derstood, it is astounding that engineers should
perpetrate the gross error of making a sharp bend in a reinforcing rod
under stress.

The second point to which attention is called may also be illustrated by
Fig. 1. The rod marked 3 is also like the truss-rod of a queen-post
truss in appearance, because it ends over the support and has the same
shape. But the analogy ends with appearance, for the function of a
truss-rod in a queen-post truss is not performed by such a reinforcing
rod in concrete, for other reasons than the absence of a post. The
truss-rod receives its stress by a suitable connection at the end of the
rod and over the support of the beam. The reinforcing rod, in this
standard beam, ends abruptly at the very point where it is due to
receive an important element of strength, an element which would add
enormously to the strength and safety of many a beam, if it could be
introduced.

Of course a reinforcing rod in a concrete beam receives its stress by
increments imparted by the grip of the concrete; but these increments
can only be imparted where the tendency of the concrete is to stretch.
This tendency is greatest near the bottom of the beam, and when the rod
is bent up to the top of the beam, it is taken out of the region where
the concrete has the greatest tendency to stretch. The function of this
rod, as reinforcement of the bottom flange of the beam, is interfered
with by bending it up in this manner, as the beam is left without
bottom-flange reinforcement, as far as that rod is concerned, from the
point of bend to the support.

It is true that there is a shear or a diagonal tension in the beam, and
the diagonal portion of the rod is apparently in a position to take this
tension. This is just such a force as the truss-rod in a queen-post
truss must take. Is this reinforcing rod equipped to perform this
office? The beam is apt to fail in the line, _A B_. In fact, it is apt
to crack from shrinkage on this or almost any other line, and to leave
the strength dependent on the reinforcing steel. Suppose such a crack
should occur. The entire strength of the beam would be dependent on the
grip of the short end of Rod 3 to the right of the line, _A B_. The grip
of this short piece of rod is so small and precarious, considering the
important duty it has to perform, that it is astounding that designers,
having any care for the permanence of their structures, should consider
for an instant such features of desi