Download Free Pavement Deflection Data Exchange Book in PDF and EPUB Free Download. You can read online Pavement Deflection Data Exchange and write the review.

Nondestructive deflection testing (NDT) devices have become integral tools in the evaluation and analysis of pavement facilities. Historically, the data produced by deflection devices have been stored in output files with the type, extent, and organization of collected data being left to the discretion of the individual equipment manufacturers. This document describes a device-independent universal pavement deflection data exchange (PDDX) specification that utilizes the data management concept of section blocks, similar to the software initialization file format used by many computer operating systems. The use of section blocks has proven to be an efficient and flexible method in the management of data and can be applied successfully to pavement deflection testing technology.
This report documents the research performed on evaluation of pavement deflection equipment under Contract DTFH61-85-C-00115 for the Federal Highway Administration. The following devices were included in side-by-side field tests conducted in the Austin, Texas area during the week of August 11, 1986: the Benkelman Beam, C.E.B.T.P. Curviameter, Dynaflect, Dynatest Falling Weight Deflectometer (FWD), Kuab FWD, Phonix FWD, and the Road Rater. The report includes descriptions and comparisons of the devices through information obtained from a literature search, field tests and user survey conducted for this study. The side-by-side test program was performed over a broad range of pavement structures, including thick and thin flexible and rigid pavements, and composite pavements. The measured deflections were compared statistically. Mechanistic interpretations of the measured deflection basins were made and compared.
The objective of this study was to develop an approach for incorporating techniques to interpret and evaluate deflection data for network-level pavement management system (PMS) applications. The first part of this research focused on identifying and evaluating existing techniques, seeking out those that were simple, reliable, and easy to incorporate into current PMS practices, as well as those that produced consistent results. The second part of the research detailed the development of guidelines for the application of recommended techniques and procedures for determining optimum falling weight deflectometer (FWD) test spacing and data collection frequency. While there are many viable techniques available for evaluating the structural capacity of pavements that use FWD for project-level analysis, many of these techniques are time consuming and require an experienced analyst. As a result, using pavement deflection testing for network-level analysis has been limited to date. This guide provides information for the assessment of pavement structural performance for PMS applications. It reflects the general findings presented in the accompanying final report, Simplified Techniques for Evaluation and Interpretation of Pavement Deflections for Network-Level Analysis (FHWA-HRT-12-023).
Pavement deflection measurements, together with backcalculation procedures, are widely used to estimate the layer moduli of pavement - subgrade systems. Sensitivity analysis of a sample problem indicates that conclusions drawn from static analyses with regards to deflection sensitivity to variation in layer moduli may apply when characterizing uncertainty associated with the interpretation of the falling weight deflectometer (FWD) data. The uncertainty associated with the values of the backcalculated parameters from deflection data is investigated in this paper using an elastodynamic, stochastic finite element approach. The results of the simulations indicate that, in order to properly estimate surface layer moduli, loading frequencies higher than that of excitation by typical FWD loading are required. The low sensitivity of deflection uncertainty to random variations in surface modulus, when compared with that associated with subgrade modulus, is demonstrated to contribute to high variations in backcalculated surface modulus from measured surface deflections. Although focus is placed on uncertainties in elastic modulus and deflection, the methodology presented in the paper can be used to quantify uncertainties associated with other layer properties and pavement responses.
The objective of this study is to develop a mechanistic-empirical method for assessing pavement layer conditions and estimating the remaining life of flexible pavements using multi-load level Falling Weight Deflectometer (FWD) deflections. A dynamic finite element program, incorporating a stress-dependent soil model, was developed to generate the synthetic deflection database. Based on this synthetic database, the relationships between surface deflections and critical pavement responses, such as stresses and strains in each individual layer, have been established. A condition assessment procedure for asphalt pavements that uses multi-load level FWD deflections has been developed using these relationships. The verification study was conducted using field data.
The proceedings of June 1993 international symposium held in Atlanta, Georgia, called specifically to develop and standardized evaluation procedures for non-destructive methods of testing pavements. The 29 papers discuss analytical models and techniques, measurement and calculation techniques in the field and laboratory, problems and errors associated with backcalculation methods and design parameters, and testing for other pavement uses. Also includes a history of the quest for a standard and the status of that effort. Reproduced from typescripts. Annotation copyright by Book News, Inc., Portland, OR