According to the National Asphalt Pavement Association, out of the 2.8 million miles of paved roads in the US, approximately 94% is surfaced with asphalt. Also, 2,664 out of the 3,330 runways of the Federal Aviation Administration (FAA) are surfaced with asphalt, as well. This is how important the evaluation of asphalt-cracking resistance is. There are different types of asphalt tests out there and depending on the location, use and cost one may be better than the other.
During the winter season, just like in Minnesota, low-temperature cracks can lead to pavement damage. This pavement distress can then lead to minor or even major accidents. Engineers are recommending effective testing methods to improve the resistance of asphalt pavement to low-temperature. These tests examine the performance of mixtures and structures designed to better handle the cold. The Minnesota Department of Transportation (MnDoT) was using disk-shaped compact tension (DCT) but found indirect tensile asphalt cracking test (IDEAL-CT) to be more convenient and reduced wait time.
In an article featured in Minnesota’s Transportation Research Blog, MnDoT assessed IDEAL-CT to see whether it can be added to a series of tests as part of a new balanced mix design (BMD) approach. They write, “Low-temperature testing of mixtures found that samples from each season resisted aging well and offered good to excellent cracking resistance when mixtures included optimal asphalt binder content. In the 2018 asphalt mixtures, results showed that the time between molding and testing samples can vary by as long as two weeks without affecting IDEAL-CT results. Cracking resistance in the 2018 mixtures generally improved with higher binder content.”