TY - JOUR

T1 - Comparison of feldspar and meta-halloysite geopolymers by alkaline and acidic activation

AU - Nana, Achile

AU - Tchummegne, Ida Kouam

AU - Tome, Sylvain

AU - Adesina, Adeyemi

AU - Alomayri, Thamer

AU - Kaze, Rodrigue Cyriaque

AU - Kamseu, Elie

AU - Kumar, Sanjay

AU - Leonelli, Cristina

AU - Singla, Rashmi

N1 - Funding Information: This project received the contribution of the Royal Society and the African Academy of Science through the funding FLAIR to Dr. Elie Kamseu. Grant; FLR\R1\201402. The contribution of the European Union and OEACP R&I through financial contribution No. PRICNACEEPER: MD2022 is great fully acknowledged. Financial contribution from the 2021 TWAS-UNESCO-CSIR Postdoctoral Fellowship (2021, FR number: 3240321623) is acknowledged. Dr Achile Nana thanks the contribution of the Alexander von Humboldt Foundation (AvH), the German Ministry for Economic Cooperation and Development (BMZ) and the African-German Network of Excellence in Science (AGNES, 2023).

PY - 2024/4/19

Y1 - 2024/4/19

N2 - Geopolymerization, a sustainable route to advanced binders, has traditionally been explored using common activators and single precursors such as metakaolin. Although previous investigations have explored the potential of feldspathic minerals, particularly with metakaolin as a partial replacement, there remains a gap in understanding the nuances of feldspar-phosphate-based geopolymers. This study seeks to fill this gap by providing an in-depth investigation of the properties and reactivity behaviour of three different feldspar quarry wastes, each modified with meta-halloysite at a 15% inclusion rate. This research not only evaluates the effects of both acidic and alkaline activators on the resulting geopolymer properties, but also explores the broader implications of such modifications in different environments at ambient conditions. Using a series of experimental assessments, we have explored how the mineralogical and crystalline identities of these feldspars influence key aspects such as reaction kinetics, physico-mechanical performance, structural and microstructural properties, and even thermal behaviour. The results of the physico-mechanical properties showed that lower water absorption (i.e. less than 9.2%) as well as higher flexural (i.e. about 30 MPa) and compressive strength (i.e. about 40 MPa) can be achieved with the feldspar-based geopolymer in alkaline medium. In acidic medium, the highest flexural and compressive strengths were less than 10 and 19 MPa, respectively, with about 13.5% of water absorption. In acidic to basic medium, the highest cumulative pore volume of the geopolymers increases from 26.5 to 75.2 mm3/g, respectively. The outcomes of this study hold promise for tailoring geopolymer properties for various applications and provide a basis for further work in this area.

AB - Geopolymerization, a sustainable route to advanced binders, has traditionally been explored using common activators and single precursors such as metakaolin. Although previous investigations have explored the potential of feldspathic minerals, particularly with metakaolin as a partial replacement, there remains a gap in understanding the nuances of feldspar-phosphate-based geopolymers. This study seeks to fill this gap by providing an in-depth investigation of the properties and reactivity behaviour of three different feldspar quarry wastes, each modified with meta-halloysite at a 15% inclusion rate. This research not only evaluates the effects of both acidic and alkaline activators on the resulting geopolymer properties, but also explores the broader implications of such modifications in different environments at ambient conditions. Using a series of experimental assessments, we have explored how the mineralogical and crystalline identities of these feldspars influence key aspects such as reaction kinetics, physico-mechanical performance, structural and microstructural properties, and even thermal behaviour. The results of the physico-mechanical properties showed that lower water absorption (i.e. less than 9.2%) as well as higher flexural (i.e. about 30 MPa) and compressive strength (i.e. about 40 MPa) can be achieved with the feldspar-based geopolymer in alkaline medium. In acidic medium, the highest flexural and compressive strengths were less than 10 and 19 MPa, respectively, with about 13.5% of water absorption. In acidic to basic medium, the highest cumulative pore volume of the geopolymers increases from 26.5 to 75.2 mm3/g, respectively. The outcomes of this study hold promise for tailoring geopolymer properties for various applications and provide a basis for further work in this area.

KW - Calorimetry study

KW - Feldspar quarry waste

KW - Geopolymeric binder

KW - Microstructure

KW - Phosphoric acid

KW - Porosity

UR - http://www.scopus.com/inward/record.url?scp=85188704893&partnerID=8YFLogxK

U2 - 10.1016/j.conbuildmat.2024.135953

DO - 10.1016/j.conbuildmat.2024.135953

M3 - Article

AN - SCOPUS:85188704893

VL - 424

JO - Construction and Building Materials

JF - Construction and Building Materials

SN - 0950-0618

M1 - 135953

ER -