Check for Development Length

Development length

Project: Designed by: by: Sheet  __ of ___ 

Checked by: 10-Sep-12

Date: Part of structure:

Job no:

Contents:

Location:

CHECK FOR DEVELOPMENT LENGTH

Development Length = (ø x σs ) / 4 Ƭbd

(Clause 26.2.1, IS-456 2002)

Ø=

Dia of bar 

σs =

Stress in steel =

Ƭbd =

Bond Stress in Concrete

460 N/mm

2

3.3 N/mm

2

Design Bond stress may be increased by 60% for deformed bars Therefore, al allowable b bo ond st stress fo for co concrete

2

=3.3 x 1.6

Development Length = (Ø x fy) / 4 x τbd =

5.28 N/mm

(Development length in Tension)

22 Ø

 Anchorage value for 90 degree bend = 2 x 4 Ø =

8 Ø (Development length in Tension with 90 degree bend)

(4 Ø for each 45 degree bend subject to max of 16 Ø) For bars having 90 degree bend, development length in Tension Tension =

14 Ø

For Bars in Compression design bond stress may be increased by 25% Therefore, allowable bond stress for concrete Development Length in Compression

=3.3 x 1.6 x 1.25 = = (Ø x460) / 4x6.6=

6.6 N/mm

2

18 Ø

For anchorage in Compression, only the length of bar in bend is to be considered and no anchorage effect is to be considered.

Page 1

(Development length in Compression)