Potential of Thermoset Polyolefins for FRP Concrete Reinforcing Bars

ABSTRACT Although thermoset polyolefins offer resistance to hydrolytic degradation and favorable processing characteristics, their potential as matrix systems for fiber‐reinforced polymer (FRP) concrete reinforcing bars has received limited attention. This is the first comprehensive review assessing thermoset polyolefins for FRP bars. Following the PRISMA 2020 guidelines, this review evaluates preparation methods, additive strategies, processing characteristics, and mechanical, thermal, and durability performance of thermoset polyolefins. The review identifies crosslinked polyolefins (XLPOs) and poly(dicyclopentadiene) (pDCPD) as the two primary thermoset polyolefin categories. XLPOs are limited by insufficient mechanical properties and poor fiber wettability associated with their semicrystalline morphology, restricting their use as primary matrices for structural FRP reinforcement. By contrast, pDCPD exhibits low initial viscosity, tunable gel time, low cure shrinkage, and high glass transition temperature ( T _g ), along with moderate mechanical properties and greater ductility relative to epoxy and vinyl ester resins. However, data on its alkaline durability in simulated concrete environments, oxidative stability, and fiber‐sizing compatibility remain limited, representing critical research gaps for broader adoption in FRP bar applications.