Abstract

This study reports the reinforcing efficiency of glass fibre addition in the low volume fly ash concrete upto 25% cement replacement level. Micro mechanical action of glass fibres in fly ash concrete are discussed with respect to different percentage of glass fibre addition. Glass fibres in concrete improves the matrix densification, refinement of microstructure, reduction of voids, minimize cracking due to stresses, and enhance durability to reinforcement corrosion, sulphate attack, and alkali-silica expansion. The experimental test results showed that 25% fly ash with 0.3% glass fibers addition in concrete provided highest compressive strength upto 51.45 at 28 days and a flexural strength of 5.15 MPa. Further tests on ultrasonic pulse velocity exhibited the quality of various concrete mixes and conform to the standard requirement for a high quality concrete.

Key words: Compressive strength, fly ash, flexural strength, glass fibres, superplasticizer.