Setting Time and after Setting Properties of High Calcium Fly ash Geopolymerswith Different Concentration of Sodium Hydroxide

Archives of Metallurgy and Materials

article

Rosnita Mohamed¹  Rafiza Abd Razak¹  Mohd Mustafa Al Bakri Abdullah¹  Liyana Ahmad Sofri¹  Ikmal HakemAziz¹  Noor Fifinatasha Shahedan¹ 

[1]Universiti Malaysia Perlis ,(UniMAP), Geopolymer& Green Technology, Centre of Excellence

[2]Universiti Malaysia Perlis ,(UniMAP), Faculty of Chemical Engineering Technology

[3]Universiti Malaysia Perlis ,(UniMAP), Faculty of Civil Engineering Technology

关键词: high calcium fly ash geopolymers;    setting time;    heat evolved;    early age properties;    concentration of sodiumhydroxide;   

DOI  :  10.24425/amm.2022.137791

学科分类：物理（综合）

来源: Akademia Gorniczo-Hutnicza im. Stanislawa Staszica / University of Mining and Metallurgy

【 摘 要 】

Setting time in geopolymers is known as the time taken for the transition phase of liquid to solid of the geopolymer system inwhich is represented in the initial setting and final setting. Setting time is significant specifically for application in the constructionfield. This study intends to determine the setting time of high calcium fly ash geopolymers and the properties of the geopolymersafter setting (1-day age). This includes the determination of heat evolved throughout geopolymerization using Differential Scanning Calorimeter. After setting properties determination includes compressive strength and morphology analysis at 1-day age. Highcalcium fly ash was used as geopolymer precursor. Meanwhile, for mixing design, the alkali activator was a mixture of sodiumsilicate and sodium hydroxide (concentration varied from 6M-14M) with a ratio of 2.5 and a solid-to-liquid ratio of 2.5. From thisstudy, it was found that high calcium fly ash geopolymer with 12M of NaOH has a reasonable setting time which is suitable foron-site application as well as an optimal heat evolved (–212 J/g) which leads to the highest compressive strength at 1-day age andno formation of microcracks observed on the morphology. Beyond 12M, too much heat evolved in the geopolymer system cancause micro-cracks formation thus lowering the compressive strength at 1-day age.

【 授权许可】

CC BY-NC