FRA clarifies on road materials used for potholes
Please be assured that we definitely are not using soil or dirt.
The material that you may have seen in potholes under repair, which is not asphalt, is a stone aggregate material known as AP40.
AP40 is the material that is used in road construction immediately beneath the asphalt layer, and there are a number reasons why it is currently being used in our pothole repair works:
■ It is used during periods of intense and prolonged rainfall that occurs over a period of several days or weeks. In this instance AP40 is a temporary fill and is placed for economic reasons, it does become dislodges if the rainfall is intense or persistent, but so does newly-laid asphalt under similar weather conditions. AP40 is significantly less expensive that Asphalt and can be easily reinstated.
AP40 is also used for deep potholes. If a pothole is more than two to three inches deep, we cannot effectively fill it with only Asphalt – Asphalt place in thick layers becomes deformed under pressure because it is a flexible filler. We use the AP40 stone to provide a solid base for the Asphalt layer that provides the flexible pavement and sealed the road structure. When using AP40 for this purpose we fill the entire pothole with the stone, compact it and then leave it to stabilise over a few days, and to be become more embedded by vehicle movement, then we remove the upper layer of AP40 and replace it with Asphalt to complete the repair.
■ There was a very short period, around the Suva Peninsula Coronavirus lock-down when we were unable to access the Rewa Asphalt Plant, so for that short period we used AP40 in some locations.