The writer is utterly at a loss to know what Professor Ostrup means by his first few paragraphs.  He says that in the first point two designs are mentioned and a third condemned.  The second design, whatever it is, he lays at the writer’s door in these words:  “The author’s second design is an invention of his own, which the Profession at large is invited to adopt.”  In the first point sharp bends in reinforcing rods are condemned and curves recommended.  Absolutely nothing is said of “a reinforced concrete beam arranged in the shape of a rod, with separate concrete blocks placed on top of it without being connected.”

In reply to Professor Ostrup, it should be stated that the purpose of the paper is not to belittle the importance of the adhesion or grip of concrete on steel, but to point out that the wonderful things this grip is supposed to do, as exhibited by current design, will not stand the test of analysis.

Professor Ostrup has shown a new phase of the stress in shear rods.  He says they are in bending between the centers of compressive resultants.  We have been told in books and reports that these rods are in stress of some kind, which is measured by the sectional area of the rod.  No hint has been given of designing stirrups for bending.  If these rods are not in shear, as stated by Professor Ostrup, how can they be in bending in any such fashion as that indicated in Fig. 12?

Professor Ostrup’s analysis, by which he attempts to justify stirrups and to show that vertical stirrups are preferable, merely treats of local distribution of stress from short rods into concrete.  Apparently, it would work the same if the stirrups merely touched the tension rod.  His analysis ignores the vital question of what possible aid the stirrup can be in relieving the concrete between stirrups of the shear of the beam.

The juggling of bending moments in beams is not compensating.  The following is a concrete example.  Some beams of a span of about 20 ft., were framed into double girders at the columns.  The beams were calculated as partly continuous, though they were separated at their ends by about 1-1/2 or 2 ft., the space between the girders.  The beams had 1-1/8-in. tension rods in the bottom.  At the supports a short 1/4-in. rod was used near the top of the beam for continuity.  Does this need any comment?  It was not the work of a novice or of an inexperienced builder.

Professor Ostrup’s remarks about the shifting of the neutral axis of a beam and of the pressure line of an arch are based on theory which is grounded in impossible assumptions.  The materials dealt with do not justify these assumptions or the hair-splitting theory based thereon.  His platitudes about the danger of misplacing reinforcement in an arch are hardly warranted.  If the depth and reinforcement of an arch ring are added to, as the inelastic, hinge-end theory would dictate, as against the elastic theory, it will strengthen the arch just as surely as it would strengthen a plate girder to thicken the web and flange angles.