Alkali Resistant (AR) Glass Fibre Influence on Glass Fibre Reinforced Concrete (GRC) Flexural Properties

Abstract

Glass fibre reinforced concrete (GRC) is lightweight material mostly used for façade panels and decorative elements. GRC can be made using two methods – spraying and premixing. Glass fibre in both cases has main influence on material flexural properties and ductility. Historically ordinary E type glass fibre has been used, but during concrete aging and alkaline medium fibres become fragile (weight and diameter loses). New type, alkali resistant (AR) glass fibres have been developed. In this research AR glass fibre amount and length influence on GRC flexural properties is investigated. Fibre length was changed from 6 mm till 41 mm for different samples and cut during spraying process. Fibre amount was changed from 0–7%. Samples were analysed using SEM-EDX to evaluate AR glass fibre and concrete matrix bond. GRC mechanical properties was evaluated using four-point bending tests and characterised by level of proportionality (LOP) and modulus of rupture (MOR).