An investigation of the pull-out strength of asphalt concrete exposed to varying freezing and thawing cycles

摘要

The effects of freezing-thawing on the pull-out strength of the asphalt concrete were investigated. The pull-out strength and ultrasound velocity of the asphalt core samples were exposed to different freezing-thawing cycle and examined experimentally. 30 asphalt core samples of 10 cm diameter and with the length-to-diameter ratio of 1/1 according to ASTM C/42 42M criteria. Extraction tests were conducted according to ASTM D2172 using the centrifuge extractor with 3600 revaluations to determine the quantity of bitumen for all the core samples. The experimental results show that the samples with high pull-out strengths also have high ultrasound values. When the ultrasound velocity values are considered for the asphalt concrete cores, the samples with high ultrasound velocity also have high porosity ratios. When the samples are subjected to freezing and thawing cycles, the greater number of cycles result in a decrease in the ultrasound velocity showing that as the freezing and thawing cycles increase, the pores in the asphalt samples also increase.