Study of Cold Recycling Techniques: Third Part (Cold Recycled Mix Design Using Emulsions)

Abstract

Presently there is no universal or standard mixture design method for cold recycled mixes when using asphaltic emulsions as recycler additive. Nortwithstanding, most mix designs are based on the Marshall method but with procedures diferents from those used in the design of hot asphalt mixes. The present work correspond to the third and final publication on the subjet of cold recycling. In the first publication (Tenoux and García, 1999) the basic foundations of cold recycling were presented and in the second (Thenoux and García, 2000) appeared the component stages of a cold recycling project and the most important aspects that must be considered in each one. This third part, presents the results of a study centered on the research of mix design methodologies for cold recycled mixed with emulsions, to be applied in Chile. The related research, was carried out mainly at the laboratory. Five different emulsion were tested: CSS-1h, CMS-2, CMS-2h, CSS-1h with SBR (called Polymuls-Lh) and CSS-1h with polymers SBS (called CSS-1E). Once the briquettes were prepared and tested, the evaluation of their structural results concluded that the best results were obtained with the combined mix of CSS-1h emulsion and SBR polymers, reaching structural values (a2) around 0,35 (according to correlation with the AASHTO Structural Design Methodology). On the other hand, the lowest structural values (approximately 0,30) were obtained with the CMS-2emulsion.