For control of cracking, the strength of the steel
in the reinforcement has no influence on the amount of reinforcement needed,
only the area of the cross section.
When the reinforcement
is assigned a structural role, the fact the steel is stronger, does not mean
necessarily that you reduce the amount of reinforcement in the same
proportions. Because
by the requirements of the minimum amount, in the vast majority of cases, steel
does not display even half of the resistance.
It is the parameter of
steel in the masonry reinforcement which really improves the mechanical
performance in the wall is ductility, not resistance. For this reason, to
prevent cracking, moving forces with the reinforcement it is preferable that
the steel has a high percentage of deformation at failure (that is the
parameter which determines ductility) than high resistance.
