ordinary portland cement

cement

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July 1, 2026

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Ordinary Portland cement is a finely ground powder, typically gray, made by burning and grinding limestone and clay or shale. Patented in 1824 by Joseph Aspdin, it was named for its resemblance to portland stone when set.1

When mixed with water, the anhydrous calcium silicates and other components in Portland cement undergo a chemical reaction called hydration. This process causes the cement to harden and gain strength.1

Portland cement is composed of four main compounds: tricalcium silicate (C₃S), dicalcium silicate (C₂S), tricalcium aluminate (C₃A), and tetra-calcium aluminoferrite (C₄AF). There are five standardized types of Portland cement in the United States, including ordinary (Type I), modified (Type II), high-early-strength (Type III), low-heat (Type IV), and sulfate-resistant (Type V).23

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cement
Types of portland cement
…for Testing and Materials (ASTM): ordinary (Type I), modified (Type II), high-early-strength (Type III), low-heat (Type IV), and sulfate-resistant (Type V). In other countries Type II is omitted, and Type III is called rapid-hardening. Type V is known in some European countries as Ferrari cement.
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…for Testing and Materials (ASTM): ordinary (Type I), modified (Type II), high-early-strength (Type III), low-heat (Type IV), and sulfate-resistant (Type V). In other countries Type II is omitted, and Type III is called rapid-hardening. Type V is known in some European countries as Ferrari cement.
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