Strengthening of hybrid glass fiber reinforced recycled hot-mix asphalt mixtures.

• The indirect strength of fibrous mix is 39.4% higher than the plain mix. • The rut-depth of fibrous mixtures satisfied the 12.5 mm specification of TxDOT. • The glass fiber is utilized as a strengthening material for the 50% recycled asphalt mixture. This study presents strengthening effect on the reclaimed hot-mix asphalt concrete associated with the reinforcement of hybrid rod-shaped glass fibers and ball-shaped glass-fiber powder to the mix. The toughening effects of the reinforced mixtures were characterized using indirect tensile, dynamic modulus, and hamburg wheel-tracking tests. The rod-shaped hybrid fibers, coated by the polypropylene resin, consist of the macro dimension of rod-shape glass fiber in 10–15 mm of length and the relatively micro size of the fiber in 4–6 mm of length separately. The ball-shaped glass fiber powder, which was coated by the polyethylene resin, was mixed with the macro and micro rod-shape fibers and the reclaimed hot-mix asphalt concrete. The indirect tensile strength test of the fibrous mixtures resulted in about 1.4 times higher strength than those of the plain mixtures. Lower moisture susceptibility, better performance of dynamic modulus at low and high temperatures and superior rut resistance of the fibrous asphalt mixtures were also observed. [ABSTRACT FROM AUTHOR]