The use and definition of high-strength concrete (HSC) has seen a gradual and continuous development over many years. In the 1950s, concrete with a compressive strength of 5000 psi (34 MPa) was considered high strength. In the 1960s, concrete with compressive strengths of 6000 and 7500 psi (41 and 52 MPa) were produced commercially. In the early 1970s, 9000 psi (62 MPa) concrete was produced. Today, compressive strengths approaching 20,000 psi (138 MPa) have been used in cast-in-place buildings. Laboratory researchers using special materials and processes have achieved “concretes” with compressive strengths in excess of 116,000 psi (800 MPa) (Schmidt and Fehling 2004). As materials technology and production processes evolve, it is likely.
