Accession Number : ADA266327


Title :   Investigation of the Microstructural Mechanism of Relaxation and Fracture Healing in Asphalt


Descriptive Note : Final rept. 15 Aug 1990-12 Apr 1993


Corporate Author : TEXAS TRANSPORTATION INST COLLEGE STATION


Personal Author(s) : Little, Dallas N ; Prapnnachari, S ; Letton, Allen ; Kim, Y R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a266327.pdf


Report Date : 12 Apr 1993


Pagination or Media Count : 173


Abstract : Two major research issues are addressed. The first issue is the microstructural components of asphalt cement which influence and/or control relaxation and creep under mechanical loading. The second and allied issue is the identification and evaluation of asphalt cement and asphalt concrete microstructural components that influence and/or control the microdamage (microfracture) healing of asphalt concrete mixtures. A unique approach, for the study of asphalt cement, is used to evaluate the mechanism of relaxation and creep and the microstructural components controlling this mechanism within asphalt cement. This approach involves the study of infrared spectral peak shifts and peak geometry changes due to the application of mechanically-induced stress. This approach is demonstrated to be successful and determines that the primary microstructural component of the asphalt cement related to creep and relaxation deformation is aliphatic appendages to the various molecular species. The nature of these appendages, i.e., shape and length, are strongly related to equilibrium modulus, zero shear viscosity and microdamage healing.... Fracture healing, FTIR, Asphalt, Micromechanisms of fracture asphalt modification, Viscoelastic correspondence principle.


Descriptors :   *ASPHALT , *CONCRETE , *FRACTURE(MECHANICS) , FRACTALS , CONTROL , TEMPERATURE , MICROSTRUCTURE , OPTICAL DETECTION , MODIFICATION , INFRARED SPECTRA , VISCOSITY , RELAXATION , GEOMETRY , CREEP , LENGTH , AGGREGATES(MATERIALS) , CEMENTS , MIXTURES , HEALING , STRAIN(MECHANICS) , LOADS(FORCES) , DEFORMATION , VISCOELASTICITY , DAMAGE ASSESSMENT , SHAPE , X RAY DIFFRACTION


Subject Categories : Ceramics, Refractories and Glass
      Construction Equipment, Materials & Supplies


Distribution Statement : APPROVED FOR PUBLIC RELEASE