Multiscale study of fibre orientation effect on pullout and tensile behavior of steel fibre reinforced concrete

摘要

The tensile response of steel fibre reinforced concrete (SFRC) placed in a given structural element is strongly dependent on the final fibre distribution and orientation with respect to the load direction. In this work, fibre orientation effect was investigated in multi-scale through double-sided inclined fibre pullout test and SFRC dogbone specimen tension test. A numerical model based on Lattice Discrete Particle Model-Fibre (LDPM-F) was developed considering fibre bridging effect by modelling individual fibre, randomly placed within the matrix according to the given fibre volume fraction. The SFRC numerical model validation was achieved by well predicting the mechanical response as well as the failure pattern of SFRC under tension. Both fibre pullout test and SFRC tension test revealed that the fibre inclined angle with respect to tensile load, increasing from 0 degrees to 60 degrees, leads to greater ductility. Lower fibre content SFRC with oriented fibres showed greater energy absorption capacity than SFRC with higher fibre content. Relevance of fibre orientation for bond-slippage behavior and tensile properties of SFRC was highlighted. This fibre orientation control concept may promote the material development of cost effective but performance superior SFRC. (C) 2021 Elsevier Ltd. All rights reserved.