Future of Bridge Construction – ASFINAG Expert Dr. Michael Kleiser

Johannes:
Today marks the first episode where we converse with an Austrian expert, specifically with Dr. Kleiser from ASFINAG. He is an exceptionally experienced bridge engineer, having spent 13 years across various engineering firms, notably in bridge construction. Currently, he has been serving as a bridge expert at ASFINAG for another 13 years. ASFINAG, which stands for “Autobahnen- und Schnellstraßen-Finanzierungs-Aktiengesellschaft,” is wholly owned by the Austrian state and serves as the equivalent of Switzerland’s Astra or Germany’s Autobahn GmbH. Dr. Kleiser also lectures at the TU Vienna. Welcome, Michael.

Dr. Kleiser:
Hello!

Johannes:
To start off, Michael, what particularly attracts you to bridge construction?

Dr. Kleiser:
Bridge construction is, in my view, the pinnacle of building disciplines. This might be seen differently by others, but for me, it embodies the ultimate challenge. Bridges have historically stood as symbols of architectural culture. They even grace our currency, symbolizing not only architectural heritage but societal cohesion. Bridge construction demands immense engineering knowledge and skill, challenging engineers to blend efficiency, economy, cultural and aesthetic considerations seamlessly. It’s a discipline that I believe not only showcases the pinnacle of engineering expertise but also serves to honor the profession itself.

Johannes:
Could you provide some context about ASFINAG? How many bridges does it manage on the highways?

Dr. Kleiser:
While I don’t have the exact figure, there are over 5,000 structures ranging from small culverts to major valley bridges like the Europabrücke near Innsbruck. Given Austria’s mountainous terrain, we boast several remarkable constructions.

Johannes:
Okay.

Johannes:
That’s likely more than in Switzerland, which makes sense given Austria’s larger area. Can you describe your role as a bridge expert at ASFINAG?

Dr. Kleiser:
I operate not in a field capacity but within a supportive department, known as Engineering, where I serve as an expert. We’re essentially at the forefront of knowledge, consolidating expertise from innovation and best practices. My responsibilities include not only contributing to the innovation of bridge construction at ASFINAG but also disseminating this knowledge to operational units, providing support and guidance on complex issues, particularly in relation to contract management and technical queries.

Johannes:
Does this involve new construction as well as maintenance?

Dr. Kleiser:
It encompasses both new construction and maintenance. Our department is part of ASFINAG’s Asset Management, where we not only guide physical maintenance and set standards but also ensure that this knowledge is effectively applied by the construction departments to realize these projects.

Johannes:
Is there a clear distinction when it comes to maintenance, between renovating or completely rebuilding a bridge? This likely leads to a project within ASFINAG. Does the process differ significantly between constructing a bridge on undeveloped land compared to demolishing and rebuilding? Are these handled by different teams, or is it essentially the same process?

Dr. Kleiser:
Fundamentally, these are two distinct challenges. Constructing a bridge on undeveloped land is a different discipline compared to renovation within our existing network. Renovation or rebuilding within the existing infrastructure presents its own set of complex conditions. Initially, the critical step is to accurately assess the bridge’s condition.

Based on the assessment, we then decide whether to continue maintenance, enhance its structural capacity, or opt for demolition and reconstruction. This decision is complex and often involves consultation with an internal committee of experts. Construction on undeveloped land generally allows for more freedom, with environmental impact assessments playing a significant role. Thus, new constructions and renovations within the existing infrastructure are quite different, each with its unique set of challenges.

Johannes:
Regarding demolition, is the foundation usually replaced, or can the existing foundation be reused when maintaining a bridge?

Dr. Kleiser:
It depends on the new structure to be placed. If constructing a new bridge, higher loads typically necessitate the reinforcement of the foundation as per regulations. Of course, we aim to avoid excessive reinforcement of foundations whenever possible.

Johannes:
That’s intriguing. What are the greatest challenges in bridge construction currently?

Dr. Kleiser:
The foremost challenge is undoubtedly climate change, a concern familiar to all. The focus on sustainability has become paramount in our operations for several years. Another significant issue is the aging infrastructure. In the next 20-30 years, many bridges constructed in the mid to late 20th century will reach the end of their service life and will need reevaluation. Some may undergo another cycle of maintenance, but many will require demolition and reconstruction. This presents a massive portfolio of projects, implicating substantial CO2 emissions. Addressing how to reduce or altogether prevent these emissions will be a formidable challenge.

Johannes:
So, aging infrastructure and sustainability are major concerns. Costs and safety are likely additional considerations, right?

Dr. Kleiser:
Indeed, costs are always a consideration, partially factored into our planning. We engage in long-term planning within our department to forecast our budgeting needs accurately. However, the primary focus remains on maintaining our existing infrastructure, with no new constructions planned. The challenge lies in managing the aging bridge assets, a task that is inevitable.

Johannes:
What solutions are being considered for these future challenges?

Dr. Kleiser:
We have contemplated several approaches. The primary goal is to extend the operational life of bridges through various research initiatives. Although the options for extracting additional load-bearing capacity from existing bridges are limited, there are innovative methods, such as reinforcing with carbon fiber laminates or using ultra-high-performance concrete, aimed at preserving structural integrity. When replacement is unavoidable, the focus will shift towards utilizing environmentally friendly materials and construction methods to minimize CO2 emissions. This journey towards sustainable bridge construction is ongoing, and while initial strategies are in place, the road ahead is lengthy.

Johannes:
I’d like to delve deeper into the topic of extending the lifespan of bridges. How significant is the issue of corrosion? Would you say it’s the primary concern, and what are the major damages or problems associated with it?

Dr. Kleiser:
Corrosion, especially in reinforced concrete or prestressed concrete construction, is indeed at the root of many issues. The future lies in utilizing materials immune to corrosion, such as fiber-reinforced polymers including glass and carbon fibers. Though initially more expensive, these materials prove cost-effective over the lifecycle due to their durability and lack of corrosion. Ultra-high performance concrete also plays a significant role, offering a dense matrix that prevents water and thus chloride penetration, a key factor in preventing corrosion.

Johannes:
So, materials like carbon or stainless steel would be used in areas exposed to de-icing salts or sea spray, for example, but not necessarily everywhere due to cost considerations?

Dr. Kleiser:
Precisely. These materials will be applied efficiently, such as in bridge supports directly exposed to corrosive elements. Future construction might avoid such issues altogether by designing overpasses without central supports, though this approach may initially increase costs. It’s essential to think ahead and consider the future in these decisions.

Johannes:
How straightforward is it to justify higher initial costs for a bridge that may last an additional ten years? Is this a challenging concept to introduce?

Dr. Kleiser:
The argument is based on lifecycle costs. This approach is increasingly adopted by infrastructure owners as it’s recognized that building with the future in mind not only saves costs over time but also reduces CO2 emissions. Knowing the carbon footprint of construction and maintenance allows planners to incorporate CO2 considerations right from the start, aiming to lower emissions. The idea of pricing CO2 emissions and integrating them into the overall cost assessment is gaining traction, providing a comprehensive view of economic and environmental impacts.

Johannes:
Moving to your next solution – material efficiency for CO2 savings. I’ve heard about a new ecological balance tool; could you explain a bit about it?

Dr. Kleiser:
We’ve developed a tool for calculating the ecological balance, leveraging a database aligned with the construction industry standards in Austria, including concrete, steel, asphalt, and timber sectors. This ensures that the tool is as accurate as the data it’s based on. Our aim is to make environmental considerations a standard part of the planning process by providing a straightforward tool that integrates seamlessly into engineers’ current workflows. By adopting a simple, universally accessible format, we encourage all planning offices to factor in ecological impacts from the outset. This tool has been made mandatory for all new constructions on our network from the beginning of the year, ensuring that ecological balance assessments guide the choice of the most sustainable variant for implementation.

Johannes:
Do you envision applying this tool for maintenance activities as well, even for smaller measures?

Dr. Kleiser:
Yes, the mindset needs to shift towards incorporating this tool in maintenance as well. While its impact might be less pronounced in preservation since maintaining the substance of bridges already contributes significantly to sustainability, it’s crucial that this ecological consciousness permeates all levels of planning and execution. We aim for a holistic approach where functional, economical, and ecological considerations are balanced, and this tool is a step towards embedding sustainability in every aspect of our work, from new constructions to routine maintenance.

Dr. Kleiser:
This pertains to the preliminary design stage, where variant studies are conducted and significant decisions can be made. It’s crucial to apply this tool early on, even when only the main or rough quantities of a bridge project are known. This initial phase allows for an early estimation of CO2 emissions, guiding the choice of materials and construction methods. The aim is to set the course right from the start, as changes become more challenging once projects move into tendering or detailed design phases.

Johannes:
I also see the value in applying this tool for maintenance in the future, enabling the collection of data that could be useful for comparing the durability of structures. It might be beneficial to integrate additional databases, such as load and weather data. How do you envision the future in this regard? Do you see BIM integration or will it remain a standalone tool?

Dr. Kleiser:
The current tool, an Excel file, is intended as a temporary measure to prepare planning offices. Over time, commercial tools will likely supersede it, integrating directly into existing systems like BIM. The goal is to establish a methodology and database that other tools can utilize, simplifying the process for planners and ensuring the results are verifiable and transparent. The diversity of tools and methodologies has led to inconsistent outcomes, underscoring the need for standardization. Our tool has initiated this process, but it’s expected to evolve. The principle of standardization and uniformity will remain crucial.

Johannes:
I particularly appreciate the boldness in mandating its use among engineers and incorporating it smoothly into the workflow, ensuring it does not add extra work. Have you received any feedback on this approach?

Dr. Kleiser:
While the implementation in projects is just beginning, the feedback from planners and construction firms has been positive. There’s a strong interest in a unified data pool. Associations and industries have welcomed this standardization, allowing for a consistent basis for comparison and calculation. This broad acceptance suggests a successful integration into daily practices. The tool is designed to align with existing work processes, facilitating its adoption. It’s crucial, however, that this tool influences the design phase, encouraging planners to explore more sustainable variants and innovative solutions in bridge construction. The potential for CO2 savings in bridge construction is immense, and initial studies confirm this, highlighting the shift towards more efficient and environmentally friendly building practices.

Dr. Kleiser:
The discussion on CO2 emissions is essential, as it influences the shift in planning approaches, encouraging engineers to explore innovative solutions.

Johannes:
Is there a recognition or evaluation system in place for projects that adopt these measures, particularly in terms of CO2 savings compared to standard constructions?

Dr. Kleiser:
Our strategy involves conducting variant studies, including at least one conventional (functional and economical) design and another focused on sustainability, potentially at a higher cost but with a lower carbon footprint. The goal is to compare these variants and select the most balanced option, not solely based on cost but also considering CO2 savings. This approach ensures a thoughtful selection process that incorporates both economic and environmental factors.

Johannes:
Regarding eco-friendly materials, we’ve previously discussed CO2-reduced cement. Are there other materials or considerations to keep in mind?

Dr. Kleiser:
Significant research and development are ongoing in reducing CO2 emissions from cement, leading to innovative products already available on the market. We’ve also established guidelines in Austria for using CO2-reduced concrete in engineering construction, expanding beyond traditional applications. It’s crucial to acknowledge that while reducing cement content may seem straightforward, it demands careful consideration of durability and meticulous execution on-site to maintain the structural integrity and longevity of concrete constructions.

Johannes:
Let’s touch on the importance of communication and interaction with various stakeholders in bridge construction and within ASFINAG. How challenging is this aspect?

Dr. Kleiser:
Effective communication is vital, both on construction sites and within ASFINAG’s different departments. We’ve fostered excellent collaboration across various areas, from digitalization and project development to asset management. Understanding each other’s perspectives is key, as is the case with integrating sustainability and BIM into our projects. The shared challenges of sustainability and climate change have united us, focusing our collective efforts on common goals.

Johannes:
It seems there’s also a significant political influence, setting the agenda for these initiatives, correct?

Dr. Kleiser:
Indeed, political directives have shaped our objectives in recent years. However, our proactive stance on sustainability and CO2 reduction predates these mandates, reflecting an inherent recognition of the challenges and opportunities that lie ahead. Our efforts, such as developing tools for CO2 assessment and advocating for eco-friendly construction practices, have been motivated by a commitment to future-proofing our infrastructure, independent of political trends.

Johannes:
Interesting. Do you think artificial intelligence (AI) could play a role in communication and planning in the future? How do you see its potential?

Dr. Kleiser:
Yes, AI is a significant trend we cannot ignore, and ASFINAG has already started exploring ways to leverage it for our benefit. While we must approach it cautiously, AI offers the potential to fill gaps in our data landscape with new insights. However, it’s crucial to remember that AI-generated data may not always align with factual accuracy, presenting a challenge in maintaining our commitment to truthfulness. Despite these concerns, AI’s ability to connect disparate data sets and offer new perspectives is invaluable, and we’re exploring its application in optimizing infrastructure maintenance among other areas.

Johannes:
That’s a positive outlook. Lastly, would you like to share any advice for young civil engineers entering the field?

Dr. Kleiser:
Certainly. I often tell students that civil engineering is a career of the future. The coming decades will bring about significant changes, unlike the past where processes were more or less standardized. The challenges of climate change and CO2 reduction introduce new criteria, requiring innovative thinking. There’s a substantial need for civil engineers, and I believe it promises a bright future. The era of engineers in the 19th century was marked by groundbreaking developments, and we might be on the cusp of a new golden age for engineers, driven by the necessity to address climate change and sustainability in our constructions.

Johannes:
A final thought?

Dr. Kleiser:
Regulations and standards have their place in ensuring quality and uniformity, but they can also stifle innovation. We might need to rethink and possibly streamline these to foster more creative and sustainable solutions. The challenge is to balance the need for standardization with the flexibility to innovate. The analogy of moving from “lighthouses to strings of lights” beautifully encapsulates our goal: to spread knowledge and innovation widely, making it accessible to all. Thank you for having me on the Concretely podcast; it’s been a pleasure discussing these important issues.

Johannes:
Thank you, Michael, for your insights and for joining us today.

Link ASFINAG: www.asfinag.at