1 Introduction
2 Material Properties and Preparation for Test
2.1 Cement, Substitutive Cementitious Materials and Filler
Component | OPC | SF | FA | QP | RS | NS |
---|---|---|---|---|---|---|
CaO | 66.1 | 0.95 | 2.53 | 0.27 | 21.2 | 2.06 |
SiO2 | 19.0 | 92.6 | 66.2 | 97.9 | 54.7 | 71.4 |
Al2O3 | 4.83 | 0.36 | 20.4 | 0.51 | 11.0 | 12.7 |
SO3 | 2.17 | 0.81 | – | – | 0.91 | 0.17 |
Fe2O3 | 3.68 | 0.96 | 4.72 | 0.05 | 4.27 | 4.39 |
MgO | 2.19 | 1.03 | 0.99 | – | 1.75 | 2.16 |
K2O | 1.07 | 2.16 | 0.73 | 0.01 | 3.17 | 4.18 |
TiO2 | 0.26 | – | 0.94 | 0.13 | 0.46 | 0.57 |
Na2O | 0.11 | 0.64 | 0.37 | – | 1.91 | 1.91 |
P2O5 | 0.14 | 0.15 | 0.64 | 1.06 | 0.15 | 0.15 |
2.2 Fine Aggregates
Type | BSGSSD | BSGOD | UW (kg/m3) | WA (%) | FM | Void ratio (%) | % passing 0.08-mm sieve |
---|---|---|---|---|---|---|---|
NS | 2.66 | 2.64 | 1709 | 0.93 | 3.09 | 35.3 | 2.65 |
RS | 2.46 | 2.34 | 1471 | 5.12 | 3.19 | 37.1 | 1.48 |
2.3 Fibers
2.4 Chemical Admixtures
2.5 Mixing
2.6 Casting and Method of Cure
2.7 Autogenous Shrinkage
3 Packing Density Test
3.1 Dry Packing Density Test with Recycled Sand
Index | Volume-base (unit: m3) | Mass-base (unit: kg/m3) | ||||||
---|---|---|---|---|---|---|---|---|
OPC | FA | RS | Total | OPC | FA | RS | Theoretical wt | |
D-RS-1 | 0.405 | 0.045 | 0.550 | 1.00 | 1276 | 113 | 1353 | 2741 |
D-RS-2 | 0.450 | 0.050 | 0.500 | 1.00 | 1418 | 125 | 1230 | 2773 |
D-RS-3 | 0.495 | 0.055 | 0.450 | 1.00 | 1559 | 138 | 1107 | 2804 |
D-RS-4 | 0.540 | 0.060 | 0.400 | 1.00 | 1701 | 150 | 984 | 2835 |
Index | Solid ratio | Void ratio | ||||
---|---|---|---|---|---|---|
Loose | Rodded | Vibrated | Loose | Rodded | Vibrated | |
D-RS-1 | 0.487 | 0.574 | 0.611 | 0.513 | 0.426 | 0.389 |
D-RS-2 | 0.470 | 0.557 | 0.584 | 0.530 | 0.443 | 0.416 |
D-RS-3 | 0.456 | 0.539 | 0.565 | 0.544 | 0.462 | 0.436 |
D-RS-4 | 0.441 | 0.522 | 0.546 | 0.559 | 0.479 | 0.454 |
3.2 Wet Packing Density Test with Recycled Sand
Index | Volume-base (m3) | ||||||
---|---|---|---|---|---|---|---|
OPC | FA | SF | QP | RS | W | Total | |
W-RS-1 | 0.260 | 0.029 | 0.072 | 0.000 | 0.442 | 0.196 | 1.0 |
W-RS-2 | 0.260 | 0.029 | 0.054 | 0.018 | 0.441 | 0.197 | 1.0 |
W-RS-3 | 0.260 | 0.029 | 0.036 | 0.036 | 0.441 | 0.199 | 1.0 |
W-RS-4 | 0.259 | 0.029 | 0.018 | 0.054 | 0.440 | 0.200 | 1.0 |
Index | Mass-base (kg/m3) | ||||||
---|---|---|---|---|---|---|---|
OPC | FA | SF | QP | RS | W | Theoretical wt | |
W-RS-1 | 820 | 72 | 161 | 0 | 1088 | 196 | 2337 |
W-RS-2 | 819 | 72 | 120 | 48 | 1086 | 197 | 2343 |
W-RS-3 | 818 | 72 | 80 | 96 | 1084 | 199 | 2348 |
W-RS-4 | 817 | 72 | 40 | 143 | 1082 | 200 | 2354 |
Index | Solid ratio | Void ratio | ||||
---|---|---|---|---|---|---|
Loose | Rodded | Vibrated | Loose | Rodded | Vibrated | |
W-RS-1 | 0.7748 | 0.7747 | 0.7866 | 0.2252 | 0.2253 | 0.2134 |
W-RS-2 | 0.7753 | 0.7767 | 0.7871 | 0.2247 | 0.2233 | 0.2129 |
W-RS-3 | 0.7868 | 0.7912 | 0.7934 | 0.2132 | 0.2088 | 0.2066 |
W-RS-4 | 0.7836 | 0.7815 | 0.7926 | 0.2164 | 0.2185 | 0.2074 |
3.3 Dry and Wet Packing Density Test Results with Natural Sand
Volume-base (m3) | Void ratio (solid ratio) | ||||||
---|---|---|---|---|---|---|---|
C | SF | QP | NS | W | Total | ||
W-NS-1 (Reference) | 0.283 | 0.018 | 0.053 | 0.432 | 0.214 | 1.0 | 0.215 (0.785) |
Mass-base (kg/m3) | |||||||
C | SF | QP | NS | W | Total | ||
891 | 39 | 141 | 1,158 | 214 | 2,443 |
4 UHPC/UHPFRC and Mechanical Properties
4.1 UHPC
Index | Mix design (kg/m3) | W/B | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
OPC | FA | SF | QP | RS | NS | W | SP | SSF | ||
NS-U-20 (W-NS-1) | 891 | – | 39.3 | 141 | – | 1150 | 214 | 42.9 | – | 0.20 |
NS-U-16 | 931 | – | 41.0 | 147 | – | 1201 | 179 | 44.8 | – | 0.16 |
RS-U-20 (W-RS-3) | 818 | 72.1 | 80.1 | 95.6 | 1084 | – | 199 | 42.6 | – | 0.20 |
RS-U-18 | 823 | 72.6 | 80.6 | 96.2 | 1092 | – | 193 | 42.9 | – | 0.18 |
RS-U-17 | 832 | 73.4 | 81.5 | 97.2 | 1104 | – | 184 | 43.4 | – | 0.17 |
RS-U-16 | 842 | 74.2 | 82.4 | 98.3 | 1116 | – | 175 | 43.9 | – | 0.16 |
RS-F-17-1.0 | 832 | 73.4 | 81.5 | 97.2 | 1104 | – | 184 | 48.8 | 78 | 0.17 |
RS-F-17-2.0 | 832 | 73.4 | 81.5 | 97.2 | 1104 | – | 184 | 48.8 | 156 | 0.17 |
RS-F-17-3.0 | 832 | 73.4 | 81.5 | 97.2 | 1104 | – | 184 | 48.8 | 234 | 0.17 |
RS-F-16-2.0 | 842 | 74.2 | 82.4 | 98.3 | 1116 | – | 175 | 49.3 | 156 | 0.16 |
4.1.1 Flowability of Fresh Mixtures
Type | UHPC | UHPFRC | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
NS-U-20 | NS-U-16 | RS-U-20 | RS-U-18 | RS-U-17 | RS-U-16 | RS-F-17–1.0 | RS-F-17–2.0 | RS-F-17–3.0 | RS-F-16–2.0 | |
No jolting | 23.9 | 11.4 | 24.9 | 16.9 | 14.1 | 14.0 | 13.1 | 13.8 | 11.5 | 10.5 |
Jolting | 25.4 | 13.6 | 25.4 | 22.1 | 18.6 | 16.8 | 18.5 | 18.0 | 16.0 | 13.7 |
4.1.2 Voids, Absorption and Density of Hardened Concretes
4.1.3 Compressive Strength
Index | Compressive strength | Flexural strength | Index | Compressive strength | Flexural strength | ||||
---|---|---|---|---|---|---|---|---|---|
7d | 28d | Elastic modulus | 7d | 28d | Elastic modulus | ||||
NS-U-20 | 60.2 | 90.1 | 43,773 | 11.1 | NS-U-16 | 63.7 | 112 | 48,043 | 13.5 |
RS-U-20 | 64.4 | 86.3 | 37,355 | 8.38 | RS-F-17-1.0 | 75.6 | 100 | 43,506 | 9.41 |
RS-U-18 | 65.0 | 87.4 | 35,544 | 10.6 | RS-F-17-2.0 | 84.5 | 128 | 46,867 | 11.9 |
RS-U-17 | 65.5 | 102 | 40,153 | 11.0 | RS-F-17-3.0 | 84.5 | 113 | 46,645 | 18.1 |
RS-U-16 | 60.7 | 97.4 | 41,231 | 8.12 | RS-F-16-2.0 | 89.6 | 108 | 47,502 | 14.0 |
4.1.4 Flexural Strength and fr/fc
4.2 UHPFRC
4.3 Elastic Modulus and Poisson’s Ratio
4.3.1 Elastic Modulus
4.3.2 Poisson’s Ratio
Index | RS-U-20 | RS-U-16 | NS-U-20 | NS-U-16 | RS-F-17–1.0 | RS-F-17–2.0 | RS-F-17–3.0 |
---|---|---|---|---|---|---|---|
Poisson’s ratio | 0.187 | 0.199 | 0.215 | 0.216 | 0.215 | 0.216 | 0.197 |
4.4 Autogenous Shrinkage
5 Discussion
5.1 Experimental Versus Theoretical Packing Density Approach
5.2 Effect of Using Recycled Sand on Microstructural Properties
5.2.1 Porosity (MIP)
Item | NS-U-16 | RS-U-16 | RS-F-17-2.0 |
---|---|---|---|
Total porosity (%) | 10.3 | 14.2 | 12.5 |
Average pore diameter (nm) | 14.2 | 18.7 | 20.3 |
5.2.2 SEM
5.3 Environmental Impacts and Economical Aspects
Input material | Database name | Published year | Source |
---|---|---|---|
OPC | Cement, Portland (ROW), Cut-off | 2018 | SimaPro 9.0 |
Silica fume | Silica fume, densified (GLO), Cut-off | 2018 | SimaPro 9.0 |
Quartz powder | Limestone, Crushed for mill (CH), Cut-off | 2018 | SimaPro 9.0 |
Water | Tap water(ROW), Cut-off | 2018 | SimaPro 9.0 |
Natural sand | Sand(GLO), Cut-off | 2018 | SimaPro 9.0 |
Recycled sand | Recycled sand | 2022 | Kim and Jang (2022) |