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New universal procedure to evaluate the ductility of all kind of asphalt binders at a wide range of temperatures. Ductility Asphalt Test (DAsT)

Type of activity
Competitive project
Acronym
DAsT
Funding entity
AGENCIA ESTATAL DE INVESTIGACION
Funding entity code
RTI2018-096224-J-I00
Amount
169.400,00 €
Start date
2019-10-01
End date
2022-09-30
Keywords
asphalt binders, bituminous mixtures, carreteras, cracking, ductilidad, ductility, fatiga, fatigue, fisuración, ligantes bituminosos, mezclas bituminosas, pavements, pavimentos, roads
Abstract
One of the most common distresses observed in asphalt pavements is cracking, normally caused by the combination of thermal gradients,
traffic loads and the ageing of the asphalt binder. Nothing can be done to avoid the first two causes, but the third one can be improved by
studying the binder behaviour. With time, asphalt binders undergo what it is a called ageing, which essentially increases the stiffness of the
material. Once the binder is too stiff, traffic loads and thermal gradients produce cracks in the mixture, which allows rainfall water to
penetrate in the pavement and further damaging the pavement structure with time. For that reason, many test procedures try to
characterize the asphalt binders to help avoid or delay this kind of problems.
The main property of the binder that can be related with in-field cracking of the asphalt mixture is ductility at service temperatures. This
property is measured using an apparatus that pulls apart a sample of binder at a constant speed until the specimen breaks (ASTM D 113
and UNE EN 13589). The ductility is normally measured as the distance the specimen can elongate before breaking. However, when
ductile and/or modified binders are tested the elongation can be so high that the apparatus is not long enough to perform the test
successfully.
The aim of this project is to develop a new test procedure that is able to measure successfully the ductility of wide range of types of asphalt
binders at a wide range of temperatures. This new procedure will help stablish the range of service temperatures of the binder according to
the environmental conditions, in similar manner the SUPERPAVE procedure does but with the main advantage of using only one test and
requiring a much simpler test equipment. A new test geometry will be proposed based on an existing test procedure that has had great
success on characterizing cracking behaviour on asphalt mixtures, the Fenix test. This new procedure will be able to show differences
between ductile and/or modified binders, covering the gap left by the existing ductility related procedures. The better characterization of
ductile binders will help improve the design of asphalt mixtures. This should translate in higher durability of mixtures in the field, which
should suppose an important reduction in conservation costs, consumption of raw materials and emission of greenhouse gases.
This research project addresses the challenge number 4: Sustainable, smart and integrated transport of the 2018 call for I+D+i Research
Challenges projects of the Spanish Ministry of Science, Innovation and Universities. Specifically, this project is contained in the point 1 that
promotes the research and application of new advanced transport materials, pavements and infrastructures, including the development of
technologies related to the circular economy (eco-design, re-use, recuperation, re-fabrication and recycling). The development of a new
test procedure to optimize the binder selection for the mixture taking into account the environmental conditions, as stated in this project,
will help increase the service life of road pavements, minimizing conservation operations and reducing the consumption of raw materials
and the emission of greenhouse gases.
Scope
Adm. Estat
Plan
Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020
Call year
2019
Funcding program
Programa Estatal de I+D+i Orientada a los Retos de la Sociedad
Funding call
Retos de Investigación: Proyectos de I+D+i
Grant institution
Agencia Estatal De Investigacion

Participants