It has been recognised with growing concern that agricultural and industrial wastes are increasingly produced in large volume. In order to reduce environmental hazards and conserve natural resources, the use of waste materials in highway pavements would be extremely effective in terms of recycling waste materials. The main purpose of this study was to investigate the effects of waste materials as filler on the performance of hot mix asphalt (HMA) mixtures. HMA mixtures containing waste glass powder (WGP), waste brick powder (WBP), rice husk ash (RHA) and stone dust (control mixture) were fabricated and the optimum asphalt binder content was determined for each mixture. The properties of HMA mixtures were investigated by Marshall, indirect tensile stiffness modulus and indirect tensile fatigue tests. The results indicated that WGP and WBP mixtures exhibited higher fatigue life and better performance than other mixtures. In addition, it was determined that there was no considerable difference in the perform...

Laboratory investigation of hot mix asphalt containing waste materials

Assessment of mechanical properties of rice husk ash modified asphalt mixture

Pavement and mix design represent one of the key components within the life cycle of a road infrastructure, with links to political, economic, technical, societal and environmental issues. Recent researches related to the characteristics of materials and associated behavior models both for materials and pavement, made it appropriate to consider updating current pavement design methods, and especially in the USA this has already been in process while in Europe uses of the methods developed in the early 1970s. Thus, this paper firstly presents a brief historical overview of pavement design methods, highlighting early limitations of old empirical methods. Afterwards, French, UK and Shell methods currently in use in Europe will be presented, underlining their main components in terms of methodology, traffic, climatic conditions and subgrade. The asphalt mix design and modeling in Europe are presented with their inclusion in the pavement design methods. Finally, the main challenges for the development of a European pavement design method are presented as well as the recent research developments that can be used for that method.

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Main flexible pavement and mix design methods in Europe and challenges for the development of an European method

Fatigue performance evaluation of SBS modified mastic asphalt mixtures

In this study, various fatigue criteria for indirect tensile (IDT) fatigue tests were evaluated and a new approach to identify the fatigue failure was proposed based on a crack-length criterion. The IDT fatigue tests were conducted to characterize the fatigue behavior of various asphalt mixtures, such as three warm mix asphalt mixtures and a polymer-modified asphalt mixture. During the IDT tests, digital cameras were mounted to monitor crack growth on the both faces of a specimen. Existing three fatigue failure criteria were evaluated regarding to fatigue-crack development. Then, a crack-length limit was proposed as a fatigue criterion. The IDT strength tests were also conducted to determine fracture energy of the mixtures. Based on the new fatigue criterion, a fatigue performance model was constituted with dissipated and fracture energy parameters. The fatigue model proposed in this study successfully predicted the fatigue lives of the mixtures with a high level of accuracy. The main advantage of this fatigue model is that it does not need a transfer function to convert the fatigue life to crack length or area, because fatigue-crack length is directly determined from the crack-length limit.

Fatigue Analysis of Asphalt Concrete under Indirect Tensile Mode of Loading Using Crack Images

This study investigates the fatigue characteristics of typical bituminous materials used in roadapplications. Fatigue testing was performed in a four-point bending beam test apparatusunder controlled strain and stress conditions. Fatigue life was defined using the classicalapproach as the number of cycles, N f , to 50% reduction in the initial stiffness modulus. It hasalso been defined in terms of macro-crack initiation, N 1 . A different approach, based on thelinear reduction in stiffness during a particular stage of a fatigue test, was introduced todefine a damage parameter and the evolution of this damage parameter with number of cycleswas used to characterise fatigue life. Furthermore, refinements to the linear damage modelwere introduced to take into account the difference in the evolution of dissipated energybetween controlled strain and stress testing modes. These modifications have enabled theidentification of a unique fatigue damage rate for both controlled strain and stress test modes.

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I. Artamendi

Papers

Different approaches to depict fatigue of bituminous materials