maximun rebar spacing in shear walls 1

[jenaro]

I am building a 30-story RC building. It has two big shear walls all along its height. Dimensions are: 40 cms thick, 4 m. width and free span between sucesive floors is 3.00 m.
My problem is: original design is for Nro 4 horizontal reinforcement spaced 0.25m (hooks) and the same for vertical reinforcement. I can not get this diameter any more and need to change to Nro 5 wich can be easily found now. ¿MAY I CHANGE REBAR SPACING FROM 25 CM TO 39 CM?. And, ¿wich is the maximun allowed rebar spacing here?. ¿wich code paragraph rules this?.

Thanks a lot

 

[Riz]

The area of reinforcement provided has to be re-checked against what was allowed for in the design if one wants to substitute rebar size.
The spacing between rebars are a function of, amongst many, the following:
Concrete crack control;
Congestion of rebars;
Tension or compression face of wall;
Shrinkage and temperature effects;
etc

 

[ckorski]

The maximum spacing of rebars is not much of a factor here, but the effect on minimum spacing on the shorter side. The toleraces due to aggregate size, minimum concrete cover, min req'd spacing in relation to your rebar size, min required steel area per cross sectional area of concrete must be throughly checked against the actual effects of loads in all directions. Workability of concrete between these rebars is of high importance and must be considered in consonance with requirements mentioned above.