## 1 Introduction  
Plastics cover a wide range of synthetic polymers, being used for the production of a very wide range of products that are extensively used in our everyday life. They are applied in many industry sectors, such as building and construction, electronics, automotive, agriculture, health, packaging, and energy [1], making the world plastic production increase year by year at a rate of about 4%, reaching almost 350 million tonnes in 2017 (65 million tonnes in Europe) [2]. After use, 42% of post-consumer waste plastics are incinerated and 27% are lost in landfills [1]. Only the remaining share (31%) is recycled. Packaging is the most demanded sector with 40% of all plastic production, 63% of all plastic waste, and 83% of all plastic that is recycled [3]. In terms of polymer, roughly 50% of plastic packaging waste from households is plastic film, mainly in the form of low-density polyethylene (LDPE) [3, 4]. Plastic film includes all flexible packaging, such as grocery bags, food storage bags, product wraps, cling wrap, etc. They are mostly single-use plastic products. Despite the benefits of plastics, the way some plastic products are produced, used, and discarded poses some problems. Most of them come from fossil sources being non-biodegradable, which leads to high contamination with ecological and health implications [5]. To minimize these problems, recycling rate targets have been imposed [6] and a transition to a circular economy has been fostered [7; 8]. In a circular economy, plastic waste is considered as a resource capable of substituting virgin material. As an alternative to virgin polymers, plastic waste has been used as additives to modify bitumen with the purpose of enhancing asphalt concrete (AC) mixtures with economic and environmental benefits [9; 10]. The modification can be done either by mixing the additive previously with bitumen (wet process) [11] or by adding the additive directly to aggregates during the blending process (dry process) [9; 12; 13]. The dry process is simpler and more economical than the wet one [9], being considered by many researchers to be the best one [14; 15]. The addition of waste thermoplastic polymers has been widely studied, e.g., polyethylene (PE) [15; 16], polypropylene (PP) [11], polystyrene (PS) [17], polymerizing vinyl chloride (PVC) [10], polyethylene terephthalate (PET) [18], as well as combined polymers [9]. Regarding plastic film waste, studies have been conducted using plastic film from the agricultural sector [12; 19] or focusing on specific plastic sources, like bags [20]. There appears to be a gap in the literature regarding the incorporation of plastic film waste (in flakes) collected as urban waste in AC mixtures, which represent a huge percentage of plastic packaging waste. AC mixtures are subjected to traffic loads as well as climatic loads over their lifetime. In contrast to traffic loads, which have been investigated in several studies, the effect of climatic conditions (moisture, oxygen, heat, cold, ultraviolet (UV) light, freeze-thaw cycles, etc.) during prolonged periods is not well established, mainly when the AC mixtures have additives incorporated, even though they contribute considerably to the degradation of the pavement structures. Moisture susceptibility, defined as the loss of mechanical characteristics of materials resulting from the presence of water in AC mixtures, is commonly evaluated using the indirect tensile strength ratio (ITSR). This susceptibility is a complex process that depends on several factors, such as aggregate mineral composition, bitumen grade, bitumen-aggregate adhesion, and air voids (not only the content but also their distribution and connectivity) as well as the interaction between them [21; 22; 23; 24; 25]. In general, plastic waste additives increase moisture resistance of AC mixtures [16]. But, regrettably, this is not always the case [9]. The incorporation of additives might increase AC mixtures behaviour complexity. [PERSON], et al.