Archives for November 22, 2013

The compressive strength of concrete is expressed in Megapascals (MPa) or pounds per square inch (psi) at an age of 28 days. Since the strength is constantly increasing, the reference strength chosen by industry is 28 days. Typical strengths are in the range of 25 – 35 MPa (3,600 – 5,000 psi). On my bridge […]