Ageing Behavior of Porous and Dense Asphalt Mixtures in the Field

Bitumen ageing is one of the principal factors causing the deterioration of asphalt pavements. As bitumen ages, the pavement loses its ability to relax stresses during loading/unloading and thermal cooling process, thus the risk of cracking increases. Oxidation and ultraviolet (UV) radiation are believed to be the main factors that can cause...

Continuum-based micromechanical models for asphalt materials: Current practices & beyond

The mechanical properties of asphalt mixture are always required for the evaluation of the durability of pavements. In order to obtain these properties without conducting expensive laboratory tests and using calibrated empirical models, research studies have been carried out to develop micromechanics-based models. Continuum-based...

The effect of ageing on chemical and mechanical properties of asphalt mortar

Asphalt mortar is a mixture of bitumen, filler, and sand. Mortar plays an important role in asphalt mixtures as it serves as the adhesive between the coarser aggregates. Due to the effect of bitumen ageing, the chemical and mechanical properties of asphalt mortar evolve with time. The mortar becomes more brittle and prone to cracking, thus...

Direct Tensile Test to Assess Healing in Asphalt

Asphalt concrete has the advantageous ability to heal. During rest<br/>periods, damage present In the material is restored to a certain extent.<br/>Healing of the material can be observed in iis regaining of strength<br/>and stiffness after rest periods. In this paper, a new test method is presented.<br/>It was developed to increase the...

American and European Mix Design Approaches Combined: Use of NCHRP Performance Indicators to Analyze Comité Européen de Normalisation Test Results

This paper describes a project that is part of NL-LAB, a larger, long-term program at Delft University of Technology, Netherlands, which aims to establish the predictive capacity of the current European functional tests for Dutch asphalt concrete (AC) mixtures. In this NL-LAB program, the functional characteristics of resistance to rutting (EN...