Steel/concrete ration - limit - why actually?
Steel/concrete ration - limit - why actually?
(OP)
Hallo
What is actually the reason for the limit of reinforcement steel in concrete stuctures like for example in columns. I think the most allowed ratio is 10%. Some codes say even 6%.
But what is the theory behind? Is it just to prevent a better workability? To avvoid concrete pockets? fire resistance?
Tom
What is actually the reason for the limit of reinforcement steel in concrete stuctures like for example in columns. I think the most allowed ratio is 10%. Some codes say even 6%.
But what is the theory behind? Is it just to prevent a better workability? To avvoid concrete pockets? fire resistance?
Tom






RE: Steel/concrete ration - limit - why actually?
The reinforcing limit provides some guarantee of the failure mode of a reinforced concrete member. By insuring that the reinforcing bar(s) yield before the concrete reaches its compressive failure strain, evidence of the condition will become apparent. Flexural members will deform and tension cracks will appear. Too much reinforcing will push the failure mode toward crushing of the concrete (instead of 'stretching' of the steel). Brittle failure of this nature occurs suddenly and with no readily visible warning.
Ralph
Structures Consulting
Northeast USA
RE: Steel/concrete ration - limit - why actually?
RHTPE is only refering to the steel in tension in a flexural member (beam) to limit the rupture mode to a ductile one (as Canada code for example limit you to do so). But note that some code accept concrete crushing as a valid rupture mode too in other part of the world (as EURO for example).
What you are refering to, the maximum steel in axial member, serve purpose of workability when placing and compacting the concrete in beam/column joint. See comments in your respective region concrete code (ex : clause 10.9.2 for Canadian A23.3-04 Code)
RE: Steel/concrete ration - limit - why actually?
RE: Steel/concrete ration - limit - why actually?
RE: Steel/concrete ration - limit - why actually?
Maximum column reinforcement limitation is for constructability. Try the search. It works. I found this recent thread. Started by "BauTomTom". Is that you?
thread507-302810: max Ratio Reinforcement to Concrete area ?
RE: Steel/concrete ration - limit - why actually?
R10.9.1 states that the limit is based on practical considerations and the availability of experimental data.
RE: Steel/concrete ration - limit - why actually?
Regards
Tom
RE: Steel/concrete ration - limit - why actually?