Experimental investigation of corroded steel H-pile repaired with ultrahigh-performance concrete (UHPC) under eccentric axial compression loads

Corrosion-induced deterioration in steel H-piles reduces load-carrying capacity and structural performance. Replacing corroded H-piles is often impractical due to cost and accessibility constraints. This paper investigates the effectiveness of repairing severely corroded H-piles subjected to eccentric axial loads using ultrahigh-performance concrete (UHPC) plates. The UHPC plates, reinforced with carbon fiber-reinforced polymer (CFRP) grids, are bolted to the steel H-piles using high-strength bolt connectors (HSBCs). Nine full-scale 120 in. (3048 mm) long H-piles HP10×42 were repaired with UHPC plates and subjected to axial compression loads at eccentricities of 0%, 10%, and 30%. Corrosion was simulated by reducing the thickness of the flanges and web, creating cuts and voids. The repaired piled with 0.75 in. (19 mm) diameter HSBC displayed a strength increase of 348% while those with 1 in. (25.4 mm) diameter HSBC and CFRP grid exhibited a 422% increment.