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Some lessons are learned the hard way

Image: Consequences of steel fiber — Use of steel fibers instead of rebar allowed the top of this dome to cave in twice during construction. To repair this dome, we installed a rebar grid covered with welded wire fabric and re-sprayed both the urethane and shotcrete.

Consequences of steel fiber — Use of steel fibers instead of rebar allowed the top of this dome to cave in twice during construction. To repair this dome, we installed a rebar grid covered with welded wire fabric and re-sprayed both the urethane and shotcrete.


Never Use Steel Fibers Instead of Rebar in a Monolithic Dome

One day in 1979 (we had been building Monolithic Domes for about three years) a US Steel Company salesman showed up selling steel fibers. He told me if I used steel fibers I would not have to use rebar in my Monolithic Domes anymore.

I subsequently studied the steel fibers, and thought they seemed like a great alternative. The materials US Steel gave me looked good. I asked Dr. Arnold Wilson about them. He said he did not believe steel fibers would work. I should have backed off right then, but I didn’t.

It all really seemed to make sense. So in about 1980 I built a 50’ dome with them and then a 60’ and another 60’ and a 75’. Boy, was it easy. We came up with a way to use the fibers that was almost flawless — and we were really starting to congratulate ourselves.

We had a project to do in Oklahoma which involved two big domes, each 105’ in diameter. We built the first one and had it almost finished when the top fell in. When it fell, we thought one of the contractors helping us had opened both doors and let the air pressure drop too soon. So we put it back to together. Everything seemed fine, so we started on the next dome. When we had almost finished the second dome, we were taking a break when KABOOM! the top came crashing down out of the first dome again. We immediately switched back to rebar and rebuilt both domes.

During the rebuilding process my brother, Randy, called me from a job in Iowa to tell me another fiber dome caved in. We replaced the fibers with rebar and finished that dome up as well.

We had one more big dome in North Dakota under construction at the same time using the steel fibers. It was located in Fargo and was 105’ in diameter. The crew there got it up, finished and solid. We wondered if we had done something wrong on the other two projects. But, by then I made up my mind that I wanted nothing more to do with fibers.

When spring came in North Dakota, it was time to cut the seed potatoes. The big dome with the steel fibers was being used for seed cutting space with the seed cutter located dead center. About twelve women worked all day, every day around that seed cutter. At noon one day they all went home for lunch. When they came back, they found the top 35 feet of the dome laying on the seed cutter, having smashed it flat. Had it not been for their lunch break, they all would have surely died.

It probably would have been the end of the dome business. As it was, US steel got out of the steel fiber business. The next year there were law suits, and it turned out that US Steel had evidence in their files proving the fibers did not work properly with shotcrete. It was a terrible mess. It cost US Steel a lot of money, it cost my insurance company a lot of money, and it almost ended in a real tragedy.

So, I gave up on fibers- until about five years ago. In 1999, another steel fiber company came knocking. This company’s propaganda said they make a hook steel fiber that they say will do everything but wine and dine you. So, we built a 20’ dome with it, for the sake of experimentation. We call it the “fiber shell,” and it is located here on our property. You can see eighteen large cracks in it. Those cracks are growing larger each year, the fibers are not doing the job.

When a regular Monolithic dome has a crack in it, the rebar can take up the pressure, and stops the crack from growing. But when a fiber dome has a crack in it, it means you have broken a fiber, if you break one fiber, then you break two and then you break three and so forth.

About a year ago I had a pastor contact me from Colorado. He had a steel fiber dome that was built by an early competitor of mine who had continued to use steel fibers— even after I had stopped. Despite my experiences, he still thought they were a great idea and built this guy a church. In the fifteen years ensuing, the cracks have opened up so much you can stick your hand through the wall of the church. His engineer, as well as my engineer condemned the building. It was not safe and will continue to deteriorate until it falls in.

March 22, 2004