Evaluating the effect of macro-synthetic fibre on the mechanical properties of roller-compacted concrete pavement using response surface methodology

Abstract

This study provides guidance for the design of macro-synthetic reinforced roller-compacted concrete pavement (RCCP) with appropriate consistency and enhanced mechanical performance for pavement applications. The response Surface Methodology was used to study the effects of fibres (0–0.5%), cement (300–350 kg/m3) and water (120–150 kg/m3) on the Vebe time, compressive and flexural strength, and fracture energy of RCCP. The interaction between these three factors were examined modelled using a statistical regression model, showing that the addition of macro-synthetic fibres to the RCCP mixture linearly reduces the RCCP consistency (Vebe time), while fibres do not significantly affect the compressive strength. Based on three-point bending test results on notched beam, fibre, cement, and water linearly affect the flexural strength. However, fibre tended to influence the fracture energy more significantly than flexural strength. It was found that the mortar-fibre interaction highly affects the RCCP post-cracking behavior Therefore, hardening of the post-cracking zone in the load-CMOD curve is expectable for high-flexural strength RCCP at a high volume fraction of fibres.