concrete

We have been fascinated, confused and intrigued by Roman “concrete” for three decades. Pompeii is going to solve it for us

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Almost 2,000 years have passed since Mount Vesuvius unleashed a pyroclastic hell that devastated everything that was around it. That was what ended Pompeii, but it was also what gave it eternity. The Roman city began to be excavated in 1739 and, we believe, a third of the city is still underground. That’s why it still continues to surprise us. A work half done. That week in the summer of the year 79 AD, the first domes of the X insula of the IX regio was under construction. This is not surprising, of course. All of Pompeii had been under construction for almost two decades (since the earthquake of 62). However, the curious thing is that on the night of August 24, the workers were caught with everything bogged down. Plumb lines, chisels and weights; stacked tiles, tufa bricks; amphorae filled with lime, reused demolition materials and piles of pozzolans scattered on the ground. Everything has remained there, untouched, until a team from the MIT Department of Civil Engineering found and cataloged them. “The weapon of crime.” By reconstructing the scene and studying the processes, researchers concluded that these masons left incontrovertible evidence of how they mixed “hot” quicklime with volcanic ash to create concrete capable of repairing itself. In fact, as Miguel Ángel Criado collectsthings go further: the chemical and crystallographic analysis of the materials reveals quicklime (calcium oxide) in the structural concrete and slaked lime (calcium hydroxide) in the finishing mortars, thus confirming a double differentiated use. Have we finally found the key to Roman concrete? A recurring question. In 2023, I already said that “Every so often, the world rediscovers Roman concrete and is amazed by the durability of a material that allows Agrippa’s Pantheon to stand for 2,000 years.” “While modern concrete cracks after a few decades,” they usually add. By the way, “almost with the same regularity, there is some scientist or engineer who claims to have found the key secret to making this so.” But the truth, the true truth, is that despite its undoubted historiographical interest (and its potential for illuminate our knowledge of the masonry practices of 1st century Rome), the hype is always unjustified. The two mistakes of Roman concrete. When talking about Roman concrete, a lot of mistakes are usually made, but there are two recurring ones: the first is “the survivor’s bias.” As Manuel F. Herrador reminded usprofessor of Structural Concrete at the School of Civil Engineering of the Universidade da Coruña, the idea of ​​the extraordinary quality of Roman concrete comes from studying, precisely, the best structures they made, the ones that have been best preserved. Instead, most of what the Romans built has already completely disappeared and cannot be studied. The second error is even more basic and is based on ignoring that with Roman concrete we couldn’t do even a tenth of the things we do today with modern concrete. For example, today we can make long and relatively narrow “pieces” thanks to reinforced concrete. That was impossible with Roman construction techniques and is what makes our structures corrode faster. Who wouldn’t like a Roman concrete…? We already knew that Roman concrete is not a single miraculous material, but a family of recipes adapted to local environments and resources (ports, temples, roads, thermal baths). This finding only confirms it; but, in a calculated way, it is used to take advantage of the expectation that this material generates in the public imagination. And if it weren’t for making invisible the excellent work of contemporary researchers, it wouldn’t be a problem either. Because what is evident is that we do not make “Roman-style concrete” not because of ignorance; we don’t do it because we don’t want tobecause it does not serve the world we want to build. Image | Andy Holmes In Xataka | We have a problem with concrete: the same technology that allowed us to build the modern world threatens its future

We have a problem with wind blades and another with concrete. Spain has decided to resolve both at the same time

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In the Algete workshops, north of Madrid, the remains of a crushed wind blade await their second life. For years he captured the wind in a park in Cadiz; Today it is part of an experimental concrete slab. Spain is finding an unusual way to unite two environmental challenges: the recycling of thousands of wind blades that accumulate as waste and the urgency of reducing the carbon footprint of concrete, one of the most polluting materials on the planet. From the blades to the ground. Acciona and Holcim have developed successfully a new sustainable concrete made from recycled wind turbine blades. The project, named Blade2Buildis part of a European innovation initiative in the circular economy. The prototype consists of a slab of more than 120 square meters built in the Demoparque of the Acciona Technology Center, in Algete (Madrid). As the company explainsthe composition incorporates materials from wind turbine blades in fiber form as a partial replacement for natural aggregates. In other words, crushed shovels are used to replace some of the gravel or sand normally used in concrete. The mix. The base of the new concrete is an ecological version developed by Holcima type of material designed to minimize its environmental impact. In this case, the formula includes 11% recycled components, including fibers from crushed wind blades. This technology, known as ECOCycle, allows you to reuse materials that would otherwise end up as waste, without compromising the strength or durability of the product. A low CO₂ emission cement is also used, manufactured with less clinker —the substance obtained by heating limestone to more than 1,400 °C and which is mainly responsible for the emissions of traditional cement. According to Holcim This combination reduces the carbon footprint of the final product by almost half. In addition, the glass fibers and resins of the blades act as internal reinforcement, improving the material’s resistance to traction and fractures. The energy that once moved with the wind now settles in the earth. The dilemma of the shovels. In the coming years, thousands of wind blades will stop spinning in Europe. Silent, gigantic, they will remain on dry land after two decades facing the wind. It is calculated which will be about 14,000an avalanche of materials—fiberglass, carbon and resins—that will add up to between 40,000 and 60,000 tons of waste. They are made to last, not to disappear. And that is the great dilemma: their resistance, the same that made them useful, now condemns them. In the United States, the consequences of not planning the end of the cycle have already been seen: in 2020, an aerial photo of a landfill in Wyoming, taken by Bloombergshowed hundreds of half-buried wind blades. The scene went viral and served as a warning to Europe, which is now working on solutions that allow its materials to be recovered instead of burying them. ¿Does it really work? The first trials are promising. According to Holcimthe resulting concrete maintains the necessary structural properties and meets durability standards. The shredded blade fibers not only reinforce the material, but also improve its flexibility and resistance to fracture. It is not the only case. The University of Burgos has been experimenting with its own method for several years, based on the use of TPA (Wind Turbine Blade Grinding), a material obtained by cutting and grinding the blades into tiny fragments. The Sustainable Construction Research group (Sucons) has even paved a 50-meter street on the Milanera campus with this type of concrete. But it is not Acciona’s first project. As part of the #TurbineMade initiative, one of the blades in the Tahivilla park in Cadiz was transformed into a limited series of sports shoes manufactured together with the El Ganso brand. As explained by the companythose recycled soles symbolize their commitment to achieving 100% sustainable materials in their collections. The paradox is unique. The same materials that once helped produce clean energy can now be used to reduce emissions from the most polluting industry. If concrete was the material of the 20th century, perhaps the material of the 21st is the one that manages to build without destroying. And in Spain, at least, they have already begun to do so. Shovel by shovel. Image | FreePik and FreePik Xataka | Spain has become the first European country to break with gas. The only problem is that the invoice says something else.

In 2016, a construction manager lost his 16,000 euro Rolex in a concrete pour. So he sued his company

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The story of a construction manager in Parma (Italy) has hit the local media for having lost a luxurious watch Rolex Daytona valued at around 16,000 euros while working on one of the construction sites that he had to supervise as part of his job. As if it were not striking enough that a construction worker (no matter how much of a construction manager he was) I had a Rolexand took him as if nothing had happened to an environment as hostile as a work in progress, the employee decided to add a twist to the drama of the story: sue the company, accusing it of being responsible for the loss of the valuable watch. Two courts had to show him what seemed obvious. Luxury formwork In May 2016, the person in charge of a construction site in the Italian city of Parma carried out the usual prior verifications when pouring concrete necessary to build the foundation of a building. Apparently nothing out of the ordinary in the reality of thousands of works anywhere in the world, except for the detail that this employee wore a Rolex Daytona on his wrist. In one of these verifications, the person in charge detected that one of the pumps in charge of pumping the concrete into the intended hole was not working properly, which prompted him to take control himself at that precise moment and personally manipulate the nozzle of one of the machines to instruct his colleagues on how to pour it correctly. While holding a metal chain anchored to the end of the concrete mixer chute to control the direction in which the material should be poured, he waited for the staff to reactivate the pump. It was then that, when the spill resumed, something happened that triggered the loss. According to the witnesses called to testify in the trial: “Within minutes of resuming concrete pouring, while still holding the supply pipe as described, another sudden blockage occurred. Without giving him time to break free and move away, the pipe moved with a sudden and violent jerk, with such force that it lifted him off the ground and threw him several meters away.” After the incident, the construction manager composed himself and warned that his Rolex Daytona had disappeared from his wrist: everything indicated that the valuable Swiss watch had disappeared in the middle of the quick-setting concrete. At that same moment, exhaustive searches were launched, even within the mix, but the watch was never recovered. Outraged by the mishap, the employee blamed both the company and the machinery for the accident and filed a lawsuit requesting full compensation for the lost watch due to the malfunction of the concrete pumping system. According to collect The Italian newspaper Corriere di Bologna, in its statement, stated verbatim: “You owe me my Rolex Daytona for 16,000 euros; it is your fault and the machine’s fault.” Common sense two courts Italian justice was clear, and it was clear on two occasions: the responsibility fell on the construction manager for not being sufficiently cautious. After lose the lawsuit In the first instance, the construction manager submitted the first ruling to the Court of Appeal of Bologna, which determined – for the second time – that “it is seriously unsustainable that directing the trunk of a concrete mixer to direct the pouring of concrete on foundations under construction is an activity that can be carried out wearing a 16,000 euro watch”, as literally stated in the ruling signed by judges Rossi, Gaudioso and Mazze who formed the court. In their resolution, the magistrates concluded that the employee did not adopt the essential “expertise and diligence” measures, which made any claim against the company inadmissible. For this reason, the employee not only lost the valuable watch, but was also forced to pay an additional 2,500 euros in legal costs. The Rolex it cost him money even after losing it. In Xataka | Rolex is tired of theft and counterfeiting: they want to use NFT chips and blockchain-based certificates of authenticity Image | Rolex, Unsplash (Troy Mortier)

Raise a wall that protects the entire continent, but instead of concrete, drones

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In recent weeks, a Succession of incursions of drones and airplanes Russians About the heavens From Poland, Romania, Estonia, Denmark and Norway has evidenced the vulnerability of European airspace. The violations have forced to close civil airports, activate NATO fighters and use missiles to tear down devices whose price is just a fraction of the projectiles thrown against them. The alarm has spread from the Baltic to the Atlantic, and in Europe it has taken strength An idea: The answer must be a coordinated effort on the continental scale. The concept “Drones Wall”. Yes, under the impulse of the European Commissioner of Defense, Andrius Kubilius, the idea of A “drone wall” that protects all of Europe in the face of Russian threat. The initiative raises a multilayer system with radars, acoustic sensors, interception platforms, short -range anti -aircraft artillery and defensive drones, all connected to the network to share data in real time between countries. The objective is to achieve interoperability and common coverage that allows detect and neutralize drones In seconds. The project, which will be presented at the Copenhagen informal summit, extends beyond border countries with Russia to cover the entire continent, also integrating spatial capabilities in collaboration with the European Space Agency. Ukraine, the partner. A central aspect is the participation of Ukrainethat after more than three years of war has become the armed force more experienced In the world in defense against Drones swarms. Its manufacturers, supported by the immediate feedback of the front, They have developed industries capable of adapting designs in a matter of weeks, something that contrasts with the rigidity of the European arms industry. kyiv has offered Share knowledge, send technical teams to train NATO armies and participate in the joint development of systems. Several countries, including United Kingdom and Denmarkthey have already begun to weave industrial alliances with Ukrainian manufacturers to produce drones in common, aware that the future of air defense goes through a close integration with the innovative capacity of Ukraine. Politics, money and the EU. The drone wall project advances in parallel to a large -cut financial initiative: a 140,000 million loan from euros to Ukraine based on frozen Russian assets in the EU. Germany, who had been reluctant, has shown willingness to support The plan, convinced that without those funds It will be impossible Replace the void left by the American withdrawal. The formula would avoid direct confiscation of the funds, preserving international legality, but would allow Generate immediate resources to sustain the warlike ukrainian effort. Hungary, despite its proximity to Kremlin, It has not blocked So far the sanctions, but the fear of a veto forces Brussels to explore legal ways that raffle the need for unanimity. The interrelation between financing to Ukraine and the deployment of a continental drone shield underlines that European defense can no longer separate from kyiv’s survival. Berlin’s doubts. Despite the enthusiasm of Brussels and the East countries, German Defense Minister Boris Pistorius, He has cooled This week expectations. In his opinion, the idea that a wall of drones can be operational in three or four years, when the processes of acquisition and technological development are much slower. Pistorius insists on Prioritize flexible capabilitiesthat allow to adapt to a technology in constant evolution, rather than commit to a rigid and high cost concept. His words reflect a latent tension between those who demand speed and forcefulness, Like the Baltic or Polandand those who advocate prudence and financial sustainability, Like Germany. However, even the most skeptical coincide in the need to spend massively in anti -Didstock defense, even if it is outside the framework of a common wall. UK’s role: Project Octopus. In parallel, the United Kingdom has announced Your own contribution to a joint program with Ukraine, called Project octopusdestined to produce in British factories low -cost interceptors that can be manufactured in series and deploy in a matter of weeks. These devices, effective against The Iranian Shahedthey have a production cost ten times minor that the equivalent systems and could become the backbone of the short -range European air defense. London plans Share intellectual property with kyiv and supply the drones to both Ukraine and NATO countries, thus expanding their strategic influence. British involvement also seeks to compensate for its departure from the EU, showing that it remains a pillar of the European defense against Russia. New strategic balance. The initiative of the drone wall is framed in a broader context: progressive separation of the United Statesdriven by Trump’s policy. The partial abandonment of Washington has crystallized the evidence that the main military ally of Europe is no longer the United States, but Ukraine itselfwhich brings more than 700,000 active combatants, an agile arms industry and the determination to resist Moscow. Europe, therefore, aims to stop seeing kyiv as a mere consumer of military aid and starting to integrate it as a Security provider. The industrial agreements in drones are the first step of a symbiosis that could redefine continental defensive architecture. Between urgency and uncertainty. Under this scenario, Europe faces A crossroads: You need to act quickly to cover its vulnerabilities to Russian drones, but at the same time you must manage expectations and avoid financial or technological commitments that are unfeasible. The drone wall symbolizes EU’s will to build A common defenseinteroperable and sustained, but its success will depend on the ability to reconcile the demands of the eastern flank with the caution of the western nucleus. The Collaboration with Ukrainefinancing based on frozen Russian assets and British involvement They point to a future in which European security is built on its own pillars, or less dependent on the United States. In that transformation, drones do not seem only tactical tools: they have become the emblem of a Europe that desperately seeks shield his sky while redefine your place in the global strategic order. Image | Khamenei.ir, Nara, Rawpixel In Xataka | Russian drones are paralyzing airports in Europe. There is a background reason: 250,000 casualties in … Read more

In 1975 they buried “the worst car in the world” under a 45 -ton concrete vault. Now, they have opened the time capsule

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Is it possible to maintain an unchanged object over the years, the decades or even the centuries? This is what the time capsules try to get, containers in which a sample of various objects is saved with the intention of checking years later if they have resisted the passage of time. Or with the intention that, in the future, the descendants of our descendants have objects that allow them to understand how we lived. Those Time capsules They have buried themselves for scientific purposes (The MIT has several distributed by their facilities that celebrate special events) or have been sent to space. But they have also resulted in crazy particular projects such as Harold Davisson, a local merchant who decided that his was going to contain a car. Specifically, a completely new Chevrolet Vega. Finally open This year, summer in Seward (Nebraska) began in a different way. Hundreds of people gathered in this town of less than 7,000 inhabitants to contemplate what life was 50 years ago. They did not project a documentary on the wall, neither did any of the people live then. They simply opened the one that, in their day, was the largest time capsule in the world. 50 years ago, Harold Davisson, a city place decided to bury thousands of objects so that their grandchildren had a first -hand contact with the past. How did he? Simp NBC News. Among the thousands of objects were letters written by Trish Davisson’s parents, the son who fulfilled his father’s dream when he opened the time capsule. But also thousands of objects donated by neighbors 50 years ago. One of them, they collect in the American environment, was excited to discover the invitation of their wedding. But, without a doubt, the most striking object recovered was a completely intact Chevrolet Vega. The car was a purchase of the creator of the time capsule, who looked around the cheapest car he could buy. Its price was not accidental. The Vega gave so much reliability problems that was known by the nickname “Worse car in the world”. Released in 1970, it is not uncommon for the creator of this time capsule will find the car at a good price. He Chevy Vega was born to be the best car among the most affordable options on the market. From maintenance to fuel consumption, with the Volkswagen Beetle and the first Japanese compacts pressing in the market. But Chevrolet wanted to hurry to throw the car that the result was catastrophic. Fifty years after your purchase, now nobody knows what will happen to this Vega so particular. In MotorpasionTrish Davisson’s words rescue who points to this Vega could be the model with less kilometers from all over the world. With small damage of rust on the hood and in the steering wheel, they now consider if the car will end in a museum although nothing has been confirmed. The Chevrolet Vega was, last July, the crown jewel of the opening of the time capsule. This has also been surrounded by a certain controversy because for years it was the largest time capsule in the world. In 1983, however, Guinness record judges withdrew this category after Oglethorpe University (Georgia, United States) protest ensuring that its time capsule not only It was bigger, it was also older. Angry with the situation Davisson decided that he was going to build a new pyramid -shaped appendix to recover the throne. Since 2000, however, the record has a time capsule designed in Guilford (Surrey, United Kingdom) in which representative objects have been kept on what life was like during the change of millennium. Photo | Isommerer and Sentemalan In Xataka | For Shaquille O’Neal the biggest obstacle to conducting a supercar is its height: they have manufactured a tailored corvette

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

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