Ternary Blended Cementitious Matrix for Vegetable Fiber Reinforced Composites

The present work analyses the behaviour of different binder matrices in order to implement the addition of paper pulp as reinforcement for cementitious composites and assesses the composites flexural properties with time. To prevent microfibers degradation in high-alkaline environments, lower alkaline matrices may be developed. In the present study ternary binder matrices containing ordinary Portland cement (OPC), gypsum (G) and fluid catalytic cracking catalyst residue (FC3R) are presented for that purpose. To assess the performance of the alternatives matrices, pH and conductivity evolution with time were monitored. Also flexural tests were carried out with the intention of evaluate the efficiency of the matrix to preserve fibres within the composite. According to pH and conductivity results is proved that this ternary system offers lower values at early stages (at 3 days) when compared to OPC systems. This inferior alkalinity might be associated to the better mechanical performance with time of the composites when the ternary matrix is used. After 10 months ageing, all the mechanical properties were higher when compared to composites using OPC. Particularly remarkable is the preservation after ageing of the specific energy and deflection at the modulus of rupture when the low-alkalinity matrices were employed, on the contrary what occurred with samples containing OPC where specific energy and deflection were nearly disappeared.