Pultruded GFRP Stay in Place Formwork as Beams

Abstract

Commercially available Fiber Reinforced Polymer (FRP) off the shelf structural shapes have great potential as stay in place forms for concrete structures. This system simplifies and accelerates construction, and the non corrosive FRP forms can fully or partially replace steel rebar reinforcement. This report has described structurally integrated stay in place (SIP) FRP forms including their advantages and limitations. It provides a thorough review of the basic principles and research findings to date on stay in place FRP forms for concrete structures. Open forms which are used for flexural members like beams, slabs, bridge decks etc. have been discussed in this report. Open forms are particularly well suited for applications where positive bending is involved. This is because the inherent location of the formwork, at the bottom of the member, allows it to provide tensile reinforcement for resisting positive moments. This resistance, however, can only occur if sufficient shear connection exists between the concrete and the formwork. Literature review about open formwork addresses FRP profiles that have potential as structural forms, various bond mechanisms and flexural members that have been developed and studied is presented. It has also described various concerns that are related with open stay-in-place formwork. Implementation of the technology in the field is focused through examples of field applications on the advantage offered by these materials over conventional materials of construction. Overall this study has shown the feasibility and effectiveness of the FRP formwork system for civil engineering applications.