corner on the axial stiffness of the right-angled concrete rectangular column, calculate the increased area △A required for a single corner longitudinal reinforcement. ssa ;

[0012] S5. Considering the impact of missing concrete at the rounded corner on the bending stiffness of the right-angled concrete rectangular column, the required increase in area △A for a single corner longitudinal reinforcement is calculated. ssf ;

[0013] S6. Calculate the final area increment △A of a single corner longitudinal reinforcement. s =max(△A) sc △A ssa △A ssf )

[0014] S7. Calculate the area A of a single corner longitudinal reinforcement after the area is increased. s * = A s +△A s ;

[0015] S8, according to A s The results indicate that the corner longitudinal reinforcement in a concrete rectangular column with rounded chamfers should be either single or double reinforcement.

[0016] S9. Based on the completed technical parameters, select the corresponding stirrups, corner longitudinal bars, and internal longitudinal bars to construct the steel cage. At the same time, construct a template with rounded corners based on L1, L2, and r. After surrounding the steel cage with the template, pour concrete to complete the construction of the concrete rectangular column with rounded corners.

[0017] A further improvement to the present invention includes the following steps in step S3:

[0018] S31. Calculate the distance b from the maximum compression edge of the right-angled concrete rectangular column section to the neutral axis under vertical eccentric load;

[0019] S32. Assume that the sector-shaped reinforced concrete region with radius r at the corner of a concrete rectangular column with rounded chamfers has the same load-bearing and bending resistance as the square region with side length r at the corner of a right-angled concrete rectangular column.

[0020] S33. Calculate the axial compressive force N1 and bending moment M1 that the missing concrete portion at the corner of a concrete rectangular column with rounded chamfers should bear. The formulas for calculating N1 and M1 are as follows:

[0021]

[0022]

[0023] S34. Convert N1 and M1 into the increment ΔA of the cross-sectional area of ​​a single corner longitudinal reinforcement. s1 and △A s2 The calculation formula is as follows:

[0024]

[0025]

[0026] S35. Calculate the increase in the area of ​​the corner reinforcement △A using the variable estimation method. s2 Calculate the error △A sc ';

[0027] S36. Calculate △A sc =△A s1 +△A s2 +△A sc '.

[0028] A further improvement to the present invention is that step S4 specifically includes the following steps:

[0029] S41. Determine the elastic modulus E of the concrete for a right-angled rectangular concrete column based on the concrete strength grade and steel reinforcement grade. c and the elastic modulus E of the corner longitudinal ribs s ;

[0030] S42. Calculate the axial stiffness contributed by the missing concrete portion in the corner region of a concrete rectangular column with rounded chamfers, as follows:

[0031]

[0032] S43. Based on the principle of equivalent material substitution for different elastic moduli, calculate the increased area ΔA required for a single corner longitudinal reinforcement to ensure consistent column axial stiffness. ssa The specific formula is as follows:

[0033]

[0034] A further improvement to the present invention includes the following steps in step S5:

[0035] S51. Determine the elastic modulus E of the concrete for a right-angled rectangular concrete column based on the concrete strength grade and steel reinforcement grade. c and the elastic modulus E of the corner longitudinal ribs s ;

[0036] S52. Calculate the bending stiffness contributed by the missing concrete portion in the corner region of a concrete rectangular column with rounded chamfers, as follows:

[0037]

[0038] S53. Based on the principle of equivalent material substitution for different elastic moduli, calculate the increase in area △A required for a single corner longitudinal rib to ensure consistent bending stiffness. ssa The announcement is as follows:

[0039]

[0040] A further improvement to the present invention is based on the calculated A. s *Value, when A s *Value less than 490mm 2 When using a single longitudinal reinforcement bar in the corner area of ​​a concrete rectangular column with rounded chamfers, the cross-sectional area of ​​the single longitudinal reinforcement bar in the corner area is greater than A. s *and less than or equal to 490mm 2 , when A s *Value greater than or equal to 490mm 2 When using parallel reinforcement in the corner area of ​​a concrete rectangular column with rounded chamfers, the total cross-sectional area of ​​the parallel reinforcement is greater than A. s *

[0041] The present invention also proposes a concrete rectangular column with rounded chamfers, which is designed and manufactured by the above-mentioned manufacturing method for concrete rectangular columns with rounded chamfers.

[0042] Compared with the prior art, the present invention has the following advantages: the present invention can design concrete rectangular columns with rounded corners without secondary decoration, and the concrete rectangular columns with rounded corners have the same load-bearing and bending resistance as concrete rectangular columns designed by conventional methods. Attached Figure Description

[0043] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the parameters of the right-angled concrete rectangular column and the concrete rectangular column with rounded chamfer in step S1 of the manufacturing method of the concrete rectangular column with rounded chamfer of the present invention.

[0045] Figure 2 The manufacturing method of the concrete rectangular column with rounded chamfer of the present invention is based on the calculation of △A by the variable assignment estimation method in step S36. sc 'Result diagram;'

[0046] Figure 3 The manufacturing method of the concrete rectangular column with rounded chamfer of the present invention is based on the calculation of △A by the variable assignment estimation method in step S54. ssf Result diagram;

[0047] Figure 4 This is a schematic cross-sectional view of the concrete rectangular column with rounded chamfers of the present invention when it is single-reinforced.

[0048] Figure 5 This is a cross-sectional schematic diagram of the corner of the concrete rectangular column with rounded chamfers of the present invention when the reinforcing bars are arranged in a parallel manner. Detailed Implementation

[0049] The technical solutions of various embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0051] A method for manufacturing a rectangular concrete column with rounded chamfers is described, aiming to produce a rectangular concrete column with cross-sectional side lengths L1 = 700 mm, L2 = 700 mm, and a corner radius r = 100 mm. The specific steps are as follows:

[0052] S1. Based on the design objective of the concrete rectangular column with rounded corners, a right-angled concrete rectangular column with right angles at all four corners is designed using design software. The side lengths L1 and L2 of the cross-section of the right-angled concrete rectangular column are consistent with the side lengths of the cross-section of the concrete rectangular column with rounded corners. The right-angled concrete rectangular column and the concrete rectangular column with rounded corners have the same concrete cover thickness c = 25mm. The design diameter of the stirrups in the right-angled concrete rectangular column is determined to be d1 = 12mm, the design diameter of a single corner longitudinal reinforcement is d2 = 25mm, and the design cross-sectional area of ​​a single corner longitudinal reinforcement is A. s The concrete strength grade is C60 (f c =27.5MPa, E c =3.6*10 4 MPa), steel grade is HRB400 (f y =360MPa, E s =2.0*10 5 MPa);

[0053] S2. Determine the rounding radius r of the concrete rectangular column with rounded chamfers, and determine the design value f of the concrete compressive strength based on the concrete strength grade and steel reinforcement grade. c and the design value of tensile strength f of the corner longitudinal reinforcement y Under the ultimate limit state of bearing capacity, the stress level of the concrete in a right-angled rectangular concrete column within a square region with side length r at the corner reaches the design value f. c And the stress component σ1 generated by axial pressure and the stress component σ2 generated by bending moment satisfy the formula:

[0054] σ1+σ2=f c ;

[0055] S31. Calculate the distance b from the maximum compression edge of the right-angled concrete rectangular column section to the neutral axis under vertical eccentric load;

[0056] S32. Assume that the fan-shaped reinforced concrete region with a corner radius of r of the concrete rectangular column with rounded chamfers has the same design value f of concrete compressive strength as the square reinforced concrete region in step S2. c Design value of tensile strength f of corner longitudinal reinforcementy ;

[0057] S33. Calculate the axial compressive force N1 and bending moment M1 that the missing concrete portion at the corner of a concrete rectangular column with rounded chamfers should bear, using the following formulas:

[0058]

[0059]

[0060] S34. Convert N1 and M1 into the increment ΔA of the cross-sectional area of ​​a single corner longitudinal reinforcement. s1 and △A s2 The formula is as follows:

[0061]

[0062]

[0063] S35. Calculate △A s2 The calculation difference △A caused by the simplification of the calculation formula sc ', for △A s2 The simplified calculation formula is as follows:

[0064]

[0065]

[0066] Calculate △A using the variable assignment estimation method. sc The maximum value of ', such as Figure 2 As shown, the calculation results indicate that when c = 25mm, d1 = 12mm, and d2 = 25mm, and r varies within the range of (100–250mm) and b varies within the range of (400–800mm), △A sc The range is 0–180 mm. 2 To ensure that the final design parameters meet the strength requirements, △A sc Round up to 200mm 2 ;

[0067] S36. Obtain the final △A sc The formula and calculation results are as follows:

[0068]

[0069] S41. Determine the elastic modulus E of the concrete for a right-angled rectangular concrete column based on the concrete strength grade and steel reinforcement grade. c and the elastic modulus E of the corner longitudinal ribs s ;

[0070] S42. Calculate the axial stiffness contributed by the missing concrete portion in the corner area of ​​a concrete rectangular column with rounded chamfers. The calculation formula is as follows:

[0071]

[0072] S43. Based on the principle of equivalent material substitution for different elastic moduli, calculate the increased area ΔA required for a single corner longitudinal reinforcement to ensure consistent column axial stiffness. ssa The formula and calculation results are as follows:

[0073]

[0074] S51. Determine the elastic modulus E of the concrete for a right-angled rectangular concrete column based on the concrete strength grade and steel reinforcement grade. c and the elastic modulus E of the corner longitudinal ribs s ;

[0075] S52. Calculate the bending stiffness contributed by the missing concrete portion in the corner area of ​​a concrete rectangular column with rounded chamfers, using the following formula:

[0076]

[0077] S53. Based on the principle of equivalent material substitution for different elastic moduli, calculate the increase in area △A required for a single corner longitudinal rib to ensure consistent bending stiffness. ssf The announcement is as follows:

[0078]

[0079] S54, Regarding △A ssf Perform variable assignment estimation, such as Figure 3 As shown, the results indicate that when c = 25 mm, d1 = 12 mm, and d2 = 25 mm, the ΔA of L1 within the range of (600-1000 mm) and r within the range of (100-250 mm) is... ssf The calculation results range from 0 to 14 mm. 2 To ensure that the final design parameters meet the stiffness requirements, △A ssf Round up to 20mm 2 ,Right now:

[0080] ΔA ssf =20 (mm) 2 );

[0081] S6. Based on the above calculation results, calculate the final area increment ΔA of a single corner longitudinal reinforcement. s =max(△A) sc △A ssa △A ssf ):

[0082] ΔA s =max(ΔA) sc ΔA ssa ΔA ssf ) = 386 (mm) 2 );

[0083] S7. Calculate the cross-sectional area A of a single corner longitudinal reinforcement after the area is increased. s * = A s +△A s The calculation results are as follows:

[0084] A s * =A s +ΔA s =877 (mm) 2 >490 (mm) 2 );

[0085] S8. Based on the final obtained A s *As a result, due to A s *Greater than 490mm 2 Therefore, the corner areas of the concrete rectangular column with rounded chamfers are reinforced with parallel bars, and the total cross-sectional area of ​​the parallel bars is greater than A. s * Select two 25mm diameter steel bars to form a parallel reinforcement bar, based on the available steel bar specifications. Figure 5 As shown;

[0086] S9. Based on the parameters obtained after the design is completed, select the corresponding stirrups (d1 = 12mm) and corner longitudinal bars (d2 = 25mm, in parallel bar form) to make a steel cage. At the same time, make a template with rounded corners based on L1 = 700mm, L2 = 700mm, and r = 100mm. Finally, surround the steel cage with the template and pour concrete to complete the construction of the concrete rectangular column with rounded corners.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a concrete rectangular column with rounded chamfers, characterized in that, Specifically, the following steps are included: S1. Based on the design parameters, design a right-angled concrete rectangular column with right angles, and determine the design diameter of the stirrups in the right-angled concrete rectangular column as follows: d 1. Design diameter of a single corner longitudinal reinforcement bar d 2. The area of ​​the design section for a single corner longitudinal reinforcement is: A s The side lengths of the two sides of the right-angled concrete rectangular column section L 1 and L 2. The two sides of the cross-section of the right-angled concrete rectangular column with rounded chamfers are consistent with each other, and the concrete protective layer thickness of the right-angled concrete rectangular column and the concrete rectangular column with rounded chamfers is the same. c ; S2. Determine the fillet radius of the concrete rectangular column with rounded chamfers. r The design value of concrete compressive strength is determined based on the concrete strength grade and the steel reinforcement grade. f c and the design value of tensile strength of corner longitudinal reinforcement f y Under the ultimate limit state of bearing capacity, it is assumed that the stress level of the concrete in a square region with side length r at the corner of a right-angled concrete rectangular column reaches the design value. f c And the stress component generated by axial pressure and stress components generated by bending moment The two and f c The relation satisfies the formula: ; S3. Considering the impact of missing concrete at the rounded corner on the bearing capacity of the right-angled concrete rectangular column, calculate the area increase required for a single corner longitudinal reinforcement. △A sc ; S4. Considering the impact of missing concrete at the rounded corner on the axial stiffness of the right-angled concrete rectangular column, calculate the increased area required for a single corner longitudinal reinforcement. △A ssa ; S5. Considering the impact of missing concrete at the rounded corner on the bending stiffness of the right-angled concrete rectangular column, calculate the increased area required for a single corner longitudinal reinforcement. △A ssf ; S6. Calculate the final area increment of a single corner longitudinal reinforcement bar. △A s =max( △A sc , △A ssa , △A ssf ); S7. Calculate the cross-sectional area of ​​a single corner longitudinal reinforcement after the area is increased. A s * = A s + △A s ; S8, according to A s * The results determined that the corner longitudinal reinforcement in the concrete rectangular column with rounded chamfers should be either single or double reinforcement. S9. Based on the completed technical parameters, select the corresponding stirrups, corner longitudinal bars, and internal longitudinal bars to fabricate the steel cage. Simultaneously, according to... L 1. L 2. r The process involves creating a formwork with rounded corners, surrounding the reinforcing cage with the formwork, and then pouring concrete to complete the construction of a rectangular concrete column with rounded corners.

2. The method for manufacturing a concrete rectangular column with rounded chamfers according to claim 1, characterized in that, Step S3 specifically includes the following steps: S31. Calculate the distance from the maximum compression edge of the right-angled concrete rectangular column section to the neutral axis under vertical eccentric load. b ; S32. Assume the radius of the corner region of a concrete rectangular column with rounded chamfers is... r The fan-shaped reinforced concrete area and the square area with side length r at the corner of the right-angled concrete rectangular column have the same load-bearing and bending resistance. S33. Calculate the axial compressive force that the missing concrete portion at the corner of a concrete rectangular column with rounded chamfers should withstand. N 1 and bending moment M 1, N 1 and M The calculation formula is as follows: ； ； S34, will N 1 and M 1. The increment of the cross-sectional area of ​​a single corner longitudinal reinforcement bar △A s1 and △A s2 The formula is as follows: ； ； S35. Calculate the increase in the area of ​​corner reinforcement using the variable estimation method. △A s2 Calculation error △A sc ' ; S36, Calculate △A sc = △A s1 + △A s2 + △A sc ' .

3. The method for manufacturing a concrete rectangular column with rounded chamfers according to claim 1, characterized in that, Step S4 specifically includes the following steps: S41. Determine the elastic modulus of concrete for a right-angled rectangular concrete column based on the concrete strength grade and steel reinforcement grade. E c and the elastic modulus of the corner longitudinal ribs E s ; S42. Calculate the axial stiffness contributed by the missing concrete portion in the corner region of a concrete rectangular column with rounded chamfers, as follows: ； S43. Based on the principle of equivalent material substitution for different elastic moduli, calculate the increased area required for a single corner longitudinal reinforcement to ensure consistent column axial stiffness. △A ssa The formula is as follows: 。 4. The method for manufacturing a concrete rectangular column with rounded chamfers according to claim 1, characterized in that, Step S5 specifically includes the following steps: S51. Determine the elastic modulus of concrete for a right-angled rectangular concrete column based on the concrete strength grade and steel reinforcement grade. E c and the elastic modulus of the corner longitudinal ribs E s ; S52. Calculate the bending stiffness contributed by the missing concrete portion in the corner region of a concrete rectangular column with rounded chamfers, as follows: ； S53. Based on the principle of equivalent material substitution for different elastic moduli, calculate the increased area required for a single corner longitudinal reinforcement to ensure consistent bending stiffness. △A ssa The calculation formula is as follows: 。 5. The method for manufacturing a concrete rectangular column with rounded chamfers according to claim 1, characterized in that: Based on the calculation A s * Value, when A s *Value less than 490mm 2 When using a single longitudinal reinforcement bar in the corner area of ​​a concrete rectangular column with rounded chamfers, the cross-sectional area of ​​the single longitudinal reinforcement bar in the corner area is greater than [missing information]. A s *and less than or equal to 490mm 2 ,when A s *Value greater than or equal to 490mm 2 When using a parallel reinforcement configuration in the corner area of ​​a concrete rectangular column with rounded chamfers, the total cross-sectional area of ​​the parallel reinforcement is greater than [missing information]. A s * 6. A concrete rectangular column with rounded chamfers, characterized in that: A concrete rectangular column with rounded chamfers is manufactured using the manufacturing method of any one of claims 1-5.

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