PSI / compressive strength PSI, or pounds per square inch, measures the compressive strength of concrete after it has cured. It indicates how much pressure the concrete can withstand before failing.
Compressive strength is one of the most important specifications for concrete because it reflects durability and load-carrying capacity. Engineers select different PSI values depending on how the concrete will be used, such as sidewalks, driveways, or heavy-duty pavements. Test cylinders are commonly used to verify that the finished concrete achieves the required strength after curing.
Frequently Asked Questions About PSI / compressive strength
What does PSI mean in concrete?
Pounds per square inch, the measure of compressive strength a concrete mix reaches after curing. It indicates how much pressure the concrete can withstand before failing.
Why does compressive strength matter?
It reflects durability and load-carrying capacity, and it is one of the primary specifications for any sidewalk, curb or driveway mix.
How is strength verified?
Test cylinders are cast from the delivered concrete and broken in a lab at set intervals, commonly 7 and 28 days.
When is design strength reached?
Concrete is typically specified at 28-day strength, though it continues gaining strength slowly beyond that point.