Effects of NaOH concentrations on physical and electrical properties of high calcium fly ash geopolymer paste
Source abstract
Abstract
Abstract The effects of sodium hydroxide (NaOH) concentration on setting time, compressive strength and electrical properties at the frequencies of 100 Hz–10 MHz of high calcium fly ash geopolymer pastes were investigated. Five NaOH concentrations (8, 10, 12, 15 and 18 molar) were studied. The liquid to ash ratio of 0.4, sodium silicate to sodium hydroxide ratio of 0.67 and low temperature curing at 40 °C were selected in making geopolymer pastes. The results showed that NaOH concentration had significant influence on the physical and electrical properties of geopolymer paste. The pastes with high NaOH concentrations showed increased setting time and compressive strength due to a high degree of geopolymerization as a result of the increased leaching of silica and alumina from fly ash. The dielectric constant and conductivity increased with NaOH concentration while tan δ decreased due to an increase in geopolymerization. At the frequency of 103 Hz, the dielectric constants of all pastes were approximately 104 S/cm and decreased with increased frequency. The relaxation peaks of tan δ reduced with an increase in NaOH concentration and ranged between 2.5 and 4.5. The AC conductivity behavior followed the universal power law and the values were in the range of 3.7 × 10−3–1.5 × 10−2 at 105–106 Hz.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Concrete and Cement Materials Research · Innovative concrete reinforcement materials · Smart Materials for Construction
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (35)
Show source-provided references
1. A review on the utilization of fly ash10.1016/j.pecs.2009.11.003 ↗
2. Comparative study on the characteristics of fly ash and bottom ash geopolymers10.1016/j.wasman.2008.06.023 ↗
3. Workability and strength of coarse high calcium fly ash geopolymer10.1016/j.cemconcomp.2006.11.002 ↗
4. High strength geopolymer using fine high calcium fly ash10.1061/(ASCE)MT.1943-5533.0000161 ↗
5. Thermal evolution and crystallization kinetics of potassium-based geopolymer10.1016/j.ceramint.2010.08.008 ↗
6. Thermal behaviour of inorganic geopolymers and composites derived from sodium polysialate10.1016/S0025-5408(02)01022-X ↗
7. Mechanism of geopolymerization and factors influencing its development: a review10.1007/s10853-006-0401-4 ↗
8. A study on electrical conductivity of chemosynthetic Al2O3–2SiO2 geoploymer materials10.1016/j.jpowsour.2008.03.021 ↗
9. Geopolymer technology: the current state of the art10.1007/s10853-006-0637-z ↗
10. Alkali-activated binders: a review: Part 1. Historical background, terminology, reaction mechanisms and hydration products10.1016/j.conbuildmat.2007.10.015 ↗
11. Preparation of fly ash and rice husk ash geopolymer
12. Utilization of blended fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash in geopolymer10.1016/j.wasman.2009.09.040 ↗
13. Properties of inorganic polymer (geopolymer) mortars made of glass cullet10.1007/s10853-011-6107-2 ↗
14. Production of geopolymeric binder from blended waste concrete powder and fly ash10.1016/j.conbuildmat.2012.04.044 ↗
15. Prediction early age compressive strength of OPC-based geopolymers with different alkali activators and seashell powder by gene expression programming10.1016/j.ceramint.2012.07.086 ↗
16. Production geopolymers by Portland cement: designing the main parameters’ effects on compressive strength by Taguchi method10.1016/j.matdes.2012.04.045 ↗
17. A novel aluminosilicate geopolymer materials with low dielectric loss10.1016/j.matchemphys.2011.06.039 ↗
18. Structure, ionic conduction and dielectric relaxation in a novel fast ion conductor, Na2Cd(SO4)210.1021/cm0626637 ↗
19. Electrical conductivity and dielectric property of fly ash geopolymer pastes10.1007/s12613-011-0406-0 ↗
20. Influence of NaOH solution on the synthesis of fly ash geopolymer10.1016/j.mineng.2009.03.022 ↗
21. American Society for Testing and Materials (ASTM) C191-08. Standard test method for time of setting of hydraulic cement by Vicat needle; 2008.
22. American Society for Testing and Materials (ASTM) D1633-00. Standard test methods for compressive strength of molded soil–cement cylinders; 2007.
23. Kasap · 2002
24. Dielectric measurements to characterize the microstructural changes of young concrete
25. Calorimetric study of alkaline activation of calcium hydroxide-metakaolin solid mixtures10.1016/S0008-8846(00)00435-X ↗
26. Effect of SiO2 and Al2O3 on the setting and hardening of high calcium fly ash-based geopolymer systems10.1007/s10853-012-6353-y ↗
27. Effect of chemical admixtures on properties of high-calcium fly ash10.1007/s12613-011-0448-3 ↗
28. Compressive strength and microstructural characteristics of class C fly ash geopolymer10.1016/j.cemconcomp.2009.11.003 ↗
29. The effects of Na2O/SiO2 molar ratio, curing temperature and age on compressive strength, morphology and microstructure of alkali-activated fly ash-based geopolymers10.1016/j.cemconcomp.2011.03.006 ↗
30. Alkali-activated complex binders from class C fly ash and Ca-containing admixtures10.1016/j.jhazmat.2009.08.110 ↗
31. Microstructure of different NaOH molarity of fly ash based green polymeric cement
32. Effect of the alkali metal activator on the properties of fly ash-based geopolymer10.1021/ie980804b ↗
33. NaOH-activated ground fly ash geopolymer cured at ambient temperature10.1016/j.fuel.2011.01.018 ↗
34. Characterization and monitoring of cement-based systems using intrinsic electrical property measurement10.1016/S0008-8846(02)00824-4 ↗
35. The complex impedance response of fly-ash cement revisited10.1016/j.cemconres.2004.01.013 ↗