The 1994 T.R.Higgins Lecture:

Composite FrameConstruction

Lawrence G. Griffis

AuthorLawrence G. Griffis, P.E. is seniorvice president and director of struc-tural engineering for Walter P.Moore and Associates, Inc. inHouston, Texas.

Mr. Griffis has served as princi-pal-in-charge or project managerfor numerous large projects utiliz-ing structural steel, concrete andcomposite framed construction.Several recent projects include the1,047-bed Veterans AdministrationMedical Center Hospital Replace-ment/Modernization in Houston,Texas; The Orlando Arena, a16,200-seat multi-purpose facilityfor the City of Orlando, Florida; TheChevron Tower in downtown Hous-ton, Texas, a 52-story compositeframed office tower; and the GreatAmerican Pyramid, a 22,000-seatspecial events arena for the City ofMemphis, Tennessee.

Mr. Griffis has authored severaltechnical publications on the sub-ject of composite frame construc-tion and numerous case historiesfor projects completed under hisdirection. Active in many technicalcommittees and societies, he pres-ently serves as a member of theASCE Committee on Steel Build-ings, the ASCE Committee onComposite Construction, the Build-ing Seismic Safety Council TaskCommittee 11 on Composite Struc-tures, and the ASCE Seven WindLoad Subcommittee. He is also aprofessional member of AISC andhas given several talks at the Na-tional Engineering Conference.

Mr. Griffis received both hisbachelor of science degree in civilengineering and a master of sci-ence in structural engineering fromthe University of Texas at Austin.

SUMMARYOver the last 25 years, innova-

tive structural systems have

evolved in tall building designwhereby structural steel and rein-forced concrete have been com-bined to produce a building with theadvantages of each material,namely, the inherent stiffness andeconomy of reinforced concreteand the speed of construction,strength and light weight of struc-tural steel.

This paper explores, through aseries of recent case histories, whythe designers of tall buildings in theUnited States, use compositeframe structures. The advantagesand disadvantages of this type ofbuilding system are addressed.Potential problems this type ofstructure poses to designers andbuilders, and the need for a clearunderstanding by the steel erectorof the design assumptions, arepointed out.

The future of composite-frameconstruction may very well lie in thearea of low-rise construction, par-ticularly in high seismic zones.Phase Five of the United States-Japan Cooperative Research Pro-gram will focus on composite andhybrid structures. It is expectedthat this joint research effort willproduce significant new informa-tion about the design and behaviorof composite components and sys-tems. A new chapter coveringcomposite elements and systemswill appear in the 1994 NEHRPRecommended Provisions for theDevelopment of Seismic Regula-tions for New Buildings by theBuilding Seismic Safety Council.This new design standard and theresults of new research expected tocome out of the United States-Japan program should afford theUnited States designers and build-ers the opportunity to expand thefrontier of composite construction.

1-1 2003 by American Institute of Steel Construction, Inc. All rights reserved.

This publication or any part thereof must not be reproduced in any form without permission of the publisher.

COMPOSITE FRAME CONSTRUCTION

by Lawrence G. Griffis, P.E.

HISTORICAL OVERVIEW OF COMPOSITE CONSTRUCTION

Although many modern students and practitioners of structural engineering tend to think thatcomposite construction is a product of recent design and construction practice, it actually beganjust prior to the start of the twentieth century.

In the USA, composite construction first appeared in the year 1894 when both a bridge and abuilding were constructed. The bridge was the Rock Rapids Bridge in Rock Rapids, Iowa. AViennese engineer named Joseph Melan obtained a patent for bending steel I-beams to thecurvature of an arch and then casting them in concrete. He submitted calculations to verify hiscomposite design. The building was the Methodist Building in Pittsburgh constructed usingconcrete encased steel floor beams. It so happens that a fire in a nearby building in 1897 spreadto this structure and destroyed the contents but not the frame of the Methodist Building. Already,one of the advantages of construction frame construction was realized - namely fire protection.

As additional buildings and bridges were constructed using steel wrapped in concrete toward theend of the nineteenth century, a need for research testing arose to better understand the behavior.A set of systematic tests for composite columns was begun at Columbia University's CivilEngineering Laboratories in 1908. This was followed by tests of composite beams in theDominion Bridge Company's fabrication shop in Canada by Professor H.M. McKay of McGillUniversity in 1922-4.

The first record of composite construction appearing in a US building code was in 1930 when theNew York City Building Code first allowed extreme fiber stresses of 138 MPa (20 ksi) rather thanthe 124 MPa (18 ksi) value traditionally allowed for noncomposite beams.

Shear connectors were also recognized in this early composite construction as an effective meansto enhance the natural bond between steel and concrete. In 1903, Julius Kahn received a USpatent on composite beams where shearing tabs in the beam flanges were bent upward to projectinto the slab. Different types of shear connectors have been proposed over the ensuing 90 yearsincluding some types still documented in the AISC Manual of Building Construction. It was in1954 when welded headed metal studs were first tested at the University of Illinois. In 1956, atthe completion of the tests, a formula for the design capacity of these connectors was published.The welded headed metal stud has now become the dominant method of transferring shearbetween steel and concrete. The first bridge to use these connectors was the Bad River Bridge in

Lawrence G. Griffis is Senior Vice President and Director of Structural Engineering,Walter P. Moore and Associates, Inc., Houston, Texas

1-3 2003 by American Institute of Steel Construction, Inc. All rights reserved.

This publication or any part thereof must not be reproduced in any form without permission of the publisher.

Pierre, South Dakota built in 1956. Also in 1956, IBM's Education Building in Poughkeepsie,New York became the first building to use headed stud connectors. The second floor was formedwith a 38 mm deep, 06 mm thick steel composite deck, using wires welded to the top flutes ofthe deck to achieve composite action between the metal deck and the hardened concrete.

The widespread use of composite metal decks began to flourish in the 1950s in buildingconstruction. The metal deck acted as a form for the wet concrete thus reducing concreteformwork costs. The deck was shaped in such a manner as to ensure composite action so that itcould serve as the positive one way reinforcement for the final hardened concrete slab.Composite action was first achieved through the use of wires welded to the deck. More recently,the standard way it is accomplished in modern composite decks is through embossmentsmanufactured into the deck to achieve composite action with the concrete. The composite metaldeck and the welded headed stud have gained such widespread popularity in modern buildingconstruction that it has become virtually the only system used in building floor construction forsteel and composite frame buildings in the last 25 years. One of the first modern buildings usingthis technique of construction was the Federal Court House in Brooklyn, New York designed in1960. Today almost all steel and composite framed buildings utilize this method of floorconstruction.

The first tall building boom occurred in the USA in the 1920s and 1930s when high risestructures such as the Empire State Building and the Chrysler Building were built. Many of theseearly vintage steel frames utilized the protection that the concrete afforded the frame when it wascast around it for resistance against fire and corrosion. Only until the 1960s with the advent ofmodern composite frame construction have engineers actively sought rational methods to takeadvantage of the stiffening and strengthening effects of reinforcing bars and concrete on thecapacity of the embedded steel frame. The late Dr. Fazlur Kahn, in his early discussion ofstructural systems for tall buildings, first proposed the concept of a composite frame system1,2 inthe Control Data Building in Houston, Texas in 1970. Since that time composite frameconstruction has been utilized on many high rise buildings all over the world and its usage, with acomposite column as the key element, is well documented in the work of the Council on TallBuildings and numerous other publications3-7.

FROM PRACTICE TO THEORY TO RESEARCH TO CODE DEVELOPMENT

The development of composite construction in the USA vividly exhibits the rather unique andbackwards sequence of events leading to the widespread use of a new construction method. Thefirst step involves the conception of a new idea that has the potential to save time and money inthe final product. The first priority is to construct the system, one that usually has a very limiteddesign experience extrapolated from a well known current theory. After the system has beendeveloped and constructed, the design theory is refined to justify its widespread usage. Finally,usually after a considerable period of time, research is conducted to verify the design theories, andmodify them as required. Only much later, often many years, are these practices codified tolegalize what was already done. This practice, although scientifically illogical, is borne out ofnecessity and