Substitution of Synthetic Fibers by Bio-Based Fibers in a Structural Mortar

Abstract

The use of bio-based material is now widespread in insulation concrete, for example hemp concrete. The bio-based materials in concrete provide many advantages: lightness, sound and thermal insulation, hydrothermal regulation while contributing to a reduction in the environmental impact due to the carbon capture during the plant growth. The development of materials incorporating plant is therefore an important objective for the construction. The next step will be to introduce bio-based materials in structural mortars and concretes. The project FIBRABETON proposes to substitute synthetic or metallic fibers by natural fibers in screed and slab. After a selection of biomass on the resources availability, separation and fractionation are the key step in processing to obtain technical natural fibers. Bulk fiber shaping and packaging methods for easy handling and transportation are tested. Then, functionalization of technical natural fibers by physical & chemical treatments to improve the durability with cement paste is carried out. The second step concerns the introduction of treated or not treated fibers in mortar and concrete formulations. The variation of the nature of the biomass, fibers shape and dosage in concrete are studied. The workability, the compressive strength and withdrawal resistance are measured in order to obtain the best formulation parameters. The evolution of properties over time is also evaluated. The project FIBRABETON is carried out with ESTP, FRD and Vicat and is subsidized by ADEME, Grand Est region and FEDER.