IF articles

Summary - The service life of a road and rail superstructure is strongly affected by the bearing capacity of the subgrade. The action of thickening the soil is an operation of absolute importance, because in addition to ride comfort, it ensures stability and the absence of failure, i.e., the functionality of the superstructure during operation. Often, the soils encountered during the construction of a road infrastructure are not suitable to guarantee, over time, the bearing characteristics necessary to ensure satisfactory durability and regularity of the work itself. In recent years, the use of aggregates from recycling of construction and demolition waste (C&D) has become increasingly popular for both economic reasons and environmental sustainability. Therefore, this study aims to analyze the compaction procedures of mixtures of natural and/or recycled materials to be used for the construction of road and rail embankments or foundations with suitable performance characteristics. The experimental investigation was conducted at the Laboratory of Road Construction of the University of Basilicata. Numerous mixtures were studied, the composition of which for five of them was optimized in addition to the Proctor test, with the dynamic/impulsive Vibrating Hammer test, which allows different stresses to be imparted to the soil than traditional ones. The materials investigated are pozzolan alone and mixed with C&D, clay loam soil and granular quarry mix (limestone). Expecting that the effectiveness of compaction with the Vibrating Hammer depends on both the type of material compacted and the compaction time, the authors investigated the possibility of optimizing pozzolan and C&D mixtures. Specifically, they identified the compaction technique that allows the material to provide the best bearing performance and, with reference to the impulsive compaction technique, defined the optimal compaction time.

Key Words: Compaction, Proctor test, Vibrating Hammer, C&D, Optimal compaction time.

https://www.medra.org/servlet/view?lang=it&doi=10.57597/IF.12.2023.ART.1