ABSTRACT
The demand for fatigue-resistant materials in new construction as well as for repair and strengthening of existing structures necessitates the search for innovative solutions. Strain-hardening cement-based composites (SHCCs) are a prominent candidate with this regard. They exhibit a considerable tensile strain capacity resulting from multiple fine cracks, while fibre bridging capacity and pull-out behaviour play vital roles with respect to mechanical properties of the composites. The pull-out behaviour of a single fibre from the matrix is commonly assessed by pull-out tests. Depending on the fibre type, the pull-out behaviour can be strongly influenced by such parameters as embedded length, fibre inclination angle and type of loading. Specifically, cyclic loading may promote damage development in inclined fibres due to their high local deformations at the edges of fibre tunnel on the crack faces. The article at hand is an experimental-virtual investigation on the influence of inclination angles of polyvinyl-alcohol (PVA) microfibre on their pull-out behaviour under quasi-static monotonic and cyclic loading. First, the pull-out behaviour of PVA microfibres with different inclination angles is experimentally characterized in monotonic and cyclic regimes. Next, the fibre failure modes and damage types are assessed by means of electron microscopy, so that the specific phenomena can be recognised. A finite element model is also developed to simulate the behaviours of the fibre and matrix during fibre pull-out.
