Reinforcement Detailing of Beams from ETABS output

Ans-

Aim - Detailed designed of RCC Beam in ETABS and reinforcement detailing.

Procedure-

1. First download ETABS file and save then run for analysis.
2. Go to Design option – concrete frame design- start design then go to design info and design longitudinal reinforcement and shear reinforcement.

As per question we are selecting to continuous beam-

1. Along Grid A 3 span beam required reinforcement detail

Longitudinal R/f-

Shear Reeinforcement

Along Grid 3 Longitudinal and shear required reinforcement of 7 span beam

Detailing rule of any reinforced concrete member-

1. Minimum reinforcement for shrinkage & temperature.
2. Ultimate limit state design rebar requirement
3. Ductility rebar requirement

Which is greater in above should be drawn in RC.

Grid A Beam data-

Beam size-300X500 mm, Grade of conc- 25 mpa, Long r/f- fe500, Shear r/f -Fe415, Effective depth of beam- 450mm.

• As per IS-13920-2016 clause-6.2.1

So minimum r/f = 332 Sq mm

maximum r/f =3338 sq mm

Devlopment length =41 D

Additional r/f guideline from IS 13920-2016 clause6-

Sketch of reinforcement detail of grid A beam-

Additional check as per IS 13920-2016 Clause 6.3.3-

1) Sway shear force to right

From Etabs Envelope option -

Force to Right Force to Left

Mas=173.97 kNm Mah=234 kNm

Mbh=292.99 kNm Mbs=155 Knm

Vd+l=92 KN Vd+l=70Kn

Lab= 4.725 m Lab=4.725 m

After Calculation

Vua=46 Kn Vua= 185 KN

Vub=230Kn Vub=45 KN

Existing shear capacity in beam as per IS456-2000-

Vus =(0.87XfyXAsvXd)/Sv

=245 Kn

Reason for failure of the mid span- The beam along grid A at the mid span failed due to overstress , beacuse the stress has increased allowable stress, so reduce or increased loading or used higher grade of concrete.