Application of bio-inspired nanocomposites for enhancing impact resistance of cementitious materials

Bio-inspired Polyvinyl Alcohol (PVA)/ Montmorillonite (MMT) nanocomposite films were synthesized and applied to High Performance Concrete (HPC) cylinders as coatings. Drop tower tests were performed to evaluate the effects of nanocomposite films on the impact response of the concrete. The preliminary results show that applying PVA/MMT nanocomposite film with 25 vol% MMT as coatings with an approximate thickness of 160 µm, demonstrated an improvement on the impact resistance of the concrete for a strain rate (∼102/s). For specimens subjected to the same impact energy, the damage pattern changed from complete fracture of an uncoated concrete cylinder, to only localized surface damage on the coating and the concrete cylinder substrate at the impacted region. Finite element simulations of the impact tests indicate that robust stiffness, tensile strength and toughness of the nanocomposite film, and strong bonding between the film and concrete have induced strong confinement effects to the brittle concrete cylinder substrate. This work demonstrates the potential application of bio-inspired PVA/MMT nanocomposites as protective coatings for cementitious structures.