ive the shear per stirrup, but even advocates of this
method acknowledge that they can not. To apply the common analogy of a
truss: each shear member would represent a tension web member in the
truss, and each would have to take all the shear occurring in a section
through it.

If, for example, shear members were spaced half the depth of a beam
apart, each would take half the shear by the common method. If shear
members take vertical shear, or if they take tension, what is between
the two members to take the other half of the shear? There is nothing in
the beam but concrete and the tension rod between the two shear members.
If the concrete can take the shear, why use steel members? It is not
conceivable that an engineer should seriously consider a tension rod in
a reinforced concrete beam as carrying the shear from stirrup to
stirrup.

The logical deduction from the proposition that shear rods take tension
is that the tension rods must take shear, and that they must take the
full shear of the beam, and not only a part of it. For these shear rods
are looped around or attached to the tension rods, and since tension in
the shear rods would logically be imparted through the medium of this
attachment, there is no escaping the conclusion that a large vertical
force (the shear of the beam) must pass through the tension rod. If the
shear member really relieves the concrete of the shear, it must take it
all. If, as would be allowable, the shear rods take but a part of the
shear, leaving the concrete to take the remainder, that carried by the
rods should not be divided again, as is recommended by the common
method.

Bulletin No. 29 of the University of Illinois Experiment Station shows
by numerous experiments, and reiterates again and again, that shear rods
do not act until the beam has cracked and partly failed. This being the
case, a shear rod is an illogical element of design. Any element of a
structure, which cannot act until failure has started, is not a proper
element of design. In a steel structure a bent plate which would
straighten out under a small stress and then resist final rupture, would
be a menace to the rigidity and stability of the structure. This is
exactly analogous to shear rods which cannot act until failure has
begun.

When the man who tears down by criticism fails to point out the way to
build up, he is a destructive critic. If, under the circumstances,
designing with shear rods had the virtue of bein