Title:
72-Story High-Rise With 83 MPa Fly Ash Concrete--A Case History
Author(s):
F. David Anderson
Publication:
Symposium Paper
Volume:
114
Issue:
Appears on pages(s):
607-624
Keywords:
coefficient of variation; compressive strength; fly ash; concrete construction; high-rise buildings; high-strength concretes; water-reducing agents; Materials Research
DOI:
10.14359/2184
Date:
5/1/1989
Abstract:
Describes recently completed construction of a 175,000 mý (1.85 million ftý) 72-story office building. A unique feature of the structural system is the high-strength reinforced concrete-structural steel composite columns. Conventional aggregates and portland cement, with about 29 percent fly ash replacement, produced average 56 day compressive strengths of over 83 Mpa (12,000 psi), easily surpassing the design specified strength of 69 Mpa (10,000 psi). Most of the concrete was placed at a slump of 200 mm (8 in.), using a high-range water-reducing admixture. The structural design was based on 16 exterior columns, an arrangement that allowed excellent utilization of tenant space. Preconstruction research and development of the high-strength fly ash concrete mix designs proceeded simultaneously with the architectural and structural design. Results of these tests produced important data on modulus of elasticity, shrinkage, and creep that influenced the composite column design. Much of the concrete was placed under hot weather conditions typical of Texas, where summer ambient temperatures sometimes exceed 40 C (104 F). While fly ash was employed in all of the concrete mixes, this paper focuses on the high-strength aspects in which the use of fly ash was an essential ingredient.