BACKGROUND: Pavement deflections obtained from falling weight deflectometer (FWD) measurements and roughness obtained from longitudinal profile measurements are used together with other measurements to assess pavement condition and performance. These measurements are influenced by the temporal and/or diurnal variations; their consideration is necessary for accurate assessment of pavement condition.
The Long-Term Pavement Performance Program (LTPP) Seasonal Monitoring Program (SMP) was initiated to obtain data on the influence of temporal variations on pavement deflection and roughness. However, the temporal and diurnal data contained in the LTPP database (see Special Note A) have not been applied to improve the practices of measuring deflection and roughness, and their use has not been demonstrated. Also, recent work completed under NCHRP Project 20-50(22), “LTPP Data Analysis: Feasibility of Using LTPP data to improve Use of FWD and Longitudinal Profile Measurements” identified some of the issues related to the use of FWD and longitudinal profile measurements and proposed a preliminary research plan for addressing these issues (see Special Note B). However, additional research was needed to further define and address the issues associated with the effects of temporal and diurnal variations on FWD and longitudinal profile measurements, and to develop guidelines to improve these measurements and their use in evaluating pavement condition.
OBJECTIVE: The objective of this research was to develop guidelines for improved use of FWD and longitudinal profile measurements data in evaluating pavement condition by considering the effects of temporal and/or diurnal variations. The research was to address both asphalt and concrete pavements and focus on using the data available in LTPP database (including those for SMP test sections).
Status: Research is complete. The contractor's final report will be published as NCHRP Web Only Document 416.
