Implementation of Rolling Wheel Deflectometer (RWD) in PMS and Pavement Preservation.

摘要

The rolling wheel deflectometer (RWD) offers the benefit to measure pavement deflection without causing any traffic interruption or compromising safety along tested road segments. This study describes a detailed field evaluation of the RWD system in Louisiana in which 16 different test sites representing a wide array of pavement conditions were tested. Measurements were used to assess the repeatability of RWD measurements, the effect of truck speeds, and to study the relationship between RWD and falling weight deflectometer (FWD) deflection measurements and pavement conditions. Based on the results of the experimental program, it was determined that the repeatability of RWD measurements was acceptable with an average coefficient of variation at all test speeds of 15 percent. In addition, the influence of the testing speed on the measured deflections was minimal. The scattering and uniformity of the FWD and RWD data appears to closely follow the conditions of the roadway. Both test methods appear to properly reflect pavement conditions and structural integrity of the road network by measuring a greater average deflection and scattering for sites in poor conditions. RWD deflection measurements were in general agreement with FWD deflections measurements; however, the mean center deflections from RWD and FWD were statistically different for 15 of the 16 sites. This study developed and validated a direct and simple model for determining the pavement structural number (SN) using RWD deflection data. To develop this model, the relationship between the average RWD surface deflection and the peak FWD deflection was investigated. The developed model correlates a pavement's SN to two RWD-measured properties (average RWD deflection and RWD index).