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The mechanical testing of asphalt concrete mixtures using digital image correlation



Title: The mechanical testing of asphalt concrete mixtures using digital image correlation
Author(s): Y. Seo, Y. R. Kim
Paper category : conference
Book title: Fifth International RILEM Conference on Reflective Cracking in Pavements
Editor(s): C. Petit, I.L. Al-Qadi and A. Millien
Print-ISBN: 2-912143-47-0
e-ISBN: 2912143764
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 155 - 162
Total Pages: 8
Nb references: 3
Language: English


Abstract: The digital image correlation (DIC) method, a noncontact, full field displacement measurement technique, is applied to mechanical testing of asphalt concrete. A single digital camera acquires images of an area of interest from a specimen in undeformed and deformed states. These images are correlated to determine deformations, and advanced mathematical procedures are applied to these deformations to calculate strains. In this research, the DIC technique has been applied to the following three test setups: (1) a double-notched prismatic specimen subjected to axial tension; (2) a 75 mm diameter cylindrical specimen subjected to axial tension; and (3) an indirect tension test (IDT) on specimens with a 100 mm diameter. To verify the accuracy of the DIC measurements, displacements in a specimen measured by the DIC are compared against those measured by Linear Variable Differential Transducers (LVDTs). It is verified from the cylindrical specimen testing that the DIC method is applicable to a curved surface of 75 mm diameter specimen. In IDT, the center strain and Poisson's ratio are determined from the horizontal and vertical displacements measured by DIC using linear viscoelastic solutions. The use of Poisson's ratio as an indicator of microcracking is confirmed. When strains are localized due to significant damage in the specimen regardless of test type, the localized strains determined from the 4 ~ 5 mm wide process zone are found much larger than the average strain calculated from 50 mm gauge length. This error limits the use of linear elastic or linear viscoelastic solutions in characterizing specimens with significant damage.


Online publication: 2004-04-15
Publication type : full_text
Public price (Euros): 0.00


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