Part II of III
As I began pursuing knowledge of thin shelled concrete, I started looking for an engineer. I also started to learn as much as I could myself. I learned about a shape that was designed by a Mexican architect Felix Candella, that was doubly curved known as a hyperbolic paraboloid. The name comes from a section through the shape that in one direction gives a pair of hyperpolis and in another direction a parabola.
I kept growing in background and met with a local engineer who said he knew how to do it. As I began to learn more myself, it wasn’t long before I realized my engineer didn’t really know anything about it. So I was sort of stumped. About this time, the representative of Portland Cement, Carl Roesser, stopped by my office. In those days Portland Cement Association (PCA) had representatives that would visit architects that had problems and Carl visited my office. I discussed my dilemma with him and he said,
“Oh, PCA’s head of advanced engineering, Al Parme, has been working on this very thing. I think you should get down to Chicago to meet him.”
Carl set up an appointment and I did just that. Al was an older man–very friendly and helpful. He showed me work he had been doing on a theory he had been developing with hyperbolic paraboloids. He said that it hadn’t been tested yet but he was sure he was right. So I asked him if he knew of an engineer I could engage to apply his theory. He then asked me,
“What’s your background?”
“I graduated in the architectural engineering program at the University of Illinois.”
“That’s great. You do it. I’ll help you.”
So I reported all this back to the committee at St. Edmund’s, explained how experimental it was but shared also the confidence I had in Al and the PCA.The committee voted to cancel their previous approval and instructed me to proceed with investigating a design with a thin shelled concrete roof.
The next day I got going on the design using thin shelled concrete and contacted Felix Candella in Mexico City who was the only architect known anywhere who had been working with thin shelled forms. He suggested I bring my sketches and come down to meet with him.
When I told Dolores–who was pregnant with our third child John at this point, she said,
“That’s going to be expensive. Where will we get the money?”
I went to the bank and got a loan for my airplane ticket and miscellaneous expenses.
I remember getting to Mexico City and somehow finding Candella’s office. I introduced myself and showed him the sketches I had made. He pointed out that based on his experience, the changes I’d have to make included adding substantial buttresses along the lower side of the shell. I spent a couple days working on analyzing the engineering based on his theory and in a few days flew back home.
So now I had Felix Candella’s experience with actually building thin shells and Al Parme with a theory that had not yet been tested and the two were significantly different. Using my engineering training to the best of my ability, I analyzed the two approaches.
Boy, that Professor Morgan at Illinois, and what he taught me! Doing concrete engineering required the use of many handbooks, formulas, etc. Professor Morgan taught that we could understand the stress in a structural form—what was in the steel and what was in the concrete—so that we could first visually see what was going on in a structural form in our minds and then use the handbooks, formulas, etc. That was one of the many reasons why I highly regarded and highly respected Professor N. D. Morgan.
After analyzing the two approaches to the best of my ability, I called Al Parme and told him what I was doing. He told me to come on back down so that we could take a look at it.
I remember so well that by Al’s evaluation based on his theory, there would be no need for the large buttresses Candella said I would have to have.
After spending more time in my office trying to understand the two theories, I concluded that I was sure Al’s was correct. So I called him back again and took another trip to Chicago to explain my thinking.
Al told me that Portland Cement Association was interested in building a model to test his theory and that we would use my building to test it. He explained that PCA would install instrumentation which would evaluate the stress, strain and deflection of all aspects of the structure. After the concrete was poured and had cured a full 28 days, we would slowly lower the form to see how the structure performed. Though the form work was now free of the structure, it was still in place below the structure itself. If there was a problem we could then address it.
I reported everything I had learned to the St.Edmund’s building committee and with their approval I proceeded with the design.