Characterization and properties of cementitious composites with cellulose fiber, silica fume and latex

[Display omitted] •To evaluate the influence of silica fume, cellulose and latex on composites.•Study an optimized formulation for the cementitious composite.•The cellulosic fiber significantly increased the mechanical performance.•Latex significantly influenced the reduction of the modulus of rupture.•Optimized composite had 13.55% silica fume, 14.55% cellulose and 1.40% latex. In this investigation, the behavior of the composites was analyzed through mechanical and physical tests, scanning electron microscopy and X-ray diffraction at 28 days cure time. Central composite design with four center points and using alpha for orthogonality of 1.41421, resulting in 18 experiments, was used. The diffractograms show a possible decrease of portlandite in mixtures with the presence of silica fume and natural rubber latex. Micrographs show a good synergy between cellulose fiber and natural rubber latex. In addition, the cellulose fibers are predominantly stripped from the matrix during fracture of the composites. The regression models were validated and it was possible to obtain an ideal composite with 13.55% silica fume, 14.55% cellulose fiber and 1.40% natural rubber latex, and good mechanical properties as a modulus of rupture of 13.34 MPa.