Answer / bilal ali khan

development length mostly used when beam bar are passing through column and are simply shown as ld+10d
for fe500 ld is
m40-36d
m35-40d
m30-46d
m25-49d
m20-57d
for fe415 ld is
m40-30d
m35-30d
m30-38d
m25-41d
m20-47d

Answer / rajarshi basu

As per IS 456 : 2000, Page no 42 (Clause no. 26.2.1) development length Ld is given by

Ld = (s)/(4*bd)

Let nominal diameter of the bar = 16 mm

s = Stress in bar at the section considered at design load = 0.87* fy = 0.87*500 = 435 MPa

bd = design bond stress = 1.9 MPa for M40 concrete (As per table 26.2.1.1 of IS 456 : 2000)

Also just below the table 26.2.1.1,it is mentioned that
For deformed bars the value of bd shall be increased by 60%. Hence the value of bd shall be 1.9*1.6=3.04 Mpa.

So development length of tension bars of 16mm dia (Fe 500) in M40 concrete is

= (16*435)/(4*3.04) mm = 572 mm

572/16=35.75 ~36

Therefore for M40 Grade of concrete=Developement length in tension=36 x d

where,d=dia of the bar

According to IS 13920:1993, Clause 6.2.5 it is also stated that
In an external joint,both the top and the bottom bars of the beam shall be provided with anchorage length,beyond the face of the column,equal to the developement length in tension+10 x bar diameter-Allowance for 90 degree bend.(Thats means now we have to consider the Grade of the concrete,in our case it is M40)

therefore for M40 Concrete, for an external joint anchorage should be ld+10d=36d+10d=46d

HOw much % of premium on DSR-2013 currently

0 Answers   NICE,

---

if mineral admixture add into concrete then what is the differences between full cement concrete & fly ash added concrete of their SP. Gr.?and for the changes of SP. Gr. what is the changes in concrete

0 Answers  

---

what is the compresive strength of m20 concrete at 7 day

15 Answers  

---

how to tie 10 legged stirrups

0 Answers   Khan,

---

How we decide the depth and size of footing? Give a example?

1 Answers  

---

percentage of steel in one cubic meter of concrete

1 Answers   Jacobs Zate,

---

is there any difference in footing and slab reinforcement?

2 Answers  

---

how to calculate round stirrups.

4 Answers   Infinity Engineering,

---

What is the soil bearing capacity ? And how it should be to built a multistory building ?

3 Answers   Clancy Networks, eConstruct, UltraTech,

---

What are some structures that may be subjected to fatigue?

0 Answers  

---

how do we calculate quantity of cement sand and aggregates in 1m3 of m20 m25 grade concrete?

0 Answers   Alfanar, Ancon, RAZ,

---

how to calculate the quantity of cement,sand and aggregate when the ratio of mixing is 1:2:3

0 Answers   Ajnara Group, Assosa University,

---