- 期刊
Factors Affecting Cracking of Notched Asphalt Concrete
並列摘要
This study described the testing and analysis of cracking in asphalt concrete samples in the laboratory. Semi-circular notched specimens were prepared using a Superpave Gyratory Compactor and a water-cooled masonry saw. Samples were prepared with varying material properties including air void content, mix type, and moisture condition. The specimens were tested in three-point bending and a crack was initiated at the notch tip located in the center of the flat edge of the specimen. Load and horizontal displacement data were collected in real time at different locations. The resulting load versus displacement curves for each specimen yielded parameters that were used to determine which mix type is least susceptible to crack initiation and propagation. Three different Superpave mixes with a wider range of air voids were tested under wet and dry conditions. Air voids have little effect on crack initiation and ultimate strength of a specimen, but cracks propagated faster in specimens with higher air voids. Wet samples were shown to resist failure due to cracking by exhibiting increased ductility, yet the slope of the crack propagation curve revealed that damage due to crack propagation is more extensive in wet samples. Cracking caused more damage in coarser mixes due to increased interface cracking.