Variability Of Ignition Furnace Correction Factors

"Determining the Asphalt Binder Content of Hot Mix Asphalt (HMA) by the Ignition Method," requires determination of asphalt and aggregate correction factors for asphalt mix designs for each ignition furnace used to test a design. In some cases, where there are numerous asphalt mix designs or numerous ignition furnaces testing a particular mix design, correction factors may be shared between ignition furnaces, though this practice is not strictly permitted by AASHTO T 308 without supporting evidence. The objectives of this research were to (1) determine the significant influences that affect the variability of asphalt and aggregate correction factors for ignition furnaces; (2) develop guidelines for the installation, operation, and maintenance of ignition furnaces to minimize the variability in correction factors between furnaces; and (3) develop and document a statistically valid correction factor verification procedure to identify and troubleshoot causes for non-comparing, statistically different, or biased results of AASHTO T 308. The research was conducted in three parts: (1) a study of the sensitivity of asphalt and aggregate correction factors to variation in experimental factors such as furnace type, test temperature, asphalt content, and sample mass; (2) a round-robin study to identify correction factor outliers and determine the contributory cause(s); and (3) troubleshooting of outliers from the round-robin study. The research found that the primary factors affecting asphalt and aggregate correction factors determined by AASHTO T 308 are furnace type and test temperature. Conducting the test at 800°F appears to substantially reduce the magnitude and standard deviation of the correction factors for asphalt mixtures that do not contain lime. Sharing correction factors among different ignition furnaces appears acceptable for low correction factor aggregates (0.1% or less) but is problematic for aggregates with correction factors of 1.0% or greater. The current precision estimates in AASHTO T 308 appear applicable only to mixtures with low correction factor aggregates. The key product of this research is a Proposed Standard Practice for Installation, Operation, and Maintenance of Ignition Furnaces (Appendix I). Development of a verification procedure to identify causes for non-comparing, statistically different, or biased test results from ignition furnaces was found to be premature and further research is planned.

In road projects, the pavement construction is very expensive and, therefore, the design and subsequent construction must make a proper balance between the cost and the sustainability. During the operation and maintenance period, the costs for routine maintenance (as and when pavement damage occurs) are to be kept as low as possible as there is less control towards cost of the periodic maintenance (mandatory at a contractual interval, normally 5 years). The reduction in cost for routine maintenance will relieve the project authorities from unexpected expenditures. This comprehensive text on Pavement Engineering is up-to-date with industry standards and best practices and offers an exhaustive coverage on design, construction and maintenance of pavements. The book has followed AASHTO Guide for Design of Pavement Structures, 1993, besides meeting latest code provisions and pavement design methods recommended by Indian Roads Congress (IRC) and Bureau of Indian Standards (BIS). This book has all standard topics on the subject, but differs from all other books in respect of following contents: • Pavement Engineering and Highway Geometrics • Design of Flexible Bituminous/Asphalt Pavement • Design of Rigid Concrete Pavement • Construction of Flexible Bituminous/Asphalt Pavement • Construction of Rigid Concrete Pavement • Maintenance of Flexible Bituminous/Asphalt Pavement • Maintenance of Rigid Concrete Pavement • Maintenance of other Road, Drainage and Bridge features This book refers to the web uploaded volume ‘User’s Guide for Computer Applications’ at web site www.roadbridgedesign.com to help readers learn various computer applications in pavement engineering. This book is designed to serve as a textbook for undergraduate and postgraduate students of Civil Engineering, Highway Engineering and Traffic and Transportation Engineering. TARGET AUDIENCE • BE/B.Tech, ME/MS/M.Tech (Civil Engineering and Transportation/ Highway Engineering) • Professionals of Highway/Road Construction Industry

This book presents new studies dealing with the attempts made by the scientists and practitioners to address contemporary issues in geotechnical engineering such as characterization of soil, geomaterials, soil stability and some other geomechanics issues that are becoming quite relevant in today's world. Papers were selected from the 5th GeoChina International Conference on Civil Infrastructures Confronting Severe Weathers and Climate Changes: From Failure to Sustainability, held on July 23-25, 2018 in HangZhou, China.

TRB's National Cooperative Highway Research Program (NCHRP) Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content describes proposed revisions to the American Association of State Highway and Transportation Officials (AASHTO) R 35, Superpave Volumetric Design for Hot Mix Asphalt, and AASHTO M 323, Superpave Volumetric Mix Design, to accommodate the design of asphalt mixtures with high reclaimed asphalt pavement contents.

A major result of the research conducted under the Strategic Highway Research Program from 1987 to 1993 was the development of the Superpave (Superior Performing Asphalt Pavement) system for the comprehensive design of asphalt pavements. These 14 contributions describe the experience to date in the

This volume contains contributions from international experts, reflecting the rapid advances in the design of new improved bitumen and hydraulic bound composites, the trends in the use of waste and recycled materials and up-to-date methods of testing and evaluation.