Experiments on natural fibers : durability and mechanical properties

Natural fibers are currently used in several fields of engineering. In the construction field, natural fibers represent a sustainable alternative to replace the most common synthetic and petroleum-based fibers into mortar-based composites. In particular, plant fibers into cementitious composites can considerably increase composites mechanical properties and reduces material density and weight. The most important limitation of plant fibers use is the low material durability, especially into alkaline environments. This paper investigates plant fibers alkaline sensitivity for establishing if cementitious composites reinforced with natural fibers would be appropriated for structural solutions in the construction field. Here the results of experiments on ramie, jute, hemp and sisal wires are presented. Their mechanical behavior is characterised by different boundary conditions: three solutions that simulates the most common cement mortars chemical compositions. Measurements of plant fibers strength at natural condition and after progressive time steps of immersion into the different solutions test the material durability. Hence, a method that helps to understand better plant fibers alkaline sensitivity and durability into mortar matrices.