FOAMED ASPHALT STABILIZED RECLAIMED ASPHALT PAVEMENT: A PROMISING TECHNOLOGY FOR MID-WESTERN ROADS

Recycling of the materials obtained from the milling of asphalt pavements, known as RAP (Reclaimed Asphalt Pavement), involves mixing RAP with asphalt cement/emulsion and aggregates in definite proportions to produce a new asphalt concrete mix or cold-in place recycled mixture. However, in many cases, the RAP is unusable because it is not uniform (i.e. it may originate from different sources) or the underlying pavement does not provide adequate structural support. One solution to this inadequate support problem is construction of a base with full depth reclamation (FDR) materials stabilized with foamed asphalt. The process is also suitable for moist materials since the moisture is needed to accomplish base compaction. A research project was initiated at Kansas State University to estimate the structural contribution of the foamed asphalt stabilized bases in a typical pavement structure. Four pavement test sections, three with foamed asphalt stabilized bases and one with conventional crushed stone base, were constructed at the Civil Infrastructure Systems Laboratory (CISL). Falling Weight Deflectometer (FWD) tests were conducted before accelerating loading of these test sections. The layer moduli were backcalculated from the FWD deflection data and the structural layer coefficients were estimated