Innovative cement-based material as environmental and efficient technical alternative for pavements

Over time, pavements must guarantee smooth and safe driving surface. Often, considering the remarkable age of the Italian road network and the increasing damage rate due to the increase in traffic over years, reaching adequate safety and comfort standards requires maintenance actions that involve also deep pavement layers. Consequently, the intervention becomes too burdensome and costly. In this context, ANAS, the main Italian road agency, is constantly promoting innovative design solutions aimed at maximizing technical efficiency and environmental sustainability (longer service life and reduced maintenance needs). For these purposes, particularly performing and eco-sustainable materials for binder and base layers can substitute traditional HMA guaranteeing thinner layers with, at least, same final performance. Specifically, a cement-based material, developed through laboratory studies and real-scale experiments, has been tested. It is a mixture of aggregates, potentially even entirely composed of RAP, mixed at room temperature with a specific bituminous emulsion and reactive filler. It combines rigid and flexible pavements benefits, with environmental and technical advantages: ● reduction of execution time (fluency, no need of compaction efforts); ● less air pollution (cold mix); ● high stiffness modulus (reduction in layer thickness); ● high elasticity (high fatigue resistance) and rutting resistance; ● resistance to chemical aggression and atmospheric agents; ● combination with high percentages of RAP (reduction of virgin materials); ● no temperature sensitivity of the layer. All these peculiarities mean longer service life compared to traditional pavements and make this material particularly suitable for accomplish environmental goals established by the new regulations in the context of the European Green Deal. First laboratory studies were started in 2014. Afterwards, full-scale trial sections were realized also involving an Anas road segment still under monitoring (i.e. SS3 “Flaminia”, pk. 136 + 100 to 136 + 600). Optimum performance were detected in terms of bearing capacity, fatigue, rutting and cracking. Other trial sections are scheduled in the coming year to confirm the potential of this material, particularly useful where deep and time consuming maintenance actions cannot be carried out. This paper describes the material potential, with particular reference to the results obtained with Accelerated Pavement Testing with FastFWD on the trial sections involved in the project.