RU2574087C2 - General purpose reinforcement bar of periodic profile - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: reinforcement bar of periodic profile consists of a core of a round cross-section with inclined transverse ribs of constant height on the surface. Geometrical dimensions of transverse ribs in the form of characteristic of profile

are set based on a calculation of strength characteristic of concrete between transverse reinforcement ribs by the formula: $${Б}_{Б}=\frac{R_b}{\mathrm{0,7}\cdot \sqrt{R_b\cdot }{R}_{bt}}+4$$

for the highest concrete class B 60, and which is accepted equal to at least 10 to provide concrete destruction directly under working platforms of transverse ribs when concrete achieves prism strength R_b, where t - pitch of transverse ribs; b - width of the rib upper part; h - rib height; R_b - prism strength of concrete class B 60; R_bt - concrete strength for axial tension of class B 60. Technical result consisting in maximum adhesion strength of reinforcement bars to concrete is achieved due to equality of profile characteristics and concrete strength between transverse ribs "Б"_A="Б_Б". Characteristic of concrete strength between transverse ribs is determined as per the above formula and accepted as equal to at least 10, "Б_Б"≥10.

EFFECT: improvement of reliability.

2 cl, 3 dwg

Description

                                                            The invention relates to reinforcing elements of reinforced concrete structures.

Reinforcing bars of a periodic profile are known in which sickle-shaped inclined transverse ribs alternate with hollows of a cylindrical core (TU 14-1-5254-2006 "Hire of a periodic profile for reinforcing reinforced concrete structures. Technical conditions, p.4, Fig. 1").

The disadvantage of this solution is that due to the crescent, there is a decrease in the height of the transverse ribs and, as a result, a decrease in the relative crushing area f _r and the anchoring ability of the reinforcement in concrete. When assigning the pitch of the transverse ribs of the reinforcement, the physical and mechanical characteristics of concrete and the specific operation of the supporting concrete cylinders between them are not taken into account.

Closest to the proposed solution is a reinforcing bar of a periodic profile, which includes a cylindrical core of circular cross section, longitudinal ribs and transverse ribs of constant height located at an angle to them (GOST 5781-94 “Hot-rolled steel for reinforcing reinforced concrete structures”. Technical conditions, p.3 , Fig. 1).

вне зависимости от прочности бетона между поперечными ребрами арматуры или от величины характеристики прочности бетона между поперечными ребрами $${Б}_{Б}=\frac{R_b}{\mathrm{0,7}\cdot \sqrt{R_b\cdot }{R}_{bt}}+4.$$

The disadvantage of this rod is the establishment of the geometric dimensions of the profile

regardless of the strength of concrete between the transverse ribs of the reinforcement or the magnitude of the characteristics of the strength of concrete between the transverse ribs $$B_B=\frac{R_b}{0.7\cdot \sqrt{R_b\cdot }{R}_{bt}}+\mathrm{four.}$$

The objective of the invention is the creation of a universal reinforcing bar of a periodic profile, providing a certain stress-strain state of the supporting concrete cylinders and the nature of the destruction of concrete between the transverse ribs of the reinforcement, when the adhesion of the reinforcement to concrete occurs when the concrete reaches transverse ribs of prismatic strength R _b under the working platforms, which achieves the uniform nature of the destruction of anchoring and its maximum adhesion to concrete for all classes of concrete, approx used in the manufacture of reinforced concrete structures.

, размещены с шагом, равным t=10·h÷11·h, под углом наклона к продольной оси, равным

при соотношении

не менее 10, где t - шаг поперечных ребер, b - ширина верхней части поперечного ребра, h - высота поперечного ребра, d - диаметр стержня. Для дополнительного увеличения прочности сцепления продольные ребра выполнены наклонными к продольной оси стержня.The problem is achieved in that in the known reinforcing bar of a periodic profile for reinforcing reinforced concrete structures, including a core of circular cross section, longitudinal and transverse ribs according to the invention, the transverse ribs are made of constant height and have a ratio of the width of the upper part of the rib to its height as

placed with a step equal to t = 10 · h ÷ 11 · h, at an angle of inclination to the longitudinal axis equal to

with the ratio

at least 10, where t is the step of the transverse ribs, b is the width of the upper part of the transverse ribs, h is the height of the transverse ribs, d is the diameter of the rod. To further increase the adhesion strength, the longitudinal ribs are made inclined to the longitudinal axis of the rod.

Achievable technical result - the geometric dimensions of the profile ensure the disengagement of the reinforcement with concrete when concrete reaches the transverse ribs of prismatic strength R _b under the working platforms, which ensures a uniform nature of the destruction of anchoring and its maximum adhesion to concrete for all classes of concrete used in the manufacture of reinforced concrete structures.

, размещены с шагом, равным t=10·h÷11·h, под углом наклона к продольной оси, равным

при соотношении

не менее 10, где t - шаг поперечных ребер, b - ширина верхней части поперечного ребра, h - высота поперечного ребра, d - диаметр стержня. Для увеличения прочности сцепления продольные ребра выполнены наклонными к продольной оси стержня.The specified technical result is achieved in that the transverse ribs are made of constant height and have a ratio of the width of the upper part of the rib to its height as

placed with a step equal to t = 10 · h ÷ 11 · h, at an angle of inclination to the longitudinal axis equal to

with the ratio

at least 10, where t is the step of the transverse ribs, b is the width of the upper part of the transverse ribs, h is the height of the transverse ribs, d is the diameter of the rod. To increase the adhesion strength, the longitudinal ribs are made inclined to the longitudinal axis of the rod.

The drawings show the proposed reinforcing bar, where in Fig.1 is a General view, in Fig.2, 3 is a view aa.

The reinforcing bar has a core 1 of circular cross section with a diameter of d, longitudinal ribs 2 and inclined transverse ribs 3, and the transverse ribs 3 do not intersect with the longitudinal ribs 2 having a crescent profile. Inclined transverse ribs 3 are made with a angle of coverage of the rod 180 °.

To further increase the adhesion strength, the longitudinal ribs 2 are made inclined to the longitudinal axis of the rod.

вычисленной для бетона класса В 60, и при минимальном значении Б_Б=10 составляют:The geometric dimensions of the profile are calculated based on the strength characteristics of concrete between the transverse ribs of the reinforcement $$B_B=\frac{R_b}{0.7\cdot \sqrt{R_b\cdot }{R}_{bt}}+\mathrm{four,}$$

calculated for concrete of class B 60, and with a minimum value of B _B = 10 are:

- with the ratio of the width of the transverse ribs to the height

;

;

- step of transverse ribs

t = 10 · h ÷ 11 · h;

- relative crushing area

f _r = 0.1 ÷ 0.0909;

- the angle of inclination of the transverse ribs to the longitudinal axis

.

.

Inclined transverse ribs are made with a angle of coverage of the rod 180 ° and provide the maximum possible relative collapse area f _r . An example of calculating the geometric dimensions of a profile for rebar ⌀10 mm at

B _B = 10.

The diameter of the rod d = 10 mm.

The height of the transverse rib h = 1 mm.

The width of the transverse rib in the upper part is b = 0.8-1.0 mm.

The pitch of the transverse ribs t = 10.8-11 mm.

The relative area of collapse f _r = 0,0926-0,0909.

The angle of inclination of the transverse ribs to the longitudinal axis of the rod β = 65 ° 45′-65 ° 43.8 ′.

The proposed universal reinforcing bar of a periodic profile has such geometric dimensions that it can be used in the manufacture of reinforced concrete structures from concrete of all classes presented in regulatory documents.

Claims (2)

1. A reinforcing bar of a periodic profile for reinforcing reinforced concrete structures, including a core of circular cross section, longitudinal and transverse ribs, characterized in that the transverse ribs of the bar are made of constant height and have a ratio of the width of the upper part of the rib to its height as

placed with a step equal to t = 10 · h ÷ 11 · h, at an angle of inclination to the longitudinal axis equal to

with the ratio

at least 10, where t is the step of the transverse ribs, b is the width of the upper part of the transverse ribs, h is the height of the transverse ribs, d is the diameter of the rod. 2. The reinforcing bar according to claim 1, characterized in that the longitudinal ribs are made inclined to the longitudinal axis.

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