České stavebnictví je v EU čtvrté nejhorší

Výkon českého stavebnictví byl na konci prvního čtvrtletí letošního roku z 28 zemí Evropské unie čtvrtý nejhorší. Vyplývá to z kalendářně očištěných údajů evropského statistického úřadu Eurostat. Podle nich české stavebnictví od začátku roku do konce března meziročně kleslo o 2,2 %. V zemích Evropské unie přitom sektor v souhrnu vzrostl o 2,6 %.Nejvíce stavebnictví vzrostlo v Maďarsku, téměř o čtvrtinu. Následovaly Irsko (o 21,2 %) a Estonsko (o 20,4 %). Podle prezidenta Svazu podnikatelů ve stavebnictví v ČR Václava Matyáše se není čemu divit, protože první čtvrtletí kopírovalo propad z loňského roku: „Inženýrské stavitelství, jehož nejpodstatnější součástí je dopravní infrastruktura, bylo na nižší úrovni než v krizových letech. Varující a silně znepokojivý je objem nově vypsaných veřejných zakázek, který je oproti loňskému roku o třetinu nižší. Dosavadní vývoj českého stavebnictví nevytváří předpoklady pro to, aby se v porovnání s ostatními zeměmi unie umístilo v horní části. Obávám se, že propad může pokračovat.“

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Hlavní závěry Fóra českého stavebnictví 2017

  Třináctý ročník oborové konference Fórum českého stavebnictví se zaměřil na externí a interní faktory působící v současnosti na stavebním trhu. V úvodu řada klíčových osobností vládní koalice, včetně místopředsedy vlády Andreje Babiše, a opozice diskutovala o perspektivách stavebnictví a investicích po letošních parlamentních volbách. Druhá část konference patřila odborníkům a jejich názorům na to, jak rozhýbat stagnující odvětví.
   Organizátoři konference, Svaz podnikatelů ve stavebnictví a společnost Blue Events s podporou strategického partnera Deloitte, nabídli téměř třem stovkám účastníků konference v pražském Clarion Congress Hotelu kromě plenárního programu i možnost detailní diskuse ve třech tematických panelech: "Státní správa a stavebnictví: partneři či nepřátelé?", „Jak se digitálně transformovat v podmínkách boje o přežití" a „Návrh nového stavebního zákona".

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Eindhoven to built Europe’s first 3D printed concrete house

It’s been anticipated for more than a year now, but the moment has finally arrived. After experimenting with their custom concrete 3D printer since September 2015, researchers from the Eindhoven University of Technology (TU Eindhoven) have now finally received permission from the municipality of Eindhoven to build an actual 3D printed concrete home – the first of its kind in Europe. The 3D printer itself was first unveiled at the Dutch Design Week in 2015, and was developed in collaboration with Dutch company ROHACO as part of the project 3D Concrete Printing (3DCP). The first concrete 3D printer of this size in the Netherlands, the completed machine features an extrusion printhead that can move in all directions will attached to a concrete mixer and pump. Featuring a 9 x 4.5 x 2.8m build volume, this 3D printer is considerably more accurate than competing machines of this size – as was illustrated by this student-made 3D printed pavilion unveiled last summer. The 3D printer reportedly cost around €650,000 to develop, with funding provided by ten commercial partners and the university.

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Decoding cement’s shape promises greener concrete

  Bringing order to disorder is key to making stronger and greener cement, the paste that binds concrete. Scientists at Rice University have decoded the kinetic properties of cement and developed a way to “program” the microscopic, semicrystalline particles within. The process turns particles from disordered clumps into regimented cubes, spheres and other forms that combine to make the material less porous and more durable.
  The technique may lead to stronger structures that require less concrete – and less is better, said Rice materials scientist and lead author Rouzbeh Shahsavari. Worldwide production of more than 3 billion tons of concrete a year now emits as much as 10 percent of the carbon dioxide, a greenhouse gas, released to the atmosphere.
   Through extensive experiments, Shahsavari and his colleagues decoded the nanoscale reactions — or “morphogenesis” — of the crystallization within calcium-silicate hydrate (C-S-H) cement that holds concrete together.

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Spectral Fingerprinting' detects Early Corrosion in Concrete

 Researchers at the National Institute of Standards and Technology (NIST) are using spectral techniques  to detect corrosion, the primary danger threatening the health of the steel framework within the nation’s bridges, roads and other aging physical infrastructure.
  What they have developed is a noninvasive “spectral fingerprint” technique that reveals the corrosion of concrete-encased steel before it can cause any significant degradation of the structure it supports.
  When water and oxygen corrode iron, different iron oxide products are produced, with the two most common being goethite and hematite. “The brown rust that forms when you leave a hammer out in the rain is mostly goethite, and when a steel reinforcing bar [rebar] corrodes inside a concrete bridge deck, that is mostly hematite,” said NIST physical chemist Dave Plusquellic. “We have shown in our new study with goethite, and our previous work with hematite(link is external), that terahertz radiation—electromagnetic waves with frequencies 10 to 100 times higher than the microwaves used to cook food—can detect both corrosion products in the early stages of formation.”
   Current imaging methods for uncovering corrosion use microwaves to record changes in the physical state of the affected steel, such as changes in the thickness of a rebar within the concrete of a bridge or other structure. “Unfortunately, by the time such changes are detectable, the corrosive process is already well on its way toward causing cracks in the concrete,” said physicist and NIST Fellow Ed Garboczi. 
   Additionally, Garboczi said most of the microwave imaging methods rely on comparisons with baseline measurements of the steel taken at the time of construction, a practice that only goes back about 25 years. “That’s a real problem since the average age of the 400,000 steel-reinforced concrete bridges in the United States is 50 years and there is no baseline data available for many of them,” he explained.

 

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HeidelbergCement broadens its vertical integration in NW USA

  Today, HeidelbergCement announced that its U.S. subsidiary Cadman Materials, Inc. , a LehighHanson company, has entered into an agreement with a U.S. subsidiary of CEMEX, S.A.B. de C.V. (Cemex) to buy Cemex’s Pacific Northwest Materials Business consisting of aggregate, asphalt and ready mix concrete operations in Oregon and Washington. The purchase price for the assets amounts to about USD 150 million. Closing of the transaction, which is subject to final approval by regulators, is expected during the second quarter of 2017 or soon thereafter.

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Česko si musí umět ochránit svůj stavební trh

Tomáš Koranda, člen představenstva stavební firmy Hochtief


 
Co považujete za hlavní problém českého stavebnictví?
Trochu mě znervózňuje, že se na českém trhu objevují zahraniční firmy, které tady nikdy nepodnikaly. Je tu řada italských firem, jsou tu konsorcia, kde jsou turecké, řecké nebo slovinské firmy. Dokonce z Kazachstánu. Tyhle firmy zastupují jen právní kanceláře. Přitom se účastní tendrů o velké dopravní stavby v řádu 60 miliard korun. Může to dále ohrozit celkovou kondici českého stavebnictví, které už má dost problémů kvůli složité stavební legislativě a pokračující cenové válce.

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Solar Collectors from Ultra-High Performance Concrete

 Fraunhofer ISE developed
   When integrating renewable energy into the building envelope, solar thermal plays a significant role. So far, solar thermal products were generally based on metal components that conduct heat, absorb a high fraction of solar radiation and emit little infrared radiation to prevent thermal loss. Using this state of the art technology, building integration and architectural aspects are however often neglected. In the “TABSOLAR II” project, Fraunhofer ISE together with five partners from the industry and research, is investigating the development of resource-efficient and cost-efficient products based on fluid-guiding components made of Ultra-High Performance Concrete (UHPC) that can be installed into the façade, making building envelopes suitable for the application of renewable energy.

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Programmable cement particles for stronger concrete

The discovery is an important step in concrete research
 
  Through extensive experiments, Shahsavari and his colleagues from Rice  University  decoded the nanoscale reactions of the crystallization within calcium-silicate hydrate (C-S-H) cement that holds concrete together.
   For the first time, they synthesized C-S-H particles in a variety of shapes, including cubes, rectangular prisms, dendrites, core-shells and rhombohedra and mapped them into a unified morphology diagram for manufacturers and builders who wish to engineer concrete from the bottom up.
  “We call it programmable cement,” he said. “The great advance of this work is that it’s the first step in controlling the kinetics of cement to get desired shapes. We show how one can control the morphology and size of the basic building blocks of C-S-H so that they can self-assemble into microstructures with far greater packing density compared with conventional amorphous C-S-H microstructures.”  The idea is akin to the self-assembly of metallic crystals and polymers.

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World's first 3D printed hotel, planning 3D printed homes

Over the past two years , a very exciting race has been ongoing in the construction world: Who can be the first to develop a commercially viable concrete 3D printer capable of making homes? And the competition has been very tough, as interesting and promising projects quickly began popping up all over the place. Just a few months ago, even Dubai stepped into the race with an ambitious plan, and just this week Italian manufacturers WASP announced the creation of the world’s largest Delta 3D printerwith an eye on concrete construction. But today, another team has jumped to the head of the pack, as the innovation-minded Lewis Grand Hotel in the Philippines, owned by entrepreneur Lewis Yakich, has begun work on a massive 3D printed expansion of the hotel. What’s more, they are already planning to follow this up with a series of 3D printed commercial homes. Do we have a winner?
 

 

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Conductive concrete shields electronics from electromagnetic attack

 

                                                                                             Picture: Craig Chandler

 

Nebraska engineers Christopher Tuan (left) and Lim Nguyen have developed a cost-effective concrete that shields against damaging electromagnetic energy. Electronics inside structures built or coated with this concrete are protected from electromagnetic interference. The university has signed an agreement to license this shielding technology to a Florida company. Tuan and Nguyen are standing beside a test structure at Nebraska’s Peter Kiewit Institute in Omaha.

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Bendable concrete defies conventional standards of durability and strength

Yang En-Hua, assistant professor at NTU’s School of Civil and Environmental Engineering, holds a small slab of ConFlexPave, the bendable concrete he and his team invented

Concrete is one of the most widely used construction materials in the world. And although it’s pervasive, it’s definitely not clean to produce. In fact, today’s standard Portland cement, which is extremely carbon-intensive to make, accounts for nearly 5% of the world’s total carbon emissions.
 But modern civilization as we know it would cease to exist without concrete—so engineers are working toward innovative, “greener,” energy-efficient concrete manufacturing solutions.
 Some scientists are returning to simpler times and investigating the ancient Roman secret to more ductile concrete. Geophysicists at the Stanford University School of Earth, Energy and Environmental Sciences (Stanford, Calif.) who discovered concrete-like rock deep within a dormant Italian volcano say this discovery could explain how ancient Romans invented the compound used to build structures like the still-standing Pantheon and Colosseum.

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Solar glass roofing tiles for sustainable energy


 

  Tesla, most famous for making electric cars, wants to integrate sustainable energy into our everyday lives. Recently Tesla unveiled its concept for solar glass roofing tiles that will expand the company’s vision for a future powered by integrated sustainable energy.And because about 5 million new roofs are installed in the United States every year, there’s a large market for sustainable energy sitting on top of each home. A small portion of that market is already taken up by solar panels, which are installed on about 1 million U.S. homes currently.
 But Tesla’s vision isn’t about adding sustainable energy—it’s about completely integrating it into our homes and lives. The company’s three-part solution consists of energy generation, storage, and transport with its own brand of solar roofing tiles, battery packs, and electric cars, respectively.

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Cement reabsorbs CO2 emitted when it was made

Cement manufacturing is among the most carbon-intensive industrial processes, but an international team of researchers has found that over time, the widely used building material reabsorbs much of the CO2 emitted when it was made. “It sounds counterintuitive, but it’s true,” said Steven Davis, associate professor of Earth system science at the University of California, Irvine. “The cement poured around the world since 1930 has taken up a substantial portion of the CO2 released when it was initially produced.”

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ROČNÍK 2016

 

Concept of a new low-energy tunnel kiln for energy saving and production efficiency

 Direxa Engineering, LLC, an engineering company based in Colorado, USA, and specializing in heat treatment for various industries, and its R&D projects partners Ceritherm and Seipia, both French companies, have combined their skills to develop an innovative concept for a low-consumption tunnel kiln, otherwise named the Skate-Kiln.
  The current thermal treatment equipment are becoming outdated. Following the two oil crises and the energy cost increase, the 1980s saw numerous development projects, however, none of these solutions was successful.

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Research for new concrete production technology

 Concrete: the materiál has been around since ancient Rome and is still one of the most widely used construction materials to date.
 Current concrete manufacturing practices are carbon-intensive, however. In fact, today’s standard Portland cement production accounts for nearly 5% of the world’s total carbon emissions.
 So some researchers are focusing on cleaner, greener ways to manufacture concrete and reduce this material’s carbon footprint.
 Earlier this year, researchers at Rice University in Houston, Texas, took an atomic-level look at how concrete is produced. They published the results of computer modeling studies that reveal how dislocations—or screw-like defects—in raw crystals used for concrete affect manufacturing efficiency,
 The team found that tricalcium silicates (C3S) that consist of pure rhombohedral crystals are better than others for producing “clinkers”—round lumps of C3S that, when ground into a powder, mix with water to make cement, the glue that holds gravelly concrete together. When a clinker is easy to grind, manufacturers don’t need to work as hard, the release explains. And that means the process requires less energy.

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Random gaps and particles influence concrete’s strength

  Concrete—it’s  under our feet on sidewalks, it makes up the world’s vast infrastructure network of roadways and buildings, and it can be quite beautiful. Modern civilization wouldn’t exist without it.
   Many scientists are looking to ancient technology to make modern concrete more durable and sustainable.Theyare trying to find out why ancient concrete structures like the  Coliseum in Rome stand strong and tall despite a couple thousand years of wear. What’s the difference between their concrete and mine?

 

 
 Roman concrete was not only strong and durable, but also much more environmentally friendly than the ubiquitous Portland cement used today. That’s because Portland cement production requires heating a limestone–clay mixture to 1,450°C, releasing a lot of carbon in the process—enough to account for 7% of global carbon emissions in total.  Roman construction instead used large chunks of rock (45–55% by volume) bound together by a mortar composed of 85% by volume volcanic ash mixed with water and lime, a formulation that requires much lower production temperatures and thus lower carbon emissions, too.

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Česká firma chce prorazit v Nigérii se stavebními bloky

   Před ostravskou firmou Flash Steel Power se otevírá slibná obchodní příležitost v Nigérii. Do této nejlidnatější africké země, v níž rychle roste poptávka po bytech, hodlá dodávat speciální stavební bloky. V první fázi plánuje vyvézt materiál za desítky milionů korun, a pokud se spolupráce s Nigerijci osvědčí, zahájí v zemi výrobu.
   Na financování obchodu se má podílet Česká exportní banka, která už o vývozu prefabrikovaných bloků v Nigérii jednala s tamní státní bankou Federal Mortgage Bank of Nigeria a nyní posuzuje možnost financování první etapy.
„V případě pozitivních výsledků analýzy by v úvodní fázi ČEB zafinancovala jeden konkrétní vývozní kontrakt v celkové hodnotě pět až osm milionů dolarů do výše 60 až 70 procent,“ řekl serveru E15.cz generální ředitel ČEB Karel Bureš. Zároveň dodal, že podle toho, jak by spolupráce s nigerijskou stranou probíhala, by mohlo financování dalších vývozů pokračovat.

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Thyssenkrupp: Largest Cement Contract Ever

     Cement Plant in Saudi Arabia
  Thyssenkrupp has won a contract from Yamama Saudi Cement Company, one of Saudi Arabia’s biggest cement producers, to build two turnkey cement clinker production lines.
    The two lines with an overall capacity of 20,000 tpd cement will be built at a new site around 80 km east of the capital Riyadh. It is the largest cement contract ever secured by Thyssenkrupp.
   Thyssenkrupp Industrial Solutions, the engineering and construction arm of the Thyssenkrupp Group, is delivering Engineering, Procurement and Construction (EPC) for the lump sum turnkey cement plant including the supply of all the components for the new lines, from raw material preparation to clinker manufacture to cement loading, including quality control. Both lines are scheduled to start operation in 2018.

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Green living concrete supports photosynthesis

Although the manufacture of concrete has a heavy carbon footprint, the material is still one of the most widely used construction mediums around the globe.Which is why concrete research is rife with myriad ways to make the material more green, in one way or another.
  Researchers from BarcelonaTech in Spain are working to perfect living concrete—a layered formulation that allows photosynthetic organisms, such as mosses, lichens, and other microorganisms, to grow within the material itself.
   In addition to providing aesthetics to the concrete, the organisms recycle carbon dioxide out of the air. Affixed to buildings, the concrete also helps regulate thermal conductivity, reducing buildings’ energy demands.
 That makes the new concrete the greenest we’ve seen yet—figuratively and literally.

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