The SHRP Direct Tension Specification Test-Its Development and Use
The SHRP Direct Tension Specification Test-Its Development and Use

Author: DA. Anderson

Publisher:

Published: 1995

Total Pages: 16

ISBN-13:

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This paper describes the development and use of a direct tension test for measuring the strength and failure strain of asphalt binders. This test, which is used to determine the strain at failure (strain tolerance) of asphalt binders, was selected by the Strategic Highway Research Program (SHRP) as a specification test for asphalt binders. Test methods available prior to the development of this test were found inadequate for accurately measuring the strain tolerance of asphalt binders. Therefore, these methods were judged unsuitable for specification purposes. The dog bone geometry used in the direct tension test method described in this paper is widely used for other materials. Each specimen requires slightly more than three grams of asphalt binder. The specimen is gripped using plastic inserts cast as an integral part of the test specimen. The specimen is loaded through holes in the inserts using specially designed pins that automatically align the test specimen. Specimen elongation is measured using a noncontact laser-based extensometer which provides accurate and repeatable measurements. The method is easy to use and is designed to provide the strain-at-failure-data needed for specification purposes.

Bituminous Binders and Mixes
Bituminous Binders and Mixes

Author: L. Francken

Publisher: CRC Press

Published: 2004-03-01

Total Pages: 230

ISBN-13: 0203627318

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The aim of the studies presented in this report is the implementation of rational concepts and testing procedures for the design and manufacture of bituminous materials for applications in pavement construction. Practical test procedures are recommended for binder evaluation, mix design and performance assessment of bituminous materials. The three main topics addressed are binder testing, mix design and mechanical testing of mixtures. Each is examined through interlaboratory tests and there is a literary review of existing practices and methods for the production of polymer modified binders, mixture design and the mechanical properties of mixtures.

Low Temperature Investigations on Asphalt Binder Performance -
Low Temperature Investigations on Asphalt Binder Performance -

Author: Oluranti Paul Togunde

Publisher:

Published: 2008

Total Pages: 230

ISBN-13:

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This thesis investigates and documents fundamental studies of highway materials (asphalt engineering properties) especially on different modified asphalt binders and mixtures in order to understand failure mechanisms at low temperature and superior performance of such asphalt binders with the aim of preventing premature cracking on Ontario highways. In addition, seven asphalt binders of different compositions were used as a template for study and this research work is tailored towards Superpave® performance-based specification testing with the aim of improving asphalt pavement performance under various conditions and consequently reducing premature cracking in order to achieve long lasting highways. Based on the actual applied pattern of Superpave® specification criteria, the mechanical responses of the binders are analyzed by extended bending beam rheometer (eBBR), tensile stress ductilometer (Petrotest DDA3®), compact tension test (Instron AsphaltPro®), double-edge-notched tension and single-edge-notched tension (MTS 810 universal testing machine) protocols. The objective of this study entails establishing and developing of a proper procedure for the testing of binders with the aim of ranking (grading) the performance after validation of laboratory and field experiments. Analysis of the results appears to show that the premature distress on the Highway 417 trial sections can be attributed to reversible aging tendency (wax crystallization) at low temperatures coupled with low fatigue resistance of the binders. The results suggest that different polymer modifications had significant influence on the performance of asphalt mix as demonstrated from the results obtained from essential and plastic work of fracture using double-edge-notch-tension test (DENT). Crack tip opening displacement (CTOD) parameter consistently show the performing grading of asphalt binder while compact tension test protocol provides plane strain fracture toughness (K1c) which could be used to rank binders with respect to fracture resistance at low temperature. Hence, CTOD is a promising parameter which can be used to establish performance ranking of the binders.