g the best thing to do
with the steel and concrete disposed in a beam, as far as experience and
logic in their present state could decide, nothing would be gained by
simply criticising this method of design. But logic and tests have shown
a far simpler, more effective, and more economical means of disposing of
the steel in a reinforced concrete beam.

In shallow beams there is little need of provision for taking shear by
any other means than the concrete itself. The writer has seen a
reinforced slab support a very heavy load by simple friction, for the
slab was cracked close to the supports. In slabs, shear is seldom
provided for in the steel reinforcement. It is only when beams begin to
have a depth approximating one-tenth of the span that the shear in the
concrete becomes excessive and provision is necessary in the steel
reinforcement. Years ago, the writer recommended that, in such beams,
some of the rods be curved up toward the ends of the span and anchored
over the support. Such reinforcement completely relieves the concrete
of all shearing stress, for the stress in the rod will have a vertical
component equal to the shear. The concrete will rest in the rod as a
saddle, and the rod will be like the cable of a suspension span. The
concrete could be in separate blocks with vertical joints, and still the
load would be carried safely.

By end anchorage is not meant an inch or two of embedment in concrete,
for an iron vise would not hold a rod for its full value by such means.
Neither does it mean a hook on the end of the rod. A threaded end with a
bearing washer, and a nut and a lock-nut to hold the washer in place, is
about the only effective means, and it is simple and cheap. Nothing is
as good for this purpose as plain round rods, for no other shape affords
the same simple and effective means of end connection. In a line of
beams, end to end, the rods may be extended into the next beam, and
there act to take the top-flange tension, while at the same time finding
anchorage for the principal beam stress.

The simplicity of this design is shown still further by the absence of a
large number of little pieces in a beam box, as these must be held in
their proper places, and as they interfere with the pouring of the
concrete.

It is surprising that this simple and unpatented method of design has
not met with more favor and has scarcely been used, even in tests. Some
time ago the writer was asked, by the head of an engi