10.3 UHPCC-FST Columns
325
Table 10.2 UHPCC ingredients (kg/m 3 )
Cement
Admixture (fly ash and ultra-fine slag)
Sand
Steel fiber
HRWR
Water
700
250
1200
156
22.8
152
10.3.3 UHPCC
UHPCC material was prepared by State Key Laboratory of High Performance Civil
Engineering Materials, Jiangsu Research Institute of Building Science in China. The
mixing portion of UHPCC is given in Table 10.2, mainly including the Chinese
standard Graded 52.5 P.II type Portland cement (20–30 µm in particle diameter),
the natural river sand with maximal diameter of 2.5 mm, polycarboxylic type highrange-water-reducer (HRWR) with the water-reducing ratio larger than 35% and the
admixture. The admixture is consisted of fly ash (density of 2.7 g/cm
3 ) and ultra-fine
slag (particle size of 3–6 µm, density of 2.8 g/cm
3 ), and the specific proportions
of the admixture is confidential for commercial security. The straight brass-coated
steel fiber was incorporated with the volume fraction of 2.0%, the equivalent diameter, length and tensile strength of which were 0.175 mm, 13 mm and 3000 MPa,
respectively. The slump and spread of UHPCC were about 230 mm and 610 mm
respectively, which guaranteed the workability requirements of on-site constructions.
The present UHPCC was identical with that in our previous works (Ren et al.
2016, 2017, 2018; Wu et al. 2018), in which a series of uniaxial and triaxial static
and dynamic compressive and spalling tensile tests were conducted to study the
mechanical properties of UHPCC with various types and volumetric ratios of steel
fibers. Also, the mixing and curing procedure are introduced in details.
The control specimens of UHPCC, including three cubes of 100 × 100 × 100
mm
3 and three prisms of 100 × 100 × 300 mm
3 , were cast and tested according to
the Chinese standard (GB/T 50081-2002 2003). Due to the lack of relevant common
standards, the unnotched dog-bone specimens with an overall length of 500 mm
referring to Kang and Kim 2011 were used in the direct tension test. The average
cubic compressive strength, axial compressive strength, direct tensile strength, elastic
modulus and Poisson’s ratio of UHPCC are determined as 131.5 MPa, 121 MPa,
9 MPa, 42.9 GPa and 0.23, respectively.
10.4 Field Contact Explosion Test
10.4.1 Test Setup
The field blast test was conducted at the field laboratory of China Academy of
Engineering Physics, and the test setup is shown in Fig. 10.3a and b. Considering
that the axial compression ratio of most bridge columns is relatively low under
325
Table 10.2 UHPCC ingredients (kg/m 3 )
Cement
Admixture (fly ash and ultra-fine slag)
Sand
Steel fiber
HRWR
Water
700
250
1200
156
22.8
152
10.3.3 UHPCC
UHPCC material was prepared by State Key Laboratory of High Performance Civil
Engineering Materials, Jiangsu Research Institute of Building Science in China. The
mixing portion of UHPCC is given in Table 10.2, mainly including the Chinese
standard Graded 52.5 P.II type Portland cement (20–30 µm in particle diameter),
the natural river sand with maximal diameter of 2.5 mm, polycarboxylic type highrange-water-reducer (HRWR) with the water-reducing ratio larger than 35% and the
admixture. The admixture is consisted of fly ash (density of 2.7 g/cm
3 ) and ultra-fine
slag (particle size of 3–6 µm, density of 2.8 g/cm
3 ), and the specific proportions
of the admixture is confidential for commercial security. The straight brass-coated
steel fiber was incorporated with the volume fraction of 2.0%, the equivalent diameter, length and tensile strength of which were 0.175 mm, 13 mm and 3000 MPa,
respectively. The slump and spread of UHPCC were about 230 mm and 610 mm
respectively, which guaranteed the workability requirements of on-site constructions.
The present UHPCC was identical with that in our previous works (Ren et al.
2016, 2017, 2018; Wu et al. 2018), in which a series of uniaxial and triaxial static
and dynamic compressive and spalling tensile tests were conducted to study the
mechanical properties of UHPCC with various types and volumetric ratios of steel
fibers. Also, the mixing and curing procedure are introduced in details.
The control specimens of UHPCC, including three cubes of 100 × 100 × 100
mm
3 and three prisms of 100 × 100 × 300 mm
3 , were cast and tested according to
the Chinese standard (GB/T 50081-2002 2003). Due to the lack of relevant common
standards, the unnotched dog-bone specimens with an overall length of 500 mm
referring to Kang and Kim 2011 were used in the direct tension test. The average
cubic compressive strength, axial compressive strength, direct tensile strength, elastic
modulus and Poisson’s ratio of UHPCC are determined as 131.5 MPa, 121 MPa,
9 MPa, 42.9 GPa and 0.23, respectively.
10.4 Field Contact Explosion Test
10.4.1 Test Setup
The field blast test was conducted at the field laboratory of China Academy of
Engineering Physics, and the test setup is shown in Fig. 10.3a and b. Considering
that the axial compression ratio of most bridge columns is relatively low under