Ongoing projects:
·
Investigation of Improvement of Sulfur Extended
Asphalt
·
High Strength Bases: Portland Cement and Bituminous
Stabilization.
Investigation of Improvement of Sulfur Extended Asphalt
(Principal Investigator:Dr. Amit Bhasin, UT-Austin-USA)
The crude oil produced and processed in KSA results in significant
amount of sulfur as a by-product.
Sulfur, when used as partial replacement for asphalt binder, can
significantly improve the stiffness and deformation resistance of asphalt
mixtures, which is a major source of pavement distress due to the local
climatic conditions in KSA. Therefore,
by careful incorporation of sulfur as a partial replacement of asphalt binder,
KSA can (i) consume a major crude oil by-product, (ii) reduce the use of more
expensive asphalt binder, (iii) enhance the durability of the pavement, and
(iv) promote environment friendly technologies. While the benefits of sulfur as
a partial replacement of binder are clear, it cannot be indiscriminately
replaced for asphalt in all asphalt mixtures.
This study employs the latest tools developed by the research
institutions over the last five years to evaluate material durability to
address the research goals. The findings
from this research can provide guidelines for optimal use of sulfur in asphalt
mixes without compromising its durability and long-term performance. If
properly implemented, careful use of sulfur can improve the deformation
resistance of asphalt pavements, particularly in a climate like that of KSA.
Typically, sulfur is less expensive than asphalt binder that is suitable for
KSA climate. Partial substitution of binder with sulfur has the potential to
reduce the cost of pavement construction and maintenance.
High
Strength Bases: Portland cement and Bituminous Stabilization" (Principal
Investigator: Dr.Erol Tutumluer, TEST, USA)
Soil stabilization has been widely used worldwide and is a proven
technology. This project is intended to identify soils and locally available
aggregates for constructing high strength base courses within the Kingdom of
Saudi Arabia (KSA) that will benefit from stabilization with bitumen or
Portland cement stabilization and to provide a protocol for laboratory
characterization, design, and construction of these stabilized, high strength
bases.
The nature of the desert soils in KSA, especially in the eastern
provinces, makes them amenable to treatment and stabilization with Portland
cement and with bitumen in the form of emulsion or foamed asphalt. However, the
high salt and sulphur contents interfere with Portland cement stabilization in
a deleterious manner. Therefore, this project will develop protocols for
stabilizer selection, mixture design, and performance modeling as well as
construction protocols to optimize the use of Portland cement and bitumen to
successfully treat the native soils and aggregate sources within KSA. The project outcome will bring sustainable
practices to road construction and rehabilitation projects, provide safe,
environmentally friendly and long lasting roads to public / freight, and ultimately
enable growth and economic development in the region.
Completed Projects:
The chair has successfully completed
following projects:
·
Benchmarking Pavement Practices for KSA Roadways
· Life-Cycle Assessment of Using Sulfur-Extended Asphalt in Pavements
Benchmarking
Pavement Practices for KSA Roadways
(Principal
Investigator: Dr. Ghassan Chehab, American University of Beirut, Lebanon)
The main objective of this project
was to develop benchmarks to be used by highway agencies and stakeholders in
the Kingdom of Saudi Arabia (KSA), particularly by the Ministry of Transport
(MOT) and the Ministry of Municipalities and Rural Affairs (MOMRA), for the
assessment of pavement practices and policies of the roadway sector. Practices
of interest include evaluation, planning, design, construction, specifications
and management of pavement-related aspects of the existing roadway network. The
work was conducted over the course of two years, starting March of year 2015.
Benchmarking pavement practices in
KSA was conducted against the Emirates of Dubai and Abu Dhabi in the United
Arab Emirates, the State of Qatar, and the Sultanate of Oman. The United States
of America was selected as the international benchmark country, being one of
the leading countries in both research and practice in various areas of
pavement engineering, and having the largest road network in the world.
Results from the benchmarking study
can ultimately aid highway agencies and stakeholders in performing an internal
evaluation of their current state-of-practice. The study can be used as a solid
reference for future industry and research projects in KSA. It can aid in
identifying areas of possible improvement and needs for modification of
existing practices, launching of new initiatives, creation of programs, and
adoption of new technologies.
Life-Cycle Assessment of Using Sulfur-Extended Asphalt in Pavements
(Principal Investigator: Dr. Yanfeng
Ouyang,TEST, Inc,USA)
With the excess of by-product sulfur
in many oil and gas producing countries, engineers must find new markets that
can successfully use this by-product. In the recent decades, interest in
sulfur-extended asphalt (SEA) has emerged. In order for the KSA to move forward
with the use of SEA, a comprehensive environmental assessment conducted to
better evaluate the sustainability of using sulfur in roadway construction
compared to other conventional or modified AC pavements. To ensure that a
systematic and accurate approach is used, a life-cycle assessment (LCA)
methodology has been applied to various product systems, including pavements,
to capture environmental impacts at each stage of a product’s life-cycle.
The study modeled the processes and
technologies used in the KSA by collecting questionnaire responses distributed
to various contractors, plant facilities, and Ministry of Transportation (MOT)
representations in the KSA. The main contribution of this study was an LCA
report detailing the potential environmental impacts of using SEA as well as a
LCA software (SEL2ECT v1.0) developed as part of this project. The
software allows users to calculate the life-cycle environmental impacts of
various types of pavement projects, including SEA and conventional AC
pavements. This software can be implemented by various stakeholders and
decision makers in the KSA to analyze future pavement projects to obtain an
indication of the environmental impacts of various pavement designs, including
those involving SEA.
Future project:
Influence
of asphalt binder properties on the performance of asphalts in Saudi Arabia
(Principal Investigator: Dr. Ghassan Chehab, American University of Beirut,
Lebanon)
The behavior of asphalt concrete as
a material, and the subsequent performance of a flexible pavement, is
influenced by the properties of the constitutive materials of the asphalt mix:
the aggregates, asphalt binder, and air voids, as well as their interaction.
Therefore, an understanding of the behavior of the binder in general, and under
local conditions in particular, is required to develop adequate binder
specifications that help avoid the development of distresses such as rutting,
cracking, raveling, bleeding, and shoving that deteriorate the pavement surface
and structure and significantly reduce its service life. This study is expected to conduct in
collaboration with Saudi Aramco, KFU and AUB.