Damage analysis in asphalt concrete mixtures based on parameter relationships /
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| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A & M University],
[2004]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | Asphalt pavements experience damage due to traffic loading under various environmental conditions. Damage can be caused by viscoplastic flow and microcracks, fracture due to fatigue cracking, or fracture due to thermal cracking. Asphalt pavements have the capability to remediate some of this damage depending on binder surface and rheological properties, filler surface properties, and length of rest periods. Asphalt mastic (asphalt and fine aggregates) properties play an important role in controlling damage and healing. This dissertation addresses the development of a comprehensive methodology to characterize damage and healing in asphalt mastics and mixtures. The methodology relies on nondestructive imaging techniques (X-ray CT), principles of continuum damage mechanics, and principles of micromechanics. The X-ray CT yields a damage parameter that quantifies the percentage of cracks and air voids in a specimen. The continuum damage model parameters are derived from the relationship between applied stress and pseudo strain. The micromechanics model relates the damaged mastic modulus to a reference undamaged modulus. This relationship is a function of internal structure properties (void size, film thickness, and percentage of voids), binder modulus, aggregate modulus, and bond energy between binder and aggregates. The internal structure parameters are all obtained using X-ray CT and correlated. The developed methodology was used to characterize damage in asphalt mastic and mixture specimens tested using the Dynamic Mechanical Analyzer (DMA) and dynamic creep test. The damage parameter measured using X-ray CT correlated very well with the predictions of the continuum and micromechanics models. All damage parameters were able to reflect the accumulation of damage under cyclic loading and were also able to capture the influence of moisture conditioning on damage. Although this dissertation focused on fatigue cracking at room temperatures, the methodology developed can be used to assess damage due to different mechanisms such as permanent deformation and low temperature cracking. |
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| Item Description: | "Major Subject: Civil Engineering." Vita. Abstract. Title from author supplied metadata (automated record created on Oct. 15, 2004.) Electronic resource. |
| Physical Description: | 1 online resource. |
| Format: | System requirements: Adobe Acrobat Reader. |
| Bibliography: | Includes bibliographical references. |