Performance Evaluation of 60-70 Pen. Asphalt Cement in Cold In-Place Recycling with Foamed Asphalt

The main objective of this study is to determine mix design parameters for cold recycling with foamed asphalt. First, the foaming process of laboratory foaming equipment was validated by varying the water and asphalt content. 3% water content was adopted to create the optimum foaming characteristics in terms of the expansion ratio1 and the half-time2 at 170°C under air pressure of 700 kPa and water pressure of 800 kPa. The mix design was then performed using both the indirect tensile test and the Marshall test for 36 combinations of foamed asphalt and cement content for two different gradations with two compaction methods. Effects of above-mentioned parameters were studied; maximum resilient modulus and maximum Marshall stability were both obtained around 2% foamed asphalt content.