We see these noisy trucks everywhere – ready mix concrete. Today, on Engineering Works!
Concrete is one of the handiest construction materials there is. It’s been around since the Romans. Engineers design and build streets, highways and bridges out of concrete; high-rise office buildings; dams. You can even build your house out of concrete. Take that, big bad wolf.
About three-quarters of all the concrete we use is ready mix concrete. That means it’s mixed one place but used somewhere else. It’s hard to find room for a concrete plant and its mountains of sand and gravel just anywhere. This is where the ready mix truck comes in. Ready-mix trucks haul about 340 million cubic yards of concrete – every year. That’s enough to build 78 Hoover Dams – every year.
The earliest version of a ready mix concrete truck was pulled by a horse. In 1909. Paddles connected to the cart’s wheels kept the concrete stirred up. In 1916, a contractor in Ohio came up with the first motorized concrete mover. By the 1940s, heavier trucks and stronger engines brought ready mix trucks to about what we see on the road today.
And just in case you were wondering why the big drum on the back of ready mix trucks turns around while the truck is going down the street – It keeps the cement, gravel and water inside from separating before the truck delivers the load.
Our load is just about mixed. We’re outta here.