Europe’s Longest Bridge Spans Troubled Waters

Earlier this month, Russian President Vladimir Putin got behind the wheel of a bright orange dump truck and led a convoy across the Crimea Bridge, a new bridge that links Russia to the Crimean Peninsula. The bridge, which stretches12 miles across the Kerch Strait, is now Europe’s longest bridge.

But media coverage of the bridge hasn’t focused on its length, or any of its physical properties. That’s because the new bridge connects Russia to territory it annexed from the Ukraine in 2014—an action Western governments have called illegal. To many observers, especially those in the Ukraine, the bridge was a political power move, designed to seal Russia’s hold on the region.

While the politics of the bridge are complicated, its engineering is fascinating. A bridge across the Kerch Strait has been under consideration for more than a century, but has been blocked by brutal geological and environmental conditions. Experts in the area aren’t sure how long the bridge will stand.

History

The first Russian plans for the bridge were put forward by Tsar Nicholas II in 1903, but were then sidelined by wars and economic concerns soon afterward. German engineer Albert Speer picked up the idea for the bridge in 1943, envisioning that it would aid in the Nazi takeover of Soviet Russia. Bridge construction started that year, but was halted by Soviet attacks, and much of the remaining bridge was blown up by the German army during its retreat from the region.

The next year, the Soviet Army used the leftover building materials to build a single-track railway bridge across the strait for the wartime Yalta Conference. Part of the conference delegation managed to take the train across the bridge, but seasonal ice floes took out several of the structure’s supports in early 1945, and the bridge was not repaired. More permanent plans were put on hold due to the cost of the project and the difficult building conditions across the strait.

After the Soviet Union collapsed, politics became yet another barrier to bridge building. In 1954, Soviet Russia had transferred control of the Crimean Peninsula to Soviet Ukraine, so Russia no longer had control of Crimea when the USSR disbanded. Proposed projects in the 1990s and 2000s collapsed, but in 2010, the two countries finally signed an agreement to build a bridge together.

But Russia’s annexation of Crimea in 2014 severely strained relations between the two countries. The Ukraine imposed sanctions on Crimea, effectively cutting off most of its trade and forcing it to conduct trade across the strait with Russia by ferry. These sanctions made goods expensive in Crimea, as well as limited the number of Russia tourists crossing the strait to vacation there. So, in 2015, Putin announced that Russia would build a bridge to the peninsula on its own.

Building Bridges

In early 2015, the Russian government awarded the 228billion-ruble ($3.7 billion) bridge contract to infrastructure construction firm Stroygazmontazh Ltd. (SGM), a company that specialized in pipelines but which had not previously built any major bridges. The risk of international sanctions made it difficult to attract foreign investment or obtain insurance to cover the project, and SGM eventually used a small Crimean insurance company to underwrite a potential $3 billion loss.

The physical environment also presented several barriers to bridge construction. The site’s historic significance briefly worked against the project: divers searching the sea floor in preparation for the construction found over 200 bombs and a downed WWII-era plane. The weather also posed problems in the early stages of the project. Leonid Ryzhenkin, the project’s construction director, told NPR in 2016 that poor weather had interfered with the work, making it impossible for construction vessels to leave port. To limit weather disruption, SGM put up three temporary bridges to transport workers, supplies and heavy machinery like mobile cranes and piling rigs to the build sites.

Despite these disruptions, the project was finished ahead of schedule. And while officials projected that the road portion of the bridge would be finished by the end of 2018, it’s already open to light traffic.

The finished road bridge has four lanes, with a two-lane railroad bridge planned for the end of 2019. It stretches from the town of Taman in Russia to the city of Kerch on the Crimean Peninsula, passing through Tuzla Island along the way. It covers 4 miles of open water between Taman and Tuzla, 4 miles across the sandy island, and 3.4 more miles of water from Tuzla to Crimea.

Between Tuzla and Crimea, there is a 745-foot double shipping channel arch, with one arch on the road bridge and one on the forthcoming rail bridge. Both arches have a 115-foot clearance for boats to pass underneath. The arches were built on land and towed out to sea by boat.

The road bridge is completed, and the rail bridge is on track to be finished soon. International disapproval hasn’t stopped the project’s construction—or even slowed it. But while the political and economic challenges facing the bridge have largely been overcome, there are other possible threats lurking under the waterline.

Shaky Ground

The Kerch Strait is known to be geologically unstable. A tectonic fault passes through the ocean floor under the strait, and the bedrock is covered in a layer of silt up to 197 feet thick that must be dug through to get a stable foundation. Further complicating matters is that the strait’s seismic activity can make mud volcanoes from the silt. Mud volcanoes are formed when water heated deep in the Earth’s crust mixes with underground mineral deposits, and the mixture is forced upward through a geological fault. As of 2010, Ukraine’s Department of Marine Geology and Sedimentary Ore Formation reported almost 70 mud volcanoes found in the Azov-Black Sea Basin where the Kerch Strait is located.

The bridge is supported by over 7,000 piles of three different varieties: bored piles (reinforced concrete piles poured into depressions on-site), prismatic piles (blunt, wedge-shaped supports), and tubular steel piles. These piles were driven up to 300 feet below water level because of concerns about stability.

But not everyone thinks these measures will be enough to keep the bridge steady on its perilous ground. Civil engineer Georgy Rosnovsky, who previously designed two other possible versions of the Kerch Bridge, is troubled by the current design. He believes that the bridge is necessary, but has stated that he thinks it’s being built “in the wrong place and the wrong way.” He believes the pilings need to be at least 100 meters (328 feet) long, and worries that they are not sunk deep enough into the bedrock to be stable.

Rosnovsky also thinks that the bridge’s spans (the distance between supports) aren’t long to allow ice floes through. He planned his 1993 bridge with spans of 230-660 meters (755-2,170 feet), but said that any spans over 200 meters would be safe from ice. The current design’s longest span is 227 meters, but most of the spans are much shorter than that. According to Rosnovsky, this design puts the bridge at risk of suffering the same fate as the temporary bridge that was destroyed by ice floes in 1945.

Yuri Medovar, of the Russian Academy of Sciences, is another critic of the bridge. Talking to news agency Sotavision in late 2016, Medovar expressed concern that the area hadn’t been sufficiently mapped, and that the complex geology and weather conditions would make the structure risky. He warned of the costs of poorly built bridges, citing the 2013 bridge collapse in Borisoglebsk that killed two people. “You can build everything, ” he concluded, “but how much it will cost, and how [long will it] stand?”

Despite the difficult building conditions, the bridge’s creators aren’t worried about the possibility of collapse. “It will stay intact for 100 years, Rotenberg said in an interview with the Itogi Nedeli weekly news roundup after the bridge’s inaugural drive. “At least. We guarantee that. Everything is done perfectly well.” But critics like Rosenberg aren’t satisfied. “It’s a rich firm, but it’s not built by experts. They think that money is everything,” Rosnovsky told FOCUS in 2016. “The bridges are built from the calculation of the service life of a hundred years, but I think that this bridge will be short-lived.”

Source : www.engineering.com

World’s Biggest Infrastructure Project is One You Never Heard Of

While the U.S. dawdles with much needed domestic infrastructure upgrades, China is already engaged in a project so massive that it will tilt the Earth in its favor. The trillion-dollar Belt Road Initiative (BRI) is a plan for a web of transportation routes (road, rail, shipping lanes, more—all leading to China) that will be created or expanded over the next 30-plus years. The BRI’s main purpose is to facilitate trade. China, the world’s leading producer of exports, no longer wants to rely on slow moving boats to move its goods out.

Lost in Translation

BRI not ringing any bells? This development plan for a number of megaprojects was introduced in 2013 as the One Belt One Road (OBOR). The “belt” referred to the roads, and “road,” inexplicably, the sea lanes. It was renamed the Belt and Road Initiative (BRI) at the 2017 Belt and Road Forum(BARF? Really, guys?) in Beijing.

The U.S.—and most of the West—paid scant attention. Even now, as money and concrete are pouring into projects, the U.S. continues to draw inward, led with an “America First” ideology. By the time the concrete is dry on the New Silk Road projects (China hopes to finish by 2049), the economic effect and, later, its political and even military consequences of the New Silk Road could make China the most dominant world super power for centuries to come.

Walls and Bridges

Under the Trump administration, the U.S. pulled out of the Paris Climate Accord in 2017 and then the Trans-Pacific Partnership. The proposed Mexico border wall extension will further separate the U.S. from neighbors to the South.

China’s state-run news agency responded with this during the Beijing conference, without any sense of irony: “As some Western countries move backwards by erecting ‘walls’, China is contriving to build bridges.” It was China that built the most famous wall of all time, the Great Wall, to keep out its neighbors to the North.

The New Silk Road will help China connect its far-flung provinces, but most of the development plans seem to be in neighboring countries with global trade partners. The BRI will help connect the heavily populated eastern part of the country with its Western provinces, which are considered underpopulated and underdeveloped. The highly promoted two thousand-kilometer Qinhai-Tibet railway, ostensibly built for tourism, deposits 3,000 Han Chinese (the predominant Chinese ethnic group) into Tibet, and has already made native Tibetans a minority in their own land.

While China has earmarked $900 billion to spend on the New Silk Road, the country is also prepared to loan $8 trillion to over 60 countries, many of them too poor to fund their own big infrastructure projects. One trillion dollars is said to have already been allocated by these countries. By comparison, the entire 47,000 miles of the US Interstate Highway system cost roughly half that amount ($459 billion).

Bugs Life Leads to Silk Roads

On its way to adulthood, the larvae of a certain insect, the Bombyx mori, gorge themselves on mulberry leaves and spin themselves into a cocoon so they can privately morph into an adult moth. One of these journeys was interrupted thousands of years ago, as Chinese legend has it, when a cocoon fell from a tree into a royal tea cup. A bored, but inquisitive, queen unraveled the cocoon into a one surprisingly long continuous fiber. The fiber could be spun into a thread which could produce the most luxuriant fabric. A silk industry was born.

Word of silk spread all the way to ancient Rome. Favored by Roman nobility, its trade became lucrative. Centuries of trade between Asia and Europe led to a tangle of trail and thoroughfares. Countless travelers, traders and pack animals demanded food, shelter and supplies. Marco Polo travelled along the Silk Road in the 13^th century. Towns and cities formed and grew. The Silk Road also spread wealth and facilitated cultural exchange.

The journeys along the Silk Road were not for the faint-hearted. They were plagued by bandits, extortionary rates of passage, ridiculous extremes in weather and imposing physical barriers. Some dangers were unseen. The camels carried fleas and introduced the bubonic plague to Europe.

The Silk Road name came much later, coined by German geographer Ferdinand von Richthofen in 1877 who was seeking a succinct term for the multitude of thoroughfares connecting Asia and Europe. Historians now favor the use of the more accurate “Silk Routes.”

Slow Boats to China

The Middle Ages led to ocean-going ships that took over from camel caravans over deserts and mountains. The Silk Road lapsed to serving local trade.

The modern maritime fleet relies on container ships for dry goods and tankers for liquids, both of which have reached gargantuan proportions. The biggest of all ships, a tanker, holds enough oil for 15,000 tanker trucks. Only a bit shorter, the biggest container ship carries 19,000 truck loads. Since China houses the world’s biggest labor force and produces the most goods, it makes sense that China also has the largest set of container ports to get those goods out, including the world’s biggest in Shanghai.

It’s not enough. The world’s growing appetites for goods demand that more of them arrive faster. Those ships could use more ports, and existing ports could be modernized. More ships could be built. For goods that are to be consumed and producers on the same landmass, why not connect them with modern highways and railroads? Why go around continents or through choke points (examples: the Suez and Panama canals) when you can make a relative beeline with a tractor trailer on a smooth multilane highway?

Maritime traffic dots China’s port cities. Ships squeezes through the Panama canals and Suez canals. (An interactive map, created by the data-visualization firm Kiln and University College London’s Energy Institute.)

Iron Will, Iron Road

Only China would seem to have the ability to even consider a project the magnitude of the New Silk Road. Upheavals caused by mega-projects are plagued by detractors in democracies. Transecting an unspoiled wilderness with pipelines or roads in the U.S. may be met with protest from environmentalists. Trying to move villages for a hydroelectric project will cause riots in India. In China, the national will overrides individual and special interests.

But joining the super initiative are 68 countries, all seeking benefits of trade passing through their borders—lands that time and technology may have forgotten can now hope to get into the act.

Not all countries are giving China a green light, however. Regional powers India and Japan (among others) have expressed reservations, each with a historical distrust of China’s international ambition.

What is Happening Right Now?

The New Silk Road is a big story told in billions of dollars.

In Sri Lanka (formerly Ceylon), the financially suffering Hambantota port was handed over to a Chinese company and has received almost $300 million out of a total of $1.1 billion for its revitalization. It has neighboring India a little nervous. A regional power, India has fought wars with Sri Lanka.

India’s prime minister has loudly objected to roadways cut through regions in dispute with Pakistan. Though these routes from China through Pakistan may not be officially part of the New Silk Road, they might as well be. Pakistan’s old roads will be improved, and new roads will be built. No small task, as the roads will snake over the tallest mountain range in the world with passes of over 5,000 meters. China has promised Pakistan $46 billion in energy and infrastructure—about 1/6 of Pakistan’s GDP. While the roads and rail will shortcut Chinese goods to Karachi and the Gwadar Port (half the cost of the much longer sea route), the coal power plant and hydro power stations planned will benefit the local economy for generations.

An estimated $300 billion has already been spent.

Eastward, Ho.

Tibet, annexed by China in 1951, is known for the Dalai Lama (he used to live there), yaks—and one of the most inhospitable climates in the world. China sees it as a frontier to be settled, much the same way as the US thought of its West in the 1800s. Only 2 million Tibetans occupy an area that is somewhere in size between Texas and Alaska. There are 40 Chinese cities with more people than the entire Tibet Autonomous Region. To balance the population load, a railway was built.

It was a railway they said could never be built and qualifies as one of the modern world’s engineering marvels. Opened with great fanfare in 2006, China invited travel writers seeking the ultimate luxury rail adventure. It wasn’t a luxury. Complaints include not enough oxygen (oxygen masks drop from overhead and the highest elevation is 17,000 ft.) and the vomiting. But the pristine vistas and clear skies may be enticing enough for Chinese fleeing overcrowded cities, rampant pollution and limited opportunity. They may hope to tap into timber and mineral wealth. They will need places to live and an infrastructure to support them.

Gassing up in Russia

China and Russia, “frenemies” through recent history, are acting on the opportunity provided by the void left behind by the U.S. in international relations. The China-Russian deal in 2014 has China buying 38 billion cubic meters of natural gas from Moscow for $400 billion. Parts of the New Silk Road are the pipelines that must be built to handle the flow of gas. In addition, plans call for road and rail to be newly constructed or improved (like the Trans Siberia Railway).

Chinese sources have the New Silk Road snaking through Poland and Germany, ending its western overland route by dropping off containers in London, after use of the existing Chunnel.

China’s trade with European nations is said to be a billion dollars a day and the E.U. trade with China is second only to the US—a situation that could easily switch to China’s favor with the completion of the New Silk Road.

Another country spurned by the U.S is being courted by China and included in New Silk Road projects: Iran. A New Silk Road corridor opened up in 2016 as a freight train completed a 10,000-km journey from Tehran, Iran to China.

Will it Work?

China has spent some of its 5,000 years of civilization in isolation. But since the emergence of a globalized economy, the choice has been either active participation or marginalization as the world passes by. Haltingly at first, Communist-led China has found advantage in participating in capitalist markets with its incredibly large human population. Cheap labor never seems to run out and workers work diligently for more hours per day and more days per week than in the West. Add to that the apparent disregard for costly safeguards Western nations have (arguably) put in place for protection of man and animal, of air and water, and the country has the formula for an engine to be able to make, grow or mine just about everything the rest of the world wears or uses. The New Silk Road is not only an expansion and improvement in the methods to get the goods out there at a faster rate, it creates a further dependence on China and increases its influence.

That’s if it all goes according to plan. China’s economy is deemed slow when GDP dips below 7 percent—when United States and European countries get than 2 percent growth. China’s population growth has been on a decline for decades, which will limit the labor force, if it hasn’t already. The aforementioned work conditions may also cause workers to ultimately throw a collective wrench in the engine. The smog over its cities gets thicker and the rivers have become more toxic; that will not be a cheap clean up, further slowing down the economy. China also has to play nice with others. Neighboring countries may see it as the big kid who has finally come out of his house to play but could steal their marbles. Building trust could be slow. China is also finding out that people in other countries are not as easy to control as its own. Parts of the New Silk Road stop abruptly at some countries’ borders, as their rulers fidget with more pressing issues.

Nevertheless, there is no mistaking such a huge investment will make a big difference when coupled with the force of a unified people and government and a massive investment.

Historians may one day see the New Silk Road as the catalyst for a new world order, with China on top. All without firing a shot.

Source : www.engineering.com

The new airport at the crossroads of Europe and Asia that’s vying to be the world’s largest

Istanbul’s new airport, built to replace the ageing Ataturk, will boast Europe’s largest terminal hotel, with futuristic cabin aficionados Yotel opening its first property to have both land- and air-side rooms.

The hotel will be the trendy brand’s fifth at an airport, with its pod rooms already at both Heathrow and Gatwick, and eighth overall. The deal between the start-up and airport operator iGA will see Yotel’s 451-room (102 beyond security) property establish a base in Turkey, from where it plans to open another hotel in Istanbul city centre.

The stylish, compact capsules at the heart of Yotel’s guiding principles are available to book by the four-hour period, allowing travellers with early or late flights a convenient stopping point at an airport, or those in transit the opportunity to sleep in a private space.

Yotel ceo Hubert Viriot told Telegraph Travel the Istanbul New Airport branch would be the company’s “flagship” hotel. As it stands, 14 more are in the pipeline, including one at Singapore Changi, an airport regularly voted best in the world. The remainder are planned for city centres. Viriot said Yotel is planning to open another hotel in central London, in Clerkenwell, and have a 50-strong portfolio by 2023.

“Cabins remain a very true concept for us,” he said. “A lot of our inspiration for the brand came from airlines, in terms of design and technology.

“We were amazed at the premium cabins you can find on aircraft, and you are talking about minimal space.

“We are offering really well-designed rooms. Yes, they are compact, but they have all the luxury you may expect from an upscale hotel.”

The property at the new Istanbul airport will also boast a 24-hour gym, restaurant, bar and meeting room facilities.

What is a Yotel hotel room like?

Rachel Cranshaw, one of Telegraph Travel’s hotel experts, said of the Yotel cabins at London Gatwick: “Cabins (standard sleeping one; premium/premium twin sleeping two) are full of pleasingly high-tech and space-efficient innovations: sofas glide out into beds at the touch of a button; a control panel offers a number of different lighting arrangements (ideal if you’re jet-lagged); there’s a full-length mirror behind a small space for hanging clothes, and a shoe rack at the bottom of it; a table and chair fold out from the wall and there is ample shelving space and plug sockets. There’s also a Smart TV.

“Glass-fronted en-suites have hot, powerful rain showers – just the ticket after a flight, with fluffy towels for after. Toiletries are basic: a body wash/shampoo combo only, but a bag of additional useful products is available from reception for a small fee. There’s luggage storage under the bed, which is comfortable, with a feather duvet and plenty of pillows. Hairdryers are available to borrow from reception, along with alarm clocks, ear plugs, shower caps, and extra towels/pillows/blankets.”

Why is Istanbul getting a new airport?

Ataturk, the 15th busiest airport in the world, is full to the brim so is being replaced with Istanbul New Airport, which will open later this year. Ataturk, which was hit by a bomb attack in 2016, will cease operations shortly after.

Electric passenger jet revolution looms as E-Fan X project takes off

Battery-powered air taxis and bigger hybrid planes poised to change aviation

Trains, ships and automobiles have all been swept along in recent years by the electric power revolution – and planes are next.

Passenger jets are poised for an electric makeover that could fundamentally change the economics and environmental outlook of the aviation industry. Up until now the fact that the necessary batteries weigh two tonnes each has limited the switch from fossil fuels to a totally electric-powered future.

However, last month a consortium comprising Airbus, Rolls-Royce and Siemens said they had found a way to use hybrid electric jet engines to conquer gravity. They are converting a regional jet into a demonstration plane, called the E-Fan X, which will be ready by 2020.

Paul Stein, chief technology officer at Rolls-Royce, said: “It is a two-tonne battery pack – the batteries are still fairly heavy. Beating gravity into submission is a huge challenge, so weight is a big issue.”

The BAE 146 demo aircraft, a jet that seats up to 100 people, will at first have one of its four gas turbine engines replaced with the hybrid engine. This engine will be powered by batteries and an onboard generator using jet fuel. If successful, the team will then move to two electric engines. Siemens is designing the 2MW electric motor, Rolls is building the generator that powers the engine and Airbus will integrate the system into the plane and link it to flight controls. They are developing the hybrid motor because fully electric commercial flights are currently out of reach.

Pound for pound, fossil fuels contain around 100 times as much energy as a lithium-ion battery, the most common electric power pack at present. In a car, which has its wheels planted firmly on the ground, engineering boffins can design a vehicle to offset that weight disadvantage.

But in a machine that must lift itself off the ground and propel upwards this is a much harder problem to solve.

This tricky dilemma is a challenge that has been embraced with renewed gusto in the aviation sector. “Aviation has always eluded electrification largely because of the size and weight of components involved,” Stein said. “But technology has moved on apace. Electrification is now poised to make a significant impact.”

Stein said three classes of aviation are potentially within reach of an electric engine revolution. “The smallest is air taxis, which can take 1 to 4 people up to 75 miles. For small air taxis, the battery technology is almost ready now,” he said.

Some of these air taxis look like flying cars, such as those backed by Larry Page, one of Google’s founders. Chinese-owned Terrafugia’s “roadable aircraft” drives like a typical car on the ground and fits in a standard single-car garage and can be pre-ordered for $300,000 (£224,000). Pipistrel, a Slovenian company, already makes a two-seater electric training plane. Airbus has also developed a two-seater, the E Fan, which flew across the Channel in 2015.

The second market is the small, regional jet that can carry between 10 and 100 passengers. “Our target end game is a fixed wing, regional hybrid design,” Stein said of the E-Fan X project. The third market – the short-haul commercial market, dominated by Airbus’s A320 and Boeing’s 737 – is still some way off.

Bjorn Fehrm, an aeronautical analyst at aviation Leeham News and Comment, said: “For ultra short range, it can be fully electric. For the range of today’s thousands of single aisle [A320, 737] planes, it will have to be hybrid for at least another 30 years. For long range, it’s unrealistic. There would have to be a breakthrough in fuel cells, or similar.”

Airlines are watching the evolution of electric battery technology with interest. EasyJet wants electric planes to fly passengers on its short-haul routes within 10 to 20 years. It has signed a deal with Wright Electric, a US engineering company, to develop electric-powered aircraft that could reach Paris and Amsterdam from London.

The attractions for airlines are clear; depending on the oil price, jet fuel had accounted for between 17% and 36% of their running costs over the last few years. Stein reckons the E-Fan X could produce fuel savings of 15%.

The rush to electric battery technology in the automobile sector and a renewed push by aviation is likely to lead to scientific breakthroughs in what is possible over the coming years. Samsung Electronics recently declared it increased the energy capacity of a lithium-ion battery by 45%, and decreased the time needed for a recharge, by incorporating graphene – an ultra-thin form of carbon – into the power pack. Lithium-ion battery chemistry is notoriously unstable, prone to overheating and catching fire – not ideal when cruising at 35,000 feet.

“For us, safety is paramount. The burden of proof to ensure we maintain that safety margin is very high,” Stein said. “We cannot have a battery chemistry that risks a fire.”

So, lots of big hitters are ploughing huge investment and brain-power into developing alternative battery chemistries. One promising option is a solid-state lithium battery, which replaces the liquid electrolyte of current cells with a solid substitute. Such batteries offer much higher energy densities and should also be cheap to mass produce. Huge riches await those that can crack the problem and produce a next generation power source that is cheaper and greener.

Source: www.thegardian.com

Drones more damaging than bird strikes to planes, study finds

As part of a multi-institution Federal Aviation Administration (FAA) study focused on unmanned aerial systems, researchers at The Ohio State University are helping quantify the dangers associated with drones sharing airspace with planes.

Traffic signal countdown timers lead to improved driver responses

Countdown timers that let motorists know when a traffic light will go from green to yellow lead to safer responses from drivers, research at Oregon State University suggests.

A drone for last-centimeter delivery

A new drone developed at EPFL uses cutting-edge technology to deliver parcels weighing up to 500 grams. The device will never get stuck in traffic, it’s programmed to avoid obstacles, and it can reach destinations on steep or uneven terrain. Its protective cage and foldable design mean that it can be carried around in a backpack and used in total safety.

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A Study of the Influence of the Microstructure of One Type of Bitumen Grade on the Performance as a Binder

The adhesive properties bitumen has been studied extensively due to its relevance in road construction. Further understanding on the stage of failure associated with temperature and strain rates, overall performance of bitumen as an adhesive is of high importance to the construction industry.

Dr. Hartmut Fischer and Dr. Steven Mookhoek from TNO Technical Sciences in the Netherlands studied the effects and performance of the microstructure of various samples of bitumen with comparable PEN grade (Q8, Esso, Nynas, Shell, Total and Venezuelan). The work which is published in the peer-reviewed journal, Construction and Building Materials achieved this feat by making use of a newly designed micro-tensile testing (µ-DDT) to evaluate the adhesive performance of the bituminous binders with the use of a glass-silica half ball configuration in the tensile test setup. Results were coupled the observed features in the microstructure, as determined by use of an atomic force microscopy and differential thermal analysis on the bitumen samples.

The newly evolved micro-tensile test was found to be powerful in determining adhesive/cohesive forces between the formed bonds of different bitumen samples with silica at certain strain rates, with a clear view of the adhered area from residual materials on the half-ball silica surface.

Outcomes from atomic force microscopy indicated that the bitumen samples have comparable microstructural features with the presence of perpetua and peri phase microstructure, all except for the bitumen specimen of Nynas.

In differential thermal analysis it was observed that an equal mixture of the bitumen samples with glass spheres and with Wigras filler material had a loss in thermal transition due to reduction in asphaltenes inside the bitumen samples after addition of filler particles. From this observation, asphaltenes can be said to be a strong requirement for good adhesion. The Nynas bitumen sample in contrast to other bitumen samples did not show the formation of a catana phase, and resulted in a poor adhesion to the glass-silica surface.

A two-step response was recorded with appreciate to normal force, cavitation and cohesive rupture for all bitumen specimens with a prolonged peri phase or a co-continuous micro structure except for that of Nynas, leading to a strong correlation between measurable bond strength and that of the catana/peri phase area.

In addition, it was shown that a stronger adhesive-cohesive force was determined to be found in bitumen specimen with an extended two phase microstructure compared with those with absent two phase microstructure or that of a shielded peri microstructure which depicts the importance of the peri phase on the bonding behaviors of the tested binders.

This study provides a new technique to further our knowledge on performance of bitumen as binding agent which might produce advanced and higher performance materials for pavements and highway applications.

Journal Reference

Hartmut R. Fischer, Steven D. Mookhoek. A Study of the Influence of the Microstructure of One Type of Bitumen Grade on the Performance as a Binder, Construction and Building Materials

How does LiDAR work?

The principle behind LiDAR is really quite simple. Shine a small light at a surface and measure the time it takes to return to its source. When you shine a torch on a surface what you are actually seeing is the light being reflected and returning to your retina. Light travels very fast – about 300,000 kilometres per second, 186,000 miles per second or 0.3 metres per nanosecond so turning a light on appears to be instantaneous. Of course, it’s not! The equipment required to measure this needs to operate extremely fast. Only with the advancements in modern computing technology has this become possible.

The actual calculation for measuring how far a returning light photon has travelled to and from an object is quite simple:

The LiDAR instrument fires rapid pulses of laser light at a surface, some at up to 150,000 pulses per second. A sensor on the instrument measures the amount of time it takes for each pulse to bounce back. Light moves at a constant and known speed so the LiDAR instrument can calculate the distance between itself and the target with high accuracy. By repeating this in quick succession the insturment builds up a complex ‘map’ of the surface it is measuring. With airborne LiDAR other data must be collected to ensure accuracy. As the sensor is moving height, location and orientation of the instrument must be included to determine the position of the laser pulse at the time of sending and the time of return. This extra information is crucial to the data’s integrity. With ground based LiDAR a single GPS location can be added for each location where the instrument is set up.

Generally there are two types of LiDAR detection methods. Direct energy detection, also known as incoherent, and Coherent detection. Coherent systems are best for Doppler or phase sensitive measurements and generally use Optical heterodyne detection. This allows them to operate at much lower power but has the expense of more complex transceiver requirements. In both types of LiDAR there are two main pulse models: micropulse and high-energy systems. Micropulse systems have developed as a result of more powerful computers with greater computational capabilities. These lasers are lower powered and are classed as ‘eye-safe’ allowing them to be used with little safety precautions. High energy systems are more commonly used for atmospheric research where they are often used for measuring a variety of atmospheric parameters such as the height, layering and density of clouds, cloud particles properties, temperature, pressure, wind, humidity and trace gas concentration.

Most LiDAR systems use four main components:

Lasers :

Lasers are categorised by their wavelength. 600-1000nm lasers are more commonly used for non-scientific purposes but, as they can be focused and easily absorbed by the eye, the maximum power has to be limited to make them ‘eye-safe’. Lasers with a wavelength of 1550nm are a common alternative as they are not focused by the eye and are ‘eye-safe’ at much higher power levels. These wavelengths are used for longer range and lower accuracy purposes. Another advantage of 1550nm wavelengths is that they do not show under night-vision goggles and are therefore well suited to military applications.

Airborne LiDAR systems use 1064nm diode pumped YAG lasers whilst Bathymetric systems use 532nm double diode pumped YAG lasers which penetrate water with much less attenuation than the airborne 1064nm version. Better resolution can be achieved with shorter pulses provided the receiver detector and electronics have sufficient bandwidth to cope with the increased data flow.

Scanners and Optics :

The speed at which images can be developed is affected by the speed at which it can be scanned into the system. A variety of scanning methods are available for different purposes such as azimuth and elevation, dual oscillating plane mirrors, dual axis scanner and polygonal mirrors. They type of optic determines the resolution and range that can be detected by a system.

Photodetector and receiver electronics :

The photodetector is the device that reads and records the signal being returned to the system. There are two main types of photodetector technologies, solid state detectors, such as silicon avalanche photodiodes and photomultipliers.

Navigation and positioning systems :

When a LiDAR sensor is mounted on a mobile platform such as satellites, airplanes or automobiles, it is necessary to determine the absolute position and the orientation of the sensor to retain useable data. Global Positioning Systems provide accurate geographical information regarding the position of the sensor and an Inertia Measurement Unit (IMU) records the precise orientation of the sensor at that location. These two devices provide the method for translating sensor data into static points for use in a variety of systems.

New coastal highway route for Reunion

Description

Work on a new €1.7 billion coastal road is underway around France’s Reunion Island

This new 12.3km highway (Route du Littoral) will have three lanes in each direction when it is complete in 2018.

The new offshore highway connects Saint Denis, the administrative capital of La Réunion, with La Possession.

This is a significant project and involves the use of a large fleet of heavy machinery.

Manitowoc, Grove and Potain cranes are working together to help build the new coastal road around Reunion Island.

In all large 16 cranes of various types are being used on the island, which is located to the east of Madagascar.

Meanwhile equipment from Enerpac is playing a key role in constructing a viaduct.

One of the most complex aspects of the work is the construction of the 5.4km viaduct on columns rising out from the Indian Ocean.

This is being built so that it will be able to withstand  144km/h hurricane winds as well as waves of up to 10m in height.

The project is being carried out by French consortium Bouygues Travaux Publics, VINCI Construction Grands Projets, Dodin Campenon Bernard and Demathieu Bard Construction.

Once complete, this will be the most expensive road/km funded by France.

The crane fleet in use on the project comprises two Potain MD 485B M20s, two MDT 368 As, one MD 560 B, a Potain k5-50C, a Manitowoc 12000E-1 crawler crane, seven

Grove all-terrain cranes and two Grove rough-terrain cranes. Installation of the Potain cranes was completed in September of 2015, including setting up and erecting the jibs.

The 16 cranes were supplied by contractors Vinci Construction Grands Projets and Bouygues TP which own some of the units and Grues Levages Investissements (GLI) which also provided cranes for this high-profile project on rental contracts.

GLI is Manitowoc’s official French dealer for Reunion Island, Mayotte and Mauritius and has invested heavily in supplying the cranes for this project.