?EUR??,,????'??We?EUR??,,????'???ve all heard of ?EUR??,,????'??Portland?EUR??,,????'?? cement, and most of us know there is a Portland Cement Association (PCA), but wherefore art thou Portland?

An English mason by the name of Joseph Aspdin was cooking us some finely ground limestone and clay (delicious with cabernet) in his kitchen stove and ground the mixture into a powder, which hardened with the addition of water (or cabernet). Aspdin patented the formula in 1824 and called it Portland cement, because it produced a concrete that resembled the color of the limestone quarried on the Isle of Portland, a peninsula in the English Channel.

Of course, an English connection.

If you?EUR??,,????'???re cooking up some Portland cement this weekend for your concrete needs, you?EUR??,,????'???ll need calcium silicate, silicon, aluminum and a dollop of iron. Delicious.

Tinkering with that recipe, the cement industry has come up with eight types of Portland cement! The percentage of tricalcium aluminate is one differentiating factor. How coarse or fine it is ground matters (finer ground produces ?EUR??,,????'??higher early strengths?EUR??,,????'??).

There are also a variety of blended hydraulic cements, which are produced by grinding or blending two or more types of fine ingredients like Portland cement, ground granulated blast furnace slag, fly ash, silica fume, calcined clay, hydrated lime (and the kitchen sink?).

All Portland and blended cements are, again, hydraulic cements, and fall into six designations:

• GU-general use
• HE-high early strength
• MS-moderate sulfate resistance
• HS-high sulfate resistance
• MH-moderate heat of hydration
• LH-low heat of hydration

Bon appetit!