1 Introduction
2 Literature Review
2.1 Details of Blast-Resistant Structures
2.2 Deformation Criterion of Blast-Resistant Structures
Element type | Superficial (\( {\mu}_{max} ) \)
| Moderate (\( {\theta}_{max} ) \)
| Heavy (\( {\theta}_{max} ) \)
| Hazardous (\( {\theta}_{max} ) \)
|
---|---|---|---|---|
Single-reinforced slab or beam | 1 | 2° | 5° | 10° |
Single-reinforced beam-column | 1 | 2° | 2° | 2° |
Double-reinforced beam-column without shear reinforcement | 1 | 2° | 2° | 2° |
Double-reinforced beam-column with shear reinforcement | 1 | 4° | 4° | 4° |
2.3 Blast Loads
Variables | Explosion method | Material | Loaded weight |
---|---|---|---|
Bomblet | Small briefcase | M/CE | 2–4 kg |
Large briefcase | M/CE | 4–12 kg | |
Suitcase | M/CE | 12–22 kg | |
Bicycle | M/CE | 30 kg | |
Car bomb | Sedan | HME | 250 kg |
Small van | HME | 1–2 ton | |
Large van | HME | 2–3 ton | |
Small truck | HME | 3–4 ton | |
Large truck | HME | 4–5 ton |
3 Numerical Analysis Method
3.1 Materials
3.1.1 Steel
Loading condition | Yield strength | Tensile strength | Density |
---|---|---|---|
Young’s modulus | Poisson’s ratio | etc. | |
Static load | 414 MPa | 620 MPa | 7.86 × 10−6 kg/mm3
|
2.0 × 105 MPa | 0.30 | Elongation: 18 % | |
Impact or blast load | 475 MPa | 751 MPa | 7.86 × 10−6 kg/mm3
|
2.0 × 105 MPa | 0.30 | Fracture strain: 35 % |
3.1.2 Concrete
Properties | Variables |
---|---|
Compressive strength | 45.2 MPa |
Density | 2230 kg/m3
|
Poisson’s ratio | 0.19 |
Tensile strength | 3.2 MPa |
3.2 Blast Loads
3.3 Modelling of the Specimens
4 Numerical Analysis Specimens
Specimen | Description |
---|---|
Specimen BC | Beam-column connection designed according to ACI318 and ACI352R |
Specimen BC-F | Additional four No. 11 flexural reinforcement based on Specimen BC |
Specimen BC-D | Additional four No. 11 diagonal reinforcement based on Specimen BC |
Specimen BC-F-S | Additional No. 4 shear reinforcement @300 mm based on Specimen BC-F |
Specimen BC-A | Reinforced with all type of bars including diagonal, flexural and shear reinforcement |
5 Results and Discussion
5.1 Effect of Flexural Reinforcement
Specimen | At the point A | At the point B | ||
---|---|---|---|---|
Max. deflection (mm) | Time (ms) | Max. deflection (mm) | Time (ms) | |
BC | −63.0 | 200.0 | −313.0 | 200.0 |
BC-F | −10.3 | 61.1 | −143.7 | 200.0 |
BC-D | −3.6 | 21.3 | −82.6 | 81.0 |
BC-F-S | −4.2 | 12.3 | −23.0 | 25.2 |
BC-A | −2.0 | 2.8 | −17.9 | 19.2 |
Specimen | At the Point A | At the Point B | Deflection | ||
---|---|---|---|---|---|
Support rotation | Comparison to criteria | Support rotation | Comparison to criteria | ||
BC | 17.18° | NG | 37.56° | NG | Failed |
BC-F | 2.81° | NG | 17.24° | NG | Failed |
BC-D | 0.99° | OK | 9.91° | NG | Controlled |
BC-F-S | 1.15° | OK | 2.76° | NG | Controlled |
BC-A | 0.55° | OK | 2.15° | NG | Controlled |
Type of reinforcements | Max. stress (MPa) | Max. strain | Time (ms) | |
---|---|---|---|---|
BC | Flexural bars in the top | 602.13 | 0.0386 | 200 |
BC-F | Flexural bars in the top | 513.64 | 0.018 | 200 |
Flexural bars in the bottom | 479.14 | 0.0079 | 58.3 | |
BC-D | Flexural bars in the top | 577 | 0.0327 | 169.6 |
Diagonal bars | 479.75 | 0.0089 | 58.4 | |
BC-F-S | Flexural bars in the top | 354.77 | 0.0017 | 12.3 |
Flexural bars in the bottom | 397.4 | 0.0019 | 9.7 | |
Shear reinforcement | 527.55 | 0.0214 | 191.3 | |
BC-A | Flexural bars in the top | 401.44 | 0.002 | 9.1 |
Flexural bars in the bottom | 472.67 | 0.0026 | 9.5 | |
Diagonal bars | 472.67 | 0.0027 | 9.5 | |
Shear reinforcement | 527.54 | 0.0214 | 136 |