what is the basic difference between a singly reinforce
section & a doubly reinforce section?

Answer Posted / aziz ul hakeem

Singly Reinforced Beams:
Ductile failure is always desirable and brittle failure should be always avoided.
Most beams in real life structures are Singly Reinforced Beams where steel bars are provided only in the Tension Face (hanger bars in the compression zone to hold the stirrups are not for structural reasons).
An upper limit on the amount of steel in Tension Zone is imposed to make sure that the failure should be always ductile. This is generally called As-max (based on pmax) which is about 75% of the balanced steel ratio or steel reinforcement.
Doubly Reinforced Beams:
However in real life situations where it is not possible to increase the beam depth and the applied bending moments are greater than the beams capacity with the As-max then we go for doubly reinforced beams. First the total amount of steel reinforcement is calculated and then the steel in excess of the As-max is provided both in the tension and compression zones. i.e. if 3 no. 8 bars, in excess of the As-max, are required in the tension zone then 3 no. 8 bars should be provided in compression zone and As-max+3 no. 8 bars should be provided in the tension zone.
Example:
In tension face/zone – Reinforcement Steel = As-max+3 no. 8 bars
In compression face/zone – Reinforcement Steel = 3 no. 8 bars

Is This Answer Correct ?    7 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is the soil bearing capacity for a 5 floor multistorey residential building and which type of soil ? what is plinth beam? in wall load calculation center to center column distance is considered or not/

2004


How much cum. Brick work can do by 1 madon

1350


What is aggregate?

886


Which is the direction of negative angle?

801


construction workers how much time take one work or qty

1355






Required amount of Steel bars, cement/ square feet for roofing of residential building upto 3rd floor.

1419


What is the biggest dam in america?

842


What is the difference between a wood shake and wood shingles?

897


How to calculate quantity of plum masonry in 1:3:7

2699


What ingredients with% found in ppc cement??

1774


Is it possible to make a feature using an overdefined sketch?

962


What is Grid floor and mention its advantages ?

2939


is it fair to recruit another prestressing agency once earlier agency has provided guide cone for post stressing the Concrete -I girders? It is observed that the bearing plate of another agency is not matching with the earlier one resulting in protruded strands after stressing from the face of girder. Kindly advice.

1680


Will water damage concrete?

943


How musch steel i.e. angles, channels,and square pipes are required per square feet for a steel roof of residential two storied building?

1508