Novel Ductile FRP System for Concrete Reinforcement: Concept and Experimental Characterization

Abstract

This paper presents a novel design concept for fiber reinforced polymer (FRP) composites consisting of three-dimensional (3D) printed cores and FRP helical skins as a means of ensuring adequate ductility, compared to the brittle FRP systems conventionally used for internal reinforcement. The experiment demonstrated that when the FRP skins were loaded in tension, the core-which was 3D printed using acrylonitrile butadiene styrene or polylactic acid-was gradually compressed, thereby leading to plastic deformation. This behavior ensured a nonlinear load response while eliminating the unfavorable brittle failure of the FRPs. The results also indicated that the proposed FRP composite system ensured that no premature debonding/delamination occurred between the skin-skin and skin-core. The results of the parametric experimental study indicated that design parameters such as the FRP amount, core height, core span, core shell thickness, core material, core brace, and core number (i.e., the number of inner cores used for the composite) may be optimized to realize the expected design load capacity and ductility.

Modelling of a novel strong and ductile FRP composite

“…In general, increasing FRP amount was expected to develop more notable nonlinear responses, fracture skins at a higher stress and achieve a larger ultimate strain. to calculate the required strip width for FRP skins [12]. The strip widths were therefore 10 mm, 15 mm and 20 mm for the corresponding composites having 2 mm, 3 mm and 4 mm-height cores, respectively.…”

“…inner cores used for shaping outer skins and providing designable core stiffness, strength and deformation under skin squeezing), FRP helical skins (squeezing inner cores to unfold shaped skins and resisting the opening at the core edges) have recently been developed to provide stable nonlinear tensile behavior as shown in Fig. 1(a)-(b) [12]. The composite could be extended by using multiple cores and bridges (i.e.…”

“…Although experimental results have demonstrated favorable composite responses [12], few computational tools have been calibrated for the composite. This paper aims to calibrate a Finite Element (FE) tool that are best suited for predicting the tensile behavior for the composites having various FRP amounts, core materials and configurations, i.e.…”