"Numerical analysis of Asphalt Hot Mixtures cracking".
Paving; Asphalt mixtures; cracking; particles; Extended Finite Element Method.
This doctoral thesis details a new approach to the numerical simulation of cracking in asphalt mixtures on a mesoscale. To build the model, two constituent phases of the composite material were adopted, namely the MAF (Fine Aggregate Matrix) and the ESG (Coarse Solid Skeleton), which make up the CBUQ (Hot Bituminous Concrete). In order to simulate the behaviour in a credible way, the constituent materials of each phase were studied and characterized individually, experimentally, for their numerical representations, considering basic characteristics such as size and shape, as well as their constitutive models. New technologies for generating and packing particles were used in order to build a representative set of aggregates which, once surrounded by a continuous medium defined in a pre-established domain, allowed for the construction of a model that simulates an asphalt concrete specimen. To emulate the cracking of asphalt mixtures, a numerical model geometry was defined to simulate the bending test on a semicircular sample, which was then tested virtually using the ABAQUS program, under the same boundary conditions specified for the experimental test. Once the model had been calibrated, it proved to be validated when compared to experimental results, which makes it viable for use in parametric studies and validates the technology used to represent it.