PRiSMA: Performance-Related Specifications for Hot Asphalt Mixes

Cooperating countries: Austria and Tunisia

Coordinating institution: Assoc. Prof. Dipl.-Ing. Dr. Bernhard Hofko, Technische Universität Wien, Fakultät für Bauingenieurwesen

Partner institutions: Professor Amara Loulizi, Univeristy Tunis el Manar (UTM), National School of Engineers of Tunis (ENIT)

Project duration: 1 September 2021 - 30 August 2024

Pavement construction, maintenance, and rehabilitation is a crucial component of the huge public investments worldwide. The wearing surface of a pavement is usually constructed using Hot Mix Asphalt (HMA), and represents the most cost-sensitive layer. Pavement design is performed by consultants hired during the design phase of any project. However, HMA formulation is designed by contractors engaged during the project construction. This separation through the project life cycle may cause a gap between the materials properties set during the design phase and those obtained during the construction phase. This gap usually results in unsatisfactory performance for HMA causing premature failures such as rutting, cracking, and ultimately potholes and limits the lifetime of road infrastructure significantly. Performance-Related Specifications (PRS) for HMA could overcome this gap.

PRS for HMA is a set of quality acceptance criteria for this material. PRS must be achieved using available materials in the market and current construction technologies. This concept has been implemented in several developed countries such as Austria. The proposed research cooperation project is an important milestone to promote and prepare the implementation of such a great added value concept to the road construction industry in Tunisia. This project is building new links of knowledge and science between Austria and Tunisia through the cooperation between University of Tunis el Manar (UTM) and the Technical University of Vienna (TU Wien). The project is involving Eng. Taha Ben Dhia and Professor Amara Loulizi on the Tunisian side and Professor Bernhard Hofko, Mrs Ingrid Camarago and Dr. Johnnas Mirwald on the Austrian side. Through mobility and knowledge exchange this project aims at preparing the ground in Tunisia for more efficient material assessment in road engineering, which will ensure that tax money is spent in an efficient and economical way. For Austria, this new partnership increases the knowledge on PRS on local material sources that are not available in Central and Western Europe and opens possibilities for further research cooperation in the future in this region.

The Sustainable Developments Goals (SDGs) are defined by the Division for Sustainable Development Goals (DSDG) in the United Nations Department of Economic and Social Affairs (UNDESA). There are seventeen goals set in the 2030 Agenda for Sustainable Development, which was adopted by all United Nations Member States in 2015. The cooperation research project is relevant to four goals from these SDGs, which are the following.

• Goal 4: Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all
• Goal 9: Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation
• Goal 11: Make cities and human settlements inclusive, safe, resilient and sustainable
• Goal 17: Strengthen the means of implementation and revitalize the global partnership for sustainable development

The cooperation research project is considering Performances-Related Specifications (PRS) for Hot Mix Asphalt (HMA). The investment in building roads and highways could be split into earthwork, pavement construction and structures building. The pavement has, usually, several layers. The most cost-sensitive layers are those built with HMA materials, which could be either surface or base layers. This project address the mechanical properties of these expensive and bitumen-based materials in order to bring their cost-effectiveness. This project aims to provide optimization for the pavement design especially in the bitumen treated layers. This project could, then, reduce bulk materials consumptions and decrease the carbon footprint of transportation infrastructure projects. Besides, the project may extend the durability and avoid premature failures of the pavement. Thus, the maintenance costs and pollution are moderated. This project is up to enhance the efficiency of the public investment. The sustainability is a main concern of this project. According to the SDGs, this project will meet Goal 9 under target 9.5:

“Enhance scientific research, upgrade the technological capabilities of industrial sectors in all countries, in particular developing countries, including, by 2030, encouraging innovation and substantially increasing the number of research and development workers per 1 million people and public and private research and development spending.”

Besides, it is a research project in a developing country with the help of a developed country. So, the project is up to fulfill Goal 4 under target 4.b:

“By 2020, substantially expand globally the number of scholarships available to developing countries, in particular least developed countries, small island developing States and African countries, for enrolment in higher education, including vocational training and information and communications technology, technical, engineering and scientific programs, in developed countries and other developing countries”.

The forecasted results are up to improve investment in infrastructure for transportation projects. Thus, the project may reach Goal 11 under target 11.2:

“By 2030, provide access to safe, affordable, accessible and sustainable transport systems for all, improving road safety, notably by expanding public transport, with special attention to the needs of those in vulnerable situations, women, children, persons with disabilities and older persons”.

The project is partnership program based on knowledge exchange and mobility. Then, the project is able to achieve Goal 17 under target 17.7:

“Promote the development, transfer, dissemination and diffusion of environmentally sound technologies to developing countries on favorable terms, including on concessional and preferential terms, as mutually agreed”.

The Sustainable Mobility for All (SuM4All) Initiative launched by the World Bank in agreement with the SDGs consider four aspects for mobility of goods and people which are equitability, efficiency, safety and greenish of transportation. The project could provide more efficiency and greener roads projects. It minimizes in a considerable manner the cost of the investment. Therefore, it ensures that demand for mobility is met at the least possible cost for society. Moreover, the project intends to lower the carbon footprint. The environmental footprint is reduced as well. This project is compliant with SuM4All initiative. Furthermore, the degree of implementation of PRS for HMA could be a benchmark to measure the convenience of given roads and highways projects to the SuM4All initiative.