in the steel over the supports. It might even be overstressed
in this steel, but what could happen? Not failure, for the beams are
capable of carrying their load individually, and even if the rods over
the supports were severed--a thing impossible because they cannot
stretch out sufficiently--the beams would stand.

Continuous beam calculations have no place whatever in designing
stringers of a steel bridge, though the end connections will often take
a very large moment, and, if calculated as continuous, will be found to
be strained to a very much larger moment. Who ever heard of a failure
because of continuous beam action in the stringers of a bridge? Why
cannot reinforced concrete engineering be placed on the same sound
footing as structural steel engineering?

The eighth point concerns the spacing of rods in a reinforced concrete
beam. It is common to see rods bunched in the bottom of such a beam with
no regard whatever for the ability of the concrete to grip the steel, or
to carry the horizontal shear incident to their stress, to the upper
part of the beam. As an illustration of the logic and analysis applied
in discussing the subject of reinforced concrete, one well-known
authority, on the premise that the unit of adhesion to rod and of shear
are equal, derives a rule for the spacing of rods. His reasoning is so
false, and his rule is so far from being correct, that two-thirds would
have to be added to the width of beam in order to make it correct. An
error of 66% may seem trifling to some minds, where reinforced concrete
is considered, but errors of one-tenth this amount in steel design would
be cause for serious concern. It is reasoning of the most elementary
kind, which shows that if shear and adhesion are equal, the width of a
reinforced concrete beam should be equal to the sum of the peripheries
of all reinforcing rods gripped by the concrete. The width of the beam
is the measure of the shearing area above the rods, taking the
horizontal shear to the top of the beam, and the peripheries of the rods
are the measure of the gripping or adhesion area.

Analysis which examines a beam to determine whether or not there is
sufficient concrete to grip the steel and to carry the shear, is about
at the vanishing point in nearly all books on the subject. Such
misleading analysis as that just cited is worse than nothing.

The ninth point concerns the T-beam. Excessively elaborate formulas are
worked out for the T-beam,