Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Investigation of asphalt compaction in vision of improving asphalt pavements
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials.ORCID iD: 0000-0002-5526-5896
2015 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Asphalt joints are potentially weakest parts of every pavement. Despite of their importance, reliable tools for measuring their mechanical properties for design and performance assessments are still scarce. This is particularly true for cold joints when attaching a new hot pavement to a cold existing one as in case of large patches for pavement repair. In this study, three static fracture testing methods, i.e. indirect tensile test (IDT), direct tension test (DTT) and 4 point bending (4PB), were adapted and used for evaluating different laboratory made joints. The results suggested that joints with inclined interfaces and also the ones with combined interface treatments (preheated and sealed) seemed to show more promising behaviors than the vertical and untreated joints. It was also confirmed that compacting from the hot side towards the joint improved the joint properties due to imposing a different flow pattern as compared to the frequent compaction methods. The latter finding highlighted the importance of asphalt particle rearrangements and flow during the compaction phase as a very little known subject in asphalt industry. Studies on compaction are of special practical importance since they may also contribute to reducing the possibility of over-compaction and aggregate crushing.

Therefore, in this study, a new test method, i.e. Flow Test (FT), was developed to simulate the material flow during compaction. Initially, asphalt materials were substituted by geometrically simple model materials to lower the level of complexity for checking the feasibility of the test method as well as modeling purposes. X-ray radiography images were also used for capturing the flow patterns during the test. Results of the FT on model materials showed the capability of the test method to clearly distinguish between specimens with different characteristics. In addition, a simple discrete element model was applied for a better understanding of the test results as a basis for further improvements when studying real mixtures. Then, real mixtures were prepared and tested under the same FT configuration and the results were found to support the findings from the feasibility tests. The test method also showed its potential for capturing flow pattern differences among different mixtures even without using the X-ray. Therefore, the FT was improved as an attempt towards developing a systematic workability test method focusing on the flow of particles at early stages of compaction and was called the Compaction Flow Test (CFT).

The CFT was used for testing mixtures with different characteristics to identify the parameters with highest impact on the asphalt particle movements under compaction forces. X-ray investigations during the CFT underlined the reliability of the CFT results. In addition, simple discrete element models were successfully generated to justify some of the CFT results.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. , xiv, 23 p.
Series
TRITA-BYMA, ISSN 0349-5752 ; 2015:5
Keyword [en]
Cold asphalt pavement joints, asphalt joint laboratory production, IDT joint evaluation, DTT joint evaluation, 4PB joint evaluation, joints FEM analysis. Discrete Element Modeling (DEM), X-ray Computed Tomography (CT), Compaction Flow Test (CFT), Compactability
National Category
Civil Engineering
Identifiers
URN: urn:nbn:se:kth:diva-176319OAI: oai:DiVA.org:kth-176319DiVA: diva2:866607
Presentation
2015-11-24, B3, Brinellvägen 23, Stockholm, 13:00 (English)
Opponent
Supervisors
Note

QC 20151104

Available from: 2015-11-04 Created: 2015-11-03 Last updated: 2015-11-04Bibliographically approved
List of papers
1. Fracture testing for the evaluation of asphalt pavement joints
Open this publication in new window or tab >>Fracture testing for the evaluation of asphalt pavement joints
2013 (English)In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 14, no 4, 764-791 p.Article in journal (Refereed) Published
Abstract [en]

Asphalt joints are inevitable parts of every pavement. Although much attention is dedicated to the construction of such joints, reliable tools for assessing the mechanical properties of joints for design and performance assessment are still scarce. This is particularly true for cold joints when attaching a new hot pavement to a cold existing pavement as in the case of large patches for pavement repair. This paper intends to evaluate different new or modified static fracture testing methods for ranking existing joint construction techniques. Some of these testing methods, such as indirect tensile test, direct tensile test and 4-point bending test are familiar in the field of asphalt pavement characterisation, but have scarcely been used for assessing the quality of joints so far. These three test types were adopted and evaluated for joints and the test results were analysed with finite element (FE) software ABAQUS. Different joints for testing were prepared in the laboratory using a special specimen construction procedure. The results suggest that joints with inclined interfaces seem to show more promising behaviour than vertical joints. It was confirmed that starting compaction from the hot side of the joint generally produces better results than compaction starting from the cold side of the joint. Pre-heating of the joint surface and using a bond sealant appears to provide the best results.

Keyword
cold asphalt pavement joints, asphalt joint laboratory production, IDT joint evaluation, DTT joint evaluation, 4PB joint evaluation, joints FE analysis
National Category
Infrastructure Engineering
Research subject
SRA - Transport
Identifiers
urn:nbn:se:kth:diva-134179 (URN)10.1080/14680629.2013.812979 (DOI)000330015900002 ()2-s2.0-84888129020 (Scopus ID)
Note

QC 20140122

Available from: 2013-11-18 Created: 2013-11-18 Last updated: 2017-12-06Bibliographically approved
2. Particle Flow during Compaction of Asphalt Model Materials
Open this publication in new window or tab >>Particle Flow during Compaction of Asphalt Model Materials
2015 (English)In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 100, no 15, 273-284 p.Article in journal (Refereed) Published
Abstract [en]

Compaction is one of the key phases of the pavement construction and has been subject of research for a long time. However, very little is known regarding what really happens during compaction and how the pavement structure and the aggregate skeleton of the asphaltic layer are formed. Studies on that matter are of special practical importance since they may contribute to reduce the possibility of over-compaction and aggregate crushing. In this study, a new test method (Flow Test) was developed to simulate the material flow during compaction. Initially, asphalt materials were substituted by model materials to lower the level of complexity for checking the feasibility of the new test method as well as modeling purposes. Geometrically simple materials with densest possible combinations were tested for both dry and coated mixtures. X-ray radiography images were used for evaluating the material flow during compaction for different model mixtures. Results showed the capability of the test method to clearly distinguish mixtures with different properties from one another and also the potential of such a method to be used as an evaluating tool in the field. In addition, a simple discrete element model was applied for better understanding the flow of the model material during compaction as a basis for further improvement when moving from the asphalt model material to real mixtures. Therefore, real mixtures were prepared and tested under the same test configuration as for the model materials. The overall results of the real mixtures were found to support the model material test results.

Place, publisher, year, edition, pages
Elsevier, 2015
National Category
Civil Engineering
Identifiers
urn:nbn:se:kth:diva-176318 (URN)10.1016/j.conbuildmat.2015.09.061 (DOI)000364608000029 ()2-s2.0-84944346091 (Scopus ID)
Note

Updated from Accepted to Published. QC 20160210

Available from: 2015-11-03 Created: 2015-11-03 Last updated: 2017-12-13Bibliographically approved
3. A new test to study the flow of mixtures at early stages of compaction
Open this publication in new window or tab >>A new test to study the flow of mixtures at early stages of compaction
2016 (English)In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 49, no 9, 3547-3558 p.Article in journal (Refereed) Published
Abstract [en]

Workability is one of the most commonly used indicators for the capability of asphalt mixtures tobe placed and compacted on the roads with long lasting quality and minimum maintenancethroughout its service life. Despite of valuable previous efforts for measuring and characterizingworkability, none of them has proven successful in representing the field conditions of roadconstructions. This paper is an attempt towards developing a systematic workability test methodfocusing on compaction, the so-called Compaction Flow Test (CFT), by simulating fieldcompaction at early stages and at laboratory scale with the main focus on mixture flow. The CFTwas applied for different mixtures in order to identify the parameters with highest impact on theasphalt particle movements under compaction forces. A new setting inside X-ray ComputationalTomography (CT) allowed tracing asphalt particles during the CFT and acquiring CT imagesunderlining the reliability of the CFT results. In addition, simple Discrete Element Models (DEM)were successfully generated to justify some of the CFT results.

Place, publisher, year, edition, pages
Kluwer Academic Publishers, 2016
National Category
Civil Engineering
Identifiers
urn:nbn:se:kth:diva-176317 (URN)10.1617/s11527-015-0738-8 (DOI)000379590900005 ()2-s2.0-84945556719 (Scopus ID)
Note

QC 20160818

Available from: 2015-11-03 Created: 2015-11-03 Last updated: 2017-12-13Bibliographically approved

Open Access in DiVA

Thesis(3673 kB)194 downloads
File information
File name FULLTEXT01.pdfFile size 3673 kBChecksum SHA-512
2b6f971309caa7e1a334c2c1f674fafe7f287505dd696dd2d35e125def24845be095327aa59c2ddd7f52c9bbcbb64c8cf5f675230b7b7582f292339d4855c7e6
Type fulltextMimetype application/pdf

Authority records BETA

Ghafoori Roozbahany, Ehsan

Search in DiVA

By author/editor
Ghafoori Roozbahany, Ehsan
By organisation
Building Materials
Civil Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 194 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 145 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf