Development of composite columns. Emperger's effort

Today's composite columns are made of structuralsteel, concrete and reinforcing steel. Three basictypes of composite columns can be distinguished,

completely encased composite columns, Figure la,panially encased composite columns, Figure lb, and

fiJled composite columns, Figures Id and le.Although composite columns were rarely used from

the end of W orld War Il until the early 1970' s (Viestet al. 1997, 1.13), research had started a long timebefore, at the beginning of the 20th century.Combining of these material s had a number ofmotivations, steel columns were often encased inconcrete lo protect them from fire, while concretecolumns were combined with structural steel as areinforcement.

One predecessor of the completely encased columntype was the so called Emperger-Column. It consisted

of a cast-iron section embedded in spiral-reinforcedconcrete and had been used frequently in theconstruction of high-rise buildings in the UnitedStates. The anicle describes Emperger's activities inthe field of composite columns and proves hisinfluence on the construction, which can still be felttoday. Another type of today's composite columns,

the column with a solid steel core, reminds us of theEmperger-Column and can be considered assuccessor. It wiJl be proved that Emperger was notonly a pioneer in concrete construction, but also apioneer in composite construction, who tried to link

both steel and concrete construction techniques.

bC*f~ Cy

lO'

/ / /

~ .

1:

/ // tw/

"-

-c::: -c:::l.>I'y/ / / / -,

/ /,

o) \zlO'

~.y

d

_.y

e) ~z

Holger Eggemann

T

b=b,l.

~

I

~~,.

,u

-<::~-

b)

IIz

¡-, b

y

d)

i"""

f) Iz

Figure 1Types of Composite Columns (DINV ENV 1994-1-1, Fig.

4.9)

Proceedings of the First International Congress on Construction History, Madrid, 20th-24th January 2003, ed. S. Huerta, Madrid: I. Juan de Herrera, SEdHC, ETSAM, A. E. Benvenuto, COAM, F. Dragados, 2003.

788 H. Eggemann

FRITZ VON EMPERGER (1862-1942)

This paragraph is based on a curriculum byKleinlogel, dedicated to Emperger's 70th birthday(Kleinlogel 1932). Emperger was born on January11th, 1862 in Beroun (at that time Austria, todayCzech Republic).When he began his studies in Praguein 1879, the first effects of Monier' s patents hadbecome visible in France and evoked Emperger'sinterest in the new technology. His first professionalactivities were in the field of railway and bridgeconstruction. In 1890 he settled down in Chicago as aconsultant engineer, where he worked on the planningof New York's and Boston's subways, built the firstAmerican concrete bridge in Cincinatti, Ohio anddesigned high-rise buildings.

Figure 2Medal of Honour to Emperger's 70th Birthday (Beton u.Eisen 1932,50)

After his return to Vienna in 1897, he took hisDoctor of Engineering degree in 1903. Previously, hehad founded the journal «Beton und Eisen» in 1901,today known as "Beton- und Stahlbetonbau«, since

1906 published by Wilhelm Ernst & Sohn, Berlin. In1906 he gave the idea to Germany's "Beton-Kalender«, of which he became the editor, and in

1909 he published the «Handbuch für Eisenbeton»with the same company. In 1913 Emperger washonoured by his Majesty, the Emperor of Austria,with the Knight' s Cross of the lron Crown and in thesame year received the honorary membership of theBritish Concrete Institute (Beton u. Eisen 1913, 187,290). In 1932, after years of intensive research on

almost every aspect of reinforced concrete and designand construction of many buildings, he becameDoctor honoris causa of Dresden' s Faculty of CivilEngineering, Figure 2, and al so honorary member of

Austria's Committee on Reinforced Concrete (Betonu. Eisen 1932, 50). Emperger died on February 7th,1942 in Vienna.

RESEARCH AND DESIGN OF COMPOSITE COLUMNS

First steps

In the winter of 1901/1902 Emperger started researchon concrete columns mostly reinforced withstructural steel. For several reasons he had to waituntil 1908 to have the specimens tested in Stuttgart

with Bach. AJthough Emperger didn't give explicitevidence for the problems, it can be supposed thatthere had been internal rivalry with his colleagues inVienna (Emperger 1908b, Foreword). In 1907,Emperger tested three steel columns to determine

their buckling loads (Emperger 1907a). After testing,one of those specimens, Figure 3, was bent back to itsoriginal shape by Emperger himself and filled with

concrete (Emperger 1907b, 172). Emperger wanted togive evidence for the importance of concrete filling

for steel columns. He estimated that the designformula

P = O'h (Fb + 15 F)

of Prussia's Building Regulations was unsuitable tocaJculate the ultimate load of a concrete-filled steelcolumn. The number 15 defined the relation between

Developrnent of cornposite colurnns. Ernperger's effort 789

the rnodulus of elasticity of steel and concrete.Ernperger found out that the ultirnate load of a

concrete-filled steel colurnn didn't depend on thatnurnber.

Figure 3Steel Colurnn filled with Concrete (Emperger 1907b, 173)

Emperger's addition-law

In 1908 Emperger published the results of numeroustests on reinforced concrete colurnns, arnong those thespecimen tested by Bach (Ernperger 1908).Reinforcernent was realized by both reinforcement barsand structural steel elernents. According to (Gehler1933,266), Ernperger was the first to verbalise the later

well known Addition-Law: "Nach meiner Meinung istdie Bruchlast einer Eisenbetonsaule die Summe zweierFestigkeiten, die von dern Verhaltnis der beidenElastizitatskoeffizienten nicht abhangt» (Ernperger

1908,2). In Emperger's opinion the u1timate Ioad of a

reinforced concrete column was dictated by the surn of

the strength of both steel and concrete and did notdepend on the rnodulus of elasticity. A design formula

of the Addition-Law for reinforced concrete colurnnswas given first by (Morsch [1902] 1912, 93), withsyrnbols as described in the next paragraph:

P = Fb0h + Feo,

Emperger's Patent 1911

In 1911 Ernperger applied for a Patent clairning«Hohle GuBeisensaule rnit einem Mantel ausurnschnürtern Beton [Colurnn of hollow cast-ironsection encased in hooped concrete]» (Pat. 291068).

The spacing of the hooping had to be equal to or lessthan the thickness of the surrounding concrete shell,Figure 4. Because of an objection frorn the cornpanyWayB & Freytag A.-G., it took five years until the

patent was granted in 1916 (Beton u. Eisen 1916,47).

In 1913 Ernperger published a design formula for theultirnate load of such a colurnn:

P =Fb0b + Feo, + Fpg

where°"

is the compres sive strength of the cast-ironin consicteration of buckling of the complete section,

° e is the yield point of the mi Id steel and 0b is thecornpressive strength of the concrete (Ernperger1913, 34). In the sarne book Ernperger reported

various test results of encased cast-iron colurnns. Thecolurnn sections were varied in rnany ways, and solidcores were tested too, Figure 5. During the followingyears, nurnerous buildings in Austria, Czechoslovakia

and the United States had been built with Emperger-Colurnns, but not in Gerrnany (Kleinlogel 1928, 53).

For Kleinlogel the reason had been that Gerrnany'sbuilding authorities rejected the application ofErnperger-Colurnns because of missing regulations,

and official tests had been refused because ofErnperger' s patent clairn. So in 1928 Ernpergerdecided to give up his clairns (Kleinlogel 1928, 53).

Emperger-columns in the United States

In 1915, Ernperger gave a report on hooped concrete

calurnns with salid cores at an engineering congress

790

Fig.2.

f

Figure 4Emperger-Column (Pat. 291068, Fig. 2)

H. Eggemann

p2mmna#mm

Figure 5

Emperger-Columns with Solid Cast-Tron Cores (Emperger]913,53,56)

in San Francisco, USA. He presented his Addition-Law and pointed out that the strength of the corematerial was not of great importance, both cast-ironand mild steel were possible. In 1920, Emperger-Columns were regulated in the US StandardSpecifications No. 23, Standard Building Regulationsfor the Use of Reinforced Concrete (ACI 1920).Paragraph 50 stated:

"'!T

Composite columns having a cast -iron core or center

surrounded by concrete which is enclosed in a spiral of

not less than one-half of ] per cent of the core area, and

with a pitch of not more than three inches, may be figured

for a stress of 12,000-

60 L/R, but not over 10,000 lb. persq. in. [69 N/mm~] on the cast-iron section and not more

than 25 per cent of the compressive strength . . . on the

concrete within the spiral or coreo The diameter of the

cast-iron core shall not exceed one-half of the diameter ofthe spiral (ACT ] 920, 302).

Emperger's Addition-Law was applied in amodified form, using a specified Tetmajer-Formula.This was the first official building regulation forEmperger-CoIumns. The maximum allowedcompressive strength of the concrete was 3000 lb. persq. in. (20.7 N/mm"'), so a column could be calculated

with a maximum stress on the concrete of 4. I N/m m"'.In 1928 the paragraph was amended and cores of mildsteel were permitted too (ACI 1928, 824). Thisbuilding regulations made it possible to use Emperger-Columns in the design of many high-rise buildings inthe United States, above all in Chicago:

Buildings having the Emperger typc of column,

include the following: Surf-Hotel, Chicago, elevenstoreys; two sixteen-storey apartment buildings at

Development of composite columns. Emperger' s effort 791

3730-40 Sheridan Road, Chicago; Aragon Hotel,Chicago, twelve storeys; Krolick Department Store,

Detroit, 150"200 ft. [46"61 m], twelve storeys, with

co1umn loads of 2,000,000 lb. [9 MN], and a building of

the same size for the Detroit Pressed Steel Company. Ofthese, the Surf Hotel and the Krolick Store have hollow

cast-iron cores (ENR 1930, 278).

Two other buildings in Chicago had beenmentioned before, the 16-storey McGraw- HillBuilding, see Building Case Histories, and the 30-storey Trustees Building, also known as CornProducts Building. In 1930 test results on compositecolumns were published by (Mensch 1930). Testswere made for the new Building Code Committee ofthe City of Chicago to verify Emperger's resultsunder American conditions. Mensch figured out «thatDr. Emperger' s claim of the strength of the compositecolumn being greater than the sum of its componentshas been verified by every test» (Mensch 1930, 270).

Composite Columns in Europe

Emperger complained several times about the lack of

building regulations for composite columns inEurope. «Für die beiden . . . Saulenformen bestehen

in keinem europaischen Staate Vorschriften [Thereare no regulations for these two types 01' columns inany of the European countries]» (Emperger 1931a,

265; similar 1930, 1931 b). Emperger meant the

encased steel column and his own type. At the FirstCongress of the International Association for Bridgeand Structural Engineering in Paris in 1932,Emperger mentioned more than 1000 tests oncomposite columns in Europe and about 570 in NorthAmerica. He distinguished four different types ofcomposite columns, Figure 6. Type I was called

structural steel column with concrete core, Type IIwas a steel column encased in rein1'orced concretewith lateral ties, Type 1Il was called steel columnencased in strongly hooped concrete, the Empergertype, and Type IV was a steel column with slight

hooping. Type I and Type II are in use today, of

course with modern types 01' structural steel elements.Type I now is called partially encased composite

column and Type II is known as completely encasedcomposite column. Columns with spiralreinforcement are neither used in concrete nor in

composite construction today.

Type 1. TypellI

''1<~/"

.T)]~ IL m T"eI\

Figure 6Composite Columns 1932 (Emperger 1932, 596)

In 1931, Rudol1' Saliger, Professor at ViennaUniversity, reported several test series on compositecolumns of the Bauer-Type (Saliger 1931; Bauer1930). These Columns were examined as an

alternative to steel or concrete columns in two high-rise buildings in Vienna. Saliger can be consideredEmperger's rival, as he strictly avoided callingEmperger' s name in his article. Later on, Emperger

had a dispute with Saliger about the application of theAddition-Law (Bauingenieur 1931,656). During the1930's, additional tests in Germany were made by(Memmler, Bierett and Grüning, 1934) on steel

columns 1'illed with comete and by (Gehler andAmos, 1936) on concrete columns rein1'orced with

structural steel. The latter ones led to the 1'irst Germanbuilding regulations on composite columns. They

were passed in 1943 (DIN 1045-1943). §27 d) dealtwith concrete columns reinforced with structuralsteel, Figure 7. This paragraph existed until 1972,

when the design of rein1'orced concrete columns wasbased on the ultimate load theory, and officialsdecided that structural steel members encased inconcrete should be designed to carry the loads alonewithout considering the strength of the concrete(Bonzel, Bub and Funk 1972, 49). But lack 01' steelduring war and post-war period prevented the use of

composite columns in Germany. In 1'act, engineerswere instructed to save steel by using concretecolumns with a minimum 01' reinforcement: «zurEinsparung von Stahl . . . Saulen . . . zu wahlen, derenBewehrungszahl f.l in der Nahe der unteren Grenze

liegt» (DIN 1045-1943,21).

, l, ,

1

,. ,.....~'

,

I

'~., ,, ,l ,I ,, ,

"I ,~, ,VI

"II

, II I,

',II II I,I, ,I II I

' 1 l '

792

étlMIIlllet"

tkiget

~Al

Figure 7Concrete Columns reinforced with Structural Steel (DIN1045-1943, Fig. 23)

Composite columns with solid steel core-Successor of the Emperger-Column

In 1965 Boll applied for a patent claiming a columnwith a solid steel core, with its core bearing the load andthe surrounding concrete shell providing bucklingsafety and fire protection (Off. 1559482). Later in 1969

he tried to execute such columns in a high-rise buildingin Hamburg. Lack of time prevented the approval bybuilding authorities, meaning the building had to be

constructed with regular columns (Boll and Vogel1969, 259). The connection to Emperger's column is

obvious. A solid core is surrounded by reinforcedconcrete, preventing the core from buckling. Stronghooping is provided too. Lateral reinforcement was to

be realized using bars of 12 mm, spacing 7.5 cm, Figure8. This type of column was first realised in 1976 in ahospital in Vienna (Krapfenbauer 1976). There are two

recent examples of buildings with steel core columns,one is a high-rise building in Cologne, the so-called«Kolnturrn», where steel core columns were used in thelower floors. The other is the Millenium- Tower inVienna, completed in 1999. Because of Emperger's

connection to Vienna, this building will be described inparagraph Building Case Histories. Today, this type of

column ¡¡es within the scope of Eurocode 4.

H. Eggemann

;1Zmm,Sfmb

~

;1Zmm,sfmb

RippenlofólahjOZmm

8oW!oJ¡fgewebe

SO.JS'líNS mm

~ J'lo/¡llrern;ZZOmm,SIJ7

8auóla/¡lgewe/;e Ng.

Sp.SQ.Z,S./,Smm

Figure 8

Composite Column with Solid Steel Core (Boll and Vogel1969,260)

Simplified Design Method of Eurocode 4 forComposite Columns

The simplified design method of Eurocode 4 is basedon the method developed at Bochum University by(Roik et al. 1976). Similar to Emperger's Addition-Law, the ultimate load of a composite column is:

Npl.Rd =A/Yd + Aca/cd + A/'d

where fYdis the yield strength of the structural steel,

fCdis the compressive strength of the concrete and fSdis the yield strength of the reinforcing steel. Bucklingsafety is provided by a factor k, by which the ultimate

load has to be multiplied. The factor k is given byEuropean buckling curves of Eurocode 3. It has to beca!culated as a function of the non-dimensional

slendemess A..An even more simplified design method for

composite columns for the specific needs of

architects and structural engineers during pre-dimensioning was developed at Aachen U niversity by(Eggemann 2002). It determines the factor k as a

function of the slenderness ratio L/R, where L is thelength of the column and R is the effective radius ofgyration. Furtherrnore, numerous means are provided

to ca!culate the effective radius of gyration of acomposite column with the radius of the steel sectionmultiplied by a correction factor a.

..,' ..28',"Corridor

'.J" IIJII 41

34. 1118 .10 18 26

Offíce Space *y

17 25 33 4Q

BUILDING CASE HISTORIES

DeveJopment of composite coJumns. Emperger's etfort 793

The application of composite columns, especially ofthe Emperger type, is illustrated in this paragraph bytwo old buildings and one recent example.

McGraw-Hill Building, Chicago 1929Architect: Thielbar & Fugard, ChicagoEngineer: James B. Black, Chicago

The McGraw-Hill Building in Chicago, Figure 9, wasbuiltin 1929.lt was 30to 38 m (lOOto \25 ft.) in planand 58 m (190 fI.) high with 16 storeys over ground,confer to typical floor plan, Figure 10. Emperger-Columns were used with a sol id core of cast-iron:

Cored Concrete C01umns- To conserve space thedesigners adopted a composite column known as theEmperger type, in which the use of a solid cast-iran core

'1

1,11~\',,!If~.

I~~ ~f "pt~

~Ir~ .,.~',

,

,

'

,,

'."

,

'

1

'.

;

',

~

,

',

,d í .-~C

íll

~ ú'-:;

,

.

'

1,

,,

:,'

,

' !

,

",

',

,.'

.

11"' t j'~,

l

í,1 .."1

,

',", ,; H

,', "", ~~"". 'C~l""tU.I "1111::,,<1

Figure 9

McGraw-Hill Building, Chicago 1929 (ENR 1929, 129)

permits a relatively smalI cross-section. The core is

supplemented by the usual vertical bars and spiral

reinforcement (ENR 1929, 129).

In designing the McGraw-HilI Building, the columns were

made of uniform section (24 and 26 in. square [61 and 66cm]) from basement to roof for economy, convenience

and rapidity in construction . . . The variation in carryingcapacity was obtained by reducing the cast-iron cores

gradualIy fram 12ft to 3 in. [32.4 to 7.6 cm] in diameter.

For the upper floors, where cores were not needed,

standard hooped concrete was used (ENR J930, 277).

A special detail of a column joint was developed,Figure 11. The cores were milled to be truly square

with the axis. Each core extended 5 in. (12.7 cm)above floor level, then a pipe sleeve was placed overthe coreo The pipe was filled with grout and the nextcore was set into the pipe, adjusted and fixed in theformwork before the comete was poured.

One curiosity has to be mentioned: In 1998 thebuilding was demolished and by 2000 it had been

~---.~'. -."--"54~'.~ ~:~-'-~.--~~~~~l~ :~~..-~ -. --4S19f'. -".-

TIí LOflme-" 32 39

:;]"46

,< i

~1'"'!

1I

: L': ó

CourtAbove Jrd Floor

45

">,,,,

.9

'"~43

Mic.higan Ave.

Figure 10

Typical Floor Plan, McGraw-Hill Building (ENR 1929, 130)

794

Figure 11Detail of Column-Joint in McGraw-Hill Building (ENR1929, 130)

rebuilt with the original facade attached to a newstructure. The feat was demanded by preservationistsand City Hall. The lower part of the building nowcontains a shopping mall, where one can see largeLego models ofthe building itself and five others, e.g.

Chicago's Sears Tower and John Hancock Center(skyscrapers 2002).

Telephone-Factory, Budapest 1930Architect: N. N.Engineer: Béla Enyedi, Budapest

The Telephone-Factory in Budapest, Hungary, is oneof the few documented buildings in Europe designedwith Emperger-Columns. Built in 1930, it has got aframed structure with a column spacing of about 5,60m square. For the reason of transparency and cableassembly, the structure was built 'without floor-beams, using flared heads instead, Figure 12. To

achieve the smallest possible column proportions-the company wanted columns of less than 40 cmsquare with the option of adding another storey-the

columns were designed according to the Empergertype, but with a core of mild steel instead of cast-iron:

«[Es] wurden umschnürte Stützen mit steifen

FluBeiseneinlagen, System Dr. Emperger, gewahlt»(Enyedi 1931, 242). The columns were made of

octagonal sections, 39 cm in view, and with a stronghooping (spiral reinforcement). The columns on the

basement, made of ordinary reinforced concrete, 66

cm square, had more than double the cross-sectionarea, Figure 13.

H. Eggemann

Figure 12View in First Floor of Telephone-Factory, Budapest (Enyedi1931,244)

o;C'Ji

2Q....! i

wr; ',1Qi'.1MSchnitt mz-m2

-rI}¡-.39

_.r!1.L

60,60""'S"

~"'

@""'"''

"-

,

'

.

'. .. ,

'

y< :8i./ : 39""[

~ ~

~;

~..

1o.f/\.1Q~

Schnitt m,-m,

_r:!!L,66_.-I!1L

j6.~~Qf

..M

1§~:'J~~~'

t:::J"f.,Í<_..6.L¡

~_LOQ~

Figure 13

Column Section of Telephone-FactOry, Budapest (Enyedi1931, 243)

Development of composite columns. Emperger' s effort 795

Millenium-Tower, Vienna 1999Architect: Peichl, Podrecca and Weber, InnsbruckEngineer: Tschemmernegg, Obholzer and Baumann,

Innsbruck

The 50-storey Millenium Tower in Vienna is thetallest building in Austria, with a height of 202 m,Figure 14. After construction had been started in1998, it took less than one year until its completion in

1999. The structure consists of a reinforced concretecore, while composite construction was used for theceilings and columns in the office areas(Tschemmernegg 1999, 607). The exterior columns

are made of comete filled hollow sections with solidsteel cores, Figure 15. The columns themselves havea diameter of 406.4 mm fram first to 14th floor and323.9 mm above. The cores were gradually reduced

Figure 14Millenium Tower under Construction 1999 (Tschemmemegg

1999,610)

Figure 15

Composite Column with Solid Steel Core, Millenium Tower(Angerer, Rubin and Taus 1999,642)

fram 220 mm to 85 mm, and above the 39th floor nocores were needed. Euracode 4 was used for thedesign of both structure and fire-resistance. Shearconnection between concrete and structural steel wasrealised by special nails.

ABSTRACT AND CONCLUSION

During the first half of the 20th century a lot of

research was done on composite columns. Thecombination of materials had different motivations,steel columns were often encased in concrete topratect them fram fire, while concrete columns were

combined with structural steel as a reinforcement.In 1911 the Austrian engineer Fritz von Emperger

(1862-1942) applied for a patent on the later so-called Emperger-Column, granted in 1916. Thiscolumn was made of a hollow cast-iran sectionembedded in spiral-reinforced concrete. Until the1930s, this type of column had been used in severalbuildings in the United States, one of them beeing the

30-storey Trustees Building in Chicago. In theKrolick-Warehouse in Detrait, columns reached aload-bearing capacity of 9 MN.

In 1932 Emperger gave a report on compositecolumns at the First Congress of the InternationalAssociation for Bridge and Structural Engineering.He mentioned more than 1500 tested specimens inEurope and North America, among those were 138

tests done by himself. Emperger classified four

different types of composite colurnos. The load

796

carrying capacity of a composite column was given

according to the Addition-Law drawn up byEmperger, as the sum of the strength of the steel

increased by that of the concrete.Emperger complained about the lack of design

rules for composite columns in Europe. He mentionedthe American building regulations, which gaveexplicit formulas for both the Emperger-Column andthe steeI column encased in concrete: «Für die beiden

. . . Saulenformen bestehen in keinem europaischenStaate Vorschriften [There are no regulations forthese two types of columns in any of the Europeancountries]» (Emperger 1931, 265). The researchprogram of (Gehler and Amos, 1936) led to the first

german building regulations for composite columns,

defined in the German code for reinforced concrete,DIN 1045, in 1943.

It can be said that Emperger was not only a pioneer

in concrete construction, but also a pioneer incomposite construction. Emperger' s influence on the

construction is obvious. His Addition-Law can still befound in the design method of today's Eurocode 4,and the composite column type of an encased solidsteel core used e.g. in the construction of Vienna'sMillenium Tower, reminds us of the so-calledEmperger-CoJumn and can be accounted to be its

successor.

REFERENCE LIST

ACI. 1920. American Concrete Institute. Standard

Specifications No. 23. Standard Building Regulations for

the Use of Reinforced Concrete. in: Proceedings. ACI.

Vol. 16: 283-302.

ACI. 1928. American Concrete Institute. Tentative Building

Regulations for Reinforced Concrete (E-IA-28T). in:

Proceedings. ACI. Vol. 24: 791-828.

Angerer. T.. D. Rubin. and M. Taus. 1999. Verbundstützen

und Querkraftanschlüsse beim Millenium Tower.

Stahlbau 68: 641-46.

Bauer. Bruno. 1930. Eine neuartige Herstellung vonEisenbetonbauten. Beton u. Eisen 29: 3] 2-15.

BolI. K.. and U. Vogel. 1969. Die Stahlkernstütze und ihreBemessung. Bautechnik 46: 253-62, 303-09.

Bonzel. J.. H. Bub. and P. Funk. 1972. ErHiuterungen zu den

Stahlbetonbestimmungen. Band. I, 7. Auflage. Berlin,

München. Düsseldorf: Wilhelm Ernst & Sohn.

DlN 1045. 1943. A. Bestimmungen für die Ausführung von

Bauwerken aus Stahlbeton. 4. Ausg. 1943. Berlin: Beuth

1943.

H. Eggemann

DlNV ENV 1994-1-1. Eurocode 4: Bemessung und

Konstruktion von Verbundtragwerken aus Stahl und

Beton Teil ]-1: AlIgemeine Bemessungsregeln -Bemessungsregeln für den Hochbau. Februar 1994.

Eggemann. Ho]ger. 2002. Vereinfachte Bemessung von

Verbundstützen im Hochbau. Entwicklung, historische

Bemessung und Her]eitung eines Naherungsverfahrens.

Dr.-Ing. diss.. Aachen University.

Emperger. Fritz von. 1907a. Drei Versuche mit

Eisenbetonsaulen. Beton u. Eisen 6: ]01-04.

-. 1907b Welche statische Bedeutung hat die Einbetonierungeiner Eisensaule? Beton u. Eisen 6: 172-74.

-. 1908. Versuche mit Saulen aus Eisenbeton und miteinbetonierten Eisensaulen in Stuttgart und Wien.

Forscherarbeiten auf dem Gebiete des Eisenbetons. Heft

VIII. Berlin: Wi]helm Ernst & Sohn.

-. 1913. Neuere Bogenbrücken aus umschnürtemGuBeisen, System Dr. Ing. Fritz Edler von Emperger.

Berlin: Wilhelm Ernst & Sohn.

-. ]930. Der Wettbewerb zwischen Eisen und Eisenbeton

im Hochbau. Zentralblatt der Bauverwaltung 50.

Supplement «Konstruktion und Ausführung»: K81-84.

-. 193 la. Die Saule im amerikanischen Hochhausbau.Beton u. Eisen 30: 264--65.

-. 1931b. Die umschnürte Stahlsaule. Stahlbau 4: 188-89.

-. 1932. Verbundsaulen. in: First Congress ofInternationaJAssociation for Bridge and Structural Engineering.Zurich. IABSE. Preliminary Publication. Vol 1: 595-6] 6.

ENR. ]929. Cast-Iron Cores used in Co]umns of 16-Storey

Concrete Building. Engineering News-Record, Ju]y 25:

129-31.ENR. 1930. Reinforced-Concrete Co]umns with Cast-lron

Cores. Engineering News-Record, Feb. 13: 277-78.Enyedi, Béla. 1931. Telephonfabrikgebaude bei Budapest.

Beton u. Eisen 30: 241-45.Geh]er. Willy. ] 933. Erlauterungen zu den Eisenbeton-

Bestimmungen 1932 mit Beispie]en. 5. neub. u. erg. Autl.

Berlin: Wilhelm Ernst & Sohn.

Gehler. W.. and H. Amos. 1936. Versuche an Saulen mitWalzprofilbewehrung. Deutscher AusschuB für

Eisenbeton. Heft 8]. Berlin: Wilhelm Ernst & Sohn.

Kleinlogel. A. ] 932. Zum 70. Geburtstage F. von

Empergers. Beton u. Eisen 31: 1-4.

Krapfenbauer. R. 1976. Die Verwenduug von

Kernb]ockstützen beim Neubau des AlIgemeinen

Krankenhauses in Wien. Bauingenieur 51: 307-]0.Memm]er. K., G. Bierett. and G. Grüning. 1934.

Tragfahigkeit von Stah]stützen mit Betonkern bei

mittigem Kraftangriff. Stah]bau 7: 49-53. 61-64.

Mensch. L. J. 1930. Composite Columns. Journal. ACI. No.

23. Nov. ]930: 263-80.

Mbrsch. Emi1. []902] ]9]2. Der Eisenbetonbau seine

Theorie und Anwendung. 4. vollst. neu bearb. und verm.

Aufl. Stuttgart: Konrad Wittwer.

Development of composite columns. Emperger' s etfort

Offenlegungsschrift Nr. 1559482. DeUtsches Patentamt.

Dipl.-Ing. Kuno Bol1, Stuttgart. Stahlkernstützen.

Offenlegungstag: 5. Marz 1970.

Patentschrift Nr. 291068. Kaiserliches Patentamt. Dr.-Ing.

Fritz von Emperger in Wien. Hohle GuBeisensaule mit

einem Mantel aus umschnürtem Beton. Patentiert im

Deutschen Reiche vom 24. Ianuar 1911 ab.Roik, K., R. Bergmann, H. Bode, and G. Wagenknecht.

1976. Tragfahigkeit von einbetonierten Stahlstützen.

lnstitut für konstruktiven lngenieurbau, Bochum

University, Mitteilung 76-4.

797

Saliger, Rudolf. 1931. Versuche an betonumschnürten

Stahlsaulen. Bauingenieur 12: 255-58, 282-86.Skyscrapers. 2002. www.skyscrapers.comlengJish/worldmap/

building/0.9/ I 02644/index.html

Tschemmernegg, F. 1999. Innsbrucker Mischbautechnologie

im Wiener Millenium-Tower. Stahlbau 68: 606--1].Viest,1. M., I. P. Colaco, R. W. Furlong, L. G. Griffis, R. T.

Leon, and L. A. Wyl1ie Ir. 1997. Composite Construction

Design for Buildings. New York: McGraw-Hill and

ASCE.