Striatus measures 12 by 16 metres (40 to 52 feet) and is constructed using a combination of concrete blocks and 3D-printed concrete. Its designers note that it is the geometry of the design that provides its stability.

Professor Philippe Block of ETH Zurich states, “the name Striatus reflects the bridge’s structural logic and fabrication process. In arched and vaulted structures, material is placed such that forces can travel to the supports in pure compression. Strength is created through geometry, using a fraction of the materials used in conventional concrete beams. This, furthermore, opens a breadth of opportunities to build with lower-strength and in a more ecologically friendly way.”

Unique to this structure which uses no mortar, is the ease in which it can be deconstructed and reassembled at a different location. If no longer needed, the materials can easily be separated and recycled.

The use of 3D printing for the bridge doesn’t follow what we normally think of when looking at additive manufacturing processes. The material used, the concrete ink has been developed by Holcim, a building materials and solutions company that is a leading supplier of cement, aggregates, ready-mix concrete, and now low-carbon material solutions.

CEO of Holcim, Jan Jenisch, notes in a media release that the bridge “was designed by some of the best architectural and creative minds in their fields. It demonstrates the infinite possibilities of 3D Concrete Printing to enable more sustainable, faster and effective building structures, without compromise on aesthetics and functionality. Its digital and circular design uses concrete at its best, with minimal material use and blocks that can be repeatedly reassembled and infinitely recycled.”

The concrete ink was custom-made by Holcim’s research team. It is among a generation of new inks for 3D printers that are a part of the company’s green building solutions which include ECOPact green concrete, ECOPlanet green cement, and recycled construction and demolition waste.

Holcim’s ink recently was used in the construction of a 3D-printed school in Malawi. The walls for the building were erected in 18 hours using 70% less material than if traditional concrete construction techniques were used. Holcim’s concrete inks are also being used to increase the height of wind turbine towers to harvest more energy, partnering with GE Renewable Energy and COBOD, a designer of 3D printers for the construction industry.

If you plan to visit Venice, you have up until November of this year to see Striatus in the Marinaressa Gardens on display during the Venice Architecture Biennale. My guess, it will be deconstructed and recycled after the event.

It was interesting to see the announcement of Striatus, shortly after a 3D-printed steel pedestrian bridge made its debut mid-month over the Oudezijds Achterburgwal canal in Amsterdam.

The trend to 3D-printing using a range of materials now seems well established in architecture and construction. I suspect we will see many more novel materials emerge for builds as this technology matures.

The post A New First: A 3D-Printed Concrete Bridge Using No Steel Reinforcements appeared first on Techso Mogro.

Venice Goes Under Water

If you were in Venice this week you came face-to-face with the world of the near future.

Venice has seen sea levels rise 10 centimeters (almost 4 inches) in the last 50 years. It doesn’t seem much but when you add a wind blowing from the south and high tides, you get what this city’s mayor called “climate change in action” and “a wound that will leave a permanent mark” on the city.

Water levels on two consecutive days rose 1.8 and 1.5 meters (approximately 6 and 5 feet). A meeting of the Veneto regional council had just concluded without it passing funding to tackle climate change when the building where it was sitting became inundated.

A bookstore near St. Mark’s Square, aptly named Aqua Alta (meaning high water in Italian) found itself underwater in almost two meters of water.

The city, which was founded in the year 697 CE (AD) will likely completely flood in the next 50 years without technological intervention in the form of a massive investment in protective dikes and seawall gates. Meanwhile the current attempt to do this, known as Project Moses, and designed precisely to protect the city, remains well behind schedule, over budget, fraught with corruption from politicians and contractors, and all of this still on the go sixteen years after the project was approved.

Bushfire Conversations Not to be Equated with Climate Change in Australia

The unhinged political leadership in Australia continues to ignore the climate crisis.

With bushfires threatening the state of New South Wales and the country’s largest city, Sydney, the country’s Deputy Prime Minister, Michael McCormack, described the conflagrations as old news just happening a bit earlier than normal this year.

Not to be outdone, the Prime Minister, Scott Morrison, is trying to outlaw climate protests describing those who go out on the street as “indulgent” and “radicals.” Morrison, who is big on coal, argues that China is the problem and that they need to do more. Meanwhile the country is opening a new coal mine with China the preferred customer for what is produced.

But getting back to McCormack’s comments on a radio talk show this week, he stated: “we know it’s getting drier, we know it’s getting…very warm.” Duh! But what that has to do with global warming….apparently nothing.

Too bad Greta Thunberg can’t get Down Under to shame these fellows to the core of their being.

A Report Card on the Global Response to the Climate Crisis

If you think that climate change is an existential crisis and you live in one of the 175 countries that signed the Paris Climate Agreement in 2015, then I hate to tell you, almost every signatory is failing to achieve any of the interim milestones agreed to back then.

The flaw of the Paris agreement was it was non-binding. Countries were left to set their own targets and they did. But according to the Climate Action Tracker, an organization that assesses progress related to the Agreement targets, almost none have succeeded in meeting interim milestones. Climate Action Tracker forecasts we are headed for more than twice the 2 Celsius (3.6 Fahrenheit) rise in atmospheric mean temperatures. That’s global mean temperatures rising by 4 Celsius (7.2 Fahrenheit). And at the poles expect those numbers to hit double digits.

To make matters worse, greenhouse gas emissions in 2018 rose by 2.7%.

So who among the nations of the world have been on target to meet their Paris pledges?

Morocco, and Gambia on target for a 1.5 Celsius rise, and Bhutan, Costa Rica, Ethiopia, the Philippines, and believe it or not India for a 2.0 Celsius rise, even though the latter this week has witnessed unprecedented smog enveloping the capital Delhi; the cause, vehicle traffic, cooking fires, and neighbouring farms burning their fields after harvest.

New Lancet Medical Journal Report Lays Out the Risk from the Climate Crisis to Children Born Today

Having seen the previous headline it shouldn’t be a surprise that if a child was born today it would experience a diminished quality of life from that of its parents. Besides extreme weather events, displacement from coastal cities from sea-level rise and sunshine flooding, children will experience respiratory problems from extreme atmospheric heat and pollution, increases in asthma, and exposure to tropical insect-borne diseases in temperate latitudes.

The Lancet states that “the life of every child born today will be profoundly affected by climate change, with populations around the world increasingly facing extremes of weather, food and water insecurity, changing patterns of infectious disease, and a less certain future.”

More frequent heatwaves will have a profound effect on newborns.

One of the authors of the study states:

“We roughly know what [it] looks like from a climate perspective…We have no idea what it looks like from a public health perspective, but we know it is catastrophic. We know it has the potential to undermine the last 50 years of gains in public health and overwhelm the systems we rely on.”

The study looks at 41 climate change indicators and notes that the threat to children will start in the womb and accompany them all the way to adulthood.

They are predicting:

• increases in low birth weight and neonatal deaths.
• heat stress because children find it much harder to regulate body temperature than adults.
• their less developed immune systems will make them more vulnerable to air, and waterborne diseases.
• intense heat waves will lead to increased incidents of heatstroke in teens, as well as impaired thinking for students sitting in unairconditioned schools.

And you thought parents are vigilant about children today. In the decades that follow expect hyper-vigilance in a world where the climate crisis will be in full swing.

The post A Quick Review of Climate Change in the News This Last Week appeared first on Techso Mogro.

What does a warming ocean mean for life in the sea and on land? How does a warming ocean affect weather and climate?  Should we be concerned? And if so have we got anything in our technical bag of tricks that we can deploy to stabilize the temperature rise or reverse it?

The Ocean Heat Engine and How it Works

Our atmosphere and ocean together can be described as a heat engine absorbing energy from sunlight which then gets converted to heat. The ocean is further subjected to gravitational forces caused by the pull of the Sun and Moon contributing to tides. The atmosphere and ocean share heat although the ocean is a much better heat absorber because it is more dense.

Other contributors to ocean heat include geothermal activity on the ocean floor along the edges of continental plates or over hot spots in the Earth’s crust. The level of salt in ocean water can impact its temperature. Fresh water tends to have a lower heat capacity than salt water. That’s why fresh water freezes at 0 degrees Celsius (32 Fahrenheit) while ocean water freezes at -1.9 degrees Celsius (28.58 Fahrenheit).

Like the atmosphere the ocean is layered, most dense at the bottom and least at the top. Unlike the atmosphere which is warmest at its bottom, the deepest parts of the ocean are the coldest.

Now add the Earth’s orbital tilt, and the consequential uneven distribution of sunlight falling on ocean surfaces from the poles to the equator. Then start the globe spinning and you have set the ocean and atmospheric heat engine in motion. Net heat gained in the equatorial regions is absorbed by surface ocean water, part of which evaporates into the atmosphere. Water vapour in the atmosphere increases its heat capacity leading to an exchange of heat between lower and higher elevations. The spinning earth contributes to wind movement. Winds contribute to ocean surface movement. Warm ocean water starts to move forming the currents we know as the Gulf Stream, the Kuroshio and the North Atlantic Drift. The extra heat moves poleward and counter currents of cold water and air move towards the equator, displaced by the warmer ocean water which is saltier and more dense as water evaporates from it into the atmosphere. Scientists call this movement of  warm ocean water the thermohaline circulation.

Five Implications of a Warming Ocean?

1. Changes to marine life

Warmer ocean water should change the distribution of phytoplankton (tiny plants) in the ocean and as a result the growth of zoo-plankton (tiny animals). This means more krill (the tiny shrimp zoo-plankton) for baleen whales and fish.  So isn’t this a good thing? Research has shown that initially added warmth causes a surge in marine organisms, particularly phytoplankton followed by zoo-plankton. But the latter soon consumes so much of the former that biomass crashes and shrinks by as much as 50%.

2. Changes to the polar seas

Today our polar oceans are among the most diverse marine life environments on the planet. That’s because of the upwelling of cold water from the ocean deep containing nutrient-rich food sources for the phytoplankton to thrive and grow. As the oceans warm we may witness a change in the mix of warm and cold water at the poles. The diminishing of sea ice may reduce fish stocks rather than enhance them.

3. Changes to the absorptive capacity of the ocean

A warmer ocean has the capacity to absorb more of the air that lies above it. That means more dissolved CO2. And more dissolved CO2 means more acidic oceans. And more acidic oceans means those creatures that use calcium carbonate become more vulnerable. For coral, zoo-plankton, mollusks and others it can mean extinction. Corals build coral reefs, zones of rich biodiversity in our oceans. We lose the reefs – we lose a lot.

4. Rising sea levels

When water heats it expands. It’s that simple. So a warmer ocean even without melting polar ice caps and glaciers is going to be higher. In fact scientists attribute half of the rise in sea levels to warming ocean water.

Now add the melt water from sea ice as the polar oceans heat up, or the melt from glaciers in Greenland, or the Antarctic ice sheets and shelves and you can begin to see just how significant the threat can be. The picture of Venice, Italy says it all. Our coastlines and coastal cities like Venice will be under siege from a steadily warming ocean. Add storm surges to this scenario and imagine the potential for disaster.

5. Changes to weather

A warming ocean impacts weather globally. We have seen the impact of warm ocean water through events we call “El Nino” that occur in the eastern Pacific Ocean in a cyclical manner. These periodic changes create global weather havoc affecting rainfall, temperatures and agricultural production.

A warming ocean impacts the natural cyclonic weather patterns, particularly those we call hurricanes and typhoons. These tropical storms form over warm water. Hurricane prediction models that simulate how hurricanes form and track suggest a correlation between sea surface temperatures and the storms that end up becoming the strongest.

What Can We Do About It?

Warming oceans are part of a general warming of the planet that today we describe as global warming.  So to tackle warming oceans we have to deal with the root causes of the global warming phenomenon.

We have three choices:

1. Mitigation

Reducing CO2 and other greenhouse gas emissions should reduce the amount of change we experience on the planet and hence in our oceans. This requires a commitment from all of humanity through international agreement to act. Carbon sequestration, greenhouse gas reductions, cap and trade implementation, new energy technologies, conservation – these are all policies which our governments need to legislate and enforce. The cost is high but  mitigation as a choice will cost far less than adaptation or the third option listed below.

2. Adaptation

Engineer infrastructure and come up with technological solutions to combat the consequences of warming oceans. We can seed the oceans with lime to reduce CO2 absorption precipitating the formation of limestone on the sea floor. We can build dikes, berms and higher sea walls to protect coastlines and coastal cities from rising sea levels. We can move threatened populations away from Pacific and Indian Islands, or from delta regions along coastlines that will be inundated by a warming ocean. We can strengthen our buildings to withstand more frequent and more violent storms. We can adapt crops to changing precipitation and weather patterns. We can deploy satellites in space that deflect sunlight or we fiddle with the atmosphere to create more clouds and cool down the planet artificially. The cost of geo-engineering will be enormous. Any mistakes we make could lead to the deaths of millions of humans let alone other life on the planet.

3. Do Nothing

This is always an option. We gamble that ocean warming is cyclical and that atmospheric warming in the last century is an aberration and not a consequence of greenhouse gas emissions. We react when disaster occurs suddenly or creeps up on us over time and we choose to ignore or think about the root causes.

The post Inner Space: Part 3 – What Does a Warming Ocean Mean for Our Planet? appeared first on Techso Mogro.