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The performance of lignosulfonate as a partial binder replacement in asphalt
Thesis (MEng)--Stellenbosch University, 2024.
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| Format: | Thesis |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613827225354240 |
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| access_status_str | Open Access |
| author | Murphy, Abigail |
| author2 | Goosen, Elaine |
| author_browse | Goosen, Elaine Murphy, Abigail |
| author_facet | Goosen, Elaine Murphy, Abigail |
| author_sort | Murphy, Abigail |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2024. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/131850 |
| institution | Stellenbosch University (South Africa) |
| last_indexed | 2026-06-10T12:42:19.474Z |
| 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:10019.1/131850 The performance of lignosulfonate as a partial binder replacement in asphalt Murphy, Abigail Goosen, Elaine Jenkins, K. J. Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Asphalt concrete -- Performance Pavements, Asphalt -- Design and construction Lignosulfonates -- Industrial applications Asphalt concrete -- Additives Binders (Materialss) -- Testing UCTD Thesis (MEng)--Stellenbosch University, 2024. ENGLISH ABSTRACT: The demand for bitumen in the South African pavement industry exceeds the local supply. Annually, a large portion of the South African budget is allocated to importing bitumen. This thesis aims to decrease the bitumen demand and economic influence by investigating the nature of lignosulfonate and its response to pavement performance when implemented as a 20% partial replacement binder or filler in asphalt. Two performance mechanisms are considered: (1) Asphalt susceptibility to permanent deformation through MMLS testing. (2) Binder rheology at different artificial ages i.e. unaged, RTFO-aged, and PAV-aged, through DSR and BBR testing. Asphalt mix design procedures are conducted to develop standard-, lignin-modified, and lignosulfonate filler HMA briquettes, as well as, unmodified, and lignin-modified CMA briquettes for the MMLS test. Test conditions during the simulation are set to the worst- case conditions i.e. the wet test method at 50°C, for flat free-flowing traffic. The results are discussed based on the surface condition of each specimen after the simulation and the guideline set in SANS 3001-PD1 (2016). Out of the three HMA briquette types, adding lignosulfonate as a filler shows improved resistance to permanent deformation compared to standard HMA. The CMA briquettes failed to resist the loading and conditions of the MMLS, disintegrating before the completion of the simulation. An analysis of lignosulfonate’s nature in asphalt is conducted through X-ray CT scanning completed at X-Sight X-ray Services. A void analysis is conducted for each asphalt mix, indicating that HMA has a smaller air void content than CMA. Cross-sections of the asphalt’s internal structure allow an analysis of the behaviour of lignosulfonate within the asphalt mixes. However, the lignosulfonate remained unidentified within the asphalt, therefore motivating a similarity in the molecular weight of lignosulfonate and the asphalt binder. The viscoelastic properties of the HMA binders i.e. unmodified and lignin-modified (LM) 70/100 bitumen, are determined from the DSR and BBR tests at different artificial ages and temperatures. Rheological modelling is conducted through master curves and Black Space diagrams. For master curves, the Modified Kaelble shift factor, and Generalised Logistic Sigmoidal (GLS) model is used to analyse the change in binder behaviour based on modification and ageing. The Black Space diagram is used to identify inaccuracies in the data and finds that the LM 70/100 binder at unaged and RTFO-aged conditions shows significant outliers at -12 °C. The viscoelastic behaviour, ageing-related changes, and relaxation properties in the binders are further analysed in Black Space using specific performance parameters i.e. the R-index, ∆TC, G-R, and VET parameters. The LM 70/100 binder shows conventional binder behaviour at unaged and PAV-aged conditions, but opposite behaviour at RTFO age. The creep and creep recovery of the different aged binders is analysed based on the Jnr and % recovery parameters calculated from MSCR tests conducted on the DSR. Adding lignosulfonate to the binder does not improve its elastic response, however, its recovery properties indicate that it remains adequate for use in South African climate zones up to 64 °C. AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar. Masters 2025-04-03T07:35:50Z 2025-04-03T07:35:50Z 2024-12 Thesis https://scholar.sun.ac.za/handle/10019.1/131850 Stellenbosch University xviii, 163 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Asphalt concrete -- Performance Pavements, Asphalt -- Design and construction Lignosulfonates -- Industrial applications Asphalt concrete -- Additives Binders (Materialss) -- Testing UCTD Murphy, Abigail The performance of lignosulfonate as a partial binder replacement in asphalt |
| title | The performance of lignosulfonate as a partial binder replacement in asphalt |
| title_full | The performance of lignosulfonate as a partial binder replacement in asphalt |
| title_fullStr | The performance of lignosulfonate as a partial binder replacement in asphalt |
| title_full_unstemmed | The performance of lignosulfonate as a partial binder replacement in asphalt |
| title_short | The performance of lignosulfonate as a partial binder replacement in asphalt |
| title_sort | performance of lignosulfonate as a partial binder replacement in asphalt |
| topic | Asphalt concrete -- Performance Pavements, Asphalt -- Design and construction Lignosulfonates -- Industrial applications Asphalt concrete -- Additives Binders (Materialss) -- Testing UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/131850 |
| work_keys_str_mv | AT murphyabigail theperformanceoflignosulfonateasapartialbinderreplacementinasphalt AT murphyabigail performanceoflignosulfonateasapartialbinderreplacementinasphalt |