EXPERIMENTAL INVESTIGATION ON THE USE OF C&DW MATERIALS AS AGGREGATES FOR ROAD SUB-BASE

More than 95% of road infrastructures materials consist of aggregates. Highway and construction industries consume annually a huge amount of aggregates, causing considerable energy and environmental losses (Hüseyin et al, 2007). Many country are substituting quarry aggregates with construction and demolition waste (C&DW) materials. However in Italy there is the need to overcome the distrust for the use of C&D materials. Thus, the aim of this research is to evaluate the suitability of construction and demolition waste (C&DW) materials, produced in Sardinia (Italy), from the physical and mechanical point of view. Laboratory tests were conducted to evaluate physical characteristics and also an experimental road has been built to evaluate mechanical performances in situ. The research has been divided in two main phases: in the first phase laboratory tests were carried out such as Sieve analysis, Limits of Atterberg, CBR test, L.A. abrasion test. In the second phase in situ tests were carried out consisting of: dry density of soil by sand replacement method and both static and dynamic plate tests. Other tests were carried out to study the behaviour of the material during its use (short term behaviour and in the long term), in order to evaluate environmental compatibility of the material in place under working conditions, as well as the mechanical performance in situ or in a real scale test. The first results are encouraging, the material is non-plastic, the Los Angeles abrasion test shows the tendency to fragmentation of the aggregates, but within the limits, therefore allowing their use in road sub-grade layer also the material shows good bearing capacity. The introduction in the market for the construction of roads of solid waste materials helps to limit the exploitation of renewable natural resources