Intro

🔊 Play Transcript

Johannes: Welcome to Concretely,

I’m your host Johannes Lohner and I talk with experts from various fields about the maintenance of our structures.

Our infrastructure, a foundation of our modern society, is aging. The majority of it, in industrial countries like Europe or North America, was built in the 60s and 70s. To illustrate this, I would like to talk about the example of highway bridges.

In Switzerland, there are about 4,500, in Austria 4,700, and in Germany 10 times more: 40,000. In Switzerland alone, 60% more bridges were built annually in the ten years between 1953 and 1964. This means that the number of new bridges was quadrupled every three years.

These bridges do not last forever. If we assume a lifespan of 75 years for these bridges, it means that in four years, i.e., in 2028, increasingly more resources will be needed to replace these bridges.

In the following years, between 1964 and 1980, an average of 150 highway bridges were built per year. The maximum number even reached 225 highway bridges in one year.

In Switzerland, the replacement of these 150 highway bridges would mean an average cost of 1.3 billion francs per year. These 1.3 billion francs are the costs to replace the existing bridges. However, we already spend a lot of money today to maintain the existing bridges. The biggest damage mechanism is reinforcement corrosion. Today, corrosion on Swiss road bridges costs the taxpayer 1000 CHF/minute. This figure comes from the research work of ETH Professor Ueli Angst, whom we are pleased to welcome in our second podcast episode.

But there are also indirect costs: In 2001, the total value added of traffic in Switzerland was valued at almost 60 billion francs per year. Therefore, road closures can lead to much higher socio-economic costs. Especially on traffic routes like the Brenner or the Gotthard, where there were also spalling on the intermediate ceilings in September 2023.

We are not prepared for this use of resources:

On the one hand, in terms of personnel: the upcoming wave of retirements will only exacerbate the current shortage of skilled workers.

But on the other hand, in terms of sustainability: to achieve our climate goals, we want to drastically reduce CO2 emissions in the coming years and decades.

Let’s go back to the example of Swiss highway bridges. Swiss highway bridges consist of underpasses, overpasses (bridges that go over the highway), and regular bridges that cross obstacles such as valleys or rivers. One could assume an average bridge has about 500 cubic meters of concrete. One cubic meter of concrete weighs about 2.4 tons. Of that, 1/5 is cement. The production of one ton of cement generates about 900 kg of CO2. This means that replacing 150 highway bridges per year, the concrete alone, would cause about 33,000 tons of CO2. This is about the amount of CO2 emitted by the entire agricultural sector in Switzerland.

But now we have only talked about highway road bridges. In transport infrastructure, there are also railway bridges, tunnels, retaining walls, airports, and much more. In energy, water/wastewater, and communication infrastructure, there are power pylons, canals, wastewater treatment plants, dams, weirs, and so on. And then, of course, there are many other structures such as in civil defense, industry, residential and office buildings, and so on.

The mentioned problems, however, also offer enormous opportunities. There are already many efforts today to tackle these challenges. These include computational models, sensors, image recognition, drones, sustainable materials, etc., all of which we will also discuss in this podcast.

However, these opportunities are often not fully utilized. Pilot projects are carried out, but not rolled out on a large scale or linked together. The learned is often not passed on, and the status quo is maintained. I want to find out why this is the case and what is necessary to find a solution that is useful and applicable to all parties.

Therefore, in this podcast, we will not only discuss how to strengthen the crumbling bridges but also how we can strengthen the bridges between us and reduce silo thinking. My goal is to improve building preservation together and find ways to act more resource-efficiently.

How can we do this? I think we can only achieve this if we deal more openly with problems, take responsibility, and dare to try new things, work better together, and learn from each other across industries and national borders.

That’s why I started the podcast, where I talk to various experts in the DACH region such as entrepreneurs, subcontractors, engineers, owners, operational teams, professors, startups, and so on. In these conversations, I want to learn about their perspectives, their challenges, and their views on the state of technology. I want to introduce pilot projects and new technologies, but above all, I want to provide you, the listeners, with a comprehensive insight, as well as demonstrate the impossibility of solving the problems in building preservation.

Who are the listeners? For me, it’s the entire construction industry because preservation and new construction are very closely related, but also students and pupils who want to learn more about the construction industry.

I will publish an episode every two weeks, and you can find me on my homepage at www.concrete-ly.com, but also on LinkedIn under “Johannes Lohner” or on Spotify under “Concretely”.

How can you contribute? I would be most pleased if you comment or discuss on my homepage for each episode, but also if you share the podcast with your friends and colleagues.

I look forward to welcoming you back to Concretely soon!