Prediction of Pavement Fatigue Life with Simulated Temperature Profile from Hourly Surface Temperatures

Publisher's full text
Åke Hermansson
Jesper Elsander

A typical model for predicting the fatigue life of an asphalt pavement involves mid-depth temperature and the elastic horizontal strains at the bottom of the asphalt layer. Strains are studied at the bottom of the asphalt layer as cracks are assumed to originate there. Pavement temperatures naturally experience daily fluctuations as a result of varying air temperature and solar radiation.

The amplitude of the oscillation decreases with depth and maximum temperature is reached later in the day at greater depth. During warming up, strain levels under loading increase as stiffness decreases, while the bottom of the asphalt layer is rather cold and thus sensitive to strains. At cooling down, strain decreases and the bottom layer is warm and withstands strains more easily. It is therefore proposed in this paper to use the temperature at the bottom of the asphalt layer instead of the mid-depth temperature when calculating fatigue damage. It is also proposed to use the complete temperature profile to improve the calculation of strain levels under loading. As the fatigue damage caused each hour will vary with temperature during the course of the day, it is also pointed out that the calculations might be improved by relating the distribution of traffic to the distribution of incremental fatigue damage.

A simulation model calculating the temperature profile and strain levels was developed and run for three different pavements with different thicknesses of asphalt layer. It was found that the distribution of incremental fatigue damage over a typical summer day could be completely different for different pavements.

MEET US


25-27
Aug

ICTTP 2020

ICTTP, International Conference on Traffic and Transport Psychology, is held in Gothenburg, Sweden.

LATEST NEWS


2018-11-19

Report regarding government commission on the costs of traffic to society has been submitted

Since 2013, the Swedish National Road and Transport Research Institute (VTI) has had several government commissions to produce documentation on the costs to society caused by traffic. On 1 November 2018, the agency reported its latest commission, Samkost 3....


2018-10-29

International standardisation efforts have many advantages

VTI participates in several international standardisation committees. The work is important because it helps to ensure that standards can be adapted to Swedish conditions and it also provides access to valuable contacts and networks.


2018-10-24

China wants to work with the best

Through the CTS cooperation, VTI is gaining valuable research contacts with China. The country is facing major challenges in the field of road safety but also has enormous potential.


2018-10-23

VTI participated in conference on electric roads

Systems with electrified roads are a relatively new concept and many projects have been launched in recent years. To stimulate the transfer of knowledge and collaboration, the Research and Innovation Platform for Electric Roads arranged its second...


2018-10-18

ADAS&ME is tackling the interaction between people and technology

ADAS&ME is a major EU project focused on automation, the human condition and the human environment. The budget is EUR 9.6 million and VTI is the coordinator.


2018-10-05

Users contribute to the development of train simulators

Apart from advanced driving simulators, VTI has developed several variations of train simulators which are used for training, education and research. In recent years, interest has increased drastically among major actors in the railway sector, and VTI has...