Download or read book Development of an Overlay Design Procedure for Composite Pavements written by Liangbo Hu and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The composite overlay design procedure currently used by ODOT sometimes produces very large overlay thicknesses that are deemed structurally unnecessary, especially for composite pavements already with thick asphalt overlays. This study was initiated to investigate the cause(s) and to develop a revised procedure. The current ODOT pavement overlay thickness design procedure is based on the structural deficiency approach recommended by the 1993 AASHTO Pavement Design Guide. The current procedure uses a simple, closed form procedure to back-calculate the subgrade modulus and the effective modulus of the existing pavement structure from the measured Falling Weight Deflectometer (FWD) surface deflections. The simplistic treatment of the AC and PCC layers as a combined layer in the back-calculation model was found to significantly underestimate the moduli of the existing pavement. A three-layer elastic model is adopted in lieu of the two-layer model used in the current procedure for back-calculation. The three-layer model allows the composite pavement structure to be modeled more accurately. The elastic moduli of the asphalt concrete layer and the underlying Portland cement concrete can both be back-calculated, instead of being combined as one. A revised overlay design procedure has been developed. A comparison of the revised procedure and the current procedure shows that the three-layer model produces higher effective thickness than the two-layer model for the same pavement structure. Therefore, the required overlay thickness is reduced. The revised design software has been implemented into a design software program, which also offers an optional feature that takes into consideration the temperature effects on the asphalt concrete moduli.

Download or read book Development of Rational Overlay Design Procedures for Flexible Pavements written by James A. Crovetti and published by . This book was released on 2005 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Review of ODOT s Overlay Design Procedures HMA overlays of existing HMA and composite pavements written by and published by . This book was released on 2008 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: ODOT initiated this research study to determine (1) the impact of milling off portions of the existing pavement on the structural capacity of the remaining pavement and (2) whether currently recommended HMA structural coefficients adequately reflect the structural properties of new HMA overlay materials. The study mainly focused on the impact of milling on the design of HMA overlays over existing flexible pavements and composite pavements. Volume I of the report deals with this main study focus area. During the course of the study, an additional focus area was added to the project to investigate the impact of completely milling off existing HMA layers in composite pavement systems on unbonded overlay design. Volume II of this report deals with impact of milling on unbonded overlays. Volume I describes the structural evaluation of individual flexible and composite pavement projects located at different sites throughout Ohio, as well as an analysis of the evaluation results to develop enhancements to the ODOT HMA overlay design procedure as needed. The report presents detailed descriptions of the projects evaluated, field testing procedures employed, procedures adopted for analyzing field testing data and other data collected, structural evaluation results, analysis of results, and recommendations for improvements of the current ODOT overlay design procedure. Volume II presents descriptions of the data collected, data analysis, observations, and recommendations for improvements of the current ODOT overlay design procedure.

Download or read book Improving Design Strategies for Composite Pavement Overlay written by Pawan Sigdel and published by . This book was released on 2016 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pavements need constant rehabilitation when they deteriorate with time and approach the end of their expected service lives. Overlay is the most prevalent treatment that restores its desirable condition and extends its life span of serviceability, especially for roads subjected to moderate and heavy traffic. Overlay composite design remains a major challenge due to difficulties in characterizing the complex behavior and assessing the existing condition of a combination of asphalt concrete (AC) and Portland cement concrete (PCC) layers over a soil subgrade. Deflection based design using falling weight deflectometer (FWD) deflection data offers an effective approach for overlay thickness design for composite pavements. It utilizes the deflection measurements of the pavement surface which can be used to back-calculate the subgrade and overlay composite properties and allows one to estimate the structural capacity of the existing pavement. However, the prevailing deflection based design procedure generally treats the AC and PCC as a single layer during the back-calculation and, as a result, frequently leads to less than satisfactory, usually over-conservative, design for overlay composites. The principal objective of this research is to develop improved FWD deflection based design strategies for overlay composite pavements. It is proposed that a three-layer linear elastic model be used for back-calculation of the moduli of all three layers: subgrade, PCC and AC. The structural capacity of the existing pavement is estimated using pavement surface deflections measured by FWD, the most commonly used pavement non-destructive testing (NDT) device. In the present study actual FWD deflection data for eleven construction projects are used to back-calculate the moduli of three layers. The three-layer model allows the composite pavement structure to be modeled more accurately. The elastic moduli of the asphalt concrete layer and the underlying Portland cement concrete can both be back-calculated, instead of combining them into one. The results show that the three-layer model produces higher effective thickness than the two-layer model for the same pavement structure, thereby reducing the required overlay thickness. However, there are a number of factors that can strongly influence the final overlay design thickness. The effects of computational error tolerances in back-calculation, temperature at FWD testing and variations in FWD deflection data are found significant and may cause unreliable design results and hence, two strategies to avoid excessively large or small back-calculated moduli are also explored: imposing moduli bounds and relaxing the precision convergence; they have been found very effective in mitigating the effect of large variations in deflection data. The statistical variations observed in the overlay design are also evaluated and two models are explored to improve the overall design procedure from the statistical perspective: Monte Carlo method and Point Estimation method. The effective thicknesses of existing pavement computed from reliability analysis are similar to those obtained from the proposed design method. This demonstrates the validity of the proposed design method and also the applicability of reliability based design in case the statistical parameters are available or can be obtained from engineering judgment.

Download or read book Pavement Overlay Design Procedures and Assumptions written by and published by . This book was released on 1986 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pavement Overlay Design Procedures and Assumptions Analysis of existing procedures written by and published by . This book was released on 1986 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of an Overlay Design Procedure for Flexible Pavements in Indiana written by Jay K. Lindly and published by . This book was released on 1987 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Review of ODOT s Overlay Design Procedures written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ODOT initiated this research study to determine (1) the impact of milling off portions of the existing pavement on the structural capacity of the remaining pavement and (2) whether currently recommended HMA structural coefficients adequately reflect the structural properties of new HMA overlay materials. The study mainly focused on the impact of milling on the design of HMA overlays over existing flexible pavements and composite pavements. Volume I of the report deals with this main study focus area. During the course of the study, an additional focus area was added to the project to investigate the impact of completely milling off existing HMA layers in composite pavement systems on unbonded overlay design. Volume II of this report deals with impact of milling on unbonded overlays. Volume I describes the structural evaluation of individual flexible and composite pavement projects located at different sites throughout Ohio, as well as an analysis of the evaluation results to develop enhancements to the ODOT HMA overlay design procedure as needed. The report presents detailed descriptions of the projects evaluated, field testing procedures employed, procedures adopted for analyzing field testing data and other data collected, structural evaluation results, analysis of results, and recommendations for improvements of the current ODOT overlay design procedure. Volume II presents descriptions of the data collected, data analysis, observations, and recommendations for improvements of the current ODOT overlay design procedure.

Download or read book Overlay Design and Reflection Cracking Analysis for Rigid Pavements Volume 1 Development of New Design Criteria Phases II and III Final Report written by H. J. Treybig and published by . This book was released on 1977 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Rigid Pavement Overlay Design Procedure Development of the OAR Procedure Final Report written by K. Majidzadeh and published by . This book was released on 1983 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pavement Overlay Design Procedures and Assumptions written by and published by . This book was released on 1986 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Objective Overlay Design Procedure for Composite Pavements written by Xinming Tang and published by . This book was released on 1995 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AASHTO Guide for Design of Pavement Structures 1993 written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 1993 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design related project level pavement management - Economic evaluation of alternative pavement design strategies - Reliability / - Pavement design procedures for new construction or reconstruction : Design requirements - Highway pavement structural design - Low-volume road design / - Pavement design procedures for rehabilitation of existing pavements : Rehabilitation concepts - Guides for field data collection - Rehabilitation methods other than overlay - Rehabilitation methods with overlays / - Mechanistic-empirical design procedures.

Download or read book Development of Rational Overlay Design Procedures for Flexible Pavements written by and published by . This book was released on 2005 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the findings of a research study conducted to develop procedures for the design of structural HMA overlays over existing flexible pavements in Wisconsin. The recommended procedures are presented in a hierarchal approach to allow the user the flexibility of estimating the effective structural number of an in-place HMA pavement based on visual and/or nondestructive deflection testing data and to develop overlay thickness requirements based on the structural deficiency approach.

Download or read book Asphaltic Concrete Overlays of Rigid and Flexible Pavements written by Richard W. Kinchen and published by . This book was released on 1980 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study represents the development of a mechanistic approach to asphaltic concrete overlay thickness selection for overlays of flexible, rigid, and composite pavements. The procedure utilizes a deflection analysis to determine pavement rehabilitation needs. Design guides for selecting the overlay thicknesses are presented. Tolerable deflection-traffic load relationships and the deflection attenuation properties of asphaltic concrete have been developed, representing the subgrade support conditions and properties of materials used in Louisiana. All deflection measurements on asphaltic concrete have been corrected for the effect of temperature.

Download or read book Composite Pavement Design written by National Research Council (U.S.). Highway Research Board and published by . This book was released on 1963 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nine reports on composite pavement design for the 42nd Highway Research Board Annual Meeting, January 7-11, 1963.

Download or read book Development of a Flexible Pavement Overlay Design Procedure Utilizing Nondestructive Testing Data written by Kevin D. Hall and published by . This book was released on 1990 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: