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There are several outstanding examples of high rise buildings using high strength materials around the
world, both existing and under construction or consideration. In Seattle, Washington, the Pacific First
Centre (44 storeys) and Two Union Square (62 storeys) buildings employ concrete with compressive
strength of 115 MPa; mainly used for its high modulus of elasticity of 50,000 MPa. These are extreme
examples. More commonly used high strength concrete mixes are represented by the Two Prudential
Plaza (281 m) and 311 South Wacker Drive (295 m) buildings (both in Chicago, Illinois), which use a
mix with compressive strength of over 80 MPa. Outside the US, the Miglin-Beiter building (Frankfurt,
Germany) has a 610 m height and concrete of 97 MPa compressive strength. In addition, the Petronas
Towers (Kuala Lampur, Malaysia) (450 m) employ concrete of compressive strength of 80 MPa for
the lower stories; while the BfG building (186 m), in Frankfurt, Germany, goes up to 85 MPa.
Development of high yield steel for general construction lagged behind that of concrete. Only in the
early 1990s was there widely available high yield steel, mainly from Japanese steel manufacturers,
with yield strength above 1000 MPa being tested and used. This has had an effect on high strength
materials construction economics because the decrease in column dimensions would lead to an
increase in required steel area, unless high yield steel is used.
REVIEW OF PREVIOUS STUDIES
Whereas several research projects have been concerned with the experimental behaviour of reinforced
concrete members with high strength concrete and high yield steel, very few have applied loading and
boundary conditions relevant to earthquake response. Furthermore, none of the previous projects
comprehensively and systematically addressed the range of concrete compressive strength,
longitudinal steel yield stress, transverse steel yield stress and confining steel spacing. Though, it is
noted that such early studies were most valuable in establishing trends and alerting designers to serious
issues which may affect seismic safety. In Table 1, the ranges covered by tests conducted by various
researchers are presented: the light shading indicates testing under axial force only (including eccentric
loading); the darker shade indicates combined axial-flexural loads; and blank areas were not
previously tested.
TABLE 1
RANGE OF TEST PARAMETERS FOR STEEL AND CONCRETE
(Letters allude to references, below Table 2)
f c^or f y -> (MPa)
60-80
80-100 _,
100-120
>120
300-500
a,c,d,f,l,m
cJOr
b,c,d,jq,r
b,r
500-700
d
k,p
b,d,p
b
700-900
' d
k
d
900-1100
m
>1100
With regard to confining steel characteristics and spacing tested, as identified from the published
literature, these are indicated in Table 2.