Compressive properties and analytical modelling for stress-strain curves of polyvinyl alcohol fiber reinforced concrete

The use of polyvinyl alcohol (PVA) fibers in the manufacturing of fiber reinforced concrete is considered a technological revolution in the concrete construction industry due to its advantageous mechanical properties. In this regard, this paper presents the experimental and analytical study of three different grades of PVA fiber reinforced concretes (PVAFRCs) i.e., PVAFRC30, PVAFRC50, and PVAFRC70. A total of eighteen mixes developed for three different grades of PVAFRC with various percentages of PVA fibers (0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%). Workability, and compressive strength, flexural strength, split tensile strength, load-deflection behaviour, and uniaxial compressive stress-strain behaviour of PVAFRCs have experimentally evaluated. The stress ratio, strain ratio, peak-stress, strain at peak-stress, Young’s modulus, compressive toughness index, and energy absorption capacity of PVAFRCs also have been evaluated analytically. The results indicated that the addition of PVA fibers reduced the workability of PVAFRCs mixes and caused significant changes in engineering properties of the concrete. In all three grades of PVAFRC mixes, good mechanical properties exhibited at 0.3% PVA fiber content. The modified analytical model and relationships between material parameter (βn) and modified reinforcing index (MRIV) are proposed to predict the uniaxial compressive stress-strain curves of different grades of PVAFRCs, and a good agreement with experimental results was observed. The existing relationships between material parameter and reinforcing index reported in previous studies for analytical modelling of the experimental compressive stress-strain behaviour of FRC are not able to accurately predict in case of PVAFRCs.