1 Introduction
2 Experimental Program
2.1 Configuration of Two-Way Donut-Type Voided Slab Specimens
ID | Length × width × height (mm) | Clear span (mm) | Effect depth (mm) | Top rebar | Bottom rebar | Reinforcement ratio (%) | Void former | Fixing method type | ||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
X-dir. | Y-dir. | X-dir. | Y-dir. | X-dir. | Y-dir. | Shape | Material | |||||
Solid | 3300 × 3300 × 250 | 2850 × 2850 | 217.3 | 20-D10 | 20-D13 | 0.353 | – | – | – | |||
TF–D–S–P.P | Donut | P.P | Spacer | |||||||||
TF–D–M–P.P | 0.353 [0.40] | 0.353 | Merged |
2.2 Specimen Materials
Cylinder test result | Design strength | W/C (%) | S/a (%) | Weight ratio (kg/m3) | ||||
---|---|---|---|---|---|---|---|---|
Water | Cement | Sand | Coarse aggregate | Admixture | ||||
24.2 | 24 | 56.6 | 47.4 | 193 | 341 | 837 | 985 | 1.7 |
Rebar type | Nominal strength (MPa) | Yield strength (MPa) | Yield strain (%) | Tensile strength (MPa) | Elongation (%) | Elastic modulus (GPa) |
---|---|---|---|---|---|---|
D10 | 400 | 469 | 0.20 | 648 | 17.36 | 196.1 |
D13 | 400 | 473 | 0.24 | 665 | 18.21 | 194.3 |
D6 | 440 | 528 | 0.26 | 675 | 15.28 | 205.8 |
2.3 Loading and Measurement Set-Up
2.4 Estimation of Load Bearing Capacity of Two-Way Slab Specimens
3 Test Results and Discussion
3.1 Global Failure Behavior
3.2 Load Bearing Capacity
ID | Calculation | Test results | Comparison | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
P
n
kN | I
e
× 106 mm4 | P
cr
kN | δ
cr
mm | P
y
kN | δ
y
mm | P
u
kN | δ
u
mm |
μ
| K kN/mm |
\( \frac{P_{u} }{P_{n} } \)
|
\( \frac{{P_{u} }}{{P_{u,Solid} }} \)
|
\( \frac{K}{K_{Solid} } \)
|
\( \frac{I_{e} }{I_{e,Solid} } \)
| |
Solid | 1119 | 2101 | 205.9 | 1.53 | 824.1 | 12.95 | 1238.5 | 56.60 | 4.4 | 5.27 | 1.10 | – | – | – |
TF–D–S–P.P | 1643 | 170.8 | 1.45 | 823.3 | 17.77 | 1172.5 | 60.69 | 3.4 | 6.85 | 1.05 | 0.95 | 0.73 | 0.78 | |
TF–D–M–P.P | 1172 | 1798 | 284.7 | 2.78 | 847.8 | 17.16 | 1225.1 | 70.50 | 4.1 | 6.54 | 1.05 | 0.99 | 0.78 | 0.86 |