In-Situ Testing and Instrumentation for Pavement Engineering

Maine's Weigh in Motion Pavement Instrumentation (WIMPI) site in Guilford has produced some valuable data and lessons learned. A pavement temperature - strain model has been developed and we now have a better understanding of impacts on pavements from truck loads. Based on 2008 pavement strain data, it is seen that strain levels at the bottom of pavement are well below threshold values in January - March, approach threshold levels in April/May and exceed threshold levels beginning in June. However WIMPI has limitations such as sensor survival, construction practices (thick pavement section) and at times an unreliable data collection system. In order to further develop and implement the new AASHTO mechanistic pavement design procedure there is a need to expand the collection and analysis of pavement strains and temperatures on our highways. Pavement instrumentation and in-situ testing will be used to measure the impacts on certain truck loads on the numerous highway pavement sections. It is proposed to use multi-depth portable deflectometers to determine pavement reaction to known axle and wheel loads. In addition, in-situ testing equipment will be used to measure the stiffness of pavement layers. The data will be used to predict the pavement service life and will be used in the new AASHTO pavement design guide.