Date of Completion


Embargo Period



Norman W. Garrick;Nicholas E. Lownes

Field of Study

Civil Engineering


Master of Science

Open Access

Campus Access


Performance Comparison of PG 64-22 versus PG 64-28 Asphalt in Hot Mix Asphalt Placed in Connecticut


Eight test sections were constructed on Route 59 (Easton) and Route 341 (Kent) in Connecticut in 2006. Within each location there were two sections with PG 64-22 and two sections with PG 64-28 binders. Route 341 is located in the northern part of Connecticut close to the New York State Line, whereas Route 59 is located in the southern part of Connecticut. Field performance data in terms of the amount of cracking, rutting and roughness, was collected on all test sections immediately before and after the construction in 2006 Significant amount of material was also collected during the construction for further evaluation in the laboratory conditions. Several laboratory parameters were evaluated, including low PG temperature, high PG temperature, critical cracking temperature, tensile strength ratio, and APA rutting. In order to compare the performance of PG 64-22 and PG 64-28 asphalt, the field performance data and laboratory parameters have been statistically analyzed and compared. It was found that the field cracking, roughness and rutting performances of PG 64-22 and PG 64-28 sections on Route 59 were not statistically different. Similarly, tensile strength ratio and APA rutting measured in the laboratory on PG 64-22 and PG 64-28 materials from Route 59 were not statistically different. However, field cracking and roughness on Route 341 were different for PG 64-28 and PG 64-22 sections while the laboratory parameters were the same. It was also found that field cracking correlated weakly with laboratory parameters such as true low PG, TSR (%) and critical cracking temperature.

Major Advisor

Adam M. Zofka