Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Entire DC Network
Modeling Of Asphalt Concrete For Cross-Anisotropic Visco-Elasticity And Heterogeneity, Zafrul Hakim Khan
Modeling Of Asphalt Concrete For Cross-Anisotropic Visco-Elasticity And Heterogeneity, Zafrul Hakim Khan
Civil Engineering ETDs
Asphalt Concrete (AC) is a cross-anisotropic viscoelastic material. This study has developed a methodology to backcalculate the cross-anisotropic properties of the AC layer from the Falling Weight Deflectometer (FWD) sensor and pavement response data from embedded sensors inside a pavement section. This study has also developed a two-way coupled Multiscale Finite Element Model (MsFEM) with Phase Field Fracture (PFF) to study the microstructural heterogeneity and damage of the AC layer based on the actual field loadings. A Finite Difference Time Domain (FDTD) and Machine learning-based backcalculation algorithm were developed to determine the layer thickness and dielectric constant from air-coupled Ground …
Characterization And Modeling Of Asphalt Concrete For Dynamic Properties And Performances, A S M A. Rahman
Characterization And Modeling Of Asphalt Concrete For Dynamic Properties And Performances, A S M A. Rahman
Civil Engineering ETDs
The recently developed mechanistic-empirical pavement design guide (MEPDG, also known as Pavement M-E design method) uses the nationally calibrated, binder viscosity-based dynamic modulus predictive model for the design and analysis of asphalt pavements. In this study, this model is assessed for its appropriateness for asphalt-aggregate mixtures typically used in New Mexico. In essence, this study investigates the predictability issue of complex modulus of New Mexico mixes. A total of 54 Superpave mixes with different aggregate gradations, air voids, and binder grades were collected from the mixing plants and from the pavement construction sites. The loose asphalt mixtures were then compacted, …
On Cross-Anisotropy Of Flexible Pavement Layer Materials For Improved Pavement Responses, Mesbah Ahmed
On Cross-Anisotropy Of Flexible Pavement Layer Materials For Improved Pavement Responses, Mesbah Ahmed
Civil Engineering ETDs
Pavement layer materials are typically assumed to be isotropic in determining pavement responses, such as stress and strain. The main benefit of the isotropic assumption is that stiffness defined by modulus of elasticity (E-value) is equal in all directions. In reality, stiffness along vertical and horizontal (i.e., and ) may vary due to density gradients in compacted layer materials caused by vertical compaction during construction. Therefore, pavement layer materials with different vertical and horizontal modulus (i.e., \u2260 ) are cross-anisotropic. Past studies have reported that degree of cross-anisotropy, ( ) ranges from 0.2 to 0.85 in Asphalt Concrete (AC) layers. …
Thermal Fatigue Damage Of Asphalt Pavement, Md Islam
Thermal Fatigue Damage Of Asphalt Pavement, Md Islam
Civil Engineering ETDs
Fatigue damage can be defined by a decrease in stiffness of Asphalt Concrete (AC) under repeated traffic loading. For each cycle of traffic loading, tensile strain develops at the bottom of AC layer of an asphalt pavement. Some localized damages occur in the material at minute-scale due to this developed tensile strain. These damages cause decrease in stiffness (E) of AC. Damage caused by a single vehicle is small. However the accumulated damage is not small if a large number of vehicles are considered over the design life of an asphalt pavement. After certain level of damage accumulation, bottom-up fatigue …
Modeling Moisture-Induced Damage In Asphalt Concrete, Mohammad Hossain
Modeling Moisture-Induced Damage In Asphalt Concrete, Mohammad Hossain
Civil Engineering ETDs
Moisture damage in Asphalt Concrete (AC) is not new but an unsolved problem. For decades laboratory studies have been conducted on both loose and compacted mix to understand the effects of moisture on the AC damage. Adhesive and cohesive damages are the two major types of damages occur inside the AC. Adhesive damage is a separation between aggregate and coated mastic or matrix materials and cohesive damage is the degradation of strength of matrix materials within the AC samples. In this study, Finite Element Method (FEM) modeling technique is used to identify initiation and progression of adhesive and cohesive damage. …