INFLUENCE OF SHORT FIBRES ON FRACTURE BEHAVIOUR IN TEXTILE REINFORCED CONCRETE

Textile-reinforced concrete (TRC) exhibits very favourable stress-strain behaviour, showing high load-carrying capacity, achieved after relatively high deformations and accompanied by the formation of a considerable number of fine cracks. This article addresses the influences of an additional reinforcement using short fibres of alkali-resistant (AR) glass and carbon on the fracture behaviour of this material. A series of uniaxial, deformation-controlled tensile tests were performed on TRC plates with short fibres added. Dispersed and integral short fibres of both AR glass and carbon were used in the investigation. In one regimen, testing included TRC plates with a high degree of textile reinforcement, both separate and in combination with a low degree of short fibres. In the other, experiments on TRC plates with a relatively low degree of textile reinforcement, both separate and in combination with a high degree of short fibres were performed. Very diverse effects were observed as a result of the effects of the different types of short fibre on the stress-strain relationship and cracking behaviour of TRC. In particular, a pronounced increase in the first-crack stress was observed in all cases when short fibres had been added. Still further, the influences of dispersed and integral short glass fibres on the stress-strain behaviour of TRC under tensile loading were compared. Finally, the observed phenomena were discussed and classified as to their underlying causes with the support of microscopic investigation. Further information was provided by visual inspection of the specimens' surfaces.