# Comparative \"from Cradle to Gate\" Life Cycle Assessments of Hot Mix Asphalt (HMA) Materials
###### Abstract  
The objective of this work is to compare the environmental impact of two different hot mix asphalt (HMA) materials used for road construction in Italy. The analyses used a \"from cradle to gate\" Life Cycle Assessment (LCA) boundary system and the methodology included considerations about raw materials and fuel supply, as well as transport and manufacturing processes. Primary data provided by the producers and secondary data available in the literature were used as part of the analyses. The results suggest that the proposed method offers rigorous criteria for a comprehensive assessment of the environmental impact of HMA materials, which could be used, among others, as an evaluation parameter in public bids. p 2017 9 400 (10.3390/su9030400) 9000-0001-3990/11/0000-0001-3990/11/00000-00001-3990/11/00000  
Unfortunately, the Green Public Procurement (GPP) has been poorly applied in contracts related to construction works, mainly due to two reasons [6]:  
* difficulties in obtaining services/green products suppliers; and
* procedural difficulties in the implementation of GPP. Despite this situation, the new Italian Public Procurement Code requires the administrative authorities to effectively contribute to the achievement of the environmental objectives set out in the Italian NAP GPP. These action plans, adopted by the Interministerial Decree of 11 April 2008 [7], aim at maximizing the use of GPP among public bodies in order to improve environmental, economic and industrial efficiency. The Italian GPP NAP, that was updated through the Decree of 10 April 2013, issued by the Italian Ministry of the Environment and the Protection of Natural Resources [8], contains the Minimum Environmental Criteria (MEC) requirements that should be included as part of public bids. Specifically, the Italian GPP NAP has identified a set of MEC for contracts related to the following \"product categories\": furniture; construction (construction and renovation of buildings with a focus on building materials); waste management; urban and energy services; electronic equipment; textiles and footwear; office furniture; food and catering services; building management services; and transport. For building materials, the MEC does not currently provide any formal requirement applicable to bitumen bounded road materials, which is the topic of this work, since it only stipulates regulations for cement concrete. At the international level, the Environmental Declaration of Building Products, which makes part of the Sustainability in Building Construction Specification ISO 21930:2007 [9], does not either include regulations for road materials. As can be observed, the achievement of ambitious environmentally friendly road projects in Italy, as in any other European country, is still an on-going effort. Indeed, there are several gaps and challenges in current regulations that need to be faced, especially in some of the most complex processes which include many materials and works [10]. Thus far, for example, the assessment of road sustainability is limited to the evaluation of the environmental impact assessment that should be carried out in the case of major projects. These assessments focus on the principle of environmental compatibility, which is the ability of a system or structure to get integrated into the environment without negatively affecting or damaging it [11]. Nevertheless, the fact that this approach is only applicable when the infrastructure project under consideration has national significance, restricts the possibility of having a more comprehensive vision of an Italian environmental strategy for public construction projects [12]. The implementation of such an integral vision, however, should consider that the environmental criteria go beyond the environmental performance of materials and/or construction products.