Analysis of LTPP Profile Data for Jointed Concrete Pavement Sections

1997 ◽  
Vol 1570 (1) ◽  
pp. 70-77
Author(s):  
Eric D. Moody
Keyword(s):  
Inventory Management ◽  
Surface Profile ◽  
Concrete Pavement ◽  
Pavement Performance ◽  
Vertical Acceleration ◽  
Profile Data ◽  
Absolute Increase ◽  
Statistical Measures ◽  
Jointed Concrete Pavement ◽  
Over Time

Incremental changes to a pavement-surface profile have long been considered a primary measure of pavement performance. As a result, the Long-Term Pavement Performance (LTPP) program of the Strategic Highway Research Program has allocated considerable resources for collecting accurate profile data on all general pavement studies (GPS) sites annually. As of June 1995, the profiles of the rigid pavement sites had been measured an average of four times, with many sites having been measured seven times. The data are collected and processed in the field, generating several statistical measures of pavement profile for each wheelpath, including the international roughness index (IRI), present serviceability index (PSI), slope variance, and root-mean-square vertical acceleration (RMSVA) at selected wavelengths. The focus of this analysis is on the primary profile statistic, the IRI. The profile data were downloaded from the National Inventory Management System (NIMS) and extensively analyzed using selected statistical techniques. The objective of this effort was to conduct a thorough analysis of the response variable, the IRI. The analysis included univariate, bivariate, and multivariate analytical techniques to determine which prediction variables are useful for predicting the IRI. Although many of the primary independent variables had significant correlations with the IRI, others did not. Various measures of traffic had particularly poor correlations with the IRI. Several regression models are also presented along with advantages and limitations of the prediction and response variables. The results of a detailed analysis of the within-year and year-to-year variability in IRI measurements are also included. The coefficient of variation in year-to-year measurements averaged 4.2 percent for the jointed plain concrete pavement (JPCP) sections (GPS-3) and 3.8 percent for the jointed reinforced concrete pavement (JRCP) sections (GPS-4). This degree of variability in year-to-year profile measurements tended to overshadow any absolute increase in IRI that may have been occurring in these sections. An analysis was then performed on every section to determine exactly which sections had statistically significant increases in IRI over time. Approximately 44 percent of the jointed concrete pavement sections exhibited statistically significant increases in IRI over time.

Analysis by High-Speed Profile of Jointed Concrete Pavement Slab Curvatures

2000 ◽  
Vol 1730 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Christopher R. Byrum
Keyword(s):  
High Speed ◽  
Profile Analysis ◽  
Concrete Pavement ◽  
Pavement Management ◽  
Pavement Performance ◽  
Analysis Method ◽  
Pavement Rehabilitation ◽  
Curvature Index ◽  
Jointed Concrete Pavement

A high-speed pavement profile analysis method that detects curvature present in the wheelpaths of jointed concrete pavement slabs is presented. This technique can be used to analyze slab curvatures present in pavements and caused by curling and warping forces. The FHWA Long-Term Pavement Performance (LTPP) program has obtained high-speed elevation profiles for the jointed concrete pavements in the study. This profile analysis method reads an LTPP profile and detects imperfections in the road curvature profile, which typically are joints and cracks. It then analyzes the slab regions (intact slab segments) between these numerical imperfections for the presence of curvature. The result of a profile analysis is a road profile index—the curvature index—which represents the average slab curvature present along the wheelpaths for the profile. This profile analysis method was applied to more than 1,100 LTPP GPS3 profiles. The range of the slab curvatures encountered is described, and some key factors related to apparent locked-in curvatures (related to warping and construction) are discussed. The amount of locked-in curvature in slabs significantly affects slab behavior and long-term pavement performance. Curvature information should be available to pavement rehabilitation engineers making fix type and funding decisions for pavements. This new analysis method could be implemented rapidly in routine pavement profile analysis and pavement management systems.

RkRk material measure

2019 ◽  
Vol 86 (9) ◽  
pp. 478-486 ◽  
Author(s):  
Jörg Seewig ◽  
Matthias Eifler ◽  
Dorothee Hüser ◽  
Rudolf Meeß
Keyword(s):  
Surface Profile ◽  
Profile Data ◽  
Measuring Process ◽  
Suitable Material ◽  
Precision Turning ◽  
Functional Characterisation ◽  
Ultra Precision ◽  
Measured Profile ◽  
Material Measure ◽  
Comparison Measurements

AbstractThe standard ISO 13565-2 defines the Rk parameters for the functional characterisation of technical surfaces. So far, no particular material measures for the calibration of these parameters have been defined in the international standardization. For the application and the functional behaviour of technical surfaces the Rk parameters however have a critical significance, so there is a demand by the industry to calibrate these parameters as they are increasingly applied for the quality assessment of workpieces. In the present paper, a proposal for suitable material measures is presented. An algorithm is described, which transforms the data of a real measured profile in a way that the exact defined parameters of Rk, Rpk and Rvk are equated. The material measures geometry corresponds to its later application and the target parameters are almost freely selectable. The approach for transforming surface profile data with the aid of the Abbott curve is introduced generically, solves an inverse problem and considers the influences from the manufacturing and measuring process. The designed material measure is manufactured with the aid of ultra-precision turning. In matters of the aspired industrial application, comparison measurements are carried out in order to examine the practical abilities of the material measure and the repeatability of the approach is proven.

Development of a New Faulting Model in Jointed Concrete Pavement using LTPP Data

2019 ◽  
Vol 2673 (5) ◽  
pp. 407-417 ◽  
Author(s):  
Yu Chen ◽  
Robert L. Lytton
Keyword(s):  
Prediction Models ◽  
Information Criterion ◽  
Concrete Pavement ◽  
Pavement Design ◽  
Ride Quality ◽  
Related Factors ◽  
Pavement Roughness ◽  
Proposed Model ◽  
Jointed Concrete Pavement ◽  
Two Stages

Faulting is a major and commonplace distress in jointed concrete pavement (JCP) that can directly cause pavement roughness and adversely influence the ride quality of a vehicle. Faulting also plays an essential role in concrete pavement design. Notwithstanding the importance of faulting, the accuracy and reasonability of the faulting prediction models that have been developed to date remain controversial. Furthermore, the process of faulting over time is still not fully understood. This paper proposes a novel mechanistic-empirical model to estimate faulting depth at joints in the wheel path in JCP. Two stages within the process of faulting were revealed by the model and are introduced in this study. To distinguish the two stages of faulting, an inflection point, as a critical faulting depth, was directly determined by this model and suggested to be an indicator of the initiation of erosion for concrete pavement design. The proposed model was proven accurate and reliable by using long-term pavement performance data. The parameters in the model were statistically calibrated with performance-related factors by Akaike’s Information Criterion for variable selection and performing stepwise regression.

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