GCC climate context: Structural steel strength is NOT reduced at GCC ambient temperatures (max ~55°C) — EN 1993-1-2 shows ky = 1.0 up to 400°C. However, thermal expansion is critical: a 50°C temperature differential over 30m of steel generates 18mm of movement. Expansion joints and sliding bearings must be designed accordingly.
Tools
Thermal Expansion Calculator
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.
Thermal expansion ΔL
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mm
Axial force (IPE 300)
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kN (if restrained)
Expansion joint needed?
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at ≤30m intervals
α = 12×10−6 /°C (EN 1993-1-5, Table C.1) | E = 210,000 MPa | IPE 300: A = 53.8 cm²
GCC Design Temperatures by Location
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.
Steel Strength Reduction Factors (EN 1993-1-2, Table 3.1)
GCC ambient temperatures (max 55°C at surface) fall well within the ky = 1.0 zone below 400°C — no design strength reduction is required for ambient condition checks. These factors become relevant for fire engineering (passive fire protection sizing) and process plant structures adjacent to high-temperature equipment.
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.
Reference: ISO 12944-2:2017. Corrosion category determines paint system thickness and galvanizing specification. GCC coastal areas (Gulf coast, Red Sea coast, Arabian Sea) are minimum C4; offshore and splash-zone structures are C5-M. Inland dry areas (Riyadh, Al-Khobar inland) are C3. Never specify C1/C2 for GCC outdoor steel.
C3
Inland/Dry
C4
Coastal
C5-M
Marine/Offshore
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.
Hot-Dip Galvanizing (ISO 1461)
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.
| Material thickness | Min local coating (μm) | Min mean coating (μm) | GCC note |
| ≥ 6 mm (structural sections) | 70 | 85 | C4: adequate for most GCC coastal structural steel |
| 3 mm – 6 mm | 55 | 70 | Purlins, secondary steel in non-coastal GCC |
| 1.5 mm – 3 mm (sheeting) | 35 | 45 | HVAC ductwork, cladding supports |
| Offshore / C5-M (ARAMCO) | 85 | 100 | Plus cathodic protection for submerged parts per SAES-H-001 |
ARAMCO-Specific Paint Requirements (SAES-H-001)
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.
| Service condition | Primer | Intermediate | Topcoat | Total DFT |
| Atmospheric C3 (inland plant) | Zinc-rich epoxy 75μm | Epoxy MIO 75μm | PU topcoat 50μm | 200 μm |
| Atmospheric C4 (coastal plant) | Zinc-rich epoxy 75μm | Epoxy MIO 125μm | PU topcoat 75μm | 275 μm |
| Splash zone / C5-M | TSZ spray 150μm | Epoxy sealer 50μm + MIO 200μm | PU topcoat 100μm | 500 μm |
| High temp (100–250°C) | Inorganic zinc silicate 75μm | Silicone alkyd 40μm | — | 115 μm |
GCC standard hierarchy: On ARAMCO and SABIC projects, SAES supersedes all referenced international standards where they conflict. On government projects (Ministry, MOMRA, ASHGHAL), SBC/QCS apply. European contractor projects typically use EN Eurocodes. Confirm applicable project standard at tender stage — this determines material grades, weld procedures, and inspection requirements.
GCC default bolting: ASTM A325 (Grade 8.8 equiv) for structural connections, ASTM A193 B7 for pressure flanges. A490 (Grade 10.9) reserved for high-strength connections. All high-strength bolts require pre-tensioning per AISC RCSC specification — turn-of-nut or calibrated wrench method. Verify torque wrench calibration on site per ARAMCO requirements.
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.
AISC Bolt Design Strengths — LRFD (φ = 0.75 shear / 0.90 tension)
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.
| Bolt grade | Fnv (nominal shear, MPa) | Fnt (nominal tension, MPa) | φRn / bolt (M20 single shear) |
| ASTM A325 / Gr.8.8 | 372 | 620 | 57 kN shear · 96 kN tension |
| ASTM A490 / Gr.10.9 | 457 | 780 | 70 kN shear · 121 kN tension |
| ASTM A193 B7 (flange studs) | — | 724 (fy) | Torque per ASME PCC-1 Table |
Equivalent grades caution: ASTM A572 Gr.50 and EN S355 have similar fy (345 vs 355 MPa) but different CVN requirements, weld procedures, and certification. Do NOT substitute without explicit engineering review. For ARAMCO projects, always specify ASTM grades with 3.1B MTR (dual certification not always accepted without prior approval).
Reference values — verify against the current edition of the applicable standard or manufacturer's table before design use.