Fabrics of basalt (BFs), E-glass (GFs), and carbon (CFs) fibers with the same areal density were used to prepare epoxy-based laminates. The BF laminates presented elastic moduli and strength values higher than those of the corresponding GF laminates, with tensile strength values near to that of CF laminates. Investigation of the behavior under fatigue conditions indicated superior performances of BF laminates with respect to the corresponding GF composites, with an improved capability of sustaining progressive damaging and slightly higher damping properties. As far as the fatigue behavior is concerned, BFs may therefore represent a valid substitute of GFs in structural composites.

Basalt and E-glass fibers fabrics were combined with carbon fiber fabrics in order to prepare epoxy-based interlaminar hybrid composites and to investigate the hybridization effect on the flexural and impact properties of the resulting laminates. The flexural modulus of the composites depended on their composition according to a rule of mixture, while an important synergistic effect was detected for the ultimate flexural properties. Charpy impact tests evidenced a strength increase as basalt and glass fibers content increased. Interestingly, hybridization with basalt fibers promoted an increase of the adsorbed impact energy due to an enhancement of the fracture propagation component.

Various kinds of organo-modified clays were dispersed at different amounts in an epoxy matrix. After clay addition, the viscosity of the epoxy resin resulted still acceptable for a possible usage as matrices for fiber-reinforced composites. The formation of intercalated microstructures led to substantial improvements of the thermal (glass transition temperature) and mechanical (fracture toughness) properties of the epoxy matrix. E-glass fiber/matrix interfacial shear strength was evaluated by the single-fiber microdebonding method. The introduction of organo-modified clays led to the formation of a stronger fiber-matrix interface, with an increase of the interfacial shear strength of about 30%. Concurrently, the evaluation of the fiber/matrix contact angle revealed an improved wettability when organo-modified clays were added.