Reinforced concrete - continuous vs. simple support
Reinforced concrete - continuous vs. simple support
(OP)
A concrete beam spans between two other concrete beams. Can it be designed as a simply supported beam? Bottom steel designed for beam moment, top steel provided for stirrups, concentrated loads to supporting beams. Or should it be designed as contimuous? Top steel to resist moments at supports, torsion in supporting beams.






RE: Reinforced concrete - continuous vs. simple support
You will never be wrong to assume simple support for mid-span reinforcing. Alternatively, given continuity on the ends, you _could_ design a span as two cantilevers, if you really want. The convention is somewhere between, and is based on strength and compatibility of the elements.
I jokingly tell people to "design for M=wl^2/8, and put half the steel in the top and half in the bottom, continuous throughout, develop the top at the ends and the bottom at midspan, and you're good to go." It's not quite so simple, but it gets you close without being excessive. Theoretically, in a continuous beam, once you know how much bottom mid-span reinforcement is required for your simple span, you could nearly divide it in any proportion between top end and bottom mid-span.
RE: Reinforced concrete - continuous vs. simple support
RE: Reinforced concrete - continuous vs. simple support