New Bridge Deck Cast onto Corrugated GFRP Stay-in-Place Structural Forms with Interlocking Connections

Abstract

In this study, pultruded glass fiber reinforced polymer (GFRP) corrugated plates, connected together through pin-and-eye connections, were investigated as stay-in-place (SIP) forms for concrete decks. The SIP form completely replaced the bottom layer of reinforcement, whereas a top GFRP mesh was provided. Special attention was given in simulating the details of deck connection to supporting girders. Full-scale deck specimens, including a control deck with conventional steel reinforcement, were cast on concrete supports simulating a girder spacing of 1,780 mm. The 410-mm-wide supports had a rough surface finish along with protruding steel stirrups to simulate the flange of an AASHTO type III girder. An additional cantilevered specimen was tested to examine the feasibility of using SIP forms in deck overhangs at exterior girders. The study also investigated the effects of GFRP plate thickness and bond with concrete on performance. All specimens, except the cantilevered one that failed in flexure, had a punching shear failure while the GFRP pin-and-eye connections remained intact. The system demonstrated excellent performance, with safety factors ranging from 3.5 to 4.9, relative to the half-axle service load, including impact factor, of standard design trucks. Deflections at service were less than span/1,600. The system also displayed significant deformability associated with gradual loss of strength beyond punching shear, a major advantage over conventional decks. Adhesive bond improved stiffness but had little effect on strength. Constructability issues are also addressed along with the detailing particular to this system.