A novel pull-out device used to study the influence of pressure during processing of cement-based material reinforced with coir

Abstract

This paper deals with the use of plant fibres, such as coconut, as reinforcement in cementitious materials; such additions modify the mechanical properties of the composite in its hardened state. This enhancement depends on both the fibre’s physical and chemical properties. For reinforcement of the mineral matrix, the interfacial properties are paramount in ensuring fibre effectiveness. Fibre reinforced cementitious material can also be enhanced by processing, such as extrusion, that will improve the interfacial bond by the application of pressure. An original experimental procedure has been carried out to study the influence of cementitious matrix consolidation pressure on interfacial bond strength; samples with a coir bundle were made to be submitted to pull-out tests from the hardened paste. Results show that the fibrematrix adhesion can be controlled by matrix consolidation in the fresh state. It suggests that high-pressure processing such as extrusion can improve the mechanical behaviour of the interfacial bond between coir and cementitious matrix leading to better composites mechanical properties. Therefore, forming process requires careful analysis in order to optimize the reinforcement ability of the natural fibre.