What is Portland Cement?
Did you know there are several types of cement? They all look similar—so what’s the difference between them?
Answer: It’s a gray area!
Concrete jokes aside, just like there’s a difference between concrete and cement the same is true for cement. Each has a special composition, name, and purpose. As the key ingredient for concrete, cement plays an important role in its creation process.
Introducing Portland cement
One of the most common types of cement for making concrete is Portland cement. This binding material comes in the form of a fine powder, usually in a gray color. It’s made by grinding and burning a mixture of limestone with shale or clay. In addition to concrete, you can also find it as an ingredient in stucco, mortar, and some kinds of grout. And there are five different kinds of Portland cement, too! The difference is the rate of hydration (how fast it gets hard and the type of application based on your geography.)
Mathews Readymix uses type II-b, which is made for low heat hydration (sets up slower) and sulfate resistance because of the salts in the soil. You can find it in stucco, mortar, and all grouts.
The History of Portland Cement
Portland cement was patented in 1824 by an Englishman named Joseph Aspdin. He began his humble experiments on the kitchen stove, burning a mixture of limestone and clay. From this process came the first version of Portland cement. Initially called "British cement," it was eventually named after Portland stone in the UK. When set, this cement resembles the Portland stone, a limestone from the Isle of Portland.
How cement transforms into concrete
When cement is mixed with water, a paste is formed through a chemical reaction. Water binds the rock and sand together as they harden in a process called hydration. Hydration of cement is an exothermic reaction that creates several products, the main one being calcium silicate hydrate (C-S-H) which is the primary source of concrete strength. During the first 28 days, the concrete is “curing.” This involves controlling moisture and temperature conditions, which affect strength development, durability, and permeability of the finished product. The end result is concrete, a solid, stone-like material.
Why is Portland cement used?
Portland cement is a popular choice due to its reliability (you know how it will behave) and the versatility of designs that can be created with it. At Mathews Readymix, we favor using Portland cement. We’re proud to be aligned with the PCA, which has carbon-neutral goals and has created the Roadmap to Carbon Neutrality. Their aim is to be carbon neutral by 2050 by utilizing new technology and practices, just like the National Ready Mixed Concrete Association (NRMCA). We all share a common goal to educate industry members and the general public on the sustainable benefits and initiatives of ready-mixed concrete.
So the next time you see one of our blue-striped trucks, think of all the Portland cement inside! Contact us at Mathews Readymix for all your concrete needs.