Bond, Anchorage & Development Length

# Bond, Anchorage & Development Length | RCC & Prestressed Concrete - Civil Engineering (CE) PDF Download

### Bond stress(τbd)

Where V = Shear force at any section
d = Effective depth of the section
∑ p = Sum of all perimeter of reinforcement
= n · π(ϕ)
n = Number of reinforcement
ϕ = diameter of reinforcement

Permissible bond stress

As per IS 456 : 2000

• This value of bond stress is for a plain bar in tension.
• For the deformed bar, the above value should be increased by 60%.
• For a bar in compression, the above value should be increased by 25%.

Development Length (Ld)

### Shear stress

1. For Homogeneous beam
where, q = shear stress at any section
V = shear force at any section
Moment of the area of the section above the point of consideration
I = Moment of inertia of the section
= bD3 / 12
2. For Reinforced concrete beam(i) Shear stress above NA

(ii) Shear stress below NA
q = V / bjd
Nominal shear stress, τv = V / bd

Design shear strength of concrete (τc) without shear reinforcement as per IS 456: 2000 (τc) depends on
(ii) Percentage of steel, p = Ast / bd x 100
Where, Ast = Area of steel
b = Width of the Beam
d = Effective depth of the beam

Maximum shear stress τc, max with shear reinforcement is

Minimum shear reinforcement (As per IS 456 : 2000)
ASV / bSV ≥ 0.4 / 0.87fy
This is valid for both WSM and LSM

where, ASV = Area of shear reinforcement
SV = Spacing for shear reinforcement

Spacing of shear reinforcement
Maximum spacing is a minimum of (i), (ii) and (iii)
(i)
(ii) 300 mm
(iii) 0.75 → For vertical stirrups
d → For inclined stirrups
where, d = effective depth of the section

(a) Critical section X-X at d from the face of the support

(b) Critical section X-X at the face of the support
The above provisions are applicable for beams generally carrying uniformly distributed load or where the principal load is located beyond 2d from the face of the support.

### Vertical stirrups

Shear force VS will be
Resisted by shear Reinforcement provided in 'd' length of the beam,

where, ASV = Cross-sectional area of stirrups
SV = Centre to centre spacing of stirrups

Inclined stirrups: or a series of bars bent up at different cross-section:

Bent up Bars

• Single or a group of bent up bars are provided at distance √2a = √2jd from support.

Generally, the bar should not be bent up beyond a distance l/4 from the support. Where l = length of the span.

The document Bond, Anchorage & Development Length | RCC & Prestressed Concrete - Civil Engineering (CE) is a part of the Civil Engineering (CE) Course RCC & Prestressed Concrete.
All you need of Civil Engineering (CE) at this link: Civil Engineering (CE)

## RCC & Prestressed Concrete

13 videos|42 docs|34 tests

## FAQs on Bond, Anchorage & Development Length - RCC & Prestressed Concrete - Civil Engineering (CE)

 1. What is bond length in civil engineering?
Ans. Bond length in civil engineering refers to the length of the embedded portion of reinforcement bars in concrete. It is an important factor in determining the strength and stability of reinforced concrete structures. The bond length is typically specified to ensure that the steel reinforcement effectively transfers the applied loads to the surrounding concrete.
 2. How is bond length determined in civil engineering?
Ans. The bond length in civil engineering is determined based on several factors, including the type and diameter of the reinforcement bars, the concrete cover thickness, and the type of bond between the reinforcement and the concrete. It is typically calculated using empirical formulas or determined through experimental tests. Engineers must ensure that the bond length is sufficient to prevent slippage or separation between the reinforcement and concrete, as it can lead to structural failure.
 3. What is anchorage length in civil engineering?
Ans. Anchorage length in civil engineering refers to the length of the reinforcement bar beyond the critical section where the bar is expected to develop its full strength. It is necessary to provide sufficient anchorage length to prevent the premature failure or pullout of the reinforcement bar from the concrete. The anchorage length is calculated based on factors such as the bar diameter, concrete strength, and required bond strength.
 4. How is anchorage length determined in civil engineering?
Ans. The determination of anchorage length in civil engineering involves considering various factors, such as the type of reinforcement, the concrete strength, and the design load. The length is typically calculated based on empirical formulas or established design codes and standards. The objective is to ensure that the reinforcement bar develops its full strength and remains securely anchored within the concrete.
 5. What is development length in civil engineering?
Ans. Development length in civil engineering refers to the length of reinforcement required to transfer the stress from the steel reinforcement bar to the surrounding concrete. It is crucial to provide sufficient development length to ensure the effective load transfer and prevent the failure of reinforced concrete structures. The development length is influenced by factors such as the bar diameter, concrete strength, and the required bond strength. It is typically determined using empirical formulas or specified in design codes and standards.

## RCC & Prestressed Concrete

13 videos|42 docs|34 tests

### Up next

 Explore Courses for Civil Engineering (CE) exam

### Top Courses for Civil Engineering (CE)

Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Related Searches

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

;