The American Concrete Institute (ACI) defines high-strength concrete as concrete with a compressive strength greater than 6,000 pounds per square inch (psi). Three decades ago, concrete strengths greater than 6,000 psi were considered exotic, but today they are commonplace. With improved cements, admixtures, pozzolans, and technology in proportioning, batch control, and quality, the result is consistent quality concrete strengths higher than 12,000 psi.

In the last 20 years, several projects have been constructed in the Philadelphia market using high strength concrete. These projects were mandated by the need for high axial strength in relatively small-sized columns, stiffness in shear wall buildings, or a combination of stiffness and strength in foundations. At Madison, we have been able to expand our portfolio of buildings using high-strength concrete and learned how to proportion, mix, transport, and place this material to obtain the best results.

The Lancaster Square project is one of many that our company has constructed using high-strength concrete. We have also developed expertise about finishing techniques, as all the high-strength mixes are tricky to finish successfully.

Have you worked on a project with high-strength concrete? We would love to hear about it. We would also love to hear from you about your structural engineering challenges and successes and any questions you might have. Submit your questions to Rick Stone at