## 1 Introduction  
Currently, political policies aimed at curbing the abuse of natural resources, along with problems associated with increasing quantities of waste and their disposal, have given rise to a conscientiousness leading to the reevaluation of these wastes.  
Wastes generated from abandoned mines greatly impact the environment [1]. One of the most important effects of mining is the vast quantities of waste that is generated during the process of extracting ore from the minerals [2]. These residues often have a significant environmental impact because of the elevated concentrations of heavy metals that they contain [1; 2; 3].  
In the case of the mining district of La Union, situated in the region of Murcia (Spain), the mining developments are about 3000 years old, making this region one of the oldest mining regions in Spain. The exploited minerals were principally sulfurrous ores rich in silver and lead. Mining activities in this area ended at the end of the 20 th century due to social and environmental pressure [4]. Mining operations in this area have exacted a toll on the landscape, causing the collapse of mine workingsthrough subsidence and these effects persist in the area. [PERSON] et al. [5] used the SAR interferometry technique for monitoring subsidence of the mining galleries and mapping ground movements in open pit mining in La Union [6]. Additionally, high concentrations of Pb, Zn, Cu, and As [7; 8] have contaminated the soil and the aquifers [9; 10]. Currently, there is interest in developing the site into a tourist attraction, but this activity is on hold until the environmental damage due to mining activities is ameliorated.  
Increasing demand and cost, as well as the lack of good-quality aggregates for use on wearing courses, are factors to take into account in promoting the re-use of wastes. As a consequence of the success of some studies in incorporating waste products in construction materials in order to reduce the demand on natural resources [11], many studies have aimed at the incorporation of wastes in bituminous mixes [12]. Some successful examples of using wastes in the manufacture of bituminous mixes are the use of bituminous slurry surfacing with crumb rubber for reducing the noise of the wearing course [13]; using waste materials for low temperature bituminous mixes production [14; 15; 16]; and using alternative fillers to improve the mechanical properties [17], such as sewage sludge ash [18].  
There are a large number of existing studies that have examined the total or partial substitution of natural aggregates with waste products [19]. The use of slag [20; 21; 22], municipal solid waste ash left after incineration [23], left-over waste from marble production [24; 25], plastics [26; 27], glass [28], and demolition rubble [29; 30] are some examples of wastes used in the fabrication of bituminous mixes.  
Taking into account the trends in the industrial sector and the fact that the mining district in La Union has a large volume of waste material for use, in this study, we investigate the use of mine tailings as an aggregate for making hot bituminous AC16S-type mixes for use in wearing courses.  
Since the mine tailings have a suitable Polished Stone Value (PSV) for using as a coarse aggregate in wearing courses, the aim of the present work was to investigate the feasibility to design AC16S-type mixes with two different wastes from La Union mine district (Spain)--using Spanish guidelines. In particular, the fatigue resistance measured using the four point beam fatigue test on prism-shaped specimens is examined in all the mixtures manufactured. The use of these wastes could minimize the extraction of raw materials and they could serve as an alternative for the large volume of mine tailings accumulated. This opens up a possible means of environmental restoration in the La Union mining district.