Impact of recycled glass and carbon geogrids on crack propagation resistance in asphalt concrete

The paper analyses the impact of recycled geogrid fibres on the mechanical and physical properties of asphalt concrete. Survey results indicate that the knowledge in this area is very limited. The presence of geogrid fibres from milling is an increasingly common challenge for the design of new pavements from asphalt mixtures containing recycled asphalt pavement. The adopted research procedure provided for the selection and optimisation of the content of recycled glass and carbon geogrids added to the asphalt mixture. Two reference asphalt concrete mixtures for the binder course were designed: AC 16W 35/50 KR3-4 and AC 22W 35/50 KR3-4. The research process was controlled using a factorial experiment design, including two qualitative variables: geogrid type and grain size distribution in the asphalt mixture, and two qualitative variables: share and length of geogrid fibres. The mixtures designed and prepared under laboratory conditions were subject to the test of crack propagation resistance using the SCB method. The research also included an assessment of associated properties: air void content Va, water resistance ITSR and rutting resistance PRDair, WTSair. The results of the analysis indicated a potential way to improve the fracture toughness of asphalt concrete for the binder courser by optimising geogrid parameters. Also, the potential use of recycled geogrid to make asphalt mixtures enables the implementation of sustainable development principles in the road construction sector.