Asphalt concrete pavement reinforcement through the addition of micro-fibres and steel meshes

Nowadays the deterioration of the asphalt concrete superstructures is a critical problem in the area of road construction. More specifically, the causes of the degradation can be addressed to the increase of traffic, of axle loads and/or to the use oflarger wheel paths, the influence of the thermal stresses being also important in this negative phenomenon. Form this standpoint, there is a wide diffusion of the so-called "macro-reinforcement techniques ", which have recourse to both different dimensions fibres and meshes inside the asphalt concrete wearing course. So as to assess the real benefits belonging to the application of these techniques, this study is focused on the flexural analysis of traditional and reinforced asphalt concrete specimens by means of the "Three Point Load Apparatus ". the reinforcements used for the process varying. Afterwards, starting from the results obtained from constant strain load tests, some specific parameters taken from the theory of steel fibre reinforced concrete, and accurately adapted for the purpose, were defined; their use allowed the Authors to clearly identify the post-crack resistance of the reinforced asphalt concrete specimens. In conclusion, knowing the load, the deflection and the first-crack toughness, thanks to the comparison of the "toughness indices" and of the "residual strength factor", a classification of the different typologies of reinforcement has been performed identifying, amongst them, the ones whose mechanical performances are more reliable from the viewpoint of the flexural resistance.