Tensile behavior of high-strength highly ductile fiber-reinforced concrete with embedded carbon textile grids

Abstract

Highly ductile fiber-reinforced concrete (HDC) exhibits good cracking patterns and tensile strain-hardening characteristics. Recently, a high-performance HDC was developed and named the high-strength HDC (HSHDC). Compared with ordinary HDC, HSHDC exhibits higher ultimate tensile strain (exceeding 8 %) and higher compressive strength (exceeding 100 MPa). In this study, HSHDC is applied to fabricate composites with textiles, which is named textile-reinforced HSHDC (TR-HSHDC). The main purpose is to further significantly improve the tensile strength of HSHDC to meet higher functional requirements. Thus, fifteen TR-HSHDC specimens and twelve textile-reinforced HDC (TR-HDC) specimens, and nine non-reinforced specimens were tested under uniaxial tensile loads. The test variables were the carbon textile reinforcement ratio, volume content of short fibers, and strength of matrices. The crack patterns, failure modes, stress-strain curves, and mechanical property parameters were analyzed and discussed. The test results showed that the TR-HSHDC specimens require more short fiber to exhibit multiple cracking than the TR-HDC specimens. The maximum ultimate tensile strength of the TR-HSHDC specimen with a textile reinforcement ratio of 1.05 % was up to 22.43 MPa. The stress-strain curve of the specimens can be classified as a five-stage or three-stage type by adapting the matrix type, content of short fibers, and textile reinforcement ratio. Besides, a two-stage nonlinear model was presented to predict the ultimate tensile strength and describe the stress-strain relationship of such composites.