|Castle de San Angelo, built in Rome in 138 A.D, has concrete walls. (PCA No. 13127)|
The use of concrete dates back to the Roman Empire. The Castle de San Angelo was built in Rome in 138 A.D. The stone facing was stripped away hundreds of years ago, exposing concrete that is still in good condition. In North America, it is believed that the mission priests in charge of construction learned the secret of making natural cement from the Native Americans of Mexico. The widespread knowledge and use of natural hydraulic cement was demonstrated by a diversion dam in San Diego, California. Some believe this was the first concrete structure in America, built in about 1769.
In 1824, Joseph Aspdin, a British stone mason, obtained a patent for a cement he produced in his kitchen. The inventor heated a mixture of finely ground limestone and clay in his kitchen and ground the mixture into a powder creating a hydraulic cement – one that hardens with the addition of water. Aspdin named the product portland cement because it resembled a stone quarried on the Isle of Portland off the British Coast. With this invention, Aspdin laid the foundation for today's portland cement industry. The first large use of this modern-day portland cement, and its first engineering use, was in a tunnel under the Thames River in 1828. The first recorded shipment of portland cement to the US was in 1868. The first portland cement manufactured in the US was produced at a plant in Coplay, Pennsylvania in 1871.