Full Depth Reclamation (FDR) to Repair Road Damaged in the Energy Sector

Abstract

Rehabilitating the roadways in the energy sector is one of Texas Department of Transportation’s (TxDOT) top priority activities and is also a high profile activity attracting a lot of legislative oversight. Adding to this problem is that many of these roadways are often in remote areas where there is no access to quality paving materials. In addition, there is no detour and the roadway must be opened at end of work day. The FDR offers great potential to stabilize roadways in-place making use of existing materials and determining the optimal stabilizing agent to make these roadways structurally adequate. Although TxDOT has utilized the FDR for several decades, the performance results vary. Some FDR projects last over 10 years without any distress. However, there were several premature failure occurred within one month of trafficking. This paper presented a successful FDR project using foamed asphalt. The main reason of using foamed asphalt is its one-pass operations that can open to traffic immediately after compaction. Lab mix design was conducted to determine the optimum asphalt and cement contents. FWD tests were conducted to evaluate the change of foamed asphalt base. The determined modulus from foamed asphalt base can be used for future design purpose. The backcalculated moduli for foamed asphalt base increased from 493 ksi (2 weeks after construction) to 800 ksi (6 months after construction). District personal is very pleased with the performance of FDR using foamed asphalt.