Abstract
This study involves the evaluation of fracture behavior under cyclic loading using the disk-shaped compact tension (DC(T)) test and a released energy based analysis approach. The cyclic DC(T) test was developed based on the monotonic DC(T) test (Wagoner and Buttlar, 2005); however, some modifications to the geometry and testing mode were necessary to facilitate the cyclic fracture test. The research was motivated to explore possible extensions of the DC(T) test device to consider cyclic fracture phenomena such as cyclic thermal cracking, block cracking and reflective cracking. Five different asphalt concrete mixes were tested under cyclic loading at four test temperatures (-12, 0, 10, and 20°C). After an extensive exploratory stage, the load-controlled testing mode utilizing a sine waveform and a frequency of 0.5 Hz with no rest period were selected as the standard testing parameters for this study. In addition, a peak load obtained from the monotonic DC(T) test was used as a reference value for determining loading magnitudes of the cyclic DC(T) test for a given mixture and test temperature. For data analysis, a released energy approach was introduced as a key concept for characterization of the cyclic fracture data generated in this study. Stemming from this approach, a released energy rate parameter, R2, was identified with the characteristic of mixture and temperature independence. By correlating a fracture energy based parameter to released energy rate (R2), it was shown that cyclic loading behavior could be predicted based upon three different data sets deriving from the DC(T) test: one involving a comprehensive cyclic loading testing suite; a slightly simpler method involving a limited number of required cyclic tests; and a highly simplified approach where cyclic fracture behavior was predicted from monotonie fracture test results alone (standard DC(T) fracture energy). All three prediction methods were shown to be plausible, but as expected, the more rigorous the testing suite, the more accurate the prediction. Finally, practical extensions of the work for design and analysis are provided.
Original language | English (US) |
---|---|
Pages (from-to) | 593-614 |
Number of pages | 22 |
Journal | Asphalt Paving Technology: Association of Asphalt Paving Technologists-Proceedings of the Technical Sessions |
Volume | 84 |
State | Published - 2015 |
Event | Asphalt Paving Technology 2015, AAPT 2015 - Portland, United States Duration: Mar 8 2015 → Mar 11 2015 |
Keywords
- Asphalt
- Block cracking
- Cyclic
- DC(T)
- Fatigue cracking
- Fracture
- Fracture energy
- Hysteresis loop
- Reflective cracking
- Released energy
ASJC Scopus subject areas
- Civil and Structural Engineering