how lap length is increased with increase of Grade of steel?
Answer Posted / rajarshi basu
As per IS 456 : 2000, Page no 42 (Clause no. 26.2.1) development length Ld is given by
Ld = (ï¦ï€ªï³s)/(4*ï´bd)
Let ï¦ï€ ï€½ï‚ nominal diameter of the bar = 16 mm
ï³s = Stress in bar at the section considered at design load = 0.87* fy = 0.87*500 = 435 MPa
ï´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 ï´bd shall be increased by 60%. Hence the value of ï´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
| Is This Answer Correct ? | 10 Yes | 3 No |
Post New Answer View All Answers
how to calculate spacing rod in column
Explain what is progress payment?
Is there any course for billing available in Mumbai? If yes then please mail me the details..
What is made from large rocks, which protects the base of cliffs?
How many feet are in 4 square yards?
What are the phases inspections are done by local authority while construction?
what is right & short method of measurement of slab&beam
what is derating factor in cable? what does it mean if derating factor is high/low in terms of thermal resistivity of soil?
1) What is meant by C-soil in geotechnical Engineering? 2) What is Eve board? 3) What will happen when heat is applied to cement? 4) what do you understand by the lateral dimention ?
trapozidal
what is SDLC ?and write a 'c'program for to swapping the three numbers?
what r you reqired for concrete baching plant?
what is w/c ratio in dry lean concrete for m10 mix design
How many times we can use Fresh bentonite ford wall execution? Would like to know the clear concept of recycling. After flushing can we use it for another time time for flushing? Or we have to use it for for excavation only?
HOW MANY BAGS OF CEMEMT USED IN PER M2 OF PARTITION WALL