Polyethylene Storage Tanks Strengthened Externally with Fiber-Reinforced Polymer Laminates

Area of Science:

• Materials Science
• Structural Engineering
• Civil Engineering

Background:

• Polyethylene tanks offer lightweight, corrosion-resistant storage but have low mechanical strength.
• Seismic performance of polyethylene tanks is a concern due to inherent material limitations.
• External strengthening methods are needed to improve seismic resilience.

Purpose of the Study:

• To investigate the efficacy of fiber-reinforced polymer (FRP) laminates for seismic retrofitting of polyethylene tanks.
• To assess bond strength, anchorage length requirements, and structural behavior under seismic loads.
• To evaluate the impact of surface preparation on bonding effectiveness.

Main Methods:

• Laboratory tensile testing of carbon fiber-reinforced polymer (CFRP)-strengthened polyethylene strips.
• Finite element simulations to model structural response under seismic conditions.
• Grayscale image analysis to quantify surface preparation effectiveness.

Main Results:

• Slippage observed in tensile tests unless anchorage length exceeds approximately 450 mm.
• Mechanical sanding increased surface intensity variation by over 127%, indicating improved bonding potential.
• CFRP full-wrap retrofitting significantly reduced stress and prevented buckling in simulated seismic events.

Conclusions:

• CFRP retrofitting is a viable, non-invasive strategy to enhance seismic performance of polyethylene tanks.
• Adequate anchorage length and proper surface treatment are critical for successful strengthening.
• This method provides a cost-effective alternative to tank replacement, especially in seismic zones.