AN ANALYTICAL APPROACH TO EVALUATE THE PERFORMANCE OF COLD RECYCLED ASPHALT MIXTURES

摘要

Road construction is a field of civil engineering, more than others, where is potentially possible to put into practice an effective policy of environmental protection, including significant technical-economic benefits. Considering just the huge quantity of materials employed in embankments and pavements constructions, it should be considered the opportunity to recycle waste products from industrial process or from demolition of civil buildings, which would be otherwise defined "waste". According to this purpose, already existing from several years, in-place and in-plant recycling of road pavements is a very interesting technique. Indeed, it is one of the rare example of cheap regeneration of a structure, without implying charges of transport and disposal of milled material out of the road plant. The demolition product of bituminous layers of aged road pavements in the form of milled particles, usually called RAP (Reclaimed Asphalt Pavement), is re-employed, at present, to realize new base courses or binder courses of asphalt pavements by means of a cold stabilisation process, using cement or bituminous emulsion. The state of practice of in-place cold recycling is extremely active in Europe, particularly in countries where there are fair climatic conditions (i.e. Italy and Spain). Instead the mix design has not been perfected yet and many design aspects have to be quite defined (RAP grading curve, wetting condition, binder quantity and compactive effort), especially in bituminous emulsion stabilisation. Scientific research contributions are essential to fill the current distance between practice in construction and design. With this purpose, the present memory summarizes the results of an experimental study about performances of cold recycled asphalt mixtures with bituminous emulsion and cement, highlighting the specificity of interaction between RAP and binding phase.