The development of novel “smart” structures by embedding sensing capabilities directly into the construction material during the manufacturing and deployment process has attracted significant attention in autonomous structural health monitoring (SHM). Micro-electromechanical systems (MEMS) provide vast improvements over existing sensing methods in the context of SHM of highway infrastructure systems, including improved system reliability, improved longevity and enhanced system performance, improved safety against natural hazards and vibrations, and a reduction in life cycle cost in both operating and maintaining the infrastructure. Advancements in MEMS technology and wireless sensor networks provide opportunities for long-term, continuous, real-time structural health monitoring of pavements and bridges at low cost within the context of sustainable infrastructure systems. Based on a comprehensive review of literature and vendor survey, the latest information available on off-the-shelf MEMS devices,...

As the list of states adopting the Hamburg wheel tracking device continues to grow, there is a need to evaluate how the results are used. AASHTO T-324 does not standardize the analysis and reporting of test results. Furthermore, the processing and the reporting of the results of manufacturers are not uniform. This inconsistency is partly the result of the variation of agency reporting requirements. Some requirements include only the midpoint rut depth; others include the average across the entire length of the wheel track. No guidance is given when the stripping infection point (SIP) is reported. To eliminate bias in reporting, statistical analysis was performed on more than 135 test runs on adjoining gyratory specimens. Measurement location was found to be a source of significant variation for rut depth in the Hamburg wheel tracking device. This variation was likely the result of the nonuniform wheel speed across the specimen, geometry of the specimen, and air void profile. Eliminating this source of bias when rutting results are reported is feasible although the feasibility depends on the average rut depth at the final pass. When the results of a test that has an average rut depth of less than 12 mm at the final pass is reported, the average of the measurements along a 6.4-in. path beginning at 0.5 in. from the specimen edge nearest the gear housing should be reported. When the average final-pass rut depth is greater than 12 mm, it is reasonable to report the average of the measurements just off the center of the rutting track along a 3.2-in. path beginning at 2.1 in. from the specimen edge nearest the gear housing. SIP values were also analyzed. It is reasonable to report the average of the SIP values across all locations while calculated values measured more than 2 in. from the specimen's edge are discarded and for cases in which the ratio of the stripping slope to creep slope exceeds 2.0. Validation is needed for multiple machines.