The Structural Systems oF Tall Buildings - Tall Buildings: Structural Systems and Aerodynamic Form - page 15

Figure 3.1

Ingalls Building, Cincinnati, USA, 1903

(b)

(a) (c)

Figure 3.2

Composite elements by cross-section

(New York, 1930), Seagram Building (New York, 1958)), they began to be used
frequently after the 1970s.
Composite buildings, consisting of structural system elements that are part
reinforced concrete, part steel and/or with some elements in which both steel and
reinforced concrete have been used, combine the advantages of both materials, such
as the high-strength of steel, and the fire resistance and rigidity of reinforced concrete.
There are differences in the cross-sections of composite elements ( Figure 3.2 ).
Box-section structural steel elements filled with reinforced concrete (concrete infilled
steel sections/steel encased concrete sections) ( Figure 3.2a ), structural steel elements
with reinforced concrete between their flanges ( Figure 3.2b ) and structural steel
sections encased in reinforced concrete (concrete encased steel sections) ( Figure 3.2c )
are all seen as elements of a composite structural system.
In 2004, the 508 m high Taipei 101 (Taipei) ( Figure 3.36 ), with a composite struc-
tural system, took the title of “the world's tallest building” from the Petronas Towers
( Figure 3.31 ), which has a reinforced concrete structural system. The Taipei 101 is the
first composite building to gain the title of the world's tallest.
With the use of high-strength concrete (compressive strength above 30 MPa) in the
828 m high reinforced concrete Burj Khalifa (Dubai, 2010) (compressive strength of
80 MPa); 452 m high reinforced concrete the Petronas Twin Towers (Kuala Lumpur,
1998) (compressive strength of 80 MPa) and 421 m high, composite Jin Mao Building
(Shanghai, 1999) (compressive strength of 52 MPa), the cross-sectional areas of