concrete

The Maginot line defended Europe from the Nazi invasion. History is being repeated by Russia, but now it is not just concrete

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The Maginot line It was a monumental but rigid wall initiated by France, so much, which was dodged in 1940 by the Wehrmacht through the Ardenas. Perhaps for this reason, today’s Europe assumes that no defense line can totally shield its borders, but it can channel and delay an invasion, while determining Moscow to undertake it. The crucial difference is that this time it is not just concrete. The return of an iron curtain. Eighty years after Churchill will proclaim That a “steel curtain” had fallen over Europe, the metaphor It is reversed: Now it is the western countries that raise walls, ditches and defense systems on their eastern borders. The erosion of the Security Framework after the Cold War, the Russian Invasion of Ukraine in 2022 and the perception that Moscow could redirect strength towards the Baltic or Finland countries They have triggered a vast fortification program reminiscent of the great defensive projects of the twentieth century, although with XXI technologies. The beginning. We have coming counting. From the Finnish Lapia to the Polish province of Lublin, Europe prepares to build a new “iron curtain”, but this time not ideology, but of steel and explosives. Finland, Estonia, Latvia, Lithuania and Poland, guardians of more than 3,400 kilometers of border with Russia and Belarus, have decided abandon The Ottawa Convention of 1997, which will allow them since the late 2025 to manufacture, store and deploy millions of antipersone and anti -tank mines. The measure, considered unthinkable just two decades ago, responds to the conviction that only one lethal and deterrence obstacle It can stop an eventual Russian offensive in a moment of maximum tension in the NATO eastern flank. Remains of the Maginot Line The end of a consensus. The decision is a drastic turn against international efforts that, from the 1990s, with figures ranging from Princess Diana to Tony Blair as driversThey sought to eradicate land mines due to their indiscriminate character and their devastating effect on civilians long after conflicts. That humanitarian ideal, translated into a treaty signed by 164 countries, now fades before the Russian threat, which never joined the agreement and today accumulates More than 26 million minesmassively used in Ukraine. The perception in Eastern Europe is clear: prohibiting them was a luxury of safe times; Today, national survival It demands to recover them. The epicenter: Lithuania. The most dramatic case is that of Lithuania, which must Defend 720 kilometers of border with Belarus and the Russian enclave of Kaliningrad, including the strategic Suwalki runneronly land step for NATO reinforcements towards Baltic countries. There, in villages as Šadžiūnaibarely inhabited by the elderly who remember the devastation of World War II, the inhabitants fear that their pine and birch forests, already surrounded by fences and border stalls, soon become mined fields. The contrast between rural life and imminence of a war scenario summarizes the Decision rawness. Europe divided by the original “curtain” of Churchill. NATO countries in Azul, the members of the Warsaw Pact in red, those not aligned in green and neutral gray countries (1988) Total defense and strategic urgency. Vilna plans to spend the 5.5% of your GDP In defense (more than double the United Kingdom) and has already reserved 800 million euros to produce hundreds of thousands of mines of all kinds. These will be integrated into a “counter -river” strategy that also includes dragon teeth, ditches, armed drones and long -range artillery. Lithuanian leaders, such as Defense Minister Dovile Šakalienė and her predecessor Laurynas Kasčiūnas, They argue That history shows that Russia only respects strength, and that the experience of Ukraine, which destroyed its arsenals by the treaty and today suffers millions of Russian mines in its territory, is an impossible warning to ignore. The closure of the most extensive border. With 1,340 kilometers of shared border, Finland approved the construction in 2023 of a fence that will cover 15% of its border territory, with a cost of more than 400 million dollars and completed completion for 2026. There is a nuance here: not only seeks to stop hypothetical Russian incursions, but also control the flow of citizens fleeing the conscription. The new walls and positions, even in Remote Arctic AreasThey replace the old wooden fences that only served to contain cattle, and mark a symbolic turn on a relatively permeable border. The Balkan effort. Already We tell it. Estonia was a pioneer In 2015 After the Russian annexation of Crimea, and since 2024, the three Baltic states with Poland advance in a joint fortification plan of 700 kilometers, budgeted in more than 2,000 million pounds. The measures include Anti -tanks, concrete dragon teeth, pyramids and blocks of several tons, blocked roads, mines, bridges prepared to fly and trees destined to collapse in case of invasion. In addition, more than 1,000 bunkers and deposits for ammunition and supplies are built, small but capable of resisting artillery fire and hosting squads of up to ten soldiers. In parallel, Poland builds a permanent fence Against Belarusconsidered the main ally of Moscow. Human impact and contradictions. The paradox is evident: it seeks to protect populations from a Russian aggression at the price of introduce weapons They have historically caused most of their victims among civilians, including children. In 2023, more than 2,000 people died in the world due to explosives of this type, often in countries where wars ended decades ago. Baltic governments promise that the mines will remain in deposits and will be activated only in case of emergency, with modern systems that allow to assemble them and disassemble them at a distance. However, families such as Jurate Penkovskiene, who already cava bunkers in his garden while listening to the rumble of NATO exercises, fear for security of their children if their forests become prohibited areas. The new European border. Thus, what is at stake is not only a military change, but a landscape transformation and collective psychology in Eastern Europe. Forests, lakes and border villages aim to be part of a defensive system … Read more

Germany is installing giant concrete spheres under the sea. You have a good reason: store renewable energy

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While France and Germany reinforce their energy alliances with a renewed bet For nuclear energy, within the German country they are developing a completely different system. The focus is on marine depths, with the aim of redefining the way in which renewable energy is stored. Under the sea. A group of researchers the Fraunhofer Institute of Germany They have created the Stensea project (Stored Energy AT Sea acronym). Since 2011, the equipment has worked in a solution to reduce land use, reaching the conclusion of sinking huge concrete spheres into the seabed to store energy. The operation. These spheres sink at 600 and 800 meters deep, where water pressure is so high that it can rotate turbines with great efficiency. Each one measures about 9 meters in diameter and weighs about 400 tons. The idea is that they work as giant batteries: by letting the sea water in, it moves a turbine connected to a generator. To recharge it, water pumps out, using network energy to overcome environmental pressure. A design of what a Stesea plant would be A real test. The system has already been successful at Lake Constanza, and now the next step is marked in the calendar by 2026. It is expected to install a prototype real and 3D printed on the coast of Long Beach, in California. This model can generate about 0.5 megawatts and store up to 0.4 megawatts-Hora, which would be enough to cover the consumption of a middle home in the United States for about two weeks. The future idea is ambitious: building much larger spheres, up to 30 meters in diameter, capable of storing much larger amounts of energy. The objective is to climb the system with spheres up to 30 meters in diameter, which would allow a much larger storage capacity. According to They have detailed Newatlas researchers, the estimated storage cost around the 5 cents per kilowatt-hora, a very competitive figure compared to other current solutions. Renewables in Germany. Although it seems contradictory for its climate, the country has been strongly betting on solar energy, especially In self -consumption facilities. However, it faces an important challenge: intermittent production, or Dunkelflaute. For this reason, projects such as Stesea can act as a shock absorber of the electrical system, because it stores excess renewable energy and releases it when it is most needed. So hydroelectric plants? Unlike traditional pumping storage –which requires mountains and large fresh water reserves-, this system does not need limited elevations or water resources. Its modular design allows it to install it on coasts around the world. In addition, this system has raised An economic advantage since it allows energy arbitration, buying electricity when it is cheap and selling it in moments of high demand. Forecasts The researchers They believe that this technology He has barely shown the tip of the iceberg. They estimate that, if it was deployed on a large scale, it could reach a global storage capacity of about 817,000 gigawatts-Hora. Translated to something more tangible, it would be enough to supply about 75 million homes in Europe for a whole year. However, although the project is presented as a solution to avoid intensive soil use, it does not stop moving that occupation to the seabed. Until now, the approach has been mainly technical, but it would be expected that in future phases rigorous environmental evaluations will be included that analyze its impact on oceanic ecosystems. Image | Stesea Xataka | Europe’s turn to nuclear: Germany and France have signed a pact to reconfigure the continent

Before the lack of steel, the ships of World War II began to be built with an unusual material: concrete

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Close your eyes and think about the main material of a ship. Quite possibly Wood is the first Let it come to mind, and it is normal: we have millennia sailing in wooden ships, and we continue to do so. But it is also logical that the steel that dominated the XX and XX shipsand the Current marine monstersit is around ideas. And most likely you have not thought of another material: the concrete. But yes, for 150 years we were creating concrete ships, and far from crazy, it was the most logical idea. And even used in the first and Second World War. A Frenchman. A good day from the mid -nineteenth century, a French man named Joseph-Louis Lambot It occurred to him to build a boat. Not anyone: one of reinforced concrete. There was a problem: in 1848, they had no idea what reinforced concrete was. This material, basically, is the mixture between concrete and steel. Both combine to create something with much greater structural resistance and has been since their invention the basis of the most imposing, dams and almost any construction of the last century. Well, it was Joseph-Louis that came up with the two materials. At least, I know attribute The invention of reinforced concrete to this man. As always, there is controversy with the dates, with whom he patented the reinforced concrete, who built the first slab, etc. But well: Lambot wanted to prove his invention and built a small boat less than four meters with the aim of exhibiting it in the Universal Exhibition of Paris of 1855. Enough advantages. Basically, the interior was wire mesh covered by cement and Lambot’s idea was to completely replace the wood. The invention liked it, but it really did not attract the attention of ship manufacturers. Some barges were created for European channels, but little else. Everything changed when the Italian engineer Carlo Gabellini built the Liguria in 1896. It is the one we consider as the first reinforced concrete ship designed to navigate on the high seas. And, really, it made sense to create reinforced concrete ships. It is a material that has great corrosion resistance, so the marine environment does not damage the helmet, reducing maintenance (that also has it) and extending its useful life. It offered good thermal insulation, so perishable resources could be transported in better conditions and there were no fire problems. The Namsenfjord In the absence of bread … A few years later, the construction of these concrete ships expanded and other countries began to build, especially freighters. But of course, we are in 1914 and that means something happened: the World War I. And beyond the advantages of concrete against other materials, the world was forced to create concrete ships for a very simple reason: There was no steel. The militarization and industrialization of the belligerent forces caused a situation of Steel shortage. The ships were important, since the naval supremacy It has always been a determining factor in a conflict, but with the steel necessary for a destroyer you could create many other things. And the problem is that they had to continue building ships because there were resources to move worldwide. World War I. The revolution came with the Namsenfjorda Norwegian ship that, in 1917, showed that self -propelled concrete ships could be made. It was 26 meters in length and weighed a whopping 400 tons and most importantly: the United States saw that there was a potential in these ships beyond serving as charges propelled by an auxiliary ship. Thus, they created the Emergency Fleet Corporation program with the aim of producing 24 concrete ships. It was a failure: those who completed themselves, did it after the war, so it had to be allocated in other things. One was the SS FAithwhich was going to serve in the war, but in the end it remained to be used in transport work in the United States. It was thrown in 1919, it was in service until in 1921 it was sold to Cuba and had a length of 97.54 meters. A year after Faith, the SS Selmaa huge reinforced concrete mole of 129.54 meters in length that was launched just the day when Germany signed the Treaty of Versaillesending the First World War. It ended up using as a oil tanker in the Gulf of Mexico. With candles and a secondary support motor Demolish disadvantages. With the finished war, interest in the construction of concrete ships deflated. It still had advantages, because building them was much cheaper than making them in steel or iron, but if we mentioned a series of advantages, it is important to know the disadvantages (which exceed them, and by far). To match the resistance of a steel helmet, the concrete is thicker, which has several limitations. On the one hand, it weighs more, so it also has a major draft, the displacement of the ship is slower and more fuel is needed. That is thicker implies that there is less interior space for load, since the useful volume is reduced. That weight makes engines must be more powerful and that fuel tanks are also greater, so the investment in this part is greater. The dike to build it must also be monstrous because you cannot weld parts, such as steel, and then there is resistance to impacts. Second World War. The metal breaks, yes, but it has a greater elasticity than the concrete. This material, however, is much more fragile to impacts. A collision causes a crack in the helmet, and this on a ship that weighs so much is a conviction. That is why, after the great war, the concrete ship project was abandoned, leaving its construction practically limited to the loading barges, but then World War II arrived, and the steel needs of the previous one were repeated. However, the US program was not as ambitious as the one that began 20 years before and yes, concrete ships were … Read more

Salt water, CO2 and electricity are the new recipe to create more sustainable cement and concrete

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Cement is one of the most used artificial materials on the planet, but has two problems. The first, environmentalsince its production emits a remarkable amount of greenhouse gases. The second, the shortage of raw materials such as sand, whose mined also has an environmental impact. A new material. A team of researchers from the Northwestern University and the company ️Cemex Innovation Holding has developed A new construction material through a process that combines marine water, carbon dioxide (CO2) and electricity. This new material can be used in the production of cement and concrete and, according to its developers, in its production more CO2 than it emits. That is why the new material has the ability to make the most sustainable cement and concrete production. Salt water, CO2 and current. The method to create the new material begins by introducing electrodes in the salt water to circulate an electric current that separates water molecules into hydrogen gas and hydroxide ions. As explained by the development responsibleWhile the current circulates, CO2 bubbles are added to the water in order to change the chemical composition of the water by increasing the concentration of bicarbonate ions. The ions of these two compounds (hydroxide and bicarbonate) react with other ions that can be dissolved in marine water, such as calcium and magnesium. From these chemical reactions both calcium carbonate (CACO3) and magnesium hydroxide arise. The first compound, Continue explaining the teamit is in itself a carbon sink; The second, on the other hand, is able to capture additional carbon interacting with CO2 molecules. Copying nature. According to its developers, the process is similar to that used by corals and mollusks to build their structures and shells. The key difference is that these animals use their own metabolism instead of electrical energy to detonate the chemical process. Different uses. The resulting material, a Mixture of calcium carbonate and magnesium hydroxidecan be used as a substitute for the sand or gravel used in concrete manufacturing, but can also be used to produce cement, plaster and even paint. More control. The resulting material has an important advantage and that its properties can be altered by introducing small changes in the elaboration process such as the current and its voltage, or the duration of the injection of CO2, among others. Thus it is possible to achieve a more porous or more dense and hard substance. The details of the process and its results were published In an article In the magazine Advanced Sustainable Systems. Optimizing the capture of CO2. Another important factor is the calcium carbonate ratio and magnesium hydroxide obtained in the resulting material. This ratio depends, for example, the captured amount of carbon dioxide. According to The developers explaina 50/50 mixture of the compounds can allow to capture a ton of CO2 for every two tons of material. A more harmless waste. The process, as we indicated at the beginning, begins with the separation of water molecules. This generates, in addition to the ions used to unleash the subsequent chemical, hydrogen reactions. This gas is not only harmless but can also be used as an energy reserve. Of course, because electricity is part of the manufacturing process of this material, it must be taken into account that the net emissions of its production will depend on the mix energetic. That is, if the energy used in the process emits CO2 that is not captured, part of the capture would be lost. Another detail to keep in mind is that a good part of CO2 emissions associated with cement production They are generated at a different stage of its manufacture, when the sand is crushed with the limestone and heated at high temperatures capable of decomposing calcium carbonate. This problem occurs if the material is used in the creation of the cement and not when it is mixed later with it in the production of concrete. In Xataka | Construction has a gigantic environmental problem. Its solution: Solar cement plants Image | Northwestern University

We have discovered (again) the secret of Roman concrete. Is less impressive than it seems

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It does not fail. It seems mathematical. From time to time, the world rediscovers the Roman concrete and hallucin with the durability of a material that allows the Pantheon of Agrippa to have 2,000 years standing (while modern concrete cracks within a few decades). Incidentally, almost with the same regularity, there is some scientist or engineer who claims to have found the key secret that this is. The last occasion He has touched the Massachusetts Technological Institute And, as usual, the story is not exactly what it seems. What does the study say? MIT researchers They have studied Small pieces of lime that are usually found in Roman concrete: the ‘calcium oxide’ clasts. These types of structures have been studied a lot in romas infrastructure located in maritime contexts and, for years, has been related to some “self -regime” capacity of the material. Understanding what it means. According to some scientiststhe water that would enter through the concrete cracks would drag the calcium ions of the Classos in a process that would end up calcitating and sealing the cracks. The work of the MIT of recent days, also studies those clasts in the terrestrial concrete and theorizes that they are the result of the Romans added living lime to the mixture of the concrete (instead of the dull lime – calcium hydroxide – key of the Puzolenic reactions). Beyond that, researchers They made several mixtures With living lime and verified that, according to their theory, in these new mixtures lime clasts were generated (and was calcited that repaired the cracks). As Brian Potter saysthe discovery is interesting at the historical level. But, despite the attempts to sell it as something revolutionary, it is potentially useless. Useless? Yes, useless. When talking about Roman concrete, a lot of mistakes are usually made, but there are two recurring: the first, As Manuel F. Herrador always reminds usStructural concrete professor at the University School of the University of Coruña, is “the survivor’s bias.” The idea of ​​the extraordinary quality of Roman concrete comes from studying, precisely, the best structures they did, which have best been preserved. On the other hand, most of what the Romans built has already disappeared completely and cannot be studied. The second error. We are comparing ‘churras with merinas’ at a functional level. For being clear, with the Roman concrete we could not make a tenth of the things we do with modern concrete. The clearest example is reinforced concrete (that is, the mixture of concrete with reinforcement steel). These materials allow us to solve many of the structural problems presented , We have to pay a cost. The most obvious: the structures run before. We make the concrete we want to do. This is perhaps the most important to consider when we talk about Roman concrete: we do not “concrete to the Roman” because we do not want; Because it is not worth what we want to get. The same potter It puts examples (the Hindu temples and Buddhists built to “last more than 1000 years”) that show that current science and technology allow authentic virguerías. The question is if we want to do them in a world that changes so quickly and not, no matter how much we like the Romans, we do not want. Luckily: that allows us to go much further. In Xataka | Glass is a more everyday material but its physics does not. We are not even clear if it is really a solid In Xataka | Cheaper, durable and ecological: a new material with the help of ruthenium wants to change the rules of green hydrogen Image | Renzo Vanden Bussche *An earlier version of this article was published in January 2023

He has not created a superhero, but radiation has given healing powers to the most unexpected material: to concrete

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It is difficult to imagine a world without concrete. This material has been fundamental in the history of mankind And it is still a pillar in modern construction. Although we are exploring more sustainable alternatives such as woodthere are constructions in which the concrete remains the clear protagonist. An example is nuclear power plants, which need to be resistant and well isolated. And a new study has investigated The effect of nuclear radiation on concrete. The most surprising thing is that radiation bombardment has an effect … curative. The study. The researchers at the University of Tokyo were not looking for a U -cement Self -backreparable concretebut the impact of nuclear radiation on concrete. Being the main structural material and armor in nuclear centrals and reactors, there is a concern about how radiation influences the aging of that armor. Specifically, the objective was to verify what is the impact on quartz, a common material in the rock that is used in the mixture of concrete, regardless of the part of the world in which that mixture is manufactured, and measure the impact on quartz It can help us understand how radiation affects the structure of the building. The good news is that, in theory, these concrete structures are more stable in the long term of what was believed, since radiation induces relaxation processes in quartz that allow some recovery of their internal structure. Irradia the quartz. To carry out the study, the effects of the irradiation of neutrons in different types of quartz were investigated. The synthetic, metacuarcita, sandstone and granodiorite quartz were irradiated at a temperature between 45 and 62 degrees Celsius, with a damage by displaced atom that ranged between 0.01 and 0.23 units. IPPEI Maruyama is one of those responsible for the investigation and Comment That the flow of neutron radiation “distorts the crystalline structure, causing amorphization and expansion.” This would be something negative because it implies that the material is not stable, but the surprising thing is that, due to the role of silicon and oxygen within the quartz grains, a healing process is triggered that mitigates the expansion of the volume of the material induced by Radiation. Self -repair. “At the same time there is a phenomenon in which distorted crystals recover and the expansion decreases,” says Maruyama. This is something that depends on the size of mineral crystals within concrete. For example, the largest grains showed a lower expansion, so the degradation of the concrete, which is one of the current concerns when building and maintaining nuclear centrals, could be less severe than what was thought. Likewise, the researcher confirms that “a lower radiation rate allows more time for self -reparation”, allowing nuclear energy plants to “operate safely for longer periods of time” of which it was expected initially. Next steps. There are still questions to be resolved, since the same team comments that they have a task ahead. The University of Tokyo’s team has been studying the impact of radiation on concrete since 2008, but confirms that it is an expensive field of study, so carrying out extensive research is not easy. Now, with this finding, Maruyama is confident that they will continue to explore the impact of nuclear radiation beyond quartz to, for example, see if that expansion phenomenon occurs in other minerals that make up the concrete. The objective is not only to predict how cracks are formed due to the expansion of minerals that are being bombarded by radiation, but how to select the best materials to create a much more resistant concrete for future nuclear energy plants. Beyond the centrals. We will have to see the next steps of the researchers to strengthen those first opinions of the study, but it is evident that getting a self -realistic concrete is an obsession. Due to CO2 emissions during its productionto what Its maintenance is very expensive Since it is ending world -sand reserves, having a material that repairs itself is something that different teams throughout the planet have been investigating for years. And progress has been made, such as mixtures with sugar either coffee that allow some self -repair of concrete. We will see, yes, what takes to use that new concrete on a day -to -day basis. Image | SAM300292 In Xataka | We use both cement that has become a serious problem. Solution: replace it with garbage

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