When a pavement surface begins to develop widespread surface cracking due to subgrade failure, an asphalt fabric overlay is a reliable alternative to costly excavation and replacement of the cracked and deteriorated asphalt.
Most subgrade failures arise from surface water seeping down into the pavement's aggregate base course and weakening the foundation. Once this occurs, it is not long before surface cracking appears due to the weight placed on the pavement over this weak foundation.
An asphalt fabric overlay is begun by cleaning the existing surface of dust, dirt, vegetation, and moisture. In some instances large cracks are sealed to improve the performance of the fabric by supporting it underneath. A layer of AC 20, a hot, viscous liquid asphalt, is applied at a fairly heavy volume of .2 gallons per square yard. Then, while the AC 20 is still hot, the geo textile fabric is rolled on to the surface with the use of special application equipment. Wrinkles are smoothed out and then it is ready to be paved over. A minimum of 1.5 inches of asphalt is applied and compacted. During the paving process, the AC 20 melts from the heat of the new asphalt, and the compaction forces cause the AC 20 to soak through the fabric. This creates a waterproof membrane that effectively adheres to both the new and old asphalt pavements.
Long-term field evaluations have shown that the proper use of paving fabrics in asphalt overlays can increase pavement life up to 50%. Utilizing asphalt fabric overlays will reduce maintenance costs and improve the effectiveness of your pavement management system without the need to reconstruct.