Asphalt Reflective Cracking Solutions: Accelerated Loading Trials
Thursday 19 November 2020

East Midlands Branch Event Details

Date Thursday 19 November 2020
Title Asphalt Reflective Cracking Solutions: Accelerated Loading Trials
Speakers Bachar Hakim AECOM
Sam Nicklin AECOM
Lukash Manandhar Transport for London
Event Type Online - using Teams
Time 17:00
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More details Transport for London (TfL) road network comprises large sections of asphalt overlaid concrete slabs. Over time the asphalt cracks above the concrete joints, this is due to the vertical and horizontal movement that takes place due to the imposed vehicle loading and thermal cycles. AECOM and TfL designed and ran laboratory and full scale trials to evaluate the performance of asphalt solutions with respect to reflective cracking.

Ten asphalt solutions were initially tested using the wheel tracking equipment. Then more realistic pavement and loading conditions were considered. Full scale pavements were constructed in AECOM’s test facility and subjected to accelerated loading using the Mobile Load Simulator (MLS11). Four asphalt solutions were tested; a control section of Asphalt Concrete (AC), AC with geogrid, Stone Mastic Asphalt (SMA) and Hot Rolled Asphalt (HRA). The number of load applications until crack initiation and full depth propagation were determined. The type, location and mode of crack deterioration were monitored and any evidence of interlay debonding was recorded. The results indicate HRA with PMB to be the best solution, followed by the AC and SMA. The use of geogrid did show a significant improvement of pavement performance with respect to reflective cracking.