{"id":9391,"date":"2025-10-16T09:45:00","date_gmt":"2025-10-16T07:45:00","guid":{"rendered":"https:\/\/ingenius.ecoledesponts.fr\/?p=9391"},"modified":"2025-10-31T14:54:25","modified_gmt":"2025-10-31T13:54:25","slug":"giving-concrete-a-second-life","status":"publish","type":"post","link":"https:\/\/ingenius.ecoledesponts.fr\/en\/articles\/giving-concrete-a-second-life\/","title":{"rendered":"Giving concrete a second life"},"content":{"rendered":"\n\n\n
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Source : Canva<\/figcaption><\/figure>\n\n\n\n

We spoke with Ines Dakhli, an engineer from the \u00c9cole nationale des ponts et chauss\u00e9es, who completed her final year project at the Navier Laboratory on the topic: \u201cReuse Index: Application to the Construction Sector.\u201d She is currently pursuing a PhD at the Navier Laboratory<\/a> and Environmental Research Lab<\/a>. <\/strong><\/p>\n\n\n\n

At the beginning of your research, you explored the history of concrete as a material and the evolution of design standards. What did you discover?<\/strong><\/p>\n\n\n\n

The initial goal was to understand the context in which the first regulations emerged. When was the first regulation introduced? How often have calculation methods changed? And most importantly, back when concrete was first used, were we fully aware of its properties, as we are today?<\/p>\n\n\n\n

My first discovery was that the concept of a building’s lifespan is anything but straightforward. In the beginning, design regulations were primarily drawn up with safety concerns in mind. In the early days of reinforced concrete, at the end of the 19th and beginning of the 20th century, there were numerous structural accidents, that occurred either at the end of construction or shortly after buildings were put into use, resulting in many injuries and fatalities. In 1890, the collapse of a pedestrian bridge at the World Fair caused several deaths, prompting the government to call for standardized regulations for reinforced concrete design.<\/p>\n\n\n\n

At that time, reinforced concrete was still a relatively new material, barely fifty years old. The first reinforced concrete apartment building was built around 1890, on Rue Danton in Paris. This material carried a great deal of promise. It was considered highly durable because it enabled construction of continuous surfaces, without the need for joints, which were typically associated with water and air infiltration, and other structural issues.<\/p>\n\n\n\n

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First building made from reinforced concrete, around 1890, Rue Danton, in Paris. Credit : gallica.bnf.fr \/ Biblioth\u00e8que nationale de France<\/figcaption><\/figure>\n\n\n\n

<\/em><\/p>\n\n\n\n

The first standards for reinforced concrete were introduced in 1906, and they were very different to today\u2019s Eurocodes1<\/a><\/sup>. This early document was just five pages long, containing about twenty articles. While it provided general guidelines for structural resistance calculations and construction practices, it didn\u2019t specify any numerical values for the data to be used. At the time, there wasn\u2019t the same level of hindsight and understanding of concrete that we have today, which is why concepts like sustainability were completely absent from these initial standards.<\/p>\n\n\n\n

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First set of standards for reinforced concrete (1906). Source: \u00c9cole nationale des ponts et chauss\u00e9es.<\/em><\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

Another key discovery was the role of post-war reconstruction in shaping the BA45 regulation (the Reinforced Concrete Regulation of 1945). Construction was considered a matter of public affairs, essential for both housing and for industrial recovery, so certain concrete performance thresholds were raised to accelerate construction and reduce the quantity of materials used. As a result, design was no longer solely the concern of structural engineers and architects but also involved urban planners and industrial engineers. During the 1940s and 1950s, reinforced concrete experienced significant growth, driven by the industrialization of construction. Industrial processes emerged, and began to influence the design of reinforced concrete buildings.<\/p>\n\n\n\n

Issues related to the durability of concrete only started appearing in regulations toward the end of the 20th century. Questions started to be raised concerning the durability of concrete when the first signs of degradation in reinforced concrete structures emerged (such as the corrosion of reinforcement and waterproofing issues). These issues prompted engineers to start considering long-term performance. It was with the introduction of the Eurocodes that the concept of predefined lifespans emerged: 50 years for standard buildings, 100 years for monuments and major civil engineering works, and 10 years for temporary works. In the context of reusing materials, it is very important to be aware that the elements being reused were not originally designed with a specific lifespan in mind. This makes studying deconstructed elements crucial for assessing their residual performance.<\/p>\n\n\n\n

For this historical research, you drew on the Ecole Nationale des Ponts et Chauss\u00e9es\u2019 heritage collection. What made this collection such a particularly fascinating source of information?<\/strong><\/strong><\/p>\n\n\n\n

The school\u2019s heritage collection is both extensive and unique, especially in the fields of mechanics and materials science. This is largely because the school predates the invention of the material itself, meaning it witnessed both its creation and standardization. It was one of the first institutions to offer a course on reinforced concrete and it was able to acquire resources from other schools, such as ESTP<\/a>.<\/p>\n\n\n\n

The core mission of a school is to pass on knowledge, and this is reflected in the care taken to preserve this heritage collection. Today, although we may not always appreciate the value of this heritage amid the intensity of engineering studies, its very existence is a real asset for anyone looking to put current practices into historical perspective.<\/p>\n\n\n\n

Engineering is an iterative discipline, and being familiar with the research and reflections of earlier engineers, sometimes dating back decades, seems important to me, as their insights can really enrich our own thinking.<\/p>\n\n\n\n

Part of your study focuses on an indicator that demonstrates the reuse potential of a construction element, based on <\/strong>A. Lachat\u2019s doctoral thesis<\/strong><\/a>. Can you tell us about that? <\/strong><\/p>\n\n\n\n

This multi-criteria indicator is designed to assess the reuse potential of a construction element, based on its residual mechanical properties and the regulatory, logistical, economic, and environmental context in which it is situated.<\/p>\n\n\n\n

In practical terms, the indicator is expressed as a single value, calculated by multiplying two indices, each ranging between 0 and 1. The first index is purely mechanical, and takes into account the resistance of the concrete under pressure, its aging and the deconstruction method used to recover the element. The second index encompasses all the economic, environmental and logistical characteristics. It is designed to answer questions such as: is there a real environmental benefit to reusing this element as opposed to manufacturing a new one? The answer isn\u2019t always straightforward. For example, if an element needs to be transported 500 kilometers, the environmental benefit of reuse becomes questionable, since transport can significantly increase the overall impact. These two indices are then multiplied to obtain a reuse indicator, ranging from 0 (no reuse potential) to 1 (perfectly reusable element). When this indicator was first developed, the mechanical index applied solely to concrete, while the second index could be used for any construction component. Today, it is beginning to be adopted by the teams at Vinci, particularly for secondary construction elements.<\/p>\n\n\n\n

The aim of my final-year project, and now of my doctoral research, is to explore this indicator further, examine the assumptions on which it is based, and address the many questions it raises.<\/p>\n\n\n\n

You conducted a territorial study on four urban areas: what specific insights did this provide regarding the local reuse potential?<\/strong><\/p>\n\n\n\n

Unlike studies focused on individual elements or buildings, this research adopts a broader territorial scale, at the level of municipalities, or even departments. The main question was whether local construction activity is sufficient to absorb materials recovered from demolition.<\/p>\n\n\n\n

A key finding is that it remains very difficult to accurately quantify the \u2018urban mine\u2019, in other words, the stock of available elements and materials. The data used is primarily derived from building and demolition permits, which don’t necessarily include information about reuse potential. However, this is starting to change, thanks in part to emerging tools developed by organizations such as the Scientific and Technical Center for Building (CSTB), with BTPFlux<\/a>. This is a vast and important area of research for reuse, but one that I won\u2019t be able to explore in depth for my thesis due to its complexity. It\u2019s a whole research topic in its own right.<\/p>\n\n\n\n

Another conclusion from my study is that there are far fewer demolitions today than new constructions. As a result, materials recovered from demolition alone would not be enough to meet construction demand. In Switzerland for example, it is estimated that even if all materials from demolition were reused, they would only cover one-seventh of the country\u2019s construction needs.<\/p>\n\n\n\n

Finally, a particularly noteworthy exception is the department of Paris, and especially the city center, where renovation and rehabilitation projects now outnumber new construction. It is a city governed by numerous urban regulations and roadmaps that prioritize the preservation of architectural heritage. This illustrates how the legislative framework can directly influence our building practices.<\/p>\n\n\n\n

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Example of 58 Rue Mouz\u00efa, in Paris (19th arrondissement), built in 1974 by architects Claude Parent and Andr\u00e9 R\u00e9mondet. This building initially housed the offices of the Regional Directorate for Health and Social Affairs (DRASS). After being left vacant for several years, it was rehabilitated into student housing in 2020. The architect was selected for their proposal to transform the existing building, rather than demolish it.<\/em>  Credit : CANAL architecture \u2013 Photographe Pierre L\u2019Excellent <\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

Finally, how did you come to choose this final-year project and PhD topic? <\/strong><\/strong><\/p>\n\n\n\n

From a young age, I knew I wanted to work in the construction sector. I had always dreamed of becoming an architect, but then I discovered the role of the engineer. I found out that there was a dual engineering-architecture program at the \u00c9cole Nationale des Ponts et Chauss\u00e9es.<\/p>\n\n\n\n

In my second year of that program, I developed a deeper understanding of the construction industry, and of the ecological challenges it faces. Something I hadn\u2019t fully grasped before. It was unsettling to realize the contradiction, in that there is a genuine societal need to build, yet construction comes with a heavy toll on the environment.<\/p>\n\n\n\n

Concrete is the most widely used material today. We need to build, but we also continue to demolish a large number of buildings. I began to wonder: what happens to all these elements after they\u2019ve served their purpose? Can they be reused? Could they be disassembled and reassembled like Lego bricks? This shaped the direction of my final-year project, which I used as a springboard into a PhD on this topic.<\/p>\n\n\n\n

An engineer from the \u00c9cole Nationale des Ponts et Chauss\u00e9es (Department of Civil Engineering and Construction, Structure and Architecture Unit), Ines Dakhli\u2019s PhD research is now underway within the Navier Laboratory, as part of the Environmental Research Lab Chair, under the supervision of Ad\u00e9la\u00efde Feraille, Anne-Sophie Colas, Tiffany Desbois and Ambroise Lachat. Her research focuses on developing an indicator for reuse potential and on reuse itself, with a particular emphasis on reinforced concrete structures.<\/p>\n\n\n\n

Interview by Ad\u00e8le Mazurek, head of the mediation department at the \u00c9cole nationale des ponts et chauss\u00e9es<\/em><\/p>\n\n\n\n

<\/a><\/p>\n\n\n

  1. European standards for the design and calculation of structures. \u21a9\ufe0e<\/a><\/li><\/ol>","protected":false},"excerpt":{"rendered":"

    We spoke with Ines Dakhli, an engineer from the \u00c9cole nationale des ponts et chauss\u00e9es, who completed her final year […]<\/p>\n","protected":false},"author":6,"featured_media":9371,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_related_content_post":[],"_related_content_subject":[936],"_related_content_author":[9393],"_related_content_category":[1720,1716],"_related_content_folder":[9382],"_excerpt":"25 million m\u00b2! <\/strong>That\u2019s the total surface area of housing built in France in 2024.<\/a> Concrete, the most widely used material in construction, raises significant issues related to the exploitation of natural resources and the large-scale production of waste, estimated at nearly 15 million tons per year. In the context of climate change, the construction sector is adopting various strategies in an effort to reduce its environmental impact. Among these, reusing existing structures stands out as a particularly promising solution. However, this approach also presents a range of technical, economic, legal, and social challenges.","_duration":7,"_manual_duration":false,"footnotes":"[{\"content\":\"European standards for the design and calculation of structures.\",\"id\":\"caf70949-ba23-44c2-9c6e-b8a8cb26d124\"}]"},"article-types":[13,27],"class_list":["post-9391","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","article-types-article","article-types-folder"],"has_blocks":true,"block_data":[{"blockName":"enpc\/excerpt","attrs":{"lock":[],"metadata":[],"className":"","style":""},"innerBlocks":[],"innerHTML":"","innerContent":[],"rendered":""},{"blockName":"core\/image","attrs":{"id":9371,"sizeSlug":"full","linkDestination":"none","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/10\/Ines_Source_Canva-e1760532685556.png","alt":"","caption":"Source : Canva","lightbox":[],"title":"","href":"","rel":"","linkClass":"","width":"","height":"","aspectRatio":"","scale":"","linkTarget":"","lock":[],"metadata":[],"align":"","className":"wp-block-image size-full","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"
    Source : Canva<\/figcaption><\/figure>\n","innerContent":["\n
    \"\"
    Source : Canva<\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"
    Source : Canva<\/figcaption><\/figure>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"We spoke with Ines Dakhli, an engineer from the \u00c9cole nationale des ponts et chauss\u00e9es, who completed her final year project at the Navier Laboratory on the topic: \u201cReuse Index: Application to the Construction Sector.\u201d She is currently pursuing a PhD at the Navier Laboratory and Environmental Research Lab. ","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    We spoke with Ines Dakhli, an engineer from the \u00c9cole nationale des ponts et chauss\u00e9es, who completed her final year project at the Navier Laboratory on the topic: \u201cReuse Index: Application to the Construction Sector.\u201d She is currently pursuing a PhD at the Navier Laboratory<\/a> and Environmental Research Lab<\/a>. <\/strong><\/p>\n","innerContent":["\n

    We spoke with Ines Dakhli, an engineer from the \u00c9cole nationale des ponts et chauss\u00e9es, who completed her final year project at the Navier Laboratory on the topic: \u201cReuse Index: Application to the Construction Sector.\u201d She is currently pursuing a PhD at the Navier Laboratory<\/a> and Environmental Research Lab<\/a>. <\/strong><\/p>\n"],"rendered":"\n

    We spoke with Ines Dakhli, an engineer from the \u00c9cole nationale des ponts et chauss\u00e9es, who completed her final year project at the Navier Laboratory on the topic: \u201cReuse Index: Application to the Construction Sector.\u201d She is currently pursuing a PhD at the Navier Laboratory<\/a> and Environmental Research Lab<\/a>. <\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"At the beginning of your research, you explored the history of concrete as a material and the evolution of design standards. What did you discover?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    At the beginning of your research, you explored the history of concrete as a material and the evolution of design standards. What did you discover?<\/strong><\/p>\n","innerContent":["\n

    At the beginning of your research, you explored the history of concrete as a material and the evolution of design standards. What did you discover?<\/strong><\/p>\n"],"rendered":"\n

    At the beginning of your research, you explored the history of concrete as a material and the evolution of design standards. What did you discover?<\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The initial goal was to understand the context in which the first regulations emerged. When was the first regulation introduced? How often have calculation methods changed? And most importantly, back when concrete was first used, were we fully aware of its properties, as we are today?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The initial goal was to understand the context in which the first regulations emerged. When was the first regulation introduced? How often have calculation methods changed? And most importantly, back when concrete was first used, were we fully aware of its properties, as we are today?<\/p>\n","innerContent":["\n

    The initial goal was to understand the context in which the first regulations emerged. When was the first regulation introduced? How often have calculation methods changed? And most importantly, back when concrete was first used, were we fully aware of its properties, as we are today?<\/p>\n"],"rendered":"\n

    The initial goal was to understand the context in which the first regulations emerged. When was the first regulation introduced? How often have calculation methods changed? And most importantly, back when concrete was first used, were we fully aware of its properties, as we are today?<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"My first discovery was that the concept of a building's lifespan is anything but straightforward. In the beginning, design regulations were primarily drawn up with safety concerns in mind. In the early days of reinforced concrete, at the end of the 19th and beginning of the 20th century, there were numerous structural accidents, that occurred either at the end of construction or shortly after buildings were put into use, resulting in many injuries and fatalities. In 1890, the collapse of a pedestrian bridge at the World Fair caused several deaths, prompting the government to call for standardized regulations for reinforced concrete design.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    My first discovery was that the concept of a building's lifespan is anything but straightforward. In the beginning, design regulations were primarily drawn up with safety concerns in mind. In the early days of reinforced concrete, at the end of the 19th and beginning of the 20th century, there were numerous structural accidents, that occurred either at the end of construction or shortly after buildings were put into use, resulting in many injuries and fatalities. In 1890, the collapse of a pedestrian bridge at the World Fair caused several deaths, prompting the government to call for standardized regulations for reinforced concrete design.<\/p>\n","innerContent":["\n

    My first discovery was that the concept of a building's lifespan is anything but straightforward. In the beginning, design regulations were primarily drawn up with safety concerns in mind. In the early days of reinforced concrete, at the end of the 19th and beginning of the 20th century, there were numerous structural accidents, that occurred either at the end of construction or shortly after buildings were put into use, resulting in many injuries and fatalities. In 1890, the collapse of a pedestrian bridge at the World Fair caused several deaths, prompting the government to call for standardized regulations for reinforced concrete design.<\/p>\n"],"rendered":"\n

    My first discovery was that the concept of a building's lifespan is anything but straightforward. In the beginning, design regulations were primarily drawn up with safety concerns in mind. In the early days of reinforced concrete, at the end of the 19th and beginning of the 20th century, there were numerous structural accidents, that occurred either at the end of construction or shortly after buildings were put into use, resulting in many injuries and fatalities. In 1890, the collapse of a pedestrian bridge at the World Fair caused several deaths, prompting the government to call for standardized regulations for reinforced concrete design.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"At that time, reinforced concrete was still a relatively new material, barely fifty years old. The first reinforced concrete apartment building was built around 1890, on Rue Danton in Paris. This material carried a great deal of promise. It was considered highly durable because it enabled construction of continuous surfaces, without the need for joints, which were typically associated with water and air infiltration, and other structural issues.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    At that time, reinforced concrete was still a relatively new material, barely fifty years old. The first reinforced concrete apartment building was built around 1890, on Rue Danton in Paris. This material carried a great deal of promise. It was considered highly durable because it enabled construction of continuous surfaces, without the need for joints, which were typically associated with water and air infiltration, and other structural issues.<\/p>\n","innerContent":["\n

    At that time, reinforced concrete was still a relatively new material, barely fifty years old. The first reinforced concrete apartment building was built around 1890, on Rue Danton in Paris. This material carried a great deal of promise. It was considered highly durable because it enabled construction of continuous surfaces, without the need for joints, which were typically associated with water and air infiltration, and other structural issues.<\/p>\n"],"rendered":"\n

    At that time, reinforced concrete was still a relatively new material, barely fifty years old. The first reinforced concrete apartment building was built around 1890, on Rue Danton in Paris. This material carried a great deal of promise. It was considered highly durable because it enabled construction of continuous surfaces, without the need for joints, which were typically associated with water and air infiltration, and other structural issues.<\/p>\n"},{"blockName":"core\/image","attrs":{"id":9296,"sizeSlug":"large","linkDestination":"none","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/10\/Paris_en_tenue_de_bombardement_.Agence_Rol_btv1b53004420x-1024x764.jpeg","alt":"","caption":"First building made from reinforced concrete, around 1890, Rue Danton, in Paris. Credit : gallica.bnf.fr \/ Biblioth\u00e8que nationale de France","lightbox":[],"title":"","href":"","rel":"","linkClass":"","width":"","height":"","aspectRatio":"","scale":"","linkTarget":"","lock":[],"metadata":[],"align":"","className":"wp-block-image size-large","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"
    First building made from reinforced concrete, around 1890, Rue Danton, in Paris. Credit : gallica.bnf.fr \/ Biblioth\u00e8que nationale de France<\/figcaption><\/figure>\n","innerContent":["\n
    \"\"
    First building made from reinforced concrete, around 1890, Rue Danton, in Paris. Credit : gallica.bnf.fr \/ Biblioth\u00e8que nationale de France<\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"
    First building made from reinforced concrete, around 1890, Rue Danton, in Paris. Credit : gallica.bnf.fr \/ Biblioth\u00e8que nationale de France<\/figcaption><\/figure>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":" ","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    <\/em><\/p>\n","innerContent":["\n

    <\/em><\/p>\n"],"rendered":"\n

    <\/em><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The first standards for reinforced concrete were introduced in 1906, and they were very different to today\u2019s Eurocodes1. This early document was just five pages long, containing about twenty articles. While it provided general guidelines for structural resistance calculations and construction practices, it didn\u2019t specify any numerical values for the data to be used. At the time, there wasn\u2019t the same level of hindsight and understanding of concrete that we have today, which is why concepts like sustainability were completely absent from these initial standards.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The first standards for reinforced concrete were introduced in 1906, and they were very different to today\u2019s Eurocodes1<\/a><\/sup>. This early document was just five pages long, containing about twenty articles. While it provided general guidelines for structural resistance calculations and construction practices, it didn\u2019t specify any numerical values for the data to be used. At the time, there wasn\u2019t the same level of hindsight and understanding of concrete that we have today, which is why concepts like sustainability were completely absent from these initial standards.<\/p>\n","innerContent":["\n

    The first standards for reinforced concrete were introduced in 1906, and they were very different to today\u2019s Eurocodes1<\/a><\/sup>. This early document was just five pages long, containing about twenty articles. While it provided general guidelines for structural resistance calculations and construction practices, it didn\u2019t specify any numerical values for the data to be used. At the time, there wasn\u2019t the same level of hindsight and understanding of concrete that we have today, which is why concepts like sustainability were completely absent from these initial standards.<\/p>\n"],"rendered":"\n

    The first standards for reinforced concrete were introduced in 1906, and they were very different to today\u2019s Eurocodes1<\/a><\/sup>. This early document was just five pages long, containing about twenty articles. While it provided general guidelines for structural resistance calculations and construction practices, it didn\u2019t specify any numerical values for the data to be used. At the time, there wasn\u2019t the same level of hindsight and understanding of concrete that we have today, which is why concepts like sustainability were completely absent from these initial standards.<\/p>\n"},{"blockName":"core\/image","attrs":{"id":9293,"sizeSlug":"large","linkDestination":"none","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/10\/Code1906-1024x695.png","alt":"","caption":"First set of standards for reinforced concrete (1906). Source: \u00c9cole nationale des ponts et chauss\u00e9es.","lightbox":[],"title":"","href":"","rel":"","linkClass":"","width":"","height":"","aspectRatio":"","scale":"","linkTarget":"","lock":[],"metadata":[],"align":"","className":"wp-block-image size-large","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"
    First set of standards for reinforced concrete (1906). Source: \u00c9cole nationale des ponts et chauss\u00e9es.<\/em><\/figcaption><\/figure>\n","innerContent":["\n
    \"\"
    First set of standards for reinforced concrete (1906). Source: \u00c9cole nationale des ponts et chauss\u00e9es.<\/em><\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"
    First set of standards for reinforced concrete (1906). Source: \u00c9cole nationale des ponts et chauss\u00e9es.<\/em><\/figcaption><\/figure>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    <\/p>\n","innerContent":["\n

    <\/p>\n"],"rendered":"\n

    <\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Another key discovery was the role of post-war reconstruction in shaping the BA45 regulation (the Reinforced Concrete Regulation of 1945). Construction was considered a matter of public affairs, essential for both housing and for industrial recovery, so certain concrete performance thresholds were raised to accelerate construction and reduce the quantity of materials used. As a result, design was no longer solely the concern of structural engineers and architects but also involved urban planners and industrial engineers. During the 1940s and 1950s, reinforced concrete experienced significant growth, driven by the industrialization of construction. Industrial processes emerged, and began to influence the design of reinforced concrete buildings.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Another key discovery was the role of post-war reconstruction in shaping the BA45 regulation (the Reinforced Concrete Regulation of 1945). Construction was considered a matter of public affairs, essential for both housing and for industrial recovery, so certain concrete performance thresholds were raised to accelerate construction and reduce the quantity of materials used. As a result, design was no longer solely the concern of structural engineers and architects but also involved urban planners and industrial engineers. During the 1940s and 1950s, reinforced concrete experienced significant growth, driven by the industrialization of construction. Industrial processes emerged, and began to influence the design of reinforced concrete buildings.<\/p>\n","innerContent":["\n

    Another key discovery was the role of post-war reconstruction in shaping the BA45 regulation (the Reinforced Concrete Regulation of 1945). Construction was considered a matter of public affairs, essential for both housing and for industrial recovery, so certain concrete performance thresholds were raised to accelerate construction and reduce the quantity of materials used. As a result, design was no longer solely the concern of structural engineers and architects but also involved urban planners and industrial engineers. During the 1940s and 1950s, reinforced concrete experienced significant growth, driven by the industrialization of construction. Industrial processes emerged, and began to influence the design of reinforced concrete buildings.<\/p>\n"],"rendered":"\n

    Another key discovery was the role of post-war reconstruction in shaping the BA45 regulation (the Reinforced Concrete Regulation of 1945). Construction was considered a matter of public affairs, essential for both housing and for industrial recovery, so certain concrete performance thresholds were raised to accelerate construction and reduce the quantity of materials used. As a result, design was no longer solely the concern of structural engineers and architects but also involved urban planners and industrial engineers. During the 1940s and 1950s, reinforced concrete experienced significant growth, driven by the industrialization of construction. Industrial processes emerged, and began to influence the design of reinforced concrete buildings.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Issues related to the durability of concrete only started appearing in regulations toward the end of the 20th century. Questions started to be raised concerning the durability of concrete when the first signs of degradation in reinforced concrete structures emerged (such as the corrosion of reinforcement and waterproofing issues). These issues prompted engineers to start considering long-term performance. It was with the introduction of the Eurocodes that the concept of predefined lifespans emerged: 50 years for standard buildings, 100 years for monuments and major civil engineering works, and 10 years for temporary works. In the context of reusing materials, it is very important to be aware that the elements being reused were not originally designed with a specific lifespan in mind. This makes studying deconstructed elements crucial for assessing their residual performance.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Issues related to the durability of concrete only started appearing in regulations toward the end of the 20th century. Questions started to be raised concerning the durability of concrete when the first signs of degradation in reinforced concrete structures emerged (such as the corrosion of reinforcement and waterproofing issues). These issues prompted engineers to start considering long-term performance. It was with the introduction of the Eurocodes that the concept of predefined lifespans emerged: 50 years for standard buildings, 100 years for monuments and major civil engineering works, and 10 years for temporary works. In the context of reusing materials, it is very important to be aware that the elements being reused were not originally designed with a specific lifespan in mind. This makes studying deconstructed elements crucial for assessing their residual performance.<\/p>\n","innerContent":["\n

    Issues related to the durability of concrete only started appearing in regulations toward the end of the 20th century. Questions started to be raised concerning the durability of concrete when the first signs of degradation in reinforced concrete structures emerged (such as the corrosion of reinforcement and waterproofing issues). These issues prompted engineers to start considering long-term performance. It was with the introduction of the Eurocodes that the concept of predefined lifespans emerged: 50 years for standard buildings, 100 years for monuments and major civil engineering works, and 10 years for temporary works. In the context of reusing materials, it is very important to be aware that the elements being reused were not originally designed with a specific lifespan in mind. This makes studying deconstructed elements crucial for assessing their residual performance.<\/p>\n"],"rendered":"\n

    Issues related to the durability of concrete only started appearing in regulations toward the end of the 20th century. Questions started to be raised concerning the durability of concrete when the first signs of degradation in reinforced concrete structures emerged (such as the corrosion of reinforcement and waterproofing issues). These issues prompted engineers to start considering long-term performance. It was with the introduction of the Eurocodes that the concept of predefined lifespans emerged: 50 years for standard buildings, 100 years for monuments and major civil engineering works, and 10 years for temporary works. In the context of reusing materials, it is very important to be aware that the elements being reused were not originally designed with a specific lifespan in mind. This makes studying deconstructed elements crucial for assessing their residual performance.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"For this historical research, you drew on the Ecole Nationale des Ponts et Chauss\u00e9es\u2019 heritage collection. What made this collection such a particularly fascinating source of information?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    For this historical research, you drew on the Ecole Nationale des Ponts et Chauss\u00e9es\u2019 heritage collection. What made this collection such a particularly fascinating source of information?<\/strong><\/strong><\/p>\n","innerContent":["\n

    For this historical research, you drew on the Ecole Nationale des Ponts et Chauss\u00e9es\u2019 heritage collection. What made this collection such a particularly fascinating source of information?<\/strong><\/strong><\/p>\n"],"rendered":"\n

    For this historical research, you drew on the Ecole Nationale des Ponts et Chauss\u00e9es\u2019 heritage collection. What made this collection such a particularly fascinating source of information?<\/strong><\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The school\u2019s heritage collection is both extensive and unique, especially in the fields of mechanics and materials science. This is largely because the school predates the invention of the material itself, meaning it witnessed both its creation and standardization. It was one of the first institutions to offer a course on reinforced concrete and it was able to acquire resources from other schools, such as ESTP.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The school\u2019s heritage collection is both extensive and unique, especially in the fields of mechanics and materials science. This is largely because the school predates the invention of the material itself, meaning it witnessed both its creation and standardization. It was one of the first institutions to offer a course on reinforced concrete and it was able to acquire resources from other schools, such as ESTP<\/a>.<\/p>\n","innerContent":["\n

    The school\u2019s heritage collection is both extensive and unique, especially in the fields of mechanics and materials science. This is largely because the school predates the invention of the material itself, meaning it witnessed both its creation and standardization. It was one of the first institutions to offer a course on reinforced concrete and it was able to acquire resources from other schools, such as ESTP<\/a>.<\/p>\n"],"rendered":"\n

    The school\u2019s heritage collection is both extensive and unique, especially in the fields of mechanics and materials science. This is largely because the school predates the invention of the material itself, meaning it witnessed both its creation and standardization. It was one of the first institutions to offer a course on reinforced concrete and it was able to acquire resources from other schools, such as ESTP<\/a>.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The core mission of a school is to pass on knowledge, and this is reflected in the care taken to preserve this heritage collection. Today, although we may not always appreciate the value of this heritage amid the intensity of engineering studies, its very existence is a real asset for anyone looking to put current practices into historical perspective.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The core mission of a school is to pass on knowledge, and this is reflected in the care taken to preserve this heritage collection. Today, although we may not always appreciate the value of this heritage amid the intensity of engineering studies, its very existence is a real asset for anyone looking to put current practices into historical perspective.<\/p>\n","innerContent":["\n

    The core mission of a school is to pass on knowledge, and this is reflected in the care taken to preserve this heritage collection. Today, although we may not always appreciate the value of this heritage amid the intensity of engineering studies, its very existence is a real asset for anyone looking to put current practices into historical perspective.<\/p>\n"],"rendered":"\n

    The core mission of a school is to pass on knowledge, and this is reflected in the care taken to preserve this heritage collection. Today, although we may not always appreciate the value of this heritage amid the intensity of engineering studies, its very existence is a real asset for anyone looking to put current practices into historical perspective.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Engineering is an iterative discipline, and being familiar with the research and reflections of earlier engineers, sometimes dating back decades, seems important to me, as their insights can really enrich our own thinking.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Engineering is an iterative discipline, and being familiar with the research and reflections of earlier engineers, sometimes dating back decades, seems important to me, as their insights can really enrich our own thinking.<\/p>\n","innerContent":["\n

    Engineering is an iterative discipline, and being familiar with the research and reflections of earlier engineers, sometimes dating back decades, seems important to me, as their insights can really enrich our own thinking.<\/p>\n"],"rendered":"\n

    Engineering is an iterative discipline, and being familiar with the research and reflections of earlier engineers, sometimes dating back decades, seems important to me, as their insights can really enrich our own thinking.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"Part of your study focuses on an indicator that demonstrates the reuse potential of a construction element, based on A. Lachat\u2019s doctoral thesis. Can you tell us about that? ","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Part of your study focuses on an indicator that demonstrates the reuse potential of a construction element, based on <\/strong>A. Lachat\u2019s doctoral thesis<\/strong><\/a>. Can you tell us about that? <\/strong><\/p>\n","innerContent":["\n

    Part of your study focuses on an indicator that demonstrates the reuse potential of a construction element, based on <\/strong>A. Lachat\u2019s doctoral thesis<\/strong><\/a>. Can you tell us about that? <\/strong><\/p>\n"],"rendered":"\n

    Part of your study focuses on an indicator that demonstrates the reuse potential of a construction element, based on <\/strong>A. Lachat\u2019s doctoral thesis<\/strong><\/a>. Can you tell us about that? <\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"This multi-criteria indicator is designed to assess the reuse potential of a construction element, based on its residual mechanical properties and the regulatory, logistical, economic, and environmental context in which it is situated.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    This multi-criteria indicator is designed to assess the reuse potential of a construction element, based on its residual mechanical properties and the regulatory, logistical, economic, and environmental context in which it is situated.<\/p>\n","innerContent":["\n

    This multi-criteria indicator is designed to assess the reuse potential of a construction element, based on its residual mechanical properties and the regulatory, logistical, economic, and environmental context in which it is situated.<\/p>\n"],"rendered":"\n

    This multi-criteria indicator is designed to assess the reuse potential of a construction element, based on its residual mechanical properties and the regulatory, logistical, economic, and environmental context in which it is situated.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"In practical terms, the indicator is expressed as a single value, calculated by multiplying two indices, each ranging between 0 and 1. The first index is purely mechanical, and takes into account the resistance of the concrete under pressure, its aging and the deconstruction method used to recover the element. The second index encompasses all the economic, environmental and logistical characteristics. It is designed to answer questions such as: is there a real environmental benefit to reusing this element as opposed to manufacturing a new one? The answer isn\u2019t always straightforward. For example, if an element needs to be transported 500 kilometers, the environmental benefit of reuse becomes questionable, since transport can significantly increase the overall impact. These two indices are then multiplied to obtain a reuse indicator, ranging from 0 (no reuse potential) to 1 (perfectly reusable element). When this indicator was first developed, the mechanical index applied solely to concrete, while the second index could be used for any construction component. Today, it is beginning to be adopted by the teams at Vinci, particularly for secondary construction elements.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    In practical terms, the indicator is expressed as a single value, calculated by multiplying two indices, each ranging between 0 and 1. The first index is purely mechanical, and takes into account the resistance of the concrete under pressure, its aging and the deconstruction method used to recover the element. The second index encompasses all the economic, environmental and logistical characteristics. It is designed to answer questions such as: is there a real environmental benefit to reusing this element as opposed to manufacturing a new one? The answer isn\u2019t always straightforward. For example, if an element needs to be transported 500 kilometers, the environmental benefit of reuse becomes questionable, since transport can significantly increase the overall impact. These two indices are then multiplied to obtain a reuse indicator, ranging from 0 (no reuse potential) to 1 (perfectly reusable element). When this indicator was first developed, the mechanical index applied solely to concrete, while the second index could be used for any construction component. Today, it is beginning to be adopted by the teams at Vinci, particularly for secondary construction elements.<\/p>\n","innerContent":["\n

    In practical terms, the indicator is expressed as a single value, calculated by multiplying two indices, each ranging between 0 and 1. The first index is purely mechanical, and takes into account the resistance of the concrete under pressure, its aging and the deconstruction method used to recover the element. The second index encompasses all the economic, environmental and logistical characteristics. It is designed to answer questions such as: is there a real environmental benefit to reusing this element as opposed to manufacturing a new one? The answer isn\u2019t always straightforward. For example, if an element needs to be transported 500 kilometers, the environmental benefit of reuse becomes questionable, since transport can significantly increase the overall impact. These two indices are then multiplied to obtain a reuse indicator, ranging from 0 (no reuse potential) to 1 (perfectly reusable element). When this indicator was first developed, the mechanical index applied solely to concrete, while the second index could be used for any construction component. Today, it is beginning to be adopted by the teams at Vinci, particularly for secondary construction elements.<\/p>\n"],"rendered":"\n

    In practical terms, the indicator is expressed as a single value, calculated by multiplying two indices, each ranging between 0 and 1. The first index is purely mechanical, and takes into account the resistance of the concrete under pressure, its aging and the deconstruction method used to recover the element. The second index encompasses all the economic, environmental and logistical characteristics. It is designed to answer questions such as: is there a real environmental benefit to reusing this element as opposed to manufacturing a new one? The answer isn\u2019t always straightforward. For example, if an element needs to be transported 500 kilometers, the environmental benefit of reuse becomes questionable, since transport can significantly increase the overall impact. These two indices are then multiplied to obtain a reuse indicator, ranging from 0 (no reuse potential) to 1 (perfectly reusable element). When this indicator was first developed, the mechanical index applied solely to concrete, while the second index could be used for any construction component. Today, it is beginning to be adopted by the teams at Vinci, particularly for secondary construction elements.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The aim of my final-year project, and now of my doctoral research, is to explore this indicator further, examine the assumptions on which it is based, and address the many questions it raises.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The aim of my final-year project, and now of my doctoral research, is to explore this indicator further, examine the assumptions on which it is based, and address the many questions it raises.<\/p>\n","innerContent":["\n

    The aim of my final-year project, and now of my doctoral research, is to explore this indicator further, examine the assumptions on which it is based, and address the many questions it raises.<\/p>\n"],"rendered":"\n

    The aim of my final-year project, and now of my doctoral research, is to explore this indicator further, examine the assumptions on which it is based, and address the many questions it raises.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"You conducted a territorial study on four urban areas: what specific insights did this provide regarding the local reuse potential?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    You conducted a territorial study on four urban areas: what specific insights did this provide regarding the local reuse potential?<\/strong><\/p>\n","innerContent":["\n

    You conducted a territorial study on four urban areas: what specific insights did this provide regarding the local reuse potential?<\/strong><\/p>\n"],"rendered":"\n

    You conducted a territorial study on four urban areas: what specific insights did this provide regarding the local reuse potential?<\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Unlike studies focused on individual elements or buildings, this research adopts a broader territorial scale, at the level of municipalities, or even departments. The main question was whether local construction activity is sufficient to absorb materials recovered from demolition.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Unlike studies focused on individual elements or buildings, this research adopts a broader territorial scale, at the level of municipalities, or even departments. The main question was whether local construction activity is sufficient to absorb materials recovered from demolition.<\/p>\n","innerContent":["\n

    Unlike studies focused on individual elements or buildings, this research adopts a broader territorial scale, at the level of municipalities, or even departments. The main question was whether local construction activity is sufficient to absorb materials recovered from demolition.<\/p>\n"],"rendered":"\n

    Unlike studies focused on individual elements or buildings, this research adopts a broader territorial scale, at the level of municipalities, or even departments. The main question was whether local construction activity is sufficient to absorb materials recovered from demolition.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"A key finding is that it remains very difficult to accurately quantify the \u2018urban mine\u2019, in other words, the stock of available elements and materials. The data used is primarily derived from building and demolition permits, which don't necessarily include information about reuse potential. However, this is starting to change, thanks in part to emerging tools developed by organizations such as the Scientific and Technical Center for Building (CSTB), with BTPFlux. This is a vast and important area of research for reuse, but one that I won\u2019t be able to explore in depth for my thesis due to its complexity. It\u2019s a whole research topic in its own right.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    A key finding is that it remains very difficult to accurately quantify the \u2018urban mine\u2019, in other words, the stock of available elements and materials. The data used is primarily derived from building and demolition permits, which don't necessarily include information about reuse potential. However, this is starting to change, thanks in part to emerging tools developed by organizations such as the Scientific and Technical Center for Building (CSTB), with BTPFlux<\/a>. This is a vast and important area of research for reuse, but one that I won\u2019t be able to explore in depth for my thesis due to its complexity. It\u2019s a whole research topic in its own right.<\/p>\n","innerContent":["\n

    A key finding is that it remains very difficult to accurately quantify the \u2018urban mine\u2019, in other words, the stock of available elements and materials. The data used is primarily derived from building and demolition permits, which don't necessarily include information about reuse potential. However, this is starting to change, thanks in part to emerging tools developed by organizations such as the Scientific and Technical Center for Building (CSTB), with BTPFlux<\/a>. This is a vast and important area of research for reuse, but one that I won\u2019t be able to explore in depth for my thesis due to its complexity. It\u2019s a whole research topic in its own right.<\/p>\n"],"rendered":"\n

    A key finding is that it remains very difficult to accurately quantify the \u2018urban mine\u2019, in other words, the stock of available elements and materials. The data used is primarily derived from building and demolition permits, which don't necessarily include information about reuse potential. However, this is starting to change, thanks in part to emerging tools developed by organizations such as the Scientific and Technical Center for Building (CSTB), with BTPFlux<\/a>. This is a vast and important area of research for reuse, but one that I won\u2019t be able to explore in depth for my thesis due to its complexity. It\u2019s a whole research topic in its own right.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Another conclusion from my study is that there are far fewer demolitions today than new constructions. As a result, materials recovered from demolition alone would not be enough to meet construction demand. In Switzerland for example, it is estimated that even if all materials from demolition were reused, they would only cover one-seventh of the country\u2019s construction needs.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Another conclusion from my study is that there are far fewer demolitions today than new constructions. As a result, materials recovered from demolition alone would not be enough to meet construction demand. In Switzerland for example, it is estimated that even if all materials from demolition were reused, they would only cover one-seventh of the country\u2019s construction needs.<\/p>\n","innerContent":["\n

    Another conclusion from my study is that there are far fewer demolitions today than new constructions. As a result, materials recovered from demolition alone would not be enough to meet construction demand. In Switzerland for example, it is estimated that even if all materials from demolition were reused, they would only cover one-seventh of the country\u2019s construction needs.<\/p>\n"],"rendered":"\n

    Another conclusion from my study is that there are far fewer demolitions today than new constructions. As a result, materials recovered from demolition alone would not be enough to meet construction demand. In Switzerland for example, it is estimated that even if all materials from demolition were reused, they would only cover one-seventh of the country\u2019s construction needs.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Finally, a particularly noteworthy exception is the department of Paris, and especially the city center, where renovation and rehabilitation projects now outnumber new construction. It is a city governed by numerous urban regulations and roadmaps that prioritize the preservation of architectural heritage. This illustrates how the legislative framework can directly influence our building practices.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Finally, a particularly noteworthy exception is the department of Paris, and especially the city center, where renovation and rehabilitation projects now outnumber new construction. It is a city governed by numerous urban regulations and roadmaps that prioritize the preservation of architectural heritage. This illustrates how the legislative framework can directly influence our building practices.<\/p>\n","innerContent":["\n

    Finally, a particularly noteworthy exception is the department of Paris, and especially the city center, where renovation and rehabilitation projects now outnumber new construction. It is a city governed by numerous urban regulations and roadmaps that prioritize the preservation of architectural heritage. This illustrates how the legislative framework can directly influence our building practices.<\/p>\n"],"rendered":"\n

    Finally, a particularly noteworthy exception is the department of Paris, and especially the city center, where renovation and rehabilitation projects now outnumber new construction. It is a city governed by numerous urban regulations and roadmaps that prioritize the preservation of architectural heritage. This illustrates how the legislative framework can directly influence our building practices.<\/p>\n"},{"blockName":"core\/image","attrs":{"id":9388,"sizeSlug":"large","linkDestination":"none","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/10\/CANAL-architecture-\u2013-Photographe-Pierre-LExcellent-1024x542.jpg","alt":"","caption":"Example of 58 Rue Mouz\u00efa, in Paris (19th arrondissement), built in 1974 by architects Claude Parent and Andr\u00e9 R\u00e9mondet. This building initially housed the offices of the Regional Directorate for Health and Social Affairs (DRASS). After being left vacant for several years, it was rehabilitated into student housing in 2020. The architect was selected for their proposal to transform the existing building, rather than demolish it. \u00a0Credit : CANAL architecture \u2013 Photographe Pierre L\u2019Excellent\u00a0","lightbox":[],"title":"","href":"","rel":"","linkClass":"","width":"","height":"","aspectRatio":"","scale":"","linkTarget":"","lock":[],"metadata":[],"align":"","className":"wp-block-image size-large","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"
    Example of 58 Rue Mouz\u00efa, in Paris (19th arrondissement), built in 1974 by architects Claude Parent and Andr\u00e9 R\u00e9mondet. This building initially housed the offices of the Regional Directorate for Health and Social Affairs (DRASS). After being left vacant for several years, it was rehabilitated into student housing in 2020. The architect was selected for their proposal to transform the existing building, rather than demolish it.<\/em>  Credit : CANAL architecture \u2013 Photographe Pierre L\u2019Excellent <\/figcaption><\/figure>\n","innerContent":["\n
    \"\"
    Example of 58 Rue Mouz\u00efa, in Paris (19th arrondissement), built in 1974 by architects Claude Parent and Andr\u00e9 R\u00e9mondet. This building initially housed the offices of the Regional Directorate for Health and Social Affairs (DRASS). After being left vacant for several years, it was rehabilitated into student housing in 2020. The architect was selected for their proposal to transform the existing building, rather than demolish it.<\/em>  Credit : CANAL architecture \u2013 Photographe Pierre L\u2019Excellent <\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"
    Example of 58 Rue Mouz\u00efa, in Paris (19th arrondissement), built in 1974 by architects Claude Parent and Andr\u00e9 R\u00e9mondet. This building initially housed the offices of the Regional Directorate for Health and Social Affairs (DRASS). After being left vacant for several years, it was rehabilitated into student housing in 2020. The architect was selected for their proposal to transform the existing building, rather than demolish it.<\/em>  Credit : CANAL architecture \u2013 Photographe Pierre L\u2019Excellent <\/figcaption><\/figure>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    <\/p>\n","innerContent":["\n

    <\/p>\n"],"rendered":"\n

    <\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"Finally, how did you come to choose this final-year project and PhD topic? ","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Finally, how did you come to choose this final-year project and PhD topic? <\/strong><\/strong><\/p>\n","innerContent":["\n

    Finally, how did you come to choose this final-year project and PhD topic? <\/strong><\/strong><\/p>\n"],"rendered":"\n

    Finally, how did you come to choose this final-year project and PhD topic? <\/strong><\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"From a young age, I knew I wanted to work in the construction sector. I had always dreamed of becoming an architect, but then I discovered the role of the engineer. I found out that there was a dual engineering-architecture program at the \u00c9cole Nationale des Ponts et Chauss\u00e9es.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    From a young age, I knew I wanted to work in the construction sector. I had always dreamed of becoming an architect, but then I discovered the role of the engineer. I found out that there was a dual engineering-architecture program at the \u00c9cole Nationale des Ponts et Chauss\u00e9es.<\/p>\n","innerContent":["\n

    From a young age, I knew I wanted to work in the construction sector. I had always dreamed of becoming an architect, but then I discovered the role of the engineer. I found out that there was a dual engineering-architecture program at the \u00c9cole Nationale des Ponts et Chauss\u00e9es.<\/p>\n"],"rendered":"\n

    From a young age, I knew I wanted to work in the construction sector. I had always dreamed of becoming an architect, but then I discovered the role of the engineer. I found out that there was a dual engineering-architecture program at the \u00c9cole Nationale des Ponts et Chauss\u00e9es.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"In my second year of that program, I developed a deeper understanding of the construction industry, and of the ecological challenges it faces. Something I hadn\u2019t fully grasped before. It was unsettling to realize the contradiction, in that there is a genuine societal need to build, yet construction comes with a heavy toll on the environment.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    In my second year of that program, I developed a deeper understanding of the construction industry, and of the ecological challenges it faces. Something I hadn\u2019t fully grasped before. It was unsettling to realize the contradiction, in that there is a genuine societal need to build, yet construction comes with a heavy toll on the environment.<\/p>\n","innerContent":["\n

    In my second year of that program, I developed a deeper understanding of the construction industry, and of the ecological challenges it faces. Something I hadn\u2019t fully grasped before. It was unsettling to realize the contradiction, in that there is a genuine societal need to build, yet construction comes with a heavy toll on the environment.<\/p>\n"],"rendered":"\n

    In my second year of that program, I developed a deeper understanding of the construction industry, and of the ecological challenges it faces. Something I hadn\u2019t fully grasped before. It was unsettling to realize the contradiction, in that there is a genuine societal need to build, yet construction comes with a heavy toll on the environment.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Concrete is the most widely used material today. We need to build, but we also continue to demolish a large number of buildings. I began to wonder: what happens to all these elements after they\u2019ve served their purpose? Can they be reused? Could they be disassembled and reassembled like Lego bricks? This shaped the direction of my final-year project, which I used as a springboard into a PhD on this topic.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Concrete is the most widely used material today. We need to build, but we also continue to demolish a large number of buildings. I began to wonder: what happens to all these elements after they\u2019ve served their purpose? Can they be reused? Could they be disassembled and reassembled like Lego bricks? This shaped the direction of my final-year project, which I used as a springboard into a PhD on this topic.<\/p>\n","innerContent":["\n

    Concrete is the most widely used material today. We need to build, but we also continue to demolish a large number of buildings. I began to wonder: what happens to all these elements after they\u2019ve served their purpose? Can they be reused? Could they be disassembled and reassembled like Lego bricks? This shaped the direction of my final-year project, which I used as a springboard into a PhD on this topic.<\/p>\n"],"rendered":"\n

    Concrete is the most widely used material today. We need to build, but we also continue to demolish a large number of buildings. I began to wonder: what happens to all these elements after they\u2019ve served their purpose? Can they be reused? Could they be disassembled and reassembled like Lego bricks? This shaped the direction of my final-year project, which I used as a springboard into a PhD on this topic.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"An engineer from the \u00c9cole Nationale des Ponts et Chauss\u00e9es (Department of Civil Engineering and Construction, Structure and Architecture Unit), Ines Dakhli\u2019s PhD research is now underway within the Navier Laboratory, as part of the Environmental Research Lab Chair, under the supervision of Ad\u00e9la\u00efde Feraille, Anne-Sophie Colas, Tiffany Desbois and Ambroise Lachat. Her research focuses on developing an indicator for reuse potential and on reuse itself, with a particular emphasis on reinforced concrete structures.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    An engineer from the \u00c9cole Nationale des Ponts et Chauss\u00e9es (Department of Civil Engineering and Construction, Structure and Architecture Unit), Ines Dakhli\u2019s PhD research is now underway within the Navier Laboratory, as part of the Environmental Research Lab Chair, under the supervision of Ad\u00e9la\u00efde Feraille, Anne-Sophie Colas, Tiffany Desbois and Ambroise Lachat. Her research focuses on developing an indicator for reuse potential and on reuse itself, with a particular emphasis on reinforced concrete structures.<\/p>\n","innerContent":["\n

    An engineer from the \u00c9cole Nationale des Ponts et Chauss\u00e9es (Department of Civil Engineering and Construction, Structure and Architecture Unit), Ines Dakhli\u2019s PhD research is now underway within the Navier Laboratory, as part of the Environmental Research Lab Chair, under the supervision of Ad\u00e9la\u00efde Feraille, Anne-Sophie Colas, Tiffany Desbois and Ambroise Lachat. Her research focuses on developing an indicator for reuse potential and on reuse itself, with a particular emphasis on reinforced concrete structures.<\/p>\n"],"rendered":"\n

    An engineer from the \u00c9cole Nationale des Ponts et Chauss\u00e9es (Department of Civil Engineering and Construction, Structure and Architecture Unit), Ines Dakhli\u2019s PhD research is now underway within the Navier Laboratory, as part of the Environmental Research Lab Chair, under the supervision of Ad\u00e9la\u00efde Feraille, Anne-Sophie Colas, Tiffany Desbois and Ambroise Lachat. Her research focuses on developing an indicator for reuse potential and on reuse itself, with a particular emphasis on reinforced concrete structures.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"fontSize":"small","align":"","content":"Interview by Ad\u00e8le Mazurek, head of the mediation department at the \u00c9cole nationale des ponts et chauss\u00e9es","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-small-font-size","style":"","backgroundColor":"","textColor":"","gradient":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Interview by Ad\u00e8le Mazurek, head of the mediation department at the \u00c9cole nationale des ponts et chauss\u00e9es<\/em><\/p>\n","innerContent":["\n

    Interview by Ad\u00e8le Mazurek, head of the mediation department at the \u00c9cole nationale des ponts et chauss\u00e9es<\/em><\/p>\n"],"rendered":"\n

    Interview by Ad\u00e8le Mazurek, head of the mediation department at the \u00c9cole nationale des ponts et chauss\u00e9es<\/em><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    <\/a><\/p>\n","innerContent":["\n

    <\/a><\/p>\n"],"rendered":"\n

    <\/a><\/p>\n"},{"blockName":"core\/footnotes","attrs":{"lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","fontSize":"","fontFamily":"","borderColor":""},"innerBlocks":[],"innerHTML":"","innerContent":[],"rendered":""}],"seo":{"title":"Giving concrete a second life"},"media":{"img":"\"\"","src":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2025\/10\/Ines_Source_Canva-e1760532685556.png"},"url":"\/en\/articles\/giving-concrete-a-second-life\/","related":{"post":[],"author":[{"title":"Ines Dakhli","url":"\/en\/authors\/ines-dakhli\/","id":"9393","media":"\"\"","slug":"ines-dakhli"}],"subject":[{"title":"Cities, Urban planning & Construction","url":"\/en\/subjects\/cities-urban-planning-construction\/","id":"936","media":"\"\"","slug":"cities-urban-planning-construction"}],"category":[{"title":"Article collection","url":"\/en\/articles\/category\/dossier\/","id":"1720","media":"","slug":"dossier","_related_post_type":"folder"},{"title":"Articles","url":"\/en\/articles\/category\/articles\/","id":"1716","media":"","slug":"articles","_related_post_type":""}],"folder":[{"title":"\u202fEco-building tomorrow: Rethinking practices and methods.","url":"\/en\/folders\/eco-building-tomorrow-rethinking-practices-and-methods\/","id":"9382","media":"\"\"","slug":"eco-building-tomorrow-rethinking-practices-and-methods"}]},"translated":"https:\/\/ingenius.ecoledesponts.fr\/articles\/donner-une-seconde-vie-au-beton\/","icon":"icon-article","duration":"7","custom_excerpt":"25 million m\u00b2! <\/strong>That\u2019s the total surface area of housing built in France in 2024.<\/a> Concrete, the most widely used material in construction, raises significant issues related to the exploitation of natural resources and the large-scale production of waste, estimated at nearly 15 million tons per year. In the context of climate change, the construction sector is adopting various strategies in an effort to reduce its environmental impact. Among these, reusing existing structures stands out as a particularly promising solution. However, this approach also presents a range of technical, economic, legal, and social challenges.","duration_type":"","_links":{"self":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/9391","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/comments?post=9391"}],"version-history":[{"count":4,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/9391\/revisions"}],"predecessor-version":[{"id":9437,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/9391\/revisions\/9437"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/media\/9371"}],"wp:attachment":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/media?parent=9391"}],"wp:term":[{"taxonomy":"article-types","embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/article-types?post=9391"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}