Experimental investigation of physical and mechanical characteristics of pultruded/hand lay-up gfrp thin-walled structural sections and gfrp pultruded ribbed rebars

Abstract

The paper presents the findings of an experimental study conducted to determine the physical and mechanical properties of glass fiber-reinforced polymer (GFRP) I-shaped structural profiles and surface ribbed round rebars. Two types of pultruded rebars varying in their designated diameter (8/10 mm), and two types of geometrically identical I-sections that differed in their manufacturing process (pultrude/hand lay-up), constituents, and composite lay-up were tested in a number of standard characterization tests. The stress-versus-strain curves and their associated failure mode(s) were analyzed, and a relative comparison of the respective strength/stiffness characteristics was made. The test results showed that both the I-section profile types meet the minimum strength criteria for an E17 grade composite profile, and except for the flexural response, the industry fabricated pultruded laminate outperforms the mechanical characteristics of its in-house fabricated hand lay-up technique based counterpart. The anti-shrink additives and the shear-lag effect adversely affect the resulting tensile and compressive characteristics of a GFRP rebar. A marginal increase in the rebar’s nominal diameter results in a noticeable increase in the in-plane and transverse shear strengths of the rebar; the interlaminar shear strength, however, remains invariant to such variation.