Caractérisation microstructurale et mécanique d’un composite cimentaire renforcé par des fibres de lin

Abstract

Abstract. With the purpose of the flax fibre valuing in construction materials, this study focuses on the characterizations mechanical and microstructural of flax fibre cement composite reinforced. The mechanical strength was studied as the function of fibre volume ratio and length. Meanwhile, the microstructural analysis investigated the homogeneity of fibre scattering, the interaction fibre/cement matrix and the influence of flax fibres on the defects microstructures. The results show the interesting mechanical properties of flax fibre in comparison with other fibre vegetable. But they are damaged in an alkaline environment such as concrete or cement composite. In fresh state, a good adherence between fibre and cement matrix was found. But as hydrophilic, the flax fibres absorb water and become inflated. Afterwards, the fibres return deflated at the drying time and this dry/wet cycling reduce the fibre/matrix bond. Being reinforced by the flax fibres, the brute failure of cement materials was replaced by the one more ductile when the fibre ratio increased. This transition was evaluated by the toughness indexes that allow measuring the energy absorption of flax fibre.Résumé. Dans la perspective de valorisation des fibres de lin dans les matériaux de construction, la présente étude s'intéresse à la caractérisation microstructurale et mécanique d'un composite cimentaire renforcé par des fibres de lin. Les analyses microstructurales au MEB ont été menées pour évaluer l'homogénéité de la distribution des fibres, la qualité de l'interaction fibre/matrice et l'influence de leur présence sur les défauts microstructuraux. Le comportement mécanique en flexion du mortier renforcé par les fibres de lin est étudié en fonction de la longueur et la teneur en fibres. Les résultats indiquent une bonne adhésion entre les fibres et la matrice à l'état frais. Mais les fibres étant hydrophiles, elles gonflent pendant la prise du ciment et le retrait lors du séchage engendre alors des déchaussements. Les résultats de caractérisation mécanique sont encourageants. Tout d'abord, la fissuration du mortier due au retrait au jeune âge est fortement réduite du fait de la présence des fibres. Ensuite, la rupture brutale de la matrice en monolithe laisse place à un comportement quasi-ductile quand la teneur ou la This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Assessment of Hygrothermal Performance of Raw Earth Envelope at Overall Building Scale

“…The formulation studied if made of raw earth and 3% by mass of straw fibres. This rate was previously found in the literature for cob [30][31][32][33]. The addition of vegetable fibres accelerates the drying process, reduces shrinkage cracks, and improves the cohesion and ductility of the material [34].…”

Improvement of the Thermal Properties of Cement Mortars by Adding Banana Pseudo-Trunkfibres

“…The consistency of mortars gradually decreases as the amount of fibre present in the mortar increases; this is due to a loss of handling. This trend was also observed by [24]. Consistency of mortars is almost zero at 2% fibre; because of their great flexibility, the pseudo banana trunkfibres tend to form pellets during kneading when they are in very large quantities [25] [26]; this is the reason why in the rest of our work we did not work much with mortars containing 2% fibre (Figure 9).…”

Characterization of the Clay and Fibres for Hygrothermal Modelling

“…The three-day duration allows the water to be distributed well in the fibres and the soil. Indeed, MAT376-3 the role of fibres is to distribute shrinkage cracks throughout the mass of the wall, improve the cohesion and shear strength of the wall as well as resistance to weathering [9,11,15].…”