Technical and Economical Evaluation of Cold Recycled Asphalt Using Emulsified Bitumen through Response Surface Method

One of the conventional recycling methods of asphalt mixture is the reuse of reclaimed asphalt with cement as a method for treatment of the base layer and its replacement in pavement layers. In this research, cold recycled asphalt mixture with using emulsified asphalt binder has been investigated through response surface method. In this regard, the technical and economical aspects of fabricated samples of recycled cold asphalt mixtures using crushed asphalt materials, cationic emulsified binder and Portland cement (type II) were investigated. Marshal strength and flow, bulk specific gravity and air voids of mixture were determined by experiments. By performing analysis of variance on the proposed models and determining the effective parameters, mathematical equations between independent and dependent parameters were developed and the effect of the parameters was investigated. Finally, an optimum mix design, which has 60% desirability, was suggested for cold recycled asphalt. Results showed that emulsified binder and cement content have significant effect on the marshal strength. Also, water exhibit a significant effect on the flow of asphalt mixtures.