Comprehensive evaluation of wheel-tracking rutting performance assessment tests: Fid-Bau Portal

Comprehensive evaluation of wheel-tracking rutting performance assessment tests

Alkuime, Hamza / Kassem, Emad

This study aimed to advance the implementation of the most promising wheel-tracking rutting assessment tests in the newly proposed Balanced Mixed Design (BMD) (or Performance-Engineered Mix Design method [PEMD]). In order to achieve this goal, the study examined the validity of two rutting assessment tests (i.e. Hamburg Wheel Tracking test [HWTT], and Asphalt Pavement Analyzer [APA] rut test) and three performance indicators (i.e., HWTT rut depth after 15,000 passes [HWTT₁₅₀₀₀], HWTT rut depth at 20,000 passes [HWTT₂₀₀₀₀], and APA rut depth after 8,000 cycles [APA₈₀₀₀]). A total number of 33 asphalt mixes including six Laboratory Mixed-Laboratory Compacted (LMLC), 10 Plant Mixed-Laboratory Compacted (PMLC), and 17 field projects were evaluated in this study. The results demonstrated that HWTT and APA rut test rutting performance indicators were sensitive to the variation in binder content and binder PG. Also, APA₈₀₀₀ results had low/moderate variability, while HWTT₁₅₀₀₀ and HWTT20000 had moderate variability. In addition, HWTT and APA rut test performance indicators were correlated with the observed field rutting of the evaluated field projects. Several pass/fail performance assessment thresholds were proposed including maximum rut depth of 5 mm, 10 mm, and 12.5 mm for APA₈₀₀₀, HWTT1₅₀₀₀, HWTT₂₀₀₀₀, respectively. Also, the results showed that both HWTT and APA rut test provided similar rutting assessment for the evaluated mixes. The study recommended using HWTT over APA rut test since HWTT can be also used to evaluate the resistance to both rutting and moisture damage. Also, the study recommended using HWTT₁₅₀₀₀ over HWTT₂₀₀₀₀ as a performance indicator, since it requires less testing time.