Pavements can last longer than the generally accepted 20 to 40 years life spans for new construction when designed to maintain their structural integrity over time, and when properly and periodically maintained. In general, long-life design strategies ensure that the pavement structure remains free of internal distress over time while the surface is periodically maintained.
Long-life rigid pavement design can be achieved by increasing the thickness of concrete or by using continuously reinforced concrete or steel fiber reinforced concrete. While the initial cost will be higher than for conventional 40-years design, the long-term cost savings will likely be significant.
The concept of “perpetual pavement” is used for flexible and composite pavements which draw their strength primarily from layers of hot mix asphalt concrete. To maintain integrity over time, these layers of asphalt are thick enough to prevent bottom-up alligator cracking from initiating at the bottom of the asphalt concrete structural layer. A sacrificial surface layer is normally used to provide friction and protect the pavement core from the elements.
Why Use it?
The more durable the pavement structure, the less frequent and costly will be the maintenance and rehabilitation activities needed to keep the pavement open and functional. User costs will also be minimized by reducing the frequency and duration of traffic closures. When a pavement reaches the end of its life, strong and durable structures will provide a solid foundation for re-construction and a good material source for recycling and reclaiming.
How to use it?
It is generally more sustainable to find long-term solutions and to strive for longer design lives. In Green Up users can input the expected life extension for a specific rehabilitation scenario which will reflect in the color of the heart symbol, ranging from red for short-term solutions to green for strategies that will extend the life of the structure by 30 years or longer. Consider design alternatives that result in longer life extensions.
Where to learn more and who to contact?
To estimate the life extension for a specific rehabilitation strategy the following resources are available for free, online:
To design a “perpetual” flexible pavement:
- PerRoad software and online help and guidance
European research on steel fiber reinforced roller compacted concrete for long-life pavements:
- ECOLANES Project 315030
Life cycle cost analysis resources (LCCA):