Post-cracking strength classification of macro-synthetic fibre reinforced concrete for sleeper application

Nowadays, timber and concrete are among the most extensively used materials for railway sleepers, characteristically considered as a crucial track component. However, due to recent concerns regarding the inferior quality, degradation, durability, high-cost and environmental impact of the conventional materials, this paper focuses on macro-synthetic fibre reinforced concrete (MSFRC) as a more sustainable alternative. Despite the encouraging strength characteristics of the innovative material, its practical implementation as a composite sleeper remains fairly limited due to the unknown post-cracking behaviour categorised through the fibre reinforced concrete (FRC) constitutive laws. Hence, the paper herein investigates the characteristic flexural residual strength (i.e. serviceability & ultimate) of MSFRC classified in terms of strength intervals and residual strength ratios as defined in the Fib Model Code. Experimental data will be adapted onto the design stress-strain relationship with an insightful comparison of the post-cracking propagation branch relative to different fibre volume content and fibre types. Therefore, this paper herein will present beneficial and non-beneficial behaviours of the compliant macro-synthetic fibre reinforced concrete towards railway structural applications.