Asphalt mix is the most widely used material for pavement construction in the world. The conventional asphalt mix is produced using different sizes of aggregates that are sieved, dried, heated, and coated with hot bitumen to bind them together into a dense matrix. The production, construction, and maintenance of asphalt pavement involves high amount of energy consumption, exploits our natural resources, and emits various greenhouse gases in the atmosphere. Due to the above-mentioned environmental concerns, the asphalt industry is continuously looking to shift towards sustainable pavement technologies. The recycling of asphalt pavements has been considered as one of the most effective ways to reduce the carbon footprint associated with life cycle of pavement construction. When a pavement reaches the end of its lifetime, it is no longer able to efficiently carry the traffic loads and should be replaced with a new hot mix asphalt layer with or without replacement of underlying layers. The old pavement is demolished, and the milled asphalt is generally either disposed to landfill or reclaimed in lower value applications such as unbound base layer of pavement, road shoulders, embankments, etc. However, the milled asphalt consists of valuable aggregates and binder that must be aimed to re-use in same application to support the idea of circular economy. This doctoral thesis focused on developing a framework to improve the current recycling methodology and increase the use of reclaimed asphalt in the pavement mixtures. To achieve this goal, the primary task was to study the effect of laboratory mixing conditions on high content (60%) reclaimed asphalt mixtures properties to control the mixing parameters while performance comparison. The second task was to combine warm mix asphalt with high content reclaimed asphalt mixture and compare the performance to the conventional hot mixture to warm mixtures. The third task was to design and produce 100% of reclaimed asphalt mixtures using rejuvenators from various sources and compare the performance to conventional hot mix asphalt. The fourth task was to study the effect of aging on properties of 100% reclaimed asphalt mixtures and its leaching assessment. Finally, a life cycle assessment was carried out for different scenarios of recycling asphalt pavements in order to compare the environmental benefits during the pavement life cycle.