ELAZIG GUNISIGI NEWSPAPER – April 2012
REINFORCED CONCRETE STRUCTURES
In the past month, I’ve been asked the same question twice, and I realized that it might be helpful to clarify some topics.
At the beginning of the spring semester, when I introduced the Reinforced Concrete-I course, I wanted to illustrate the content and, especially, the importance of the subject through photos. I shared some unforgettable images of the 1999 Marmara Earthquake and the 2003 Bingöl Earthquake with my students, particularly the heartbreaking and thought-provoking photo of the Çeltik Suyu YİBO debris.
One of my students asked me a question: “Professor, if reinforced concrete is such a weak system, why do we still use it? Why don’t we build with steel structures?”
I tried to explain it to this young future colleague as best as I could. Honestly, at that moment, the question didn’t seem strange to me.
Recently, a dear friend of mine visited me. He’s not a civil engineer but is part of a closely related profession. During our conversation, he asked the same question as my student, and I realized that this question is probably in many people’s minds.
Are we insisting on a weak system like reinforced concrete for no reason? This is a question that seems to concern more people than I originally thought.
When reinforced concrete structures are designed, the material is considered less durable, and the load calculations are intentionally kept higher than necessary. In other words, both the material and the load are kept on the safe side. By doing this, you add more than two safety factors to the system.
So how is it that a building still collapses despite these safety factors? The answer is, as simple as it might sound, like a joke: If you use a safety factor but then add too much arbitrariness and negligence into the system, you can easily reach the result.
It’s clear that we’ve been working hard for the past decade to eliminate safety factors from projects, especially during the construction phase.
For about the last 10 years, our projects have seen more computer-based design methods. However, if the engineer is enslaved by technology, the results after earthquakes will remain unchanged. Yet, if technology is our servant, we can come up with the right solutions.
We’ve only recently become acquainted with ready-mix concrete. Some regions only met it ten years ago, and there are still places that haven't even heard of it—I don’t even want to imagine that.
Concrete isn’t a child that you can just pour and leave without any further care. This careless attitude has led to people living in buildings that could become their graves.
As summer approaches, we’ll unfortunately see the concrete structures that haven't been maintained once again.
Despite our long list of negligence and irresponsibility, reinforced concrete buildings continue to stand strong and make an effort to survive during earthquakes.
Let’s not forget, every structure that is designed and built in accordance with standards, regardless of its load-bearing system, will be earthquake-resistant.
When we look at the Van Earthquakes, we see that even reinforced concrete buildings that clearly did not follow any rules managed to stay upright. In such large earthquakes, the fact that buildings we deem inadequate remained standing demonstrates the strength of the reinforced concrete system.
What kind of a load-bearing system is it that allows a three-story building to be designed but a seven-story one to be constructed, and still expects it to withstand an earthquake?
One thing is certain about buildings: regardless of the type of load-bearing system, structures that are designed and built in accordance with standards will be earthquake-resistant.