Pullout behavior of recycled macro fibers in the cementitious matrix: Analytical model and experimental validation

A novel mechanical recycling method has been recently developed in the authors' group for processing waste glass fiber-reinforced polymer (GFRP) composites into macro fibers, which are then incorporated into concrete to produce green fiber-reinforced concrete (FRC). The present study has been conducted for facilitating the characterization of the tensile properties of macro fiber reinforced concrete (MFRC). A trilinear bond-slip model based on the shear-lag theory has first been refined by introducing a slip coefficient to consider different slip behaviors at the final pullout stages. Such a refined trilinear bond-slip model is suitable for describing the bond-slip behavior of the recycled macro fibers embedded in the cementitious matrix. The bond parameters are obtained through an inverse analysis, in which an improved particle swarm optimization algorithm (PSO) is used. The predicted force-end slip curves are compared with the pullout test results, and a good agreement is observed counterparts with the integral absolute error (IAE) ranging from 3.05% to 5.52%, demonstrating the feasibility of the proposed analytical model. A parametric study is finally conducted to examine the sensitivity of different parameters including the fiber geometries and bond properties on the pullout behavior of the macro fibers.

Automated summary

A novel mechanical recycling method for waste GFRP composites has been developed to produce macro fibers, which are then used in the production of green FRC. The study improves the trilinear bond-slip model based on shear-lag theory by introducing a slip coefficient to consider different slip behaviors at the final pullout stages. Bond parameters are obtained through an inverse analysis using an improved PSO algorithm. The study demonstrates the feasibility of the proposed analytical model through comparison with pullout test results and explores the sensitivity of different parameters on the pullout behavior of macro fibers.