María Portela Barral: «The fact that the concrete construction sector wants to incorporate wood into its projects is great news»
Sustainable. Available. Efficient and elegant. The possibilities of wood in the construction industry are enormous. As are the challenges it faces in becoming a real alternative, or a complement, to materials as consolidated as concrete.
We talk to María Portela Barral, forestry engineer at the Higher Polytechnic School of Engineering on the Terra Campus and researcher at the Structural Wood Engineering Platform (PEMADE), about these challenges and the potential of wood. A research group that, since 2008, has worked intensively in a strategic field, taking into account the planet's objectives in areas such as sustainability.
-Your professional career is closely linked to wood as a construction material. What led you to specialize in this field?
-I studied Forestry Engineering at the Higher Polytechnic School of Engineering on the Lugo campus. Although I opted for an engineering degree, I was always attracted to the world of art, natural materials and crafts.
By chance, almost at the end of my training at this school, I came across the PEMADE laboratory and the work that its director, Manuel Guaita, was leading from the Lugo campus.
I was surprised by the cutting-edge research that existed around structural wood and the possibilities that this material offered in modern and planet-friendly construction.
I thought it was a wonderful opportunity to be able to combine my technical training and also satisfy my curiosity about a material so closely linked to the artistic, the natural and our history.
-PEMADE is a leader in research on structural wood engineering. What is the role of the laboratory in promoting sustainability in construction?
-The research and work carried out by PEMADE highlights the use of wood as a material for structural use. And this is nothing new, as we know that wood has been used to build our houses since ancient times.
Although, over the years, new materials have indeed appeared and taken center stage, the wood sector has not stopped evolving and becoming more technical. Today, it has a wide variety of approved products manufactured by cutting-edge, high-level industries.
Today, wood also occupies a leading role, together with these new materials, but in its case it shares its current innovative character with its natural origin. And therein lies one of its great advantages and what makes it such a precious commodity, its nature.
At PEMADE, we believe that wood's carbon sequestration capacity and its status as a renewable material are among the many aspects that should be emphasized in order to incorporate wood as another material for the development of our urban spaces.
We support this idea through the projects we work on and through the training in which we are also involved. This training, provided by the Polytechnic School of the Terra Campus, is essential not only to have more qualified personnel who are experts in structural wood from a technical point of view but also in the in-depth knowledge of the nature of the material. Only in this way is it possible to understand its mechanical behavior and the environmental benefits it brings to the planet and to those of us who inhabit it.
-You are currently working on your doctoral thesis on the mechanical behavior and development of wood-based construction products and systems. Could you give us a preview of some of the main lines of research?
-For the development of my thesis we wanted to study the possibilities of applying non-destructive acoustic techniques in the estimation of the mechanical properties of oak wood. Measurements were taken on trees, logs, boards and sheets with serrated joints made from this species.
The results of these measurements are compared with each other in order to find the variables that help us relate them and, in this way, starting from a measurement with these non-destructive techniques carried out on the standing tree, we could estimate the mechanical properties of the wood from that tree, which is of great interest as a tool for the selection of trees and the final destination of each one of them.
In the case of oak wood and the conditions of growth and management in our community, having research available in relation to its application as structural wood means valuing our native forest resources and providing tools that facilitate its selection and use, also offering greater added value to the final product.
-One of the challenges of building with wood is to guarantee the strength and durability of the material. How do analysis technologies, such as digital image correlation or acoustic emission, help to evaluate and improve these properties?
-Current research in the field of structural wood has shown us that there are infinite technologies that are of great help in getting to know the material better and that allow us to obtain its maximum use in quality products that have a real and successful application. Digital image correlation (DIC) is one of them.
This technique is used in different fields. In the case of PEMADE, we apply DIC as a complement to a laboratory test from which we want to extract in great detail information about what is happening in a specific area of the test piece during the test. For example, how does a wooden beam deform at the supports when subjected to the load? Or, what is the displacement that we are going to obtain in a certain connection between two wooden elements, or in a connection between wood and another material?
The quantity and quality of information obtained with the application of these techniques is of great help to understand the behavior of the material better and propose improvements in the development of new products.
The main advantage of non-destructive acoustic techniques is that, as the name suggests, it is not necessary to destroy the material; in other words, it is not required to break the wood to extract information from the test.
In the laboratory, we use this technology in the different phases of wood transformation, from tree to final product. This research provides results for the application of different acoustic equipment, which can then be incorporated at an industrial level by sawmills, technical wood manufacturers, etc. All this is designed to provide tools that help in the knowledge of the physical and mechanical properties of wood and the selection of the material.
-The use of fast-growing species such as poplar is gaining relevance in the manufacture of structural wood products. How does this trend contribute to the circular economy and the reduction of the carbon footprint?
-The boom in the use of wood in construction brings with it the need to assess the availability of the resource and optimize its use. Just as I said before, opting for the use of wood as a building material is an environmentally friendly option; the sustainability associated with the material does not only depend on the material and its nature; it also depends on how we manage it.
It is not enough to propose wood products that incorporate fast-growing species. The key is how we manage these forest plantations, how we transform the resource and how we finally apply it.
Different forest species coexist in our territory, each with specific qualities that give them certain mechanical properties. The choice of which to use will depend on our objectives in terms of resistance and durability. What is a great step forward and offers great opportunities is having characterization studies of species that until now were not included in the structural wood regulations, as is the case of poplar in Spain, and that allows, once their mechanical properties are known, to apply them safely in architectural projects.
-Research into composite materials, such as the combination of wood and concrete, seems to be opening up new possibilities. What practical applications could this technology have in construction?
-The fact that the concrete construction sector wants to incorporate wood into its projects is great news. The fact that there are more and more companies and individuals interested in building and offering buyers solutions with a lower environmental impact is a major step forward. Research in this area is focused on the development of mixed products connected in such a way that both materials work in solidarity, improving the strength, acoustic insulation and fire performance of the final product.
In short, mixed wood-concrete proposals make it possible to combine materials, take advantage of both and reduce the carbon footprint in construction.
-From your experience in research and teaching, what do you think is needed for wood to gain more prominence in the construction sector compared to materials such as concrete or steel?
-We have made great progress in publicizing the properties of wood as a structural material. Fifteen years ago, in the university world, we talked about the advantages of wood, and we gave the example of a unique project somewhere in Europe. Today we talk about all the cases, which are many, of the application of wood as a leading material in construction in Spain and Galicia. These projects are no longer so unique, and they have become part of our model of urban development.
I think the focus is already on the material. Now, we have to continue working so that these works and new projects are successfully executed and evolve properly. For this success, it is essential to have a quality forestry resource, which ensures the availability of material and its adequate, responsible and sustainable management, and also professionals who have at their disposal complete and quality training in the use of wood throughout the transformation chain of the material, including design and calculation.
-PEMADE collaborates with companies and public administrations. Could you share an example of knowledge transfer that has had a significant impact on the sector?
-PEMADE is a small research platform made up of a small group of people. Despite this, it is true that since its creation in 2008, there have been many, many projects developed in this laboratory related to the use of wood as a structural material.
We are lucky to be surrounded by companies in the sector involved in research and in making the transfer of knowledge from the university a reality, and we also have great colleagues from other universities and research centers with whom we work as a team.
I couldn't mention a specific case. I think all our work is connected, from the first project in 2008 to the projects we are currently developing. Each one is a consequence of the previous one, and this is a sign that the sector is continuing to advance and that the Administration supports us on this path.
-To conclude... What message would you give to new students who aspire to pursue a career in the field of forest engineering and sustainability in construction?
-Nowadays, being able to study a degree related to the natural environment offers you the possibility of, in the future, coming up with solutions for the conservation of natural resources and contributing to the evolution of our society from a social ecology perspective, which is key to addressing the magnitude of the climate crisis and keeping the planet habitable.
If that thought resonates with them, then they will enjoy their work very much, but also their training.