Title:
Cost of Reinforced Concrete High-Rise Columns
Author(s):
Muthia Kasi
Publication:
Symposium Paper
Volume:
90
Issue:
Appears on pages(s):
219-238
Keywords:
columns (supports); computer programs; costs; structural design; formwork (construction); high-rise buildings; reinforced concrete; reinforcing steels; General
DOI:
10.14359/1776
Date:
4/1/1986
Abstract:
In the last systematic review of reinforced concrete column costs in 1973, ACI Committee 439 limited its cost comparisons to concrete strengths from 4000 to 8000 psi and reinforcing steels with design yield of 60,000 psi with speculative estimates of steel with 80,000 psi yield. Design then was based upon the 1971 ACI Building Code. At that time the leading structural engineers had successfully utilized concrete with f'c = 9000 psi under the current code. A number of general conclusions on costs were presented as trends. To bring this review of reinforced concrete column costs up to date, we must consider changes in code requirements, more general availability of still higher strength concretes, superplasticizer admixtures, building code limitations and general lack of economy in a Grade 80 reinforcement, and later laboratory testing and field research on properties and performance of high-strength concretes. A recent detailed comparative cost study of reinforced concrete columns which resulted in appreciable cost savings in a Chicago high-rise building, reinforces some of the 1973 report under conditions today. As might be expected in dealing with the numerous variables involved in comparative column design costs, the detailed study was made effective only through a computer program. The essential features of this program are described in detail in the CRSI Bulletin.