Low temperature performance of asphalt concrete under direct tension loading

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: YALÇIN KARAKAYA

Danışman: MURAT GÜLER

Özet:

Thermal cracking is one of the major distresses in asphalt pavements and has been a serious concern especially in cold regions. There are two different mechanisms for temperature cracking in the field: Low temperature cracking associated with severe temperature drops and thermal fatigue cracking in reaction to repeated temperature cycles. In this study, in order to investigate the thermal tensile properties of asphalt concrete, Direct Tension Test (DTT) is utilized in a TSRST experimental setup. Naturally-aged asphalt concrete specimens including varying design variables of aggregate type, gradation, asphalt grade, and asphalt content is fabricated based on the Superpave method of mixture design. For each specimen the toughness and the peak stresses are calculated from the DTT test results. Then, using the statistical analysis of variance the effects of input parameters on the two output responses are investigated. Finally, the DTT results are compared with previous low temperature and thermal fatigue test results to check if any correlations exist between different methods of testing procedure. The statistical analyses indicate that while gradation, asphalt grade and asphalt content significantly affect the peak tensile stress, for toughness aggregate type and gradation seem to be the significant factors. The results of this study have shown that DTT does not correlate with the results of low temperature cracking test, nor with thermal fatigue cracking test.