What is the specific gravity (Gs) of Portland cement?

• A. 2.30 (unitless)
• B. 2.85 (unitless)
• C. 3.15 (unitless)
• D. 3.50 (unitless)

Answer: (C)

Portland cement typically has a specific gravity of approximately 3.15. Specific gravity is a measure of the density of a substance in relation to the density of water. For Portland cement, this value reflects its density and composition, which primarily includes clinker minerals such as tricalcium silicate, dicalcium silicate, tricalcium aluminate, and Tetracalcium aluminoferrite. The specific gravity of 3.15 indicates that it is significantly denser than water, which has a specific gravity of 1. Understanding the specific gravity of materials like Portland cement is crucial for various engineering applications, including mix design, where the proportions of ingredients must be accurately calculated for concrete production. Thus, choosing the correct value is essential for successful construction and material performance.