Compressive Strength (PSI)

Compressive strength measures how much load concrete can carry before it fails, expressed in pounds per square inch (PSI) and typically tested at 28 days of curing. It is the single most common spec called out on a structural drawing or mix ticket.

Common targets range from roughly 2,500–3,000 PSI for residential flatwork up to 4,000–5,000+ PSI for structural elements, footings, and exposed slabs subject to freeze-thaw. Strength is controlled primarily through the water-cement ratio.