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Sensitivity of water absorption on the performance properties of RCA and RMA stabilised with bitumen emulsion
Thesis (MEng)--Stellenbosch University, 2022.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2022
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| _version_ | 1867614088980332544 |
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| access_status_str | Open Access |
| author | Merbold, Ghiete |
| author2 | Jenkins, Kim |
| author_browse | Jenkins, Kim Merbold, Ghiete |
| author_facet | Jenkins, Kim Merbold, Ghiete |
| author_sort | Merbold, Ghiete |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2022. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/125004 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:46:29.473Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/125004 Sensitivity of water absorption on the performance properties of RCA and RMA stabilised with bitumen emulsion Merbold, Ghiete Jenkins, Kim Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Pavement engineering UCTD Bitumen -- Stability Recycled Concrete Aggregates Recycled Masonry Aggregate Pavements, Bituminous -- Water resistance Thesis (MEng)--Stellenbosch University, 2022. ENGLISH ABSTRACT: Bitumen stabilisation of bases is used to improve the strength, water resistance, stability and performance of a pavement structure by simultaneously providing a more sustainable solution to conventional methods where asphalt and natural aggregates are used. For the purpose of this research two primary goals were set out, firstly to determine the adequacy of the current stan dard water absorption test applied to recycled aggregates and then secondly to establish the potential to stabilised RCA and RMA with bitumen emulsion. Various tests were performed to investigate both initiatives and the results are presented in this research. A possible alternative to creating a bitumen stabilised material with natural aggregates, is a combination of recycled concrete and masonry. Recycled materials originate from construc tion and demolition waste and can be processed through a separation and crushing process to create concrete and masonry aggregates. Using recycled aggregates holds many benefits some of which include: minimizing the use and quarrying of natural aggregates, reduced transport costs, reusing landfill materials as well as reducing costs. Recycled Concrete Aggregates (RCA) holds beneficial p roperties s uch a s self-cementation and carbonation. However, this beneficial trait can diminish after long exposure to the outside elements. The limitations of RCA include the inconsistency of the material causing inaccurate characterisation of the material. This was one of the challenges that was faced in this study and why this report focuses on testing exposed RCA materials. Recycled concrete aggregates from three different sources, namely RCA 1, RCA 2 and RCA 3, are used in three different combinations with masonry (RMA). The three mix-combinations tested were as follows: 1. 100% RCA; 2. 75% RCA and 25% RMA; 3. 50% RCA and 50% RMA Three different water absorption tests were carried out on all three sources of material (RCA 1, RCA 2 and RCA 3) which were used in the above mentioned three mix combinations. Each test produced assorted results however only two repeats were executed for the water absorp tion tests. More repeats are recommended for future research endeavors in order to formulate correlations. The research produced two conclusions, the first being that the current standard water absorp tion test cannot be implemented on recycled aggregates and a new method must be developed. This conclusion was drawn from the results obtained from the various water absorption tests. The reason being that the standard water absorption tests does not take the cohesive nature of recycled aggregates into account as well as the brittleness of the material after soaking for an extended period. Multiple reasons were identified and stipulated in this study. The adapted Rodrigues’ method is suggested and displayed promising results. It is recommended that the test is repeated to confirm the accuracy. The second conclusion is more vague as it is still not determined if there is a potential for exposed RCA and RMA combinations to be stabilised with bitumen emulsion. This conclusion was drawn based on the characterization and per formance tests executed. Based on the results found in this research the stabilisation of RCA and RMA with bitumen emulsion is not possible. This conclusion was drawn after poor ITS and Triaxial results all under the minimum requirements stipulated in the TG2 (2020). The poor performance can however be caused by the exposure of the RCA as well as the lack of active filler added to the mixture. It is therefore recommended that the optimum active filler and bitumen content be determined for these materials. AFRIKAANSE OPSOMMING: Bitumen stabilisering van kroon lae word gebruik om die sterkte, waterweerstand, stabiliteit en werkverrigting van ’n plaveiselstruktuur te verbeter deur terselfdertyd ’n meer volhoubare oplossing te verskaf. Vir die doel van hierdie navorsing is twee primere doelwitte uiteen gesit, naamlik die toereikendheid van die huidige standaard waterabsorpsietoets toegepas op herwinde aggregate en die potensiaal om HBA en HMA met bitumen emulsie te stabiliseer. Verskeie toetse is uitgevoer om beide inisiatiewe te ondersoek en die resultate word in hierdie navorsing aangebied. ’n Moontlike alternatief om ’n bitumen-gestabiliseerde materiaal met natuurlike aggregate te skep, is om ’n kombinasie van herwonne beton en messelwerk. Herwinde materiaal kom van konstruksie- en slopingsafval en kan deur ’n skeidings- en vergruisingsproses verwerk word om beton- en messelwerk-aggregate te skep. Die gebruik van herwinde aggregate hou baie voordele in, waarvan sommige insluit, die vermindering van die gebruik en ontginning van natuurlike aggregate, verminderde vervoerkoste, hergebruik van stortingsterrein materiaal asook vermindering van koste. Die Herwinde Beton Aggregate (HBA) bevat voordelige eienskappe soos self-sementering en karbonering. Hierdie voordelige eienskap kan egter verminder word na lang blootstelling aan die buite-elemente. Die beperkings van HBA sluit in die inkonsekwentheid van die materiaal wat onakkurate karakterisering van die materiaal veroorsaak. Dit was een van die uitdagings wat in hierdie navorsing te staan gekom het en waarom die navorsing gekonsentreer het op blootgestelde RCA-materiale. Herwonne betonaggregate van drie verskillende bronne, naamlik HBA 1, HBA 2 en HBA 3, word in drie verskillende kombinasies met messelwerk gebruik. Die kombinasies behels die gebruik van 100% HBA in die mengsel, 75% HBA en 25% HMA en laastens die gebruik van 50% HBA en HMA in ’n mengsel. Drie verskillende waterabsorpsie toetse is op al drie bronne en drie verhoudings uitgevoer. Elke toets het verskillende resultate opgelewer, maar slegs twee herhalings is uitgevoer. Die navorsing het twee gevolgtrekkings opgelewer, die eerste was dat die huidige standaard waterabsorpsietoets nie op herwonne aggregate geimplementeer kan word nie en ’n nuwe metode moet ontwikkel word. Die aangepaste Rodrigues metode word voorgestel en het be lowende resultate getoon. Dit word aanbeveel dat die toets herhaal word om die akkuraatheid te bevestig. Die tweede gevolgtrekking is meer vaag aangesien dit steeds nie vasgestel is of daar ’n potensiaal is vir blootgestelde HBA- en HMA-kombinasies om met bitumen emulsies gestabiliseer te word nie. Gebaseer op die resultate wat in hierdie navorsing gevind is, is die stabilisering van HBA en HMA met bitumenemulsie nie moontlik nie. Die swak resultate kan egter veroorsaak word deur die blootstelling van die HBA sowel as die gebrek aan aktiewe vuller wat by die mengsel gevoeg word. Dit word dus aanbeveel dat die optimum aktiewe vulstof- en bitumeninhoud vir hierdie materiale bepaal word Masters 2022-01-16T18:37:55Z 2022-04-29T09:46:03Z 2022-01-16T18:37:55Z 2022-04-29T09:46:03Z 2022-04 Thesis http://hdl.handle.net/10019.1/125004 en_ZA Stellenbosch University 230 pages application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Pavement engineering UCTD Bitumen -- Stability Recycled Concrete Aggregates Recycled Masonry Aggregate Pavements, Bituminous -- Water resistance Merbold, Ghiete Sensitivity of water absorption on the performance properties of RCA and RMA stabilised with bitumen emulsion |
| title | Sensitivity of water absorption on the performance properties of RCA and RMA stabilised with bitumen emulsion |
| title_full | Sensitivity of water absorption on the performance properties of RCA and RMA stabilised with bitumen emulsion |
| title_fullStr | Sensitivity of water absorption on the performance properties of RCA and RMA stabilised with bitumen emulsion |
| title_full_unstemmed | Sensitivity of water absorption on the performance properties of RCA and RMA stabilised with bitumen emulsion |
| title_short | Sensitivity of water absorption on the performance properties of RCA and RMA stabilised with bitumen emulsion |
| title_sort | sensitivity of water absorption on the performance properties of rca and rma stabilised with bitumen emulsion |
| topic | Pavement engineering UCTD Bitumen -- Stability Recycled Concrete Aggregates Recycled Masonry Aggregate Pavements, Bituminous -- Water resistance |
| url | http://hdl.handle.net/10019.1/125004 |
| work_keys_str_mv | AT merboldghiete sensitivityofwaterabsorptionontheperformancepropertiesofrcaandrmastabilisedwithbitumenemulsion |