One World Trade Center rising on “super concrete”

“On One World Trade Center WSP Cantor Seinuk’s engineers worked on specifying the compressive strength and modulus of elasticity,” says Marcus. “But we needed even higher compressive strength—14,000 psi—for the taller One World Trade building.” Dr. Ahmad Rahimian, President of WSP Cantor Seinuk said, “For One World Trade Center we took an unconventional approach. From past experience we have learned that in high strength concrete the value determined using ACI expression for modulus of elasticity can be exceeded. Accordingly, we specified dual requirements for the shear walls concrete: A modulus of elasticity of 7,000ksi and corresponding concrete compressive strength of 12,000psi and 14,000psi. This contributed to the stiffness of the tower without the premium of calling for even higher strength concrete....