VI. RESEARCH WORK DONE IN ACADEMIC INSTITUTIONS RELATED TO THESIS WORK

B. PAVEMENT ENGINEERING AND PAVING MATERIALS
10. Experimental and Numerical Study on Mechanical Behavior of Asphalt Mix
Date of Start

May 2005
Indian Institute of Technology, Kanpur (R, I)

 

Scope and Objectives

The objective of the work is to develop a finite element method (FEM) based model to predict the mechanical behavior of asphalt mix. A hierarchical approach is proposed to develop models for pure bitumen, binder mix (a mixture of pure bitumen and aggregates smaller than or equal to 2.36 mm size) and asphalt mix. The scope of the study includes (i) experimental study on mechanical behaviour of binder mix and asphalt mix (ii) FEM modeling of asphalt mix with synthetically developed elliptical aggregates for a typical cross section and (iii) comparative study of experimental and computational results of asphalt mix.

 
Methodology
An elastic-visco-plastic model of binder mix is developed which is calibrated from the experimental results. Elliptical aggregate samples of desired volume fraction and aggregates gradation are developed synthetically by generating random non-overlapping ellipses in a predefined area. The binder mix model and the properties of the aggregates are used to develop the composite model of the asphalt mix. The numerical results from asphalt mix model in terms of load versus time curve, failure load, failure displacement and stress contour are compared with the experimental result of asphalt mix.
 
Findings and Conclusions
The force versus time plot obtained experimentally and computationally showed good match. From experiments on asphalt mix, it is seen that the fracture is initiated in between two closely spaced aggregates. Computational study could predict successfully the location of crack initiation. The maximum displacement at failure and the maximum failure load obtained from computational result for asphalt mixes with synthetic aggregates found to be matching with experimental results.