| 1. |
- Kragh, Jörgen, et al.
(author)
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Optimization of thin asphalt layers : state-of-the-art review
- 2011
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Reports (other academic/artistic)abstract
- ERA-NET ROAD initiated a transnational research project titled "Optimization of thin asphalt layers" (OPTHINAL). The DRI-BRRC-VTI Consortium was trusted with carrying out the project and began with a State-of-the-Art report covering, among other things, a literature study and an inventory of experience with using thin asphalt layers (TAL). The results of this phase of the project are given in the present report.This study was limited to thin asphalt mixtures with a maximum thickness of 30 mm, which means that surface dressings or slurry seals were outside the scope of the project. Neither were top layers of double-layer porous pavements considered as TAL, even though such top layers often are 20-30 mm thick. Mix design and optimization was the subject of another study in this project and is therefore not treated here. The main conclusions are that the application of TAL is certainly worthwhile, in particular asa renewable “skin” of a stable road construction having sufficient bearing capacity. The skin serves road users’ need for sufficient skidding resistance and other important functions.
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| 2. |
- Kragh, Jörgen, et al.
(author)
-
Optimization of thin asphalt layers, OPTHINAL. Final report
- 2011
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Reports (other academic/artistic)abstract
- ERA-NET ROAD initiated a transnational research project titled "Optimization of thin asphalt layers". Thin asphalt layers have been used extensively and with promising results for more than 15 years in several countries in Europe and abroad. They seem to be cost effective, fast to build and may have good surface properties. In recent years thin asphalt layers have been shown to imply reduced traffic noise levels, increased traffic safety (skid resistance and forward visibility during wet condition) and to be durable compared with traditional alternatives.The DRI-BRRC-VTI Consortium was trusted with carrying out the ERA-NET ROAD project and began with a State-of-the-Art report covering, among other things, a literature study and an inventory of experience with using thin asphalt layers. The results of this phase of the project were documented in a separate project report.The main conclusions were that the application of thin asphalt layers is certainly worthwhile, in particular as a renewable "skin" of a stable road construction having sufficient bearing capacity. The skin serves road users' need for skid resistance and other important functions. Compared with more conventional and traditional surfacing such as dense asphalt concrete 0/11 or stone mastic asphalt 0/11, thin asphalt layers in general come out somewhat better in most respects; for example concerning cost, use of nature resources, rolling resistance, and traffic noise emission. However, there are also drawbacks or problems under special traffic that need to be handled, for example TAL durability when exposed to wear from studded tyres. The availability of premium quality aggregate is a prerequisite for applying thin asphalt layers, and good quality aggregate may be difficult to procure.The present report looks at possibilities to optimize the application of thin asphalt layers, including an analysis of the cost of applying thin asphalt layers compared with the cost of applying more conventional solutions. The study has been limited to thin asphalt layers with a maximum thickness of 30 mm.Recommendations are given concerning the best practice in applying thin asphalt layers and suggestions are given for future research needed to fill the gaps in available knowledge.
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| 3. |
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| 4. |
- Porot, Laurent, et al.
(author)
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Bituminous binder
- 2018
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In: Testing and Characterization of Sustainable Innovative Bituminous Materials and Systems. - Cham : Springer Netherlands. ; , s. 15-74
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Book chapter (peer-reviewed)abstract
- One of the most important aspects of asphalt pavement deterioration is the ingress of water in pavement which leads to loss of the material characteristics, even material integrity with loss of aggregates. Thus the behaviour of asphalt mixture under moisture conditions is one of the key parameter for specifications. It’s a complex phenomenon which is influenced amongst other things by materials properties with wetting, cohesion and adhesion of bituminous binder and by environmental conditions with temperature, moisture, loading and layer type. It has been a research subject for a very long time and still not precisely described. A large number of test methods is available to estimate the affinity between aggregates and bituminous binders. These test methods can be subdivided in different ways; a first distinction can be based on the presence or absence of water during the test procedure. If water is present, the evaluation is in fact referred to as water sensitivity or moisture damage testing. Another distinction can be based on the type of sample that is evaluated. The test sample can be loose aggregates coated with a bituminous binder or a compacted asphalt mix sample. Lastly the individual components, bitumen and aggregate, can be tested separately through intrinsic properties. Furthermore, test results can also be based on the quantification of the test results, whether this is based on a qualitative or a quantitative evaluation. In RILEM TC 237 SIB, TG1 the main purpose was to evaluate common test methods, used to assess the affinity of bitumen to aggregate surfaces, to determine, if possible, the repeatability and reproducibility and to give recommendations for improvement. In this study both binders and aggregates have been considered. Three bituminous binders, two unmodified from different sources, one polymer modified binder, and four aggregate types, with different mineralogy, have been selected. The test methods considered in the study include the rolling bottle test, the boiling water stripping test and the bitumen bond strength test; also surface energy was investigated. This chapter presents the results of these tests and their accuracy.
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| 5. |
- Porot, Laurent, et al.
(author)
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Characterisation of complex polymer modified bitumen with rheological parameters
- 2021
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In: International Journal on Road Materials and Pavement Design. - : Taylor and Francis Ltd.. - 1468-0629 .- 2164-7402. ; 22:S1, s. S297-S309
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Journal article (peer-reviewed)abstract
- The use of modifiers for bituminous binders has become common practice to enhance the performances of asphalt materials. As a result, the binder becomes more complex, with various phase morphologies. Conventional testing methods may not always be suitable. As example, the European standardisation committee is looking at different ways to characterise Polymer modified Bitumen. The RILEM Technical Committee 272-PIM ‘Phase and Interphase behaviour of innovative bituminous Materials’, with its Task Group TG1, is evaluating different test methods for complex binders. The aim is to evaluate how these tests could address complex bituminous binders. An inter-laboratory programme was conducted with 17 laboratories. Seven binders were evaluated; two were neat bitumen and two PmB. In addition to the conventional property measurements, an extensive effort was made on investigating various rheological parameters obtained from Dynamic Shear Rheometer measurements. Some initial results are presented and discussed in view of the future revision of the European product standard EN 14023 for PmB.
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