Evaluation of resilient modulus estimation methods for asphalt mixtures based on laboratory measurements

Demirci, Canser
Resilient modulus is a property for bound and unbound pavement materials characterizing the elastic behavior of materials under dynamic repeated loading. Resilient modulus is an important design parameter for pavement structures because it represents the structural strength of pavement layers through which the thickness design is based on. In Turkey, the layer thickness design is performed using resilient modulus determined empirically from various published sources. Determining a layer modulus using empirical methods causes inaccurate design solutions, which directly affects the structural performance and the overall cost of pavement construction. In this study, the resilient moduli of bituminous mixtures are measured in the laboratory by the indirect tensile test procedure for eight asphalt concrete samples according to NCHRP and ASTM procedures. The measured moduli of samples based on the two procedures are compared with the predicted values calculated from various empirical methods using aggregate and binder properties. An evaluation of each estimation method is presented on the basis of its accuracy level. The results show that the Witczak predictive equation produces the closest estimation to the modulus of samples for both laboratory measurement methods.


Analysis of the flexural strength of prestressed concrete flanged sections
Baran, Eray; French, Catherine (Precast/Prestressed Concrete Institute, 2005-01-01)
Inconsistencies in the sectional response of prestressed concrete flanged sections predicted by the AASHTO LRFD and AASHTO Standard Specifications, including the maximum reinforcement limits, may arise due to different interpretations of the equivalent rectangular compressive stress block idealization. Strain compatibility analyses with nonlinear material properties were performed for a variety of non-rectangular prestressed concrete sections to identify the inconsistencies between the two specifications. R...
Assessment of improved nonlinear static procedures in FEMA-440
Akkar, Dede Sinan; Metin, Ash (American Society of Civil Engineers (ASCE), 2007-09-01)
Nonlinear static procedures (NSPs) presented in the FEMA-440 document are evaluated for nondegrading three- to nine-story reinforced concrete moment-resisting frame systems. Evaluations are based on peak single-degree-of-freedom displacement, peak roof, and interstory drifts estimations. A total of 78 soil site records and 24 buildings with fundamental periods varying between 0.3 s-1.3 s are used in 2,832 linear and nonlinear response-history analyses to derive the descriptive statistics. The moment magnitu...
ELMEZAINI, N; CITIPITIOGLU, E (American Society of Civil Engineers (ASCE), 1991-10-01)
A practical and powerful technique for the discrete representation of reinforcement in finite element analysis of prestressed and reinforced concrete structures is presented. Isoparametric quadratic and cubic finite elements with movable nodes are developed utilizing a correction technique for mapping distortion. Reinforcing bars and/or prestressing tendons are modeled independently of the concrete mesh. Perfect or no bond as well as any bond-slip model can easily be represented. The procedure is succes...
Analytical formulation of maximum length limits of integral bridges on cohesive soils
Dicleli, Murat (Canadian Science Publishing, 2005-08-01)
This paper presents an analytical approach for predicting the length limits of integral bridges built on cohesive soils based on the flexural strength of the abutments and the low cycle fatigue performance of the steel H-piles at the abutments under cyclic thermal loading. First, H-piles that can accommodate large inelastic deformations are determined considering their local buckling instability. Then, a damage model is used to determine the maximum cyclic deformations that such piles can sustain. Next, non...
Investigation of the Applicability of AASHTO LRFD Live Load Distribution equations for Integral Bridge Substructures
Erhan, Semih; Dicleli, Murat (SAGE Publications, 2009-08-01)
In this study, applicability of the AASHTO LRFD girder live load distribution equations (LLDEs) for integral bridge (IB) abutments and piles is investigated. For this Purpose, numerous 3-D and corresponding 2-D structural models of typical IBs are built and analyzed under AASHTO LRFD live load. In the analyses, the effect of various superstructure properties such as span length, slab thickness, girder spacing and stiffness are considered. The results from the 2-D and 3-D analyses are then used to calculate ...
Citation Formats
C. Demirci, “Evaluation of resilient modulus estimation methods for asphalt mixtures based on laboratory measurements,” M.S. - Master of Science, Middle East Technical University, 2010.