Title: "225 W. Wacker Drive"

Author(s): Jaime Moreno

Publication: Concrete International

Volume: 12

Issue: 1

Appears on pages(s): 35-39

Keywords: chlorides; creep properties; heat of hydration; shrinkage; high-rise buildings; high-strength concretes; mix proportioning; modulus of elasticity; performance; permeability; reviews; silica fume; tests; Construction

DOI:

Date: 1/1/1990

Abstract:
The development of high-strength concrete began in Chicago in 1962 with the development of 6000 psi (41 MPa) concrete, culminating in 1989 with the delivery of silica fume mixtures of 14,000 psi (96 MPa) for six stories of columns and one 17,000 psi (117 MPa) experimental column to the 225 W. Wacker project. The experimental column has provided information on structural properties of this new concrete strength. To satisfy architectural requirements, 14,000 psi (96 MPa) concrete with no silica fume in the mixture was delivered for 18 columns. The statistical history of high-strength concrete mixtures from 8000 psi (55 MPa) to 14,000 psi (96 MPa) shows coefficients of variation of 3 to 6 percent, illustrating the remarkable consistency in the mixtures. This project is representative of the state of the art of high-strength concrete in terms of strength, concrete quality, testing, construction techniques, and structural design.