This experimental research analyzes the mechanical performance and durability of façade pieces based
on Portland cement matrix and flax nonwovens as reinforcement. Two types of pozzolanic additions (silica
fume and metakaolin) combined with nonwovens subjected to different treatments to decrease their
water absorption are analyzed as potential materials for fiber-cement sheets for building envelopes with
high strength and durability. For this purpose, on the one hand, the mechanical performance and chemical
composition of various ternary compositions were studied. On the other hand, various treatments
were performed on the nonwovens and the nonwoven–matrix adherence was also analyzed. Finally,
composites were prepared from some selected treated nonwovens and matrix mixtures, and their
mechanical properties and durability were evaluated under four-point bending tests after 28 days of curing
in a humidity chamber and after accelerated aging. The composites developed with the treated nonwovens
presented very high performance combined with enough durability to be potential candidates for
the development of sustainable materials for building envelopes