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 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 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 Composite Pavement Systems written by Gerardo W. Flintsch and published by . This book was released on 2008 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composite pavement systems have shown the potential for becoming a cost-effective pavement alternative for highways with high and heavy traffic volumes, especially in Europe. This study investigated the design and performance of composite pavement structures composed of a flexible layer (top-most layer) over a rigid base. The report compiles (1) a literature review of composite pavement systems in the U.S. and worldwide; (2) an evaluation of the state-of-the-practice in the U.S. obtained using a survey; (3) an investigation of technical aspects of various alternative composite pavement systems designed using available methodologies and mechanistic-empirical pavement distress models (fatigue, rutting, and reflective cracking); and (4) a preliminary life cycle cost analysis (LCCA) to study the feasibility of the most promising composite pavement systems. Composite pavements, when compared to traditional flexible or rigid pavements, have the potential to become a cost-effective alternative because they may provide better levels of performance, both structurally and functionally, than the traditional flexible and rigid pavement designs. Therefore, they can be viable options for high volume traffic corridors. Countries, such as the U.K. and Spain, which have used composite pavement systems in their main road networks, have reported positive experiences in terms of functional and structural performance. Composite pavement structures can provide long-life pavements that offer good serviceability levels and rapid, cost-effective maintenance operations, which are highly desired, especially for high-volume, high-priority corridors. Composite pavements mitigate various structural and functional problems that typical flexible or rigid pavements tend to present, such as hot-mix asphalt (HMA) fatigue cracking, subgrade rutting, portland cement concrete (PCC) erosion, and PCC loss of friction, among others. At the same time, though, composite systems are potentially more prone to other distresses, such as reflective cracking and rutting within the HMA layer. Premium HMA surfaces and/or reflective cracking mitigation techniques may be required to mitigate these potential problems. At the economic level, the results of the deterministic agency-cost LCCA suggest that the use of a composite pavement with a cement-treated base (CTB) results in a cost-effective alternative for a typical interstate traffic scenario. Alternatively, a composite pavement with a continuously reinforced concrete pavement (CRCP) base may become more cost-effective for very high volumes of traffic. Further, in addition to savings in agency cost, road user cost savings could also be important, especially for the HMA over CRCP composite pavement option because it would not require any lengthy rehabilitation actions, as is the case for the typical flexible and rigid pavements.

Download or read book Improved design to reduce costs extend life expectancy and insure structural safety written by United States. Federal Highway Administration and published by . This book was released on 1973 with total page 280 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 Highway Research Circular written by and published by . This book was released on 1971 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Federally Coordinated Program of Research and Development in Highway Transportation Improved design to reduce costs extend life expectancy and insure structural safety written by United States. Federal Highway Administration and published by . This book was released on 1975 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Implementation of a Comprehensive Rigid Pavement Overlay Design System Into a Condensed Overlay Design Manual written by Adrianus W. Viljoen and published by . This book was released on 1985 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanistic empirical Pavement Design Guide written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 2008 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guide to Concrete Overlay Solutions written by and published by . This book was released on 2007 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide will help readers understand concrete overlays and develop confidence in their application. The guide provides the key elements of the six major types of concrete overlays along with specifics on materials, typical sections, and important construction elements.

Download or read book Concrete Pavement Design Construction and Performance Second Edition written by Norbert J. Delatte and published by CRC Press. This book was released on 2014-05-22 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition of Concrete Pavement Design, Construction, and Performance provides a solid foundation for pavement engineers seeking relevant and applicable design and construction instruction. It relies on general principles instead of specific ones, and incorporates illustrative case studies and prime design examples to highlight the material. It presents a thorough understanding of materials selection, mixture proportioning, design and detailing, drainage, construction techniques, and pavement performance. It also offers insight into the theoretical framework underlying commonly used design procedures as well as the limits of the applicability of the procedures. All chapters have been updated to reflect recent developments, including some alternative and emerging design technologies that improve sustainability. What’s New in the Second Edition: The second edition of this book contains a new chapter on sustainability, and coverage of mechanistic-empirical design and pervious concrete pavements. RCC pavements are now given a new chapter. The text also expands the industrial pavement design chapter. Outlines alternatives for concrete pavement solutions Identifies desired performance and behavior parameters Establishes appropriate materials and desired concrete proportions Presents steps for translating the design into a durable facility The book highlights significant innovations such as one is two-lift concrete pavements, precast concrete pavement systems, RCC pavement, interlocking concrete pavers, thin concrete pavement design, and pervious concrete. This text also addresses pavement management, maintenance, rehabilitation, and overlays.

Download or read book Highway Engineering written by Athanassios Nikolaides and published by CRC Press. This book was released on 2014-11-24 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt: An International Textbook, from A to ZHighway Engineering: Pavements, Materials and Control of Quality covers the basic principles of pavement management, highlights recent advancements, and details the latest industry standards and techniques in the global market. Utilizing the author's more than 30 years of teaching, researching, and consulting e

Download or read book Guide for Pavement Friction written by and published by AASHTO. This book was released on 2008 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains guidelines and recommendations for managing and designing for friction on highway pavements. The contents of this report will be of interest to highway materials, construction, pavement management, safety, design, and research engineers, as well as others concerned with the friction and related surface characteristics of highway pavements.

Download or read book Department of Transportation and related agencies appropriations for 1982 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Department of Transportation and Related Agencies Appropriations and published by . This book was released on 1981 with total page 900 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.