(Roughly) Daily

Posts Tagged ‘materials

“Of course I’d like to get beyond the concrete. But it’s really difficult. Very difficult.”*…

Felix Salmon is fascinated by concrete…

Greetings from my apartment in the most beautiful Brutalist tower in New York City (sorry not sorry, I.M. Pei.) My bookshelf contains such works as “Concrete,” “Concrete Concept” and “Toward a Concrete Utopia;” on my desk is “Concrete Planet.” Tl;dr: I’m a lover of concrete, not a hater. But… it’s still very problematic. And, as you’re about to find out, much more expensive than architects and contractors might have you believe…

He goes on, in his “Capital” column for Axios, to explain…

Concrete construction no longer lasts thousands of years, like the Pantheon in Rome. Instead, its lifespan is roughly 50-100 years, thanks to the way in which modern concrete is reinforced.

That means a multi-trillion-dollar bill is coming due right around now, in the form of concrete construction that needs noisy, dirty, expensive repair. 

Why it matters: The collapse of a residential tower in Surfside, Florida is a stark reminder of how catastrophically concrete can fail. Just as the collapse of the Morandi Bridge in Genoa caused Italy to start paying much more attention to remedial infrastructure projects, the Surfside tragedy might help focus America on the urgent need to fix buildings that are nearing the end of their initial lifespan.

The big picture: As Robert Courland explains in “Concrete Planet,” modern concrete is poured around steel rebar, which gives it tensile strength. But tiny cracks — found in all concrete — cause water to start rusting the steel, which then expands, cracking the concrete. 

Photos of the Surfside basement taken before the collapse show steel rebar breaking all the way through the concrete to the point at which it is fully exposed to the salty and humid Florida air.

By the numbers: One of the most famous concrete buildings in America, Frank Lloyd Wright’s Fallingwater, cost $155,000 to build in 1936 — about $2 million in 2001 dollars. The cost of repairs in 2001 came to $11.5 million.

Similarly, repairs to Wright’s concrete Unity Temple are estimated at roughly 20 times the original construction costs, even after adjusting for inflation. 

How it works: Once rebar starts corroding, the standard fix involves jackhammering the concrete to expose the steel, brushing the steel to remove the rust, reinforcing the rebar as necessary, and then covering it all back up again with carefully color-matched new concrete. 

That labor-intensive extreme noise and dust is actually the green, environmentally sensitive solution. The only alternative is demolition and replacement with an entirely new building — something that involves a much greater carbon footprint.

Between the lines: Because concrete fails from the inside out, damage can be hard to detect. And because concrete looksso solid and impregnable, necessary maintenance is often skipped, causing massive bills later on.

Local governments are in charge of ensuring building safety, but their willingness and ability to do so varies widely. The owners and residents of concrete buildings often try very hard not to think about corrosion, just because the costs of fixing it are so enormous.

The bottom line: The amount of money needed to fix existing infrastructure (nearly all of which is concrete, in one way or another) stands at roughly $6 trillion, according to the American Society of Civil Engineers. That number does not include homes, offices and other private buildings.

If you live in a concrete building that’s more than 40 or 50 years old, it’s an extremely good idea to check carefully on just how well it’s been maintained, lest you find yourself with an unexpected seven-figure repair bill — or worse. 

Go deeper: WLRN’s Danny Rivero clearly explains the collective action problems involved in persuading condo owners to pay for expensive repairs.

The tragedy in Surfside is just one indication that “America’s trillion-dollar concrete bill is coming due,” as @felixsalmon explains.

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As we muse on maintenance, we might spare a thought for Angelo Mangiarotti; he died on this date in 2012. An architect and designer, he made an early career stop in Chicago as a visiting professor for the Illinois Institute of Technology, during which met Frank Lloyd WrightWalter GropiusLudwig Mies van der Rohe and Konrad Wachsmann. While Mangiarotti learned from them an appreciation of materials (perhaps especially concrete) and industrial process for buildings and design production– on both of which he built– he is perhaps best remembered for his insistence, borne out in his work, on “never forgetting the real needs of users.”

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“Tossing away a piece of paper is clearly taboo”*…

 

paper

 

Today, in an age of computers, smartphones and e-books, you could be forgiven for predicting the demise of this ancient wonder material. But though there has been a small decline in the demand for so-called “graphic paper”, like newspapers and books, the paper industry is booming.

The world currently uses around 400 million tonnes of paper per year. And from money to cardboard boxes, to receipts, coffee cups, stick-on notes, baking paper, egg cartons, birthday cards, straws, wrapping paper, and, of course, papier-mâché, it’s hard to imagine modern life without it. We might be edging towards a cashless society, but the paperless society, as the American librarian Jesse Shera famously put it, “is about as plausible as the paperless bathroom”.

In fact, demand for paper is growing all over the world, and as we turn our backs on single-use plastic, paper is one of the main contenders to take its place. The last few years has seen numerous retailers announce that they are switching to paper bags, while paper-based chocolate wrappers, ready-meal trays and water bottles have also started to emerge.

In Canada, the government recently approved a ban on certain plastic items, while the EU has pledged to eradicate some of the most notorious by 2021. Some Indian states have gone further, ditching single-use plastic altogether. Many businesses have already announced that they will be replacing throw-away plastic items with paper versions.

But how sustainable is paper really? And what can be done to reduce its environmental impact?…

[Consider, among other factors, like deforestation…]

Almost every phase of paper manufacturing involves water. Scaled up to the magnitude of the industry today, a vast amount is required. To make just a single A4 sheet, you need between two and 13 litres. In China, which remains one of the leading players in the paper trade, the industry sucked up 3.35 billion tonnes (roughly three trillion litres) in 2014 – enough for about 37 billion baths.

After the pulping and bleaching is over, paper mills end up with water containing a cocktail of organic compounds, alkalis and bleach, which must be treated so that it can be disposed of safely. This can be a huge technical challenge, and some paper mills simply discharge the effluent straight into the local water supply, where it’s acutely toxic to fish and other wildlife  – even at concentrations of just 2%

For better and/or worse: “How paper is making a comeback.”

* Anne Frank, The Diary of a Young Girl

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As we muse on materials, we might recall that it was on this date in 1814 that London suffered “The Great Beer Flood Disaster” when the metal bands on an immense vat at Meux’s Horse Shoe Brewery snapped, releasing a tidal wave of 3,555 barrels of Porter (571 tons– more than 1 million pints), which swept away the brewery walls, flooded nearby basements, and collapsed several adjacent tenements. While there were reports of over twenty fatalities resulting from poisoning by the porter fumes or alcohol coma, it appears that the death toll was 8, and those from the destruction caused by the huge wave of beer in the structures surrounding the brewery.

(The U.S. had its own vat mishap in 1919, when a Boston molasses plant suffered similarly-burst bands, creating a heavy wave of molasses moving at a speed of an estimated 35 mph; it killed 21 and injured 150.)

Meux’s Horse Shoe Brewery

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Written by (Roughly) Daily

October 17, 2019 at 1:01 am

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