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Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements
CITATION: Abdrafiu, I.M. 2025. Assessing the Adoptability of Limestone Calcined Clay Cement (LC3) in Slab-like Elements. Unpublished masters thesis. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/handle/10019.1/131995
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Stellenbosch : Stellenbosch University
2025
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| access_status_str | Open Access |
| author | Abdrafiu, Idris Mayowa |
| author2 | Babafemi, Adewumi John |
| author_browse | Abdrafiu, Idris Mayowa Babafemi, Adewumi John |
| author_facet | Babafemi, Adewumi John Abdrafiu, Idris Mayowa |
| author_sort | Abdrafiu, Idris Mayowa |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | CITATION: Abdrafiu, I.M. 2025. Assessing the Adoptability of Limestone Calcined Clay Cement (LC3) in Slab-like Elements. Unpublished masters thesis. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/handle/10019.1/131995 |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/131995 |
| institution | Stellenbosch University (South Africa) |
| last_indexed | 2026-06-10T12:45:48.703Z |
| 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:10019.1/131995 Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements Abdrafiu, Idris Mayowa Babafemi, Adewumi John Combrinck, Riaan Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Construction industry -- Automation Portland cement -- Additives Clay -- Additives Building materials -- Environmental aspects UCTD CITATION: Abdrafiu, I.M. 2025. Assessing the Adoptability of Limestone Calcined Clay Cement (LC3) in Slab-like Elements. Unpublished masters thesis. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/handle/10019.1/131995 Thesis (MEng)--Stellenbosch University, 2025. ENGLISH ABSTRACT: The cement production industry significantly contributes to global CO2 emissions and consequently, to global warming. Replacing conventional Portland cement with limestone calcined clay cement (LC3) has been identified as a key strategy for reducing the environmental impact of the construction industry. However, the construction industry is laggard in adopting innovative technologies and materials, especially with cement and concrete. Lack of trust and in-depth information on the handling and potential defects associated with such materials contribute to this laggardness. This research aims to holistically investigate the fresh properties, mechanical properties and plastic shrinkage cracking of LC3 from the perspective of a concrete floor contractor who is interested in its use. CEM I was partially replaced with 30%, 45%, and 60% of commercially produced limestone and calcined clay (LC2) blend in concrete mixes to produce LC3 concrete. The flowability, rheology and fresh density of these mixes were evaluated, and their compressive and flexural performance were compared to the control. Plastic shrinkage cracking in the mixes was also examined under extreme and normal climatic conditions. Furthermore, the influence of superplasticiser on the LC3 concrete properties was investigated. Results indicate that with 30% LC2 replacement in CEM I, the flowability of the mix decreased by approximately 41%, the yield stresses (static and dynamic) were more than double, while the fresh density remained similar. The compressive strength of the LC3 concrete at 30% LC2 replacement in CEM I is comparable to the control at 7 days but has a lower strength gain at 28 and 90 days, while LC3 concrete shows higher flexural strength gain over time compared to the control. Plastic shrinkage cracking in LC3 concrete containing 30% LC2 is more than twice that of the control, with cracking intensifying with increasing LC2 content in the mix. The addition of a moderate quantity of superplasticiser to the LC3 mixes significantly improved the flowability and rheology of the mix, while the fresh density (mix containing 30% LC2 and 0.35% superplasticiser) was reduced by about 3%. Regarding mechanical performance, the addition of superplasticiser led to about 3 MPa reduction in the compressive strength at 28 days across all percentage replacements, while no notable impact on the flexural strength of LC3 concrete was recorded. In mixes which required a higher dosage of superplasticiser (0.5% and 0.65%), plastic shrinkage cracking was reduced by about 30%. In conclusion, to promote the adoptability of LC3 concrete, moderate use of polycarboxylate ether-based superplasticiser can effectively modify the rheological properties of the LC3 mixes. A replacement of up to 30% CEM I with LC2 appears suitable to achieve comparable mechanical performance to Portland cement. However, additional preventive measures are necessary to mitigate plastic shrinkage cracking, particularly in extreme climate conditions. AFRIKAANSE OPSOMMING: Die sementvervaardigingsbedryf is 'n groot bydraer tot die probleem van aardverwarming. Daarom is die vervanging van die konvensionele Portland-sement met kalksteen-gekalsineerde klei-sement (LC3) geïdentifiseer as 'n belangrike strategie om aardverwarming binne die konteks van die konstruksiesektor af te weer. Die konstruksiebedryf is egter bekend daarvoor dat dit stadig is om innoverende tegnologieë en materiale aan te neem, veral met betrekking tot sement en beton. 'n Gebrek aan vertroue en in-diepte inligting met betrekking tot die hantering en moontlike gebreke wat geassosieer word met die gebruik van sulke materiale is een van die redes vir hierdie traagheid. Daarom fokus hierdie navorsing op 'n holistiese ondersoek van die vars eienskappe, meganiese prestasie en plastiese krimpkrake wat geassosieer word met die gebruik van LC3 vanuit die perspektief van 'n betonvloerkontrakteur wat belangstel om LC3 te gebruik. CEM I is vervang met 30%, 45% en 60% van kommersieel vervaardigde kalksteen en gekalsineerde klei (LC2) mengsel in 'n betonmengsel. Die werkbaarheid, reologie en varsdigtheid van die mengsels is eerstens geëvalueer, die druk- en buigprestasie van LC3-betonmengsels is vergelyk met Portland-sementbeton, terwyl die plastiese krimp, plastiese versakking en plastiese krimpkrake van die mengsels ondersoek is met inagneming van ’n uiterste en gematige klimaat. Die invloed van superplastiseermiddel op die LC3-beton is ook ondersoek. Resultate toon dat, met die byvoeging van 30% van die LC2-mengsel, die druksterkte van die LC3-beton vergelykbaar is met die konvensionele beton na 7 dae, maar effens laer is by latere ouderdomme, terwyl die buigsterkte oor alle persentasievervangings en kuurouderdomme afgeneem het. Daarbenewens is die plastiese krimpkrake in LC3-beton wat 30% van LC2-mengsel bevat, sowat dubbel die kontrole. Die plastiese krimpkrake het toegeneem met stygende LC2-inhoud in die mengsels. Met betrekking tot die invloed van superplastiseermiddel, is 'n effense vermindering in die druksterkte van LC3-mengsels wat superplastiseermiddel bevat waargeneem in vergelyking met die sonder superplastiseermiddel, terwyl geen noemenswaardige impak van superplastiseermiddel op die buigsterkte van LC3-beton aangeteken is nie. Die plastiese krimpkrake in die LC3-mengsels is aansienlik verminder, veral met hoër superplastiseermiddel-dosisse (0.5% en 0.65%). Dus, om 'n vergelykbare sterkte met Portland-sement te bereik, is tot 30% vervanging geskik gevind, maar verhoogde voorkomingsmaatreëls moet ingestel word met betrekking tot plastiese krimpkrake, veral in uiterste klimaatstreke. Masters 2025-05-12T08:05:20Z 2025-05-12T08:05:20Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/131995 Stellenbosch University xvii, 132 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Construction industry -- Automation Portland cement -- Additives Clay -- Additives Building materials -- Environmental aspects UCTD Abdrafiu, Idris Mayowa Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements |
| title | Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements |
| title_full | Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements |
| title_fullStr | Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements |
| title_full_unstemmed | Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements |
| title_short | Assessing the adoptability of limestone calcined clay cement (lc3) in slab-like elements |
| title_sort | assessing the adoptability of limestone calcined clay cement lc3 in slab like elements |
| topic | Construction industry -- Automation Portland cement -- Additives Clay -- Additives Building materials -- Environmental aspects UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/131995 |
| work_keys_str_mv | AT abdrafiuidrismayowa assessingtheadoptabilityoflimestonecalcinedclaycementlc3inslablikeelements |