Microstructural characterization and reaction mechanism of home-brewed activator derived from eco-processed pozzolan for one-part geopolymer mortar

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials Pub Date : 2025-02-25 DOI:10.1016/j.conbuildmat.2025.140513

Gokulanathan Venkatesan , U. Johnson Alengaram , Shaliza Binti Ibrahim , Muhammad Shazril Idris Bin Ibrahim , Sharifah Binti Mohamad

{"title":"Microstructural characterization and reaction mechanism of home-brewed activator derived from eco-processed pozzolan for one-part geopolymer mortar","authors":"Gokulanathan Venkatesan , U. Johnson Alengaram , Shaliza Binti Ibrahim , Muhammad Shazril Idris Bin Ibrahim , Sharifah Binti Mohamad","doi":"10.1016/j.conbuildmat.2025.140513","DOIUrl":null,"url":null,"abstract":"<div><div>Anhydrous sodium-based commercial activators for one-part geopolymer (OGP) may cause eye damage, skin burns due to their corrosive nature, highly hygroscopic nature, high carbon footprint during production, high energy consumption, and cost. This research developed a home-brewed activator (HBA) from industrial/agro-based ash such as Eco-processed pozzolan (EPP) using an alkali fusion method. In the alkali fusion method, a mixture of sodium hydroxide (NaOH) powder and EPP at various weight ratios of 1, and 2 was calcinated in a muffle furnace at 300 °C and 500 °C for 1.5 and 3 h. Ground Granulated Blast Furnace Slag and Fly ash were used as binders for casting the OGP and two-part geopolymer (TGP) mortar specimens. From the X-ray diffraction (XRD) results, the main activator compounds such as thermonatrite (Na<sub>2</sub>CO<sub>3</sub>·H<sub>2</sub>O), natrite (Na<sub>2</sub>CO<sub>3</sub>), calcite (CaCO<sub>3</sub>) and natrosilicate (Na<sub>2</sub>Si<sub>2</sub>O<sub>5</sub>) in HBA that initiate the polymerization reaction. The OGP mortar specimen produced a 28-day compressive strength of 50 MPa under the ambient curing regime with a NaOH/EPP ratio of 1, calcination temperature of 300 °C, and duration of 1.5 h. Both the OGP and TGP mortar specimens showed the presence of calcium aluminosilicate hydrate and calcium sodium aluminosilicate hydrate (C-A-S-H/C-N-A-S-H) geopolymeric gel. The carbon efficiency of OGP mortar specimens was found 70 % lower than that of TGP mortar specimens.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140513"},"PeriodicalIF":7.4000,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Construction and Building Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0950061825006610","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Anhydrous sodium-based commercial activators for one-part geopolymer (OGP) may cause eye damage, skin burns due to their corrosive nature, highly hygroscopic nature, high carbon footprint during production, high energy consumption, and cost. This research developed a home-brewed activator (HBA) from industrial/agro-based ash such as Eco-processed pozzolan (EPP) using an alkali fusion method. In the alkali fusion method, a mixture of sodium hydroxide (NaOH) powder and EPP at various weight ratios of 1, and 2 was calcinated in a muffle furnace at 300 °C and 500 °C for 1.5 and 3 h. Ground Granulated Blast Furnace Slag and Fly ash were used as binders for casting the OGP and two-part geopolymer (TGP) mortar specimens. From the X-ray diffraction (XRD) results, the main activator compounds such as thermonatrite (Na₂CO₃·H₂O), natrite (Na₂CO₃), calcite (CaCO₃) and natrosilicate (Na₂Si₂O₅) in HBA that initiate the polymerization reaction. The OGP mortar specimen produced a 28-day compressive strength of 50 MPa under the ambient curing regime with a NaOH/EPP ratio of 1, calcination temperature of 300 °C, and duration of 1.5 h. Both the OGP and TGP mortar specimens showed the presence of calcium aluminosilicate hydrate and calcium sodium aluminosilicate hydrate (C-A-S-H/C-N-A-S-H) geopolymeric gel. The carbon efficiency of OGP mortar specimens was found 70 % lower than that of TGP mortar specimens.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Construction and Building Materials 工程技术-材料科学：综合

CiteScore

13.80

自引率

21.60%

发文量

3632

审稿时长

82 days

期刊介绍： Construction and Building Materials offers an international platform for sharing innovative and original research and development in the realm of construction and building materials, along with their practical applications in new projects and repair practices. The journal publishes a diverse array of pioneering research and application papers, detailing laboratory investigations and, to a limited extent, numerical analyses or reports on full-scale projects. Multi-part papers are discouraged. Additionally, Construction and Building Materials features comprehensive case studies and insightful review articles that contribute to new insights in the field. Our focus is on papers related to construction materials, excluding those on structural engineering, geotechnics, and unbound highway layers. Covered materials and technologies encompass cement, concrete reinforcement, bricks and mortars, additives, corrosion technology, ceramics, timber, steel, polymers, glass fibers, recycled materials, bamboo, rammed earth, non-conventional building materials, bituminous materials, and applications in railway materials.