Polymer Modified Asphalt Binders

"ASTM Publication Code Number (PCN) 04-011080-08. - "Sponsored by ASTM Committee D-4 on Road and Paving Materials."-- Foreword. - Includes bibliographical references and indexes. - Electronic reproduction; W. Conshohocken, Pa; ASTM International; 2011; Mode of access: World Wide Web; System requirements: Web browser; Access may be restricted to users at subscribing institutions.

This review explores the type of polymers used in asphalt, why they are used, where they are used in terms of applications and the benefits they offer to industry and the road user. In particular, the reader will understand how polymers can be used to enhance the functionality of asphalt, that is to overcome deterioration mechanisms by enhancing asphalt stiffness or flexibility, or by making it more resistant to deformation (rutting) caused by traffic. This review is aimed at anyone who has an interest in polymers and their highway applications. Around 400 references with abstracts from recent global literature accompany this review, sourced from the Rapra Polymer Library database, to facilitate further reading. A subject index and a company index are included.

The addition of polymers to bitumen allows the modification of certain physical properties, such as softening point, brittleness and ductility, of the bitumen. Polymer modified bitumen: Properties and characterisation provides a valuable and in-depth coverage of the science and technology of polymer modified bitumen. After an initial introduction to bitumen and polymer modified bitumen, the book is divided into two parts. Chapters in part one focus on the preparation and properties of a range of polymer modified bitumen, including polymer bitumen emulsions, modification of bitumen with poly (urethanes), waste rubber and plastic and polypropylene fibres. Part two addresses the characterisation and properties of polymer modified bitumen. Chapter topics covered include rheology, simulated and actual long term ageing studies; the solubility of bituminous binders in fuels and the use of Fourier transform infrared spectroscopy to study ageing/oxidation of polymer modified bitumen. Polymer modified bitumen is an essential reference for scientists and engineers, from both academia and the civil engineering and transport industries, interested in the properties and characterisation of polymer modified bitumen. Provides a comprehensive and in-depth coverage of the science and technology of polymer modified bitumen Focuses on the preparation and properties of a range of polymer modified bitumen, including emulsions, modification of bitumen with poly(urethanes), waste rubber and plastic as well as polypropylene fibres Addresses the characterization and properties of polymer modified bitumen, including rheology, simulated and actual long term ageing studies, and the solubility of bituminous binders in fuels

This book is dedicated to the use of nanomaterials for the modification of asphalt binders, and to investigate whether or not the use of nanomaterials for asphalt mixtures fabrication achieves more effective asphalt pavement layers. A total of 10 contributions are included. Four are related to “Binder's modification” and five to “Asphalt mixtures' modification”. The remaining contribution is a review of the effects of the modifications on nanomaterials, particularly nanosilica, nanoclays and nanoiron, on the performance of asphalt mixtures. The published group of papers fosters awareness about the use of nanomaterials to modify asphalt mixtures to obtain more performant and durable flexible road pavements.

The Virginia Department of Transportation (VDOT) specifies polymer-modified asphalt binders for certain asphalt mixtures used on high-volume, high-priority routes. These binders must meet performance grade (PG) requirements for a PG 76-22 binder in addition to elastic recovery requirements. This typically results in the use of binders containing styrene-butadiene-styrene (SBS) modifiers. However, other polymer modifiers may also be used to achieve the PG 76-22 classification. One of these modifiers is a copolymer of SBS and polyethylene (PE) (SBS-PE) another modifier is ground tire rubber (GTR). This study was undertaken to investigate the suitability of SBS PE modified PG 76-22 binder and GTR-modified PG 76-22 binder for use in Virginia. Each modified binder was used in a 12.5 mm nominal maximum aggregate size mixture to pave approximately 2.3 lane-miles. All mixtures were produced as warm mix asphalt using a foaming system. The binders evaluated included a typical SBS polymer-modified binder as a control and binders modified with SBS-PE and GTR. During construction, all processes were documented and material was sampled for evaluation. Binder and mixture tests were performed. Binder testing included performance grading and multiple stress creep and relaxation testing. Mixture testing included volumetric analysis, dynamic modulus, and flow number tests and cracking, rutting, and fatigue analysis. Binder testing indicated that the control binder and SBS PE modified binders met VDOT specifications for classification as a PG 76-22 binder; the GTR-modified binder graded to a PG 70-22 binder, as it did not meet the PG 76-22 high-temperature specification and did not pass the elastic recovery requirement. Laboratory mixture testing indicated that the performance of the SBS PE modified mixture should be similar to that of the control mixture. Laboratory test results for the GTR-modified mixture were mixed, with some indicating that the performance was similar to that of the control mixture and some indicating that the performance may be less than that of the control. Based on the study, SBS PE modified binders should continue to be allowed as an alternative to SBS-modified binder provided specifications for PG 76-22 binders are met. However, further investigation of GTR-modified binders is suggested before recommendations can be made. In addition, long-term evaluation of the field site is recommended for validation of the laboratory findings.

The project was designed to develop (1) a better quantitative understanding of the relation between laboratory accelerated binder aging and field aging, (2) a test procedure to measure properties of an aged binder that relate to failure on the road and (3) a proposed specification for estimating the relative durability of binders in the presence of oxidative aging. Tests were conducted on original base and polymer modified binders, laboratory compacted mixtures, and pavement aged binders. The project necessarily evolved to a more comprehensive approach to improving pavement service life.

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.