Void geometry analysis and multifaceted characterisation of cementitious mortar reinforced with short carbon and glass fibres – A comparative study

Abstract

This paper presents comprehensive experimental and numerical studies on void analysis, durability performance, electrical properties, and microstructural behaviour of fibre-reinforced cementitious composites (FRCC) with varying short carbon and glass fibre volume fractions. Durability and electrical properties are evaluated based on the hydrochloric acid effect, water absorption, drying shrinkage and electrical resistivity changes over time. The incorporation of CF and GF remarkably limits drying shrinkage, primarily attributed to the bridging and bonding effects of fibres within the matrix. The addition of 1.0 % carbon fibre significantly decreases the electrical resistivity and improves acid resistance performance. Furthermore, for the first time, the influence of fibre type and quantity on the formation of elongated and eccentric voids is investigated by using X-ray computed tomography (micro-CT). The results demonstrate that higher porosity leads to lower strength and durability performance, while a greater occurrence of elongated voids contributes to increased length change in shrinkage.