A laboratory and field study on 100% Recycled Cement Bound Mixture for base layers

The infrastructure system has experienced an unprecedented development in the last fifty years. Most of the road pavements have been used for over twenty years and today require increasing maintenance to keep acceptable their levels of performance. In addition, the use of virgin and raw materials has been strongly restricted by raising price and eco-friendly policies. As a result, researchers and companies have focused their attention on recycling techniques with waste and second-hand materials that could lead to the construction and restoration of civil infrastructures without negatively affecting their mechanical properties. The study presented in this paper pursues this trend of research, by the evaluation of the performance of two different 100% Recycled Cement Bound Mixture (RCBM) for base layers. Data were always compared to those obtained for a traditional Cement Bound Mixtures (CBM) entirely made of virgin aggregates. The experimental programme was divided into two different and consecutive phases: a laboratory study and a trial field phase. In the first, the aim was the mix design and the physical and mechanical characterization of three mixtures. In the second phase, a full-scale trial field was realized: in situ tests and sampling were planned in four dates, corresponding to 0, 60, 180 and 365 days of trafficking. Based on results, the replacement of virgin aggregates with waste materials in CBMs, according to these specific mix designs seems to be a practicable solution for the construction of base layers with suitable performance