Improving pavements through an innovative asphalt graphene-modified thin layer: a case study

Road agencies must prioritize efficient pavement preservation while exploring innovative materials and techniques to reduce maintenance durations, costs, and traffic disruptions. This paper presents an innovative and original graphene-modified thin asphalt layer (GMTL), positioned between the binder and wearing course, offering great potential for restoring road pavements. Various tests were conducted both in the laboratory and on the construction site to assess the impact of the GMTL. Results show a remarkable volumetric behaviour of the GMTL, with mean void values of 14.3 % at 10 cycles, 5.6 % at 120 cycles, and 4.6 % at 230 cycles along with good mixture workability. Moreover, tests performed on core samples with GMTL showed an increase of 33.2 % in indirect tensile strength and 10 % in indirect tensile stiffness modulus values. The fatigue curves show particularly high performance with a very good resistance to cyclic loads in terms of both stress and deformation. Original tests were carried out using a falling weight deflectometer (FWD) to characterize the deformability and stiffness of the pavement in a trial section. According to the results, the GMTL raises the hot mix asphalt (HMA) base stiffness by 14 % and the binder modulus by 22 %. In addition, an increase of 26 % was observed in the rigidity of the cement-treated base layer.