What are the Different Types of Cement?
First, it is important to understand that cement is just one ingredient of concrete; these two terms are not synonymous. Concrete is the mixture of water, some type of aggregate — such as crushed rocks or sand — and cement, which acts as a binder to hold all the materials together once hardened. Evidence suggests that the ancient Romans were the first to use the concrete mixture in construction, and structures like the Pantheon stand as proof of the success of their invention.
Mortar, in its most general and basic form, is referred to as Portland, or Type One, cement and is created by burning limestone with other materials at 2,642°F (1,450°C). The result is then ground to produce a fine powder, which becomes one of the components of concrete. Altering the amounts of the other materials in the burnt mixture yields several different types of Portland cement, however, each type having unique properties and strengths. The type of mortar used in building a structure should be chosen based on the structure’s purpose and environment.
Because structures have various chemical and physical requirements, eight different types are manufactured. These types are simply referred to as Type One, Type Two, Type Three, Type Four, Type Five, and Type One-A, Type Two-A, and Type Three-A. Types One through Five are distinctly different, while Types One-A, Two-A, and Three-A are modified versions of their counterparts.
Type One is suitable for most basic construction uses. Type Two is best for structures built in hot environments, or in soil or water high in sulfate. For projects requiring strength at an early stage, Type Three is ideal because it provides more strength within one week than the other types. Type Four is useful in limiting heat caused by hydration and is therefore used in massive concrete undertakings, such as dams. When soil or water is high in chemicals, Type Five should be used because it is manufactured to resist chemical erosion.
The final three types of mortar are known as the air-entrained cements, because they have microscopic air bubbles added to their mixtures to increase the durability of the concrete. Air-entrained cements are especially useful in environments that have repetitive freezes. Types One-A, Two-A, and Three-A are similar in properties to Types One, Two, and Three; the air-entrained ones simply contain air bubbles.
There are also variations on these eight types that affect the color of the resulting concrete. For instance, white can be made by leaving out raw materials such as iron and manganese, which give concrete its traditional gray coloring.
What is 42.5 Opc-bsi?
@musicshaman: We now know the Roman formula, which includes both volcanic ash and seawater and actually uses less expensive cement in smaller quantities.
There is evidently a rapid reaction when the mix made with ash hits seawater.
Thanks for this clear explanation!
So what exactly is fire cement? I always see buckets of that stuff whenever I'm in Home Depot, but I never knew what it was, or what it was used for.
Do you know?
There's also a kind of cement called slag cement.
Slag, the byproduct of iron production, is increasingly being mixed in to Portland cement, and actually improves the quality and consistency of the cement.
It's also gaining a lot of popularity lately because it's environmentally friendly, since it uses slag that would otherwise be wasted, and it is technically considered a recycled product.
Although it used to be kind of a specialty material, slag concrete has become just as common today as any other kind of cement.
Did you know that the kind of cement making process used by Romans made some of the strongest and longest lasting cement products in existence, but we have no idea what it was?
People have tried to imitate the cement production process used for buildings like the Colosseum, but no one has been able to duplicate it.
So the process that made buildings that can remain standing after exposure to the elements for hundreds of years remains lost -- at least thus far.
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