Novel percolation-based measure for fiber efficacy in fiber-reinforced concrete beams

Abstract

Fiber-reinforced concrete exhibits a heterogeneous microstructure formed by aggregates, fibers and a matrix, where the stress from external forces can lead to cracking and fracture. This paper discusses the development of a computational measure for predicting the fiber's efficacy by means of the energy absorbed within the initiated area of the cracks. The analytical development was verified with experimental data from the literature and the results were justified with numerical simulations in the elastic regime. This development couples the localization of the stress in the crack tip with the random distribution of the cracks, which leads to the spatial strain field. Such percolation-based quantification of the cracks in the early-stage particularly is useful for effective utilization of fibers during the cracking progress. © 2020 fib. International Federation for Structural Concrete