The first concrete
Everyone knows that all roads lead to Rome, but lesser known is that 5300 miles of those roads were built from concrete. From 300 B.C. to 476 A.D., the Romans used pozzolana cement from Pozzuoli, Italy, to build the Appian Way, as well as the Roman baths, the Coliseum and Pantheon, and the Pont du Gard aqueduct in southern France. The mix consisted of small gravel and coarse sand mixed with hot lime and water and horsehair to reduce shrinkage. That also is when the world saw admixtures in their most primitive forms of animal fat, milk, and blood.
Ancient Chinese used cementitious materials to hold bamboo together in boats and in the Great Wall of China, and Egyptians used lime mortars and gypsums while building the pyramids. History also suggests that Assyrians and Babylonians used clay as a bonding material.
Advent of the ready-mixed truck
Machines and methods to batch and mix the materials used in concrete paving were just being developed at the turn of the 20th century. In particular, a steam-powered concrete “paver” that mixed concrete onsite and moved with the other paving machines as the work progressed gained wide acceptance as the preferred method of producing concrete for pavement.
At first, wheelbarrows were used to “batch” and load the paver's skip hoist. Five-ton dump trucks would haul the sand and stone to the worksite and dump the materials in piles along the roadside. Then the workmen would hand-shovel the materials into wheelbarrows that also served as volumetric measures to load the skip hoist for the two-bag (about 11 cubic feet) steam-powered concrete mixer (paver).
Bags of cement also were spaced along the roadside and hand-dumped into the skip hoist in proportion to the wheelbarrow loads and batch size. A water pipe usually was laid the entire length of the job with multiple outlets to provide water for the mix. It was a slow, back-breaking process, but it got the job done and produced many concrete roads of acceptable quality for the early lightweight cars and trucks.
Concrete ships throughout history
The oldest known concrete ship was a dingy built by Joseph Louis Lambot in Southern France in 1848 and featured in the 1855 World's Fair. In the 1890s, an engineer in Italy named Carlo Gabellini built barges and small ships out of concrete; the most famous being the Liguria. On August 2, 1917, N.K. Fougner of Norway launched the first ocean-going concrete ship—an 84-foot-long boat named Namsenfjord. In the 1917, the Violette was built and currently is used as a boating clubhouse on the Medway River in England. This makes her the oldest concrete ship still afloat.
In 1917, the United State finally entered World War I and steel became scarce while the demand for ships went up. Businessman W. Lesie Comyn formed the San Francisco Ship Building Co., Oakland, Calif., to begin constructing concrete ships. The first American concrete ship, a steamer named the S. S. Faith, was launched March 18, 1918. She cost $750,000 to build. She was used to carry cargo for trade until 1921, when she was sold and scrapped as a breakwater in Cuba.
With the advent of World War II, the U.S. government contracted McCloskey & Co., Philadelphia, Pa., to construct a fleet of 24 concrete ships. Innovations in cement mixing and composition made these ships stronger than the previous attempts. After the war, several of the ships were turned into a floating breakwater in Canada and 10 more were sunk as a breakwater in Virginia. Source: concreteships.org.
Follow your nose
Form release agents evolved throughout the years from hazardous to environmentally friendly (such as vegetable oil or soy-based release agents) to downright good smelling. Appealing to people's sensual side, companies are creating scented form release agents. For the sugar tooth, bubblegum is popular. Create a fruit basket-like smell with scents such as cherry, lemon, and citrus. Go down another road altogether by requesting a custom smell.
Zelienople, Pa.-based Universal Mfg. Corp. treats its neighbors in this small town with a unique holiday display each year. The scaffolding company designs a display centered around its custom products and strings it with cheerful lights. Previous spectacles include a 70-foot-long sled complete with reindeer, a 40-foot-tall snowman, a 40-foot-tall angel, a train stretching the property's length, and a full-sized house.
Reaching for the stars
The renowned Seattle Space Needle was built for the 1962 World's Fair, when nearly 20,000 people per day visited the top. Weighing in at a massive 9550 tons, it took 467 ready-mixed trucks about 12 hours to place the 30x120-foot foundation. It was the largest continuous concrete pour in the western United States. The foundation weighs 6000 tons and has 250 tons of reinforcing steel in the base, placing the center of gravity just 5 feet above ground level. Seventy-two 30-foot long bolts attach the structure to the foundation. Victor Steinbrueck designed the Space Needle to withstand earthquakes up to a 9½ magnitude and winds up to 150 mph. The structure sways only 1 inch per 10 mph of wind speed. At the time of construction, the Space Needle was the tallest building west of the Mississippi, later replaced by the Stratosphere Tower in Las Vegas.
As famous for its mob connections as for its flashy signs and show-girls, the Stardust Hotel-Casino in Las Vegas was imploded on March 13 of this year. Fireworks showered the building—once the world's largest resort hotel—as 428 pounds of explosives rocked the 32-story building to the ground. Crews spent the preceding three months gutting the Stardust to concrete and steel in preparation for its implosion. Twenty water cannons sprayed the dust cloud.
More than 4800 pounds of dynamite imploded Pittsburgh's Three Rivers Stadium in February 2001, home to the MLB's Pittsburgh Pirates and the NFL's Pittsburgh Steelers for three decades. The landmark concrete stadium dropped almost straight down, with the closest debris settling a solid 40 feet away from the new stadiums. Seismographs recorded little ground tremor; no nearby windows cracked. Most of the approximately 180,000 tons of concrete rubble were deposited in Ohio landfills, but some was used for temporary parking between the two new Pittsburgh stadiums and for leveling low riverbank areas.
Materializing a dream
While snapping pictures with Mickey, Goofy, Donald, and other Disney pals, most visitors aren't aware of the decorative concrete all around them. For example, all the colors and textures at Disney's Pop Century Resort in Orlando were taken from Lady and the Tramp. At Disney's Animal Kingdom the rutted roads are actually made from concrete that was colored to match the nearby soil. Stones, dirt, and twigs are embedded in the road and crews rolled tires through the fresh concrete to create the remote African outback. Bob Harris, president of the Decorative Concrete Institute in Douglasville, Ga., worked at the Disney resorts and theme parks for six years casting tree branches, alligator prints, and more. In one instance, he even had his Labrador run through fresh concrete to embed the paw prints.
The Pima Freeway/Loop 101 retaining and sound walls in Scottsdale, Ariz., crawl with desert flora and fauna. Gargantuan forms were necessary to imprint 40-foot cacti and 67-foot lizards in the walls that artist Carolyn Braaksma designed. The form-liners were 6 and 8 feet tall, 30 and 40 feet in length and manufactured of elastomeric urethane to pick up fine details. Instead of traditional desert-themed colors, bold colors, such as purples, greens, and blues, accentuate the murals.
More than a bulldozer
Life came to a halt for the residents of Granby, Colo., in June 2004 as an armored bulldozer plowed through their small mountain town. The driver, Marvin Heemeyer, took revenge against town officials, who he blamed for rezoning measurements that enabled the local concrete company to open a six-acre operation neighboring his muffler repair business.
Heemeyer spent months preparing his bulldozer for the attack by welding thick steel plates with concrete reinforcement to the machine. Believing he was doing God's will, Heemeyer ultimately rammed his tank into 13 buildings, including the Mountain Park cement plant, before the tank started losing hydraulic fluid and was forced to stop. Investigators found a portable concrete mixer and other related equipment in Heemeyer's shop, leading them to believe Heemeyer built his concrete protective shield using packaged dry mix.