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Waterproofing of 3D printed concrete
Nienaber, L. 2025. Waterproofing of 3D printed concrete. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/1c802bc0-145d-4122-ab4e-de8b4bd08154
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613775464497152 |
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| access_status_str | Open Access |
| author | Nienaber, Linda |
| author2 | Combrinck, Riaan |
| author_browse | Combrinck, Riaan Nienaber, Linda |
| author_facet | Combrinck, Riaan Nienaber, Linda |
| author_sort | Nienaber, Linda |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Nienaber, L. 2025. Waterproofing of 3D printed concrete. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/1c802bc0-145d-4122-ab4e-de8b4bd08154 |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132544 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:41:30.564Z |
| 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:10019.1/132544 Waterproofing of 3D printed concrete Nienaber, Linda Combrinck, Riaan Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. Additive manufacturing -- Materials Concrete construction industry -- Technological innovations Three-dimensional printing Concrete -- Permeability UCTD Nienaber, L. 2025. Waterproofing of 3D printed concrete. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/1c802bc0-145d-4122-ab4e-de8b4bd08154 Thesis (MEng)--Stellenbosch University, 2025. ENGLISH ABSTRACT: One of the latest advancements in the concrete industry is 3D printed concrete, this is an additive manufacturing method wherein subsequent layers of concrete is placed upon each other. As the construction industry moves forward towards implementing this technique, it must first be comparable with cast concrete in terms of durability. A significant increase in porosity occurs at the interlayer of 3D printed concrete. This can be detrimental to durability as water ingress occurs more easily with an increased porosity and pore connectivity. Various chemical treatments and admixtures have been developed for cast concrete to reduce water absorption. These chemicals employ different mechanisms to achieve this, which could also impact other properties of the concrete. Research has been conducted on the effect these chemicals have on cast concrete, but not on 3D printed concrete. Several waterproofing chemicals were applied via three different application techniques: interlayer sprayed, post sprayed and integral addition. Several different chemicals that used different mechanisms of pore filling, pore lining and surface modification were applied using the three application techniques. Absorption testing was done to gauge how effective the chemical was in reducing the water absorption for 3D printed concrete. Two other durability tests, oxygen permeability index and a chloride ingress test, were conducted, and the mechanical properties were investigated through flexural and compressive testing. As the chemicals are added integrally, the fresh state properties and rheological properties were investigated to ensure the mixtures were printable. Silanes, which line the pores of concrete was effective for all three application methods. It was most effective when applied using the post spray method, however any damage to the surface significantly impacted the effectiveness. The integral and interlayer spray showed similar levels in water absorption reduction when silanes were used, however, the integral method showed an increase in flexural strength while the interlayer spray method decreased the flexural strength. The surface modifier steric acid was effective when applied using the interlayer spray method but not when using the post spray method. Crystalline admixture that fills the pores of concrete was ineffective in reducing the water absorption when used integrally. Several of the chemicals using the different application techniques were effective in reducing the water absorption of 3D printed concrete. It is recommended that silanes can be implemented using any of the three methods, and steric acid should only be implemented using the interlayer spray method. However, care should be taken when applying the chemicals using the post spray method as any damage or abrasion to the surface impacts the effectiveness of the chemicals and the interlayer spray method can negatively impact the flexural strength of the 3D printed concrete. AFRIKAANSE OPSOMMING: Een van die nuutste ontwikkelinge in die beton bedryf is 3D gedrukte beton, dit is ‘n bykomende vervaardigings metode waarin opeenvolgende lae van beton op mekaar geplaas word. Soos die konstruksie bedryf vorentoe beweeg om hierdie tegniek te implementeer, moet dit eers vergelykbaar wees met gegote beton in terme van duursaamheid. ‘n Beduidende toename in porositeit vind plaas by die tussenlaag van 3D gedrukte beton. Dit kan nadelig wees vir duursaamheid aangesien water makliker binnedring as gevolg van ‘n verhoogde porositeit en porie verbinding. Verskeie chemiese behandelings en bymiddels is reeds ontwikkel vir gegote beton om waterabsorpsie te verminder. Hierdie chemikalieë gebruik verskillende meganismes om waterabsorpsie te verminder, wat op hul beurt weer ander eienskappe van die beton kan beïnvloed. Navorsing is reeds gedoen oor die effek wat hierdie chemikalieë op gegote beton het, maar nie op 3D gedrukte beton nie. Verskeie waterdigting chemikalieë is toegedien via drie toedienings tegnieke: tussenlaag gespuit, na-gespuit en integrale toevoeging. Verskeie chemikalieë wat verskillende meganismes van porievulling, porievoering en oppervlakmodifikasie gebruik, was toegepas deur die drie toedienings tegnieke. Absorpsie toetse was gedoen om te bepaal hoe doeltreffende die verskeie chemiese middels was om water absorpsie vir 3D gedrukte beton te verminder. Twee ander duursaamheid toetse, suurstof deurlaatbaarheid indeks en ‘n chloried-indringstoets, is uitgevoer, en die meganiese eienskappe is deur buig en druktoetsing ondersoek. Aangesien die chemikalieë integraal bygevoeg word, was die vars toestand eienskappe en reologiese eienskappe ondersoek om te verseker dat die mengsel drukbaar was. Silane, wat die porieë van beton beklee, was effektief vir al drie toedienings metodes. Dit was die doeltreffendste wanneer dit met die na-gespuit metode toegedien was, maar enige skade aan die oppervlak het die doeltreffendheid aansienlik beïnvloed. Die integrale en tussenlaag bespuiting met silane het soortgelyke vlakke in water absorpsie vermindering getoon, maar die integrale metode het 'n toename in buigsterkte getoon terwyl die tussenlaag bespuitings metode die buigsterkte verlaag het. Die oppervlakmodifikasie steariensuur was effektief wanneer die tussenlaag gespuit metode toegedien is, maar nie wanneer die na-gespuit metode gebruik is nie. Kristallyn bymiddels wat die porieë van beton vul, was ondoeltreffend om die water absorpsie te verminder wanneer dit integraal bygevoeg was. Verskeie van die chemikalieë wat vir die verskillende aanwendings tegnieke gebruik was, was doeltreffend om die water absorpsie van 3D gedrukte beton te verminder. Dit word aanbeveel dat silane geïmplementeer kan word deur enige van die drie metodes te gebruik, en steariensuur moet slegs geïmplementeer word deur die tussenlaag gespuit metode te gebruik. Die gebruiker moet versigtig wees wanneer die chemikalieë met die na-gespuit metode toegedien word aangesien enige skade of skuur aan die oppervlak die doeltreffendheid van die chemikalieë kan beïnvloed en die tussenlaag bespuitings metode die buigsterkte van die 3D gedrukte beton ook negatief kan beïnvloed. Masters 2025-06-11T06:07:13Z 2025-06-11T06:07:13Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132544 en Stellenbosch University xviii, 125 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Additive manufacturing -- Materials Concrete construction industry -- Technological innovations Three-dimensional printing Concrete -- Permeability UCTD Nienaber, Linda Waterproofing of 3D printed concrete |
| title | Waterproofing of 3D printed concrete |
| title_full | Waterproofing of 3D printed concrete |
| title_fullStr | Waterproofing of 3D printed concrete |
| title_full_unstemmed | Waterproofing of 3D printed concrete |
| title_short | Waterproofing of 3D printed concrete |
| title_sort | waterproofing of 3d printed concrete |
| topic | Additive manufacturing -- Materials Concrete construction industry -- Technological innovations Three-dimensional printing Concrete -- Permeability UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132544 |
| work_keys_str_mv | AT nienaberlinda waterproofingof3dprintedconcrete |