10.5 Axial Compression Test
331
600
140
Diagonal
shear
failure
zone
1974
Failure plane
Axis
1200
1630
Diagonal shear failure zone
1977
Failure plane
Axis
(a)
(b)
Fig. 10.8 Failure mode of intact columns under axial compressive load a I-8 b I-9 (unit mm),
reprinted from Wang et al. (2020a, b), copyright 2020, with permission from Elsevier
with each other very well, including the linear ascending stage, the short platform
stage and the following fast descending stage. The maximal bearing capacity of the
two columns are 4713 kN (I-8) and 4588 kN (I-9) with the corresponding difference
of 2.7%. In Fig. 10.9b, it can be found that there exists a certain deviation in the
initial ascending stage for the two columns, probably due to the relatively larger
initial eccentricity of I-9 column compared with I-8 column. However, in terms of
their axial load capacity and failure modes, such discrepancy can be neglected, and
the present axial compression test can be regarded repeatable.
The axial capacity of present UHPCC-FST columns is also evaluated by the
existing design codes of CFST column, including the American AISC360 code
(AISC) (AISC Committee 2010), European Eurocode-4 code (EUROCODE-4) (EN
1994-1-1 2004.) and Chinese GB50936 code (GB50936-2014 2014). Table 10.3
lists the calculated and averaged experimental axial capacity of present UHPCCFST column. It is clearly shown that, the predictions of EUROCODE-4 agrees well
with the experimental results. The axial load capacity obtained from AISC code is
lower than the experimental result, probably because the confining effect of steel
tube on the core UHPCC is not fully taken into account. Besides, the calculated axial
capacity from the Chinese standard GB50936 is much larger than the test result.
According to the Chinese Standard GB50936, the confining coefficient of steel tube
for CFST column is suggested to be 0.5–2.0, while the actual confining coefficient for
the present UHPCC-FST column is determined as 0.306 based on GB50936. Besides,
the maximum compressive strength of core concrete recommended in GB50936 is
80 MPa, which is much lower than that of present UHPCC.
331
600
140
Diagonal
shear
failure
zone
1974
Failure plane
Axis
1200
1630
Diagonal shear failure zone
1977
Failure plane
Axis
(a)
(b)
Fig. 10.8 Failure mode of intact columns under axial compressive load a I-8 b I-9 (unit mm),
reprinted from Wang et al. (2020a, b), copyright 2020, with permission from Elsevier
with each other very well, including the linear ascending stage, the short platform
stage and the following fast descending stage. The maximal bearing capacity of the
two columns are 4713 kN (I-8) and 4588 kN (I-9) with the corresponding difference
of 2.7%. In Fig. 10.9b, it can be found that there exists a certain deviation in the
initial ascending stage for the two columns, probably due to the relatively larger
initial eccentricity of I-9 column compared with I-8 column. However, in terms of
their axial load capacity and failure modes, such discrepancy can be neglected, and
the present axial compression test can be regarded repeatable.
The axial capacity of present UHPCC-FST columns is also evaluated by the
existing design codes of CFST column, including the American AISC360 code
(AISC) (AISC Committee 2010), European Eurocode-4 code (EUROCODE-4) (EN
1994-1-1 2004.) and Chinese GB50936 code (GB50936-2014 2014). Table 10.3
lists the calculated and averaged experimental axial capacity of present UHPCCFST column. It is clearly shown that, the predictions of EUROCODE-4 agrees well
with the experimental results. The axial load capacity obtained from AISC code is
lower than the experimental result, probably because the confining effect of steel
tube on the core UHPCC is not fully taken into account. Besides, the calculated axial
capacity from the Chinese standard GB50936 is much larger than the test result.
According to the Chinese Standard GB50936, the confining coefficient of steel tube
for CFST column is suggested to be 0.5–2.0, while the actual confining coefficient for
the present UHPCC-FST column is determined as 0.306 based on GB50936. Besides,
the maximum compressive strength of core concrete recommended in GB50936 is
80 MPa, which is much lower than that of present UHPCC.