Improvement of High-Volume Fly Ash Cementitious Material Using Single Alkali Activation

다국어 초록 (Multilingual Abstract)

This research aimed to present the improvement of the cementitious material in high-volume fly ash using only one alkali activator. Fly ash was used as a partial replacement for Portland cement type I, varying from 0 to 60% by weight of the binder. Concentrations of NaOH varying from 0.00 to 1.25 molar were used as alkali activator. Paste properties and mortar compressive strength at the ages of 3, 7, 14, 28, 60, and 90 days of water curing were investigated. The results reveal that fly ash paste with an alkali activator provides shorter initial setting time when compared to control paste without alkali activator. The use of 0.50 molar NaOH concentration in mortar containing fly ash not exceeding 50% by weight of binder provides the highest compressive strength at any age of curing. At that concentration, there is a significant increase in the 28-day compressive strength of up to 45% over that of the control mortar. In addition, higher NaOH concentration (not exceeding 1.00 molar) has a significant positive effect on the compressive strength of mortar with higher fly ash content, especially over longer curing periods.

목차 (Table of Contents)

• Abstract
• 1. Introduction
• 2. Experimental Program
• 3. Results and Discussion
• 4. Conclusions
• References

참고문헌 (Reference)

1 Chalee, W., "Utilization of rice husk–bark ash to improve the corrosion resistance of concrete under 5-year exposure in a marine environment" 37 : 47-53, 2013

2 Richardson, I. G., "The nature of C-S-H in hardened cements" 29 (29): 1131-1147, 1999

3 Moon, J., "Strength enhancement of alkali activated fly ash cured at ambient temperature by delayed activation of substituted OPC" 122 : 659-666, 2016

4 Mohammadhosseini, H., "Strength and transport properties of concrete composites incorporating waste carpet fibres and palm oil fuel ash" 20 : 156-165, 2018

5 Neville, A. M., "Properties of concrete" Addison Wesley Longman Ltd 84-88, 1995

6 Herath, C., "Performance of high volume fly ash concrete incorporating additives : a systematic literature review" 258 : 120606-, 2020

7 Yan, B., "Modification and inplace mechanical characteristics research on cement mortar with fly ash and lime compound admixture in high chlorine environment" 8 (8): 1451-1460, 2019

8 Guojun Ke, "Mitigation Effect of Waste Glass Powders on Alkali–Silica Reaction (ASR) Expansion in Cementitious Composite" 한국콘크리트학회 12 (12): 1063-1076, 2018

9 Chindaprasirt, P., "Mechanical properties, chloride resistance and microstructure of Portland fly ash cement concrete containing high volume bagasse ash" 31 : 101415-, 2020

10 김정은, "Mechanical Properties of Energy Efficient Concretes Made with Binary, Ternary, and Quaternary Cementitious Blends of Fly Ash, Blast Furnace Slag, and Silica Fume" 한국콘크리트학회 10 (10): 97-108, 2016

11 Luo, Z., "Investigation on effect of nanosilica dispersion on the properties and microstructures of fly ashbased geopolymer composite" 282 (282): 122690-, 2021

12 Mejdi, M., "Investigating the pozzolanic reaction of post-consumption glass powder and the role of Portlandite in the formation of sodium-rich C-S-H" 123 : 105790-, 2019

13 Kunther, W., "Influence of the Ca/Si ratio on the compressive strength of cementitious calcium–silicate–hydrate binders" 5 : 1740-, 2017

14 Hefni, Y., "Influence of activation of fly ash on the mechanical properties of concrete" 172 : 728-734, 2018

15 Rattanasak, U., "Influence of NaOH solution on the synthesis of fly ash geopolymer" 22 : 1073-1078, 2009

16 Danilo Tarquini, "Extended Tension Chord Model for Boundary Elements of RC Walls Accounting for Anchorage Slip and Lap Splices Presence" 한국콘크리트학회 14 (14): 1-16, 2020

17 Komonweeraket, K., "Effects of pH on the leaching mechanisms of elements from fly ash mixed soils" 140 : 788-802, 2015

18 Yang, J., "Effect of steam curing on compressive strength and microstructure of high volume ultrafine fly ash cement mortar" 266 : 120894-, 2021

19 Chindaprasirt, P., "Effect of sodium hydroxide concentration on chloride penetration and steel corrosion of fly ash-based geopolymer concrete under marine site" 63 : 303-310, 2014

20 Sun, G., "Early activation of high volume fly ash by ternary activator and its activation mechanism" 267 : 110638-, 2020

21 Kastiukas, G., "Development of precast geopolymer concrete via oven and microwave radiation curing with an environmental assessment" 255 : 120290-, 2020

22 Keke, S., "Design method for the mix proportion of geopolymer concrete based on the paste thickness of coated aggregate" 232 : 508-517, 2019

23 Ashley Russell Kotwal, "Characterization and Early Age Physical Properties of Ambient Cured Geopolymer Mortar Based on Class C Fly Ash" 한국콘크리트학회 9 (9): 35-43, 2015

24 Rashad, A., "Cementitious materials and agricultural wastes as natural fine aggregate replacement in conventional mortar and concrete" 5 : 119-141, 2016

25 Li, W., "An review on durability of alkali-activated system from sustainable construction materials to infrastructures" 4 : 2-19, 2019

26 Luukkonen, T., "Alkali-activated soapstone waste—mechanical properties, durability, and economic prospects" 22 : e00118-, 2019

27 "ASTM C618-19, Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete"

28 "ASTM C305-14, Standard Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency"

29 "ASTM C191-19, Standard Test Methods for Time of Setting of Hydraulic Cement by Vicat Needle"

30 "ASTM C187-16, Standard Test Method for Amount of Water Required for Normal Consistency of Hydraulic Cement Paste"

31 "ASTM C150/C150M-20, Standard Specification for Portland Cement"