1.2 Test Program
3
mixture proportions are given in Table 1.1. Chinese standard Graded 52.5 P.II type
Portland cement (20 ~ 30 µm in particle diameter) from Xiaoyetian corporation,
silica fume (particle size of 0.10 ~ 0.26 µm, density of 2.1 g/cm
3 , specific surface
area of 20500m
2 /kg) from Elkem company and ultra-fine mineral admixture (density
of 2.45 g/cm
3 , specific surface area of 8500m
2 /kg, 28d activity index of 115%) from
SBT
® -HDC (V) are used as the cementitious materials. Table 1.2 lists the chemical
composition of cement and silica fume. The water-to-cementitious materials (W/CM)
ratio and HRWR-to-cementitious materials ratio are 0.16 and 0.024, respectively. Six
volume fractions (0, 0.5, 1.0, 1.5, 2.0 and 2.5%) of two typical steel fibers, including
micro-straight (diameter of 0.2 mm, length of 13 mm, tensile strength of 2800 MPa)
and hooked (diameter of 0.5 mm, length of 25 mm, tensile strength of 1200 MPa) are
incorporated, as shown in Fig. 1.1. The water-reducing ratio of the PCA
® -I polycarboxylic type HRWR is no less than 35%, which is developed by Jiangsu SOBUTE
new material Co., Ltd.
Compared with the traditional high performance concrete, the ground fine quartz
sand (the size is less than 0.6 mm) is substituted by easily obtained natural river
sand (maximal diameter of 2.5 mm). Also the partial silica fume is replaced by the
ultra-fine mineral admixture which includes fly ash and ultra-fine slag (the specific
proportions is undisclosed for commercial confidentiality). Since the production of
cement and fine quartz sand consumes much more energy and resources, and the silica
Table 1.1 Mixture proportions of UHPCC (kg/m 3 )
Cement
Silica fume
Ultra-fine mineral
admixture
Sand
Water
HRWR
Fiber content
700
140
110
1200
152
22.8
0 ~ 195
Table 1.2 Chemical composition of cement and silica fume
Composition
CaO
SiO
MgO
Fe 2 O 3
Al 2 O 3
SO 3
LOI
Cement
61.80
20.00
5.31
3.46
4.64
3.15
2.44
Silica fume
1.00
93.10
0.65
2.44
0.76
0.12
1.04
Fig. 1.1 Steel fibers a micro-straight b hooked c comparison, reprinted from Ren et al. (2018),
copyright 2020, with permission from Elsevier
3
mixture proportions are given in Table 1.1. Chinese standard Graded 52.5 P.II type
Portland cement (20 ~ 30 µm in particle diameter) from Xiaoyetian corporation,
silica fume (particle size of 0.10 ~ 0.26 µm, density of 2.1 g/cm
3 , specific surface
area of 20500m
2 /kg) from Elkem company and ultra-fine mineral admixture (density
of 2.45 g/cm
3 , specific surface area of 8500m
2 /kg, 28d activity index of 115%) from
SBT
® -HDC (V) are used as the cementitious materials. Table 1.2 lists the chemical
composition of cement and silica fume. The water-to-cementitious materials (W/CM)
ratio and HRWR-to-cementitious materials ratio are 0.16 and 0.024, respectively. Six
volume fractions (0, 0.5, 1.0, 1.5, 2.0 and 2.5%) of two typical steel fibers, including
micro-straight (diameter of 0.2 mm, length of 13 mm, tensile strength of 2800 MPa)
and hooked (diameter of 0.5 mm, length of 25 mm, tensile strength of 1200 MPa) are
incorporated, as shown in Fig. 1.1. The water-reducing ratio of the PCA
® -I polycarboxylic type HRWR is no less than 35%, which is developed by Jiangsu SOBUTE
new material Co., Ltd.
Compared with the traditional high performance concrete, the ground fine quartz
sand (the size is less than 0.6 mm) is substituted by easily obtained natural river
sand (maximal diameter of 2.5 mm). Also the partial silica fume is replaced by the
ultra-fine mineral admixture which includes fly ash and ultra-fine slag (the specific
proportions is undisclosed for commercial confidentiality). Since the production of
cement and fine quartz sand consumes much more energy and resources, and the silica
Table 1.1 Mixture proportions of UHPCC (kg/m 3 )
Cement
Silica fume
Ultra-fine mineral
admixture
Sand
Water
HRWR
Fiber content
700
140
110
1200
152
22.8
0 ~ 195
Table 1.2 Chemical composition of cement and silica fume
Composition
CaO
SiO
MgO
Fe 2 O 3
Al 2 O 3
SO 3
LOI
Cement
61.80
20.00
5.31
3.46
4.64
3.15
2.44
Silica fume
1.00
93.10
0.65
2.44
0.76
0.12
1.04
Fig. 1.1 Steel fibers a micro-straight b hooked c comparison, reprinted from Ren et al. (2018),
copyright 2020, with permission from Elsevier