Materials and Procedures for the repair of potholes in Asphalt-Surfaced pavements.

Perma-Patch , a permanent cold patch for instant repair of potholes, was a material used in the extensive tests and reports undertaken in Project H-106 " Innovative Materials Development and testing" October 1993

 In an important decision; necessitated because of the need to repair roads economically, rather than completely rebuilding them; The Federal Department of Transportation obtained 5 million dollars from the congress on the advice of the National Research Council, to study the best materials and equipment for repairing potholes. This resulted in publications of SHRP-H-348(Strategic Highway Research Project) under the auspices of the National Academy of Sciences, United States Government, and the American Association of State Highways and Transportation Officials, known as project H105 and H106

Excerpts from Strategic Highway Research Program SHRP-H-348 of the National Research Council

 In project H-105, "Innovative Materials and Equipment for Pavement Surface Repair," the researchers conducted a massive literature review and a nationwide survey of highway agencies to identify potentially cost-effective repair and treatment options. The information and findings from this study were then used in the subsequent field experiments conducted under project H-106, "Innovative Materials Development and Testing."

In the H-106 project, the installation and evaluation of many different test sections were conducted to determine the cost-effectiveness of maintenance materials and procedures. Test sections were installed at 22 sites throughout the United States and Canada between March, 1991 and February, 1992, under the supervision of SHRP representatives. The researchers collected installation and productivity information at each site and periodically evaluated the experimental repairs and treatments for 18 months following installation.

As asphalt pavements age and deteriorate, the need for corrective measures to restore safety and rideability increases. Funding for rehabilitation and overlay of these pavements is not likely to keep up with the demand, requiring more agencies to use the most cost-effective methods when patching distressed areas. The patches will also be expected to survive longer and carry more traffic loadings.

The cost most commonly associated with pothole patching is the cost of purchasing material. This is usually one of the least significant contributors to the overall cost of a patching operation. However, the material used for patching does impact the cost of the overall operation when there are differences in performance. More expensive materials that are placed with less effort and last longer can reduce the cost of the initial patching effort, as well as the amount of re-patching needed. This reduces the labor and equipment costs for the overall operation.The graph shows the percentage of failure of the materials chosen from the study by the Federal SHRP project, approximately 18 monthsafter installation. The Chart shows Perma-Patch to have the superior durability of all the innovative materials tested. 

Failure Rate of Commonly Used Pothole Patch Material

 These graphs shows the percentage of failure of the materials chosen from the study by the Federal SHRP Project, 18 months and 4.65 yrs, respectively after installation. They show Perma-Patch® to have the superior durability of all of the innovative materials tested. Slightly ahead of Perma-Patch® is the technique of spray injection using very expensive specialized equipment which is often unavailable due to mechanical difficulties and requires skilled operators. The graphs are taken from "Innovative Materials Development and Testing, Volume 2: Pothole Repair", in the SHRP-H-353 report of the Strategic Highway Research Program as reported by the National Research Council, Washington, D.C., 1993.