Durability and mechanical properties of nanocomposite fiber reinforced concrete

In this study we investigated the in uence of polypropylene/organoclay bers on durability and mechanical behaviour of concrete. Pure polypropylene bers and polypropylene nanocomposite bers of two di erent lengths (20 and 60 mm) have been mixed in concrete at two volume fractions (0.1% and 0.3%). Nanoclay addition increases bers elastic modulus (about 27%) reducing ductility. Workability of concrete is greatly in uenced by bers length and volume fraction: increasing these two values workability decreases. Fibers are not in uent on compressive and exural strength while post- cracking toughness is increased. Nanocomposite bers have a better pull-out strength due to a better friction during slipping, but this doesn’t ensure a better adhesion. Water absorption, freeze/thaw cycles and the sulfate attack test demonstrate that concrete durability increases with the volume of the ber fraction.