Mechanical properties of hemp-lime reinforced mortars: influence of the chemical treatment of fibers
Résumé
In addition to being an environmental-friendly material, hemp fibers are also inexpensive reinforcements in thermoplastics or concrete composites, due to their intrinsic mechanical, thermal, and acoustic properties. However, chemical treatments of fibers are required to enhance the matrix/fiber interface. In this article, the influence of the addition of hemp fibers chemically treated or not, on the mechanical properties of a lime composite was investigated. Mechanical properties were evaluated by ultrasonic pulse echography and four-point bending test associated with acoustic emission analysis. The physical and chemical surface modifications of the hemp fibers were monitored with gas chromatography and scanning electron microscopy. It appears that chemical modification of the fiber surface degrades the amorphous materials present in the fiber structure, which results in an increase in the surface reactivity and also improves the mechanical properties of the composites.