Properties of poly(vinyl alcohol) fiber reinforced high-performance organic aggregate cementitious material: Converting brittle to plastic

This study focuses on the development of a lightweight high-performance cementitious composite material which is reinforced with poly(vinyl alcohol) (PVA) fiber and contains poly(vinyl butyral) (PVB) as the sole aggregate. Mechanical properties such as compressive and flexural strengths, impact resistance, and fracture toughness are evaluated. PVB composite produces low average density concrete of 1548 kg/m3 (96.6 pcf) and a compressive strength of about 40 MPa (5800 psi). The addition of PVA fiber improves ductility, fracture toughness and impact resistance with fiber volume fractions. In general, the increase in fracture toughness is found to be linear with increasing fiber volume fraction, whereas the increase associated with the impact resistance is non-linear. A model based on fiber bridging mechanics and the rule of mixtures is developed to characterize fracture toughness. Comparisons are made with a lightweight concrete having equal density, and a normal-weight concrete. A good correlation is obtained for the materials tested when experimental results are compared to those predicted by the developed model.