Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Permanent deformation behaviour of open-graded bitumen rubber asphalt using the model mobile load simulator (MMLS3).
ENGLISH ABSTRACT: Permanent deformation (rutting) has been at the centre of many pavement research projects as one of the major pavement distresses. With road transport providing a cheap and more accessible trade outlet than rail transport, pavements in South Africa have become more susceptible to p...
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Stellenbosch : Stellenbosch University
2025
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613769661677568 |
|---|---|
| access_status_str | Open Access |
| author | Kasozi, Adam Matovu |
| author2 | Goosen, Elaine Simone |
| author_browse | Goosen, Elaine Simone Kasozi, Adam Matovu |
| author_facet | Goosen, Elaine Simone Kasozi, Adam Matovu |
| author_sort | Kasozi, Adam Matovu |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | ENGLISH ABSTRACT: Permanent deformation (rutting) has been at the centre of many pavement research projects as one of the major pavement distresses. With road transport providing a cheap and more accessible trade outlet than rail transport, pavements in South Africa have become more susceptible to permanent deformation. This has, therefore, led to different innovations regarding mix designs and binder modifications to try to combat this distress mechanism. This study covers the resistance of Bitumen Rubber Asphalt Open-Graded (BRAOG) mixes and the permanent deformation under Model Mobile Load Simulator (MMLS) wet trafficking. Bitumen rubber has been extensively used to surface heavily trafficked pavements in South Africa. The MMLS acts as the accelerated pavement tester while the BRAOG cores are immersed in hot water at 50 °C. This helps to simulate the sub-tropical and humid climatic regions. The bitumen rubber binder (A-R2) is isolated and exposed to a series of rheological tests using the Bending Beam Rheometer (BBR), Dynamic Shear Rheometer (DSR) and Rolling Thin Film Oven (RTFO). The Multiple Stress Creep Recovery (MSCR) hightemperature test evaluates the binder's response to permanent deformation. The MMLS results show that the exponential smoothing technique provides a more accurate rut profile than the conventional 3-point moving average smoothing technique. From the binder rheology, the rubber modification provided an increased elastic behaviour at high temperatures. In conclusion, the mixes deformed more than the acceptable 2 mm rutting limit specified in the MMLS testing protocols, but the binder played a crucial role in the resistance to rutting and moisture damage of the BRAOG mixes. It is recommended that more research is done to develop and expand the specifications for modified binders and MMLS rutting empirical protocols. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/131693 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:41:24.431Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/131693 Permanent deformation behaviour of open-graded bitumen rubber asphalt using the model mobile load simulator (MMLS3). Kasozi, Adam Matovu Goosen, Elaine Simone Jenkins, Kim Jonathan Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Asphalt concrete -- Testing Bituminous materials -- Additives Pavements, Bituminous UCTD ENGLISH ABSTRACT: Permanent deformation (rutting) has been at the centre of many pavement research projects as one of the major pavement distresses. With road transport providing a cheap and more accessible trade outlet than rail transport, pavements in South Africa have become more susceptible to permanent deformation. This has, therefore, led to different innovations regarding mix designs and binder modifications to try to combat this distress mechanism. This study covers the resistance of Bitumen Rubber Asphalt Open-Graded (BRAOG) mixes and the permanent deformation under Model Mobile Load Simulator (MMLS) wet trafficking. Bitumen rubber has been extensively used to surface heavily trafficked pavements in South Africa. The MMLS acts as the accelerated pavement tester while the BRAOG cores are immersed in hot water at 50 °C. This helps to simulate the sub-tropical and humid climatic regions. The bitumen rubber binder (A-R2) is isolated and exposed to a series of rheological tests using the Bending Beam Rheometer (BBR), Dynamic Shear Rheometer (DSR) and Rolling Thin Film Oven (RTFO). The Multiple Stress Creep Recovery (MSCR) hightemperature test evaluates the binder's response to permanent deformation. The MMLS results show that the exponential smoothing technique provides a more accurate rut profile than the conventional 3-point moving average smoothing technique. From the binder rheology, the rubber modification provided an increased elastic behaviour at high temperatures. In conclusion, the mixes deformed more than the acceptable 2 mm rutting limit specified in the MMLS testing protocols, but the binder played a crucial role in the resistance to rutting and moisture damage of the BRAOG mixes. It is recommended that more research is done to develop and expand the specifications for modified binders and MMLS rutting empirical protocols. AFRIKAANSE OPSOMMING: Permanente vervorming (spoorvorming) was die fokus van baie plaveisel navorsingspojekte as een van die groot plaveisel nood. Met padvervoer wat 'n goedkoper en meer toeganklike handelsafset bied as spoorvervoer, het paaie in Suid-Afrika meer vatbaar geword vir permanente vervorming. Dit het dus gelei tot verskillende innovasies rakende mengselontwerpe en bindmiddelmodifikasies om hierdie noodmeganisme te probeer bekamp. Hierdie studie dek die weerstand van Bitumen Rubber Asphalt Open-Graded (BRAOG) mengsels en die permanente vervorming onder Model Mobile Load Simulator (MMLS) nathandel. Bitumenrubber is op groot skaal gebruik om paaie in Suid-Afrika wat swaar verkeer hanteer, te bedek. Die MMLS dien as die versnelde plaveiseltoetser terwyl die BRAOG-kerne in warm water by 50 °C gedompel word. Dit help om die subtropiese en vogtige klimaatstreke te simuleer. Die bitumenrubberbindmiddel (A-R2) word geïsoleer en aan 'n reeks reologiese toetse blootgestel deur om die Buigbalkreometer (BBR), Dynamic Shear Rheometer (DSR) en Rolling Thin Film Oven (RTFO) te gebruik. Die Multiple Stress Creep Recovery (MSCR) hoë-temperatuur toets evalueer die bindmiddel se reaksie op permanente vervorming. Die MMLS-resultate toon dat die eksponensiële gladmaaktegniek 'n meer akkurate groefprofiel bied as die konvensionele 3-punt bewegende gemiddelde gladmaaktegniek. Vanuit die bindmiddelreologie het die rubbermodifikasie 'n verhoogde elastiese gedrag by hoë temperature verskaf. Ten slotte, die mengsels het meer vervorm as die aanvaarbare 2 mm-sporingsgrens gespesifiseer in die MMLS-toetsprotokolle, maar die bindmiddel het 'n deurslaggewende rol gespeel in die weerstand teen spoorvorming en vogskade van die BRAOG-mengsels. Dit word aanbeveel dat meer navorsing gedoen moet word om die spesifikasies vir gemodifiseerde bindmiddels en MMLS-spoorvorming se empiriese protokolle te ontwikkel en uit te brei. Masters 2025-02-06T08:02:04Z 2025-02-06T08:02:04Z 2024-12 Thesis https://scholar.sun.ac.za/handle/10019.1/131693 en Stellenbosch University xviii, 142 pages pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Asphalt concrete -- Testing Bituminous materials -- Additives Pavements, Bituminous UCTD Kasozi, Adam Matovu Permanent deformation behaviour of open-graded bitumen rubber asphalt using the model mobile load simulator (MMLS3). |
| title | Permanent deformation behaviour of open-graded bitumen rubber asphalt using the model mobile load simulator (MMLS3). |
| title_full | Permanent deformation behaviour of open-graded bitumen rubber asphalt using the model mobile load simulator (MMLS3). |
| title_fullStr | Permanent deformation behaviour of open-graded bitumen rubber asphalt using the model mobile load simulator (MMLS3). |
| title_full_unstemmed | Permanent deformation behaviour of open-graded bitumen rubber asphalt using the model mobile load simulator (MMLS3). |
| title_short | Permanent deformation behaviour of open-graded bitumen rubber asphalt using the model mobile load simulator (MMLS3). |
| title_sort | permanent deformation behaviour of open graded bitumen rubber asphalt using the model mobile load simulator mmls3 |
| topic | Asphalt concrete -- Testing Bituminous materials -- Additives Pavements, Bituminous UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/131693 |
| work_keys_str_mv | AT kasoziadammatovu permanentdeformationbehaviourofopengradedbitumenrubberasphaltusingthemodelmobileloadsimulatormmls3 |