Archives: Roman Concrete

Learning from the School of Hard Rocks

My good friend Jeff Mann, the true Yard Ramp Guy, has asked me to revisit some of my original posts. This week in my From the Archives series: Roman concrete.


It's Written in the Concrete

Though the Romans have a pretty impressive reputation, in many regards they weren't nearly so clever as people tend to think they were.

For example, their fabled legions, while effective early in Roman history, became rather useless toward the end: the knight was basically invented by barbarians looking to defeat Roman legions. Even after it became apparent that the legions were a tool of the past, the Romans foolishly just kept sticking with it.

However, one area in which they were unquestionably brilliant was in architecture and construction.

Much has been made of Roman aqueducts and other construction techniques, but one technology that doesn't get discussed nearly as much as it should is their concrete. Roman concrete—known as opus caementicium—is, interestingly, much more durable than modern day concrete.

We have many examples of Roman concrete that have survived all the way to today. The Pantheon in Rome (not to be confused with the Parthenon), for instance, is a concrete dome that has survived intact since 126 AD.

Even more impressive is Roman concrete's resistance to seawater. Seawater is incredibly corrosive to modern buildings, corroding and destroying them in mere decades. We're lucky to get 50 years out of modern concrete. Roman concrete, however, can survive immersion in seawater for centuries or even millennia; plenty of docks and pilings from Roman times can still be found off European shorelines.

What was their secret? Well, we don't know the exact composition of Roman concrete, but we do know one of the major secrets: they used volcanic ash instead of the fly ash we use today. When submerged in seawater, the seawater reacts with the mineral phillipsite, found in volcanic ash. Over time, a new mineral known as tobermorite forms in the cracks of the concrete. As it forms, the concrete actually gets stronger and stronger.

Roman concrete today is stronger than when it was first laid down.

Many people are trying to mimic Roman concrete today. Not only is it more durable and long lasting, but it's also cheaper and more environmentally friendly. The problem, of course, is the extremely long setting time: most builders don't want to wait long enough for Roman concrete to set.

Haste makes waste. Some people are okay with that. Roman concrete endures.

Yard Ramp Guy Blog: Manufacturing Outlook

This week, my friend The Yard Ramp Guy shows how his inventory contributes to the larger picture of the U.S. economy.

Click HERE to see how it all fits into place.

Archives: A Grand Old Ditch

More Locks and Funiculars

My good friend Jeff Mann, the true Yard Ramp Guy, has asked me to revisit some of my original posts. This week in my From the Archives series: the power of the mule.


The Ramp Rules & The Ditch is Cool

A Boat on the Grand Old Ditch

Construction of the Chesapeake and Ohio Canal, also known as the C&O Canal and the Grand Old Ditch, began in 1828 and finished in 1850.

It reached a final length of 184.5 miles, extending between Cumberland, MD to Washington, DC. Coal was the primary good shipped—though businesses also shipped lumber, limestone for construction, sand, flour, salt, and much more.

The canal operated until 1924, when it was finally shut down due to competition from the railroads, along with major flood damage that year.

Interestingly, the mule-drawn barges were often operated by families that lived on them, especially in the earlier years of the canal. The families would all work together to run these barges; not surprisingly, the mothers were the main figures in running everything. They steered the boats, raised the children, and did all the housework.

The men just took care of the mules and the heavy lifting.

If you've never tried to raise children while running a house, well, let's just say I'll take the heavy lifting any day. (I've never had any illusions about Maggie being the most important part of my family.)

While it operated, though, the C&O Canal contained some of the most impressive engineering designed for a canal. To aid ships in moving uphill, the canal held 74 canal locks, or enclosures: ships sailed in, the lock closed behind them, then fill slowly with water, raising the height of the ship to the next elevation level. They also built 11 aqueducts for crossing major streams and more than 240 culverts to cross smaller ones.

In addition to this was the Paw Paw tunnel, which stretched nearly a kilometer in length, the construction of which almost bankrupted the Chesapeake and Ohio Canal Company. They were forced to end construction early, failing to get all the way to Pittsburgh.

My favorite part of the canal, though, was the C&O Boat Elevator. It served to lower boats down past Georgetown, where traffic jams tended to build up. It operated exactly like a funicular, only for boats—lowering them 600 feet on the diagonal and 40 feet in elevation.

The downward journey was entirely powered by gravity, while water powered turbines would lift the empty boat carrying caisson back to the top. It's a big step up from the Diolkos. Another great example here of human ingenuity in action.

Yard Ramp Guy Blog: Moving by Mule

This week, my friend The Yard Ramp Guy makes what might be the funniest segue yet into promoting inventory.

Click HERE. I dare you to not at least smile.

Archive: Helium-Filled Holiday Wishes

What a Gas

My good friend Jeff Mann, the true Yard Ramp Guy, has asked me to revisit some of my original posts. This week in my From the Archives series: the essential nature of helium.


The Ramp Rules: Helium

Zeppelin: Unleaded

The federal government has maintained a helium storage program since WWI, with the express purpose of making sure that America never falls behind in, um, a zeppelin arms race.

The Federal Helium Program is often viewed as one of the biggest boondoggles the government keeps funding. Both Reagan and Clinton tried to get rid of it. They couldn't have been more wrong, though.

Even apart from the fact that the program pays for itself with the proceeds of the helium it sells to U.S. companies, the helium program has plenty of other benefits to keeping it around.

First off, helium provides 42 percent of the nation's supply of unrefined helium gas. Second, it's already all stored in a huge porous rock formation below the Texas Panhandle, so there isn't a lot in terms of maintenance fees.

Even if we did need to harvest more, it's not that difficult. Among other things, helium is a byproduct of harvesting natural gas in the Midwest. Most importantly, helium is surprisingly essential to industries across the board.

Here's a non-exhaustive list of helium's uses:

  1. Airships are making a major comeback (see HERE), and they obviously need lots of helium.
  2. Cryogenic purposes. Not just freezing dead bodies, but cooling the magnets in MRI scanners and other similar uses. Helium makes an extremely effective coolant and is part of the process of making oxygen-hydrogen rocket fuel.
  3. Creating stable pressurized atmospheres. Deep sea divers often use atmospheric mixes that include helium.
  4. Arc welding materials that are contaminated by air or nitrogen.
  5. Supersonic wind tunnels.
  6. Gas chromatography—a method of analyzing the components of chemicals.
  7. As a protective gas in growing silicon and germanium crystals.

Last, and certainly not least: those party balloons that float and hug the ceiling? Filled with helium. I just bought 30 of them for my grandson’s birthday party. Birthdays just wouldn’t be as fun without helium.

Yard Ramp Guy Blog: The Forklift Factor

This week, my friend The Yard Ramp Guy provides some truly remarkable news about forklifts.

Click HERE to be uplifted.

Archives: Gorge-ous

Or: Hooked on Fishing

My good friend Jeff Mann, the true Yard Ramp Guy, has asked me to revisit some of my original posts. This week in my From the Archives series:something fishy is definitely going on.


The one that didn't get away.

Fishing: It predates civilization…even the human race. (Birds fish, after all.)

There are plenty of ways people fish, ranging from fishing spears (which are really, really difficult to use) to nets. The best way, or at least most fun, is with a hook and a line. And it's a very old way.

The oldest fish hook in existence was carved out of shell. Fishing hook hunters (or stumble-uponers) found it in East Timor, and it dates back to as much as twenty-three THOUSAND years.

Shell was an extremely common material for ancient fish hooks. Our ancestors crafted hooks from bone, wood, horns, stone, bronze, and eventually iron. Each one of them, however, had problems of its own. Wood, for instance, floats, and that necessitates weights, or heavier bait. One common workaround was using multiple of these materials to leverage their strengths.

Fishing hooks became more common in the archaeological record around 7000 BC. Many of the early fishhooks lacked barbs, which would have made it much more difficult to fish with. In fact, one of the earliest types of fishing hook, known as a gorge hook, wasn't even curved.

The gorge hook is a small stick tapered to a point on each end. A small groove is cut around the middle, where a cord is tied. The cord is then wrapped along the length of the gorge hook, securing a piece of bait to it. When the fish grabs the bait, the cord comes unwound, which then results in the gorge hook turning sideways and lodging in the fish's throat.

This does require you to know the average length of fish in the area, though. The gorge hook has the distinction of being one of the few hooks that aren't prone to stabbing into your thumb.

Fishing with an antique-style hook is definitely a challenge. But the satisfaction you get makes it worthwhile.

Yard Ramp Guy Blog: Pricing Transparency

This week, my friend The Yard Ramp Guy admirably shows how transparency and honesty go hand in hand.

Click HERE to discover the best surprise.

Archives: Living Bridges

My good friend Jeff Mann, the true Yard Ramp Guy, has asked me to revisit some of my original posts. This week in my From the Archives series: if only our own infrastructure were as strong and natural as living bridges.


I've blogged a lot about bridges, I know (Sir Bridges Blog-a-Lot, eh?) but I haven't yet explored living bridges.

Meghalaya, a state in north-eastern India, is one of the wettest places in the world, getting close to 500 inches of rainfall a year. Almost three-quarters of the state is forested. One of the indigenous tribes living there, the War-Khasi, build living foot bridges from the roots of the Ficus elastica — a variety of rubber tree.

thebridgePhoto by Arshiya Urveeja Bose [CC BY 2.0], via Wikimedia Commons

To grow the bridges, the Khasis create root guidance systems out of halved and hollowed betel nut trunks. The roots are channeled to the other side of the river, where they are allowed to bury themselves in the soil on that side.

The bridges take 10 to 15 years to grow strong enough for regular use; once they do, they last incredible amounts of time with no maintenance: since they're still growing, they actually continue to grow stronger and stronger over time. Some of the older bridges are five centuries old. Many of the older, stronger bridges can support 50 or more people at once.

mfthought

Sometimes I think about crossing a bridge.

The most famous of the bridges, the Umshiang Double-Decker Root Bridge, is actually two of those bridges, with one stacked directly over the other. Local dedication to the art has kept the bridges alive and prevented them from being replaced with steel. (Steel, frankly—and with all respect to those dealing with, ahem, yard ramps—doesn't have anything near the lifespan of the root bridges and aren't nearly as sturdy.)

The root bridges aren't the only living bridges around. In the Iya Valley in Japan, there are bridges woven out of living wisteria vines. They're much less common, and only three remain. They're built by growing immense lengths of wisteria on each side of the river before weaving them together—a process that must be repeated once every three years.

These wisteria bridges are much less sturdy than the Khasi root bridges, with wooden planks spaced over seven inches apart, and they apparently shake wildly while you're on them. By all accounts, these things are terrifying to cross, which makes sense: they’re widely thought to have been designed originally for defense. The original bridges didn't even have railings.

Yard Ramp Guy Blog: Industrial Protection

This week my friend The Yard Ramp Guy makes a compelling case for worker safety.

Click HERE to peruse his perspective on proper planning.