Optimizing the formulation of flax fiber-reinforced cement composites

Because of their hydrophilic nature, flax fibers absorb water during the mixing stage and release it gradually during the curing step. Thus, the rheological properties and the setting of the cement paste are deeply disturbed. In addition, the diametrical shrinkage of the fiber in the desorption stage can lead to a weakening of the fiber–matrix bond. It is therefore necessary to carry out treatment of the fiber and/or cement mixture to prevent the fiber/matrix debonding. The results obtained from these formulations show an improvement in the rheology and the mechanical performances of the composites.