USING MODIFIED EMULSION TO IMPROVE COLD IN PLACE RECYCLING PROPERTIES (CIR)

Abstract

Cold in place recycling recycle old existing pavement layers by addition water, additives and emulsions without heat to create new binder layer. It is used in local streets, airports, parking and highway roads. CIR layer should has high stability and resistance to the moisture damage. In the research, cationic slow setting emulsion (CSS-1h) is used with copolymer styrene-butadiene rubber (SBR) to improve the stability by 39%, and the resistance of the moisture damage by 40% for CIR mix compared to emulsion only without using copolymer. Modified emulsion increases indirect tensile strength (ITS) between particles with each other by 32% for CIR mixtures, also improves cracking resistance, and rutting resistance by 71%. In Egypt, the usage of CIR layer decreases the cost, the time, increases life time of the pavement with overlay, and saves the energy in addition to environmental benefits compared to alternative maintenance methods. CIR process saves the cost by 25-40% using asphalt emulsion and 33-48% using foam bitumen.