PCI eLearning Course T115: Materials and Manufacturing of Precast, Prestressed Concrete-PCI BDM Ch 2, Reinforcement Properties

PCI BDM Ch 2, Reinforcement Properties

Pdf Summary

Chapter 2 of the PCI Bridge Design Manual discusses material properties, specifically focusing on fiber reinforced polymer (FRP) reinforcement and reinforcement sizes and properties. FRP composites are a type of material made up of a polymer matrix reinforced with fibers such as aramid, carbon, glass, or steel. They are known for their high tensile strength and are particularly suitable for applications where weight, durability, corrosion resistance, and resistance to electromagnetic currents are important factors.<br /><br />The mechanical properties of FRP can vary depending on factors such as the type and volume of fibers and resin used. Model test methods for the short-term and long-term mechanical, thermo-mechanical, and durability testing of FRP bars and laminates are available. The properties quoted for FRPs are usually those in the longitudinal direction of reinforcement, and specific properties should be obtained from the supplier.<br /><br />In terms of bridge applications, FRP tendons have been used in three prestressed concrete bridges in North America. Design criteria have been developed for using aramid and carbon fiber tendons due to their different stress-strain relationships compared to steel strand, while glass fiber tendons have been excluded due to poor resistance to creep and alkaline degradation.<br /><br />The chapter also provides information on specifications that can be used with FRP reinforcement, such as ACI 440.5 for construction with fiber-reinforced polymer reinforcing bars and ACI 440.6 for carbon and glass fiber-reinforced polymer bar materials.<br /><br />The chapter includes tables with reinforcement sizes and properties for different types of materials, as well as stress-strain curves for seven-wire low-relaxation prestressing strand.<br /><br />The chapter concludes with a list of relevant standards and publications from organizations such as AASHTO and ASTM, along with cross-references and cited references for further reading.

Keywords

FRP reinforcement

tensile strength

mechanical properties

bridge applications

aramid fiber tendons

carbon fiber tendons

glass fiber tendons

creep resistance

ACI 440.5

ACI 440.6