How to solve problem for measuring the design moment strength of a doubly reinforced concrete beam
This construction video demonstrates the example to solve the problem associated with Reinforced Concrete Design. By going through this construction video tutorial one can learn how to measure the design moment strength concerning a concrete beam that is doubly reinforced. Doubly reinforced signifies that there is steel in tension side and compression side.
The video is divided into following two parts :-
Part 1: problem description, strain/stress profiles, locating neutral axis depth
Part 2: make estimation for nominal moment, strength reduction factor, design moment strength
Doubly reinforced beams contain moment of resistance in excess of the singly reinforced beams of the similar depth for specific grades of steel and concrete.
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In doubly reinforced beams, compression steel reinforcement is done in the following conditions :
(i) some parts of a continuous beam containing moving loads sustain change of sign of the bending moment which transforms compression zone as tension zone or contrarily.
(ii) the ductility requirement should be pursued.
(iii) the reduction of long term deflection is requied.