Modified asphalt by coffee cup Fibres: An optimum mix design using response surface method

•The optimum amount of coffee cups to prevent draindown is 0.4%.•Coffee cups increased stability and air voids, dropping the flow number of asphalt.•Shredded coffee cups significantly reduced the draindown of the mixture.•0.4% coffee cups resulted in a very similar performance to the commercial fibre.•Plastics used to coat the coffee cups, increased the viscosity of bitumen.