FLEXURAL AND TENSILE CHARACTERISTICS OF POLYVINYL ALCOHOL FIBRE REINFORCED CONCRETE (PVA-FRC)

This paper presents the results of an experimental study investigating the effect of un-coated polyvinyl alcohol (PVA) fibres on the properties of hardened concrete. PVA fibre of varying length, 6 and 12 mm, with same diameter and aspect ratio (l/d) of 430 and 860, respectively, was utilised in different volume fractions of 0.125%, 0.25%, and 0.5%. In addition, 30 % fly ash was also used as partial replacement of Portland cement in all fibre reinforced concrete (FRC) mixes. Uniaxial compression, splitting tensile, modulus of rupture (MOR) and modulus of elasticity (MOE) tests were performed following the Australian Standards to evaluate the mechanical properties of PVA-FRCs. Mid-span deflection of the flexural specimens was measured by means of a linear variable differential transducer (LVDT) at the centre of each specimen and load-deflection curves were prepared. Results show that adding PVA fibres to the mix generally improve the mechanical properties of concrete. Regarding the strength, the optimum fibre content goes to 0.25 % for both fibre length and in the case of toughness and ultimate deflection 0.5 % shows the highest values