What is Portland Cement?

Joseph Aspdin, a bricklayer from England, is credited with inventing portland cement in 1824.  The named comes from its similarity to a common building stone found on the Isle of Portland in Dorset, England.  By conducting experiments in his kitchen stove, Aspdin fired ground limestone and clay together to create the first artificial cement.  This new cement was stronger than what the standard unfired crushed limestone of the day was capable of attaining.

Used throughout the world, portland cement is the most common type of cement and is the key ingredient in concrete, mortar and stucco.  When added to concrete, it is the paste that binds the aggregate (made from sand and gravel) with the water.

According to the Portland Cement Association, “Cement is manufactured through a closely controlled chemical combination of calcium, silicon, aluminum, iron and other ingredients.”  To produce portland cement, raw materials such as limestone, shell, or chalk are combined with clay, silica sand, shale, bauxite, fly ash, slag and iron.  This mixture is heated in huge cement kilns at temperatures as high as 2,700 degrees Fahrenheit.  From the extreme heat a dark grey nodular about the size of a marble is produced called a clinker.  The clinker is ground into a fine powder to make cement.  After it has cooled, it may also have a small amount of gypsum added to control the setting process. 

Wikipedia defines portland cement as "hydraulic cement (cement that not only hardens by reacting with water but also forms a water-resistant product) produced by pulverizing clinkers consisting of essentially hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an inter ground addition.”   The strength of the concrete mix depends on the reaction of these calcium silicates with the water. 

1.    cement.org/cement-concrete-basics/how-cement-is-made

2.    en.wikipedia.org/wiki/Portland_cement

The Conco Companies are one of the leading concrete contractors in the Western United States and offer a wide range of innovative, quality services.  Our concrete services include commercial, educational, parking and other construction development as well as public works projects.  We have regional offices serving Northern California, Southern California, Washington State, Oregon, Colorado and Nevada.