ly driven
into holes in a steel angle, is made more evident, Bolts in a wooden
beam built up of horizontal boards would be tightly drawn up, and the
friction would play an important part in taking up the horizontal shear.
Dowels without head or nut would be much less efficient; they would be
more like the stirrups in a reinforced concrete beam. Furthermore, wood
is much stronger in bearing than concrete, and it is tough, so that it
would admit of shifting to a firm bearing against the bolt. Separate
slabs of concrete with bolts or dowels through them would not make a
reliable beam. The bolts or dowels would be good for only a part of the
safe shearing strength of the steel, because the bearing on the concrete
would be too great for its compressive strength.

Mr. Mensch states that at least 99% of all reinforced structures are
calculated with a reduction of 25% of the bending moment in the center.
He also says "there may be some engineers who calculate a reduction of
33 per cent." These are broad statements in view of the fact that the
report of the Joint Committee recommends a reduction of 33% both in
slabs and beams.

Mr. Mensch's remarks regarding the width of beams omit from
consideration the element of span and the length needed to develop the
grip of a rod. There is no need of making a rod any less in diameter
than one-two-hundredth of the span. If this rule is observed, the beam
with three 7/8-in. round rods will be of longer span than the one with
the six 5/8-in. rods. The horizontal shear of the two beams will be
equal to the total amount of that shear, but the shorter beam will have
to develop that shear in a shorter distance, hence the need of a wider
beam where the smaller rods are used.

It is not that the writer advocates a wide stem in the T-beam, in order
to dispense with the aid of the slab. What he desires to point out is
that a full analysis of a T-beam shows that such a width is needed in
the stem.

Regarding the elastic theory, Mr. Mensch, in his discussion, shows that
he does not understand the writer's meaning in pointing out the
objections to the elastic theory applied to arches. The moment of
inertia of the abutment will, of course, be many times that of the arch
ring; but of what use is this large moment of inertia when the abutment
suddenly stops at its foundation? The abutment cannot be anchored for
bending into the rock; it is simply a block of concrete resting on a
support. The great be