Strength of Concrete
Strength is a fundamental property of concrete that determines the durability of a structure. In general, concrete has a compressive strength of about ten thousand pounds per square inch. The test result is the average of two standard-cured specimens, and no single test must fall below the specified strength fc’ by more than 3.45 MPa. In other words, if a concrete strength measurement is less than ten thousand pounds per square inch, it is not considered strong enough.
The most common way to measure the strength of concrete is with a field-cured cylinder. A cylinder is cured and casted and sent to a third-party lab for testing. This method is proven to be the most accurate and dependable, and is used extensively by many construction companies. In addition to allowing for a scientific environment, a third-party lab is unlikely to alter the results.
The compressive strength of concrete is measured by mega pascals (MPa) and pounds per square inch (Psi). However, higher values may be specified for specific applications. The compression strength of concrete can be calculated by taking the failure load and dividing it by its cross-sectional area. Depending on the structure and application, the compressive strength of concrete can range from two hundred to four thousand psi (17 MPa) for residential construction to fourteen thousand psi (30 MPa) for commercial structures.