Language: English
Strengthening of Six-Story Factory Office Premises
Carbon Fiber Reinforced Polymer(CFRP)
The CFRP fabric strengthening system successfully upgraded the 6-story factory office building to meet current operational demands and structural performance requirements. The integrated application of CFRP fabric for flexural strengthening, shear enhancement (U-wraps), and slab strengthening.
Project Overview
| Attribute | Details |
|---|---|
| Project Type | Structural strengthening of existing multi-story building |
| Structure Type | 6-story reinforced concrete frame building (factory office) |
| Primary Deficiencies | Insufficient load-carrying capacity due to aging structure and increased service loads |
| Strengthening Method | Externally bonded CFRP fabric system |
| Completion Date | 2026 |
| Material Supplier | Horse Construction |
After decades of service, the building now faces increased loading demands due to changes in occupancy patterns, addition of modern equipment, and higher live load requirements beyond the original design assumptions. The existing structural members, while adequate for their original intended use, are no longer capable of carrying the accumulated and increased service loads.
Structural Deficiencies
beams
Insufficient flexural and shear capacity to accommodate increased service loads over the building's extended operational life
slabs
Cracking and excessive deflection observed due to progressive load increases exceeding original design capacity
beam-column joints
Inadequate confinement and shear resistance under accumulated long-term stress and increased loading
Cause Analysis
Aging structure: Extended service life leading to gradual material degradation, including concrete carbonation and minor reinforcement corrosio
Increased loading over time: Changes in building usage — heavier office equipment, increased occupancy, modern HVAC and mechanical installations — have progressively raised demand beyond the original design capacity
Cumulative fatigue: Decades of repeated load cycles causing progressive damage accumulation in structural members
Functional upgrade demands: Building repurposing and facility upgrades requiring higher load capacity than originally designed
CFRP Fabric Strengthening System
Design Standards
ACI 440.2R-17: Guide for the Design and Construction of Externally Bonded FRP Systems
ACI 318-19: Building Code Requirements for Structural Concrete
Materials Specification
| Component | Specification |
|---|---|
| CFRP Fabric Type | Unidirectional carbon fiber fabric-HM-30 |
| Fabric weight | 300 g/m² (for primary reinforcement) |
| Fabric tensile strength | ≥ 3,400 MPa (per ASTM D7565) |
| Fabric modulus | ≥ 230 GPa |
| Fiber type | T700 carbon fiber |
| Impregnating resin | HM-180C3P two-component epoxy resin, 0.6-0.8 KG/sqm |
| Resin tensile strength | ≥ 30 MPa (per ASTM D638) |
| Primer | HM-180 epoxy primer |
CFRP Strengthening Advantages
Comprehensive strengthening solution: Integrated system addressing flexural, shear, and confinement deficiencies
Minimal structural impact: Lightweight CFRP fabric adds negligible dead load (< 2 kg/m² per layer
Rapid installation: Faster than traditional steel plate bonding or section enlargement methods
Conformability: Fabric conforms to complex geometries and curved surfaces
Corrosion resistance: CFRP immune to chloride attack, ideal for long-term durability
Minimal disruption: Installation can proceed with partial building occupancy
Seismic performance enhancement: Improved ductility and energy dissipation capacity through fabric wrapping
The CFRP fabric strengthening system successfully upgraded the 6-story factory office building to meet current operational demands and structural performance requirements. The integrated application of CFRP fabric for flexural strengthening, shear enhancement (U-wraps), and slab strengthening.
