Effects of Asphalt Mix Design Parameters on Pavement Cracking Performance

1. Field Performance from Pavement Management Section Location, Traffic Information, Cracking Performance Mix Design Traffic Level, Mix Size, Binder Type, % Recycled Material, Mix Volumetrics, Dry Strength, Wet Strength, TSR Effects of Asphalt Mix Design Parameters on Pavement Cracking Performance Database Microsoft Access Statistical Analysis LS Means Analysis, SAS Software -Effect of Mix Parameters on Pavement Performance -Suitability of lab testas Performance Measure Chelsea Hanson  hans2718@d.umn.edu (Advisor: Eshan V. Dave  evdave@d.umn.edu) Department of Civil Engineering, University of Minnesota Duluth INTRODUCTION and MOTIVATION RESEARCH APPROACH • Obtain asphalt mix design and field performance data from Minnesota Department of Transportation • Combine data and develop comprehensive databases in Microsoft Access • Generate queries to combine mix design data for statistical analysis • Conduct statistical analysis using SAS software for both single and multiple variable dependence • Analyze the effects of mix design parameters on pavement field performance (For example PG grade, VMA, etc.) • Thermal cracking is a severe problem in cold climate regions • At present, no pavement performance test is required as asphalt mix acceptance criteria in MnDOT 2360 specifications • Implementation of laboratory performance test can improve reliability of asphalt mix performance • Comprehensive database of existing mix designs andpavement cracking performance is needed: • Investigation of effects of mix design parameters onpavement performance • Determine which laboratory tests provide reliablemeasure of pavement performance • First phase of study narrowed lab tests down to indirect tensile strength from TSR and fracture energy from disk shaped compact tension (DCT) Indirect Tensile Strength for AASHTO T-283 (TSR) DISCUSSIONS OF RESULTS • Initial single variable analysis shows no direct correlation between most mix design parameters and indirect tensile strength of mix from TSR (Dry strength), except binder grade and PG spread • Multiple variable analysis shows significance of dry strength with pairing of some variables • SAS analysis showed statistical significance with mix parameters compared to volumetrics • Preliminary results for pavement management sections for interstate highways in Minnesota show no clear trend between transverse cracking rates and asphalt amount and mix volumetrics CONCLUSIONS and FUTURE RESEARCH • Compilation of mix design and pavement performance database followed by statistical analysis allows to determine effects of mix volumetrics and design parameters on field cracking performance • PG binder grade, PG spread, and PG LT showed correlation with indirect tensile strengths in both single and multiple variable analysis • TSR found not to be correlated to mix volumetrics or binder grade • Preliminary analysis of interstate highways in Minnesota showed minimal effects of asphalt binder content on transverse cracking • More analysis is currently underway: • Further analyze all mix design and pavement management data • Include mixes that contain RAP, RAS, etc. to quantify effects of reclaimed and recycled materials on pavement performance • Conduct statistical analysis to quantify correlation between mix design parameters and pavement performance • Determine effective laboratory performance test for acceptance of asphalt mix design criteria • Implement performance test into agency specifications