Mechanics of SFRC under tension, part I: analytical study

Abstract

This is the first of a two-part paper involving a fundamental study of mechanics of short-fibre-reinforced concrete under tension. The theory derived in this paper is validated in a second paper using experimental investigation. The composite material approach, which is based on micromechanics, is employed to describe the phenomenon in terms of constitutive properties of fibre, matrix, fibre–matrix interface and their proportioning. The tensile stress–strain behaviour of short-fibre-reinforced concrete is described with four distinct stages, namely the elastic stage, the stage of closed isolated crack development, and the stages of through-crack development both in the absence of fibre rupture and in the presence of fibre rupture. The analytical development does not require pre-assumed composite behaviour such as peak load, initial tangent modulus etc. The formulation is validated using experimental investigation, supplemented by the results of the available models in the existing literature. Given the extent of the study, it was decided to present the entire work in two parts. The general theoretical development is presented here in part I and the comparisons with test results are presented in the companion paper, as part II.