LOng-Term Development of Mechanical Strengths of Alkali-Activated Metakaolin, Slag, Fly Ash, And Blends

2015 ◽  
pp. 77-87 ◽  
Author(s):  
F. Jirasit ◽  
C. H. Rüscher ◽  
L. Lohaus ◽  
P. Chindaprasirt
Keyword(s):  
Fly Ash ◽  
Mechanical Strengths ◽  
Alkali Activated

scholarly journals Pressure-Induced Geopolymerization in Alkali-Activated Fly Ash

2018 ◽  
Vol 10 (10) ◽  
pp. 3538 ◽  
Author(s):  
Sol Park ◽  
Hammad Khalid ◽  
Joon Seo ◽  
Hyun Yoon ◽  
Hyeong Son ◽  
...  
Keyword(s):  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Elevated Pressure ◽  
X Ray Diffraction ◽  
27Al Mas Nmr ◽  
Alkali Activated

The present study investigated geopolymerization in alkali-activated fly ash under elevated pressure conditions. The fly ash was activated using either sodium hydroxide or a combination of sodium silicate solution and sodium hydroxide, and was cured at 120 °C at a pressure of 0.22 MPa for the first 24 h. The pressure-induced evolution of the binder gel in the alkali-activated fly ash was investigated by employing synchrotron X-ray diffraction and solid-state 29Si and 27Al MAS NMR spectroscopy. The results showed that the reactivity of the raw fly ash and the growth of the zeolite crystals were significantly enhanced in the samples activated with sodium hydroxide. In contrast, the effects of the elevated pressure conditions were found to be less apparent in the samples activated with the sodium silicate solution. These results may have important implications for the binder design of geopolymers, since the crystallization of geopolymers relates highly to its long-term properties and functionality.

scholarly journals Effects of Composition Type and Activator on Fly Ash-Based Alkali Activated Materials

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 63
Author(s):  
Chan-Yi Lin ◽  
Tai-An Chen
Keyword(s):  
Fly Ash ◽  
Sodium Hydroxide ◽  
Blast Furnace Slag ◽  
Raw Material ◽  
Granulated Blast Furnace Slag ◽  
Different Types ◽  
Short And Long Term ◽  
Furnace Slag ◽  
Alkali Activated

The compressive strengths of fly ash-based alkali-activated materials (AAM), produced using various activators of only sodium hydroxide, were measured. Fly ash-based AAM specimens, produced by mixing different kinds of fly ash and ground granulated blast-furnace slag (GGBFs) with an activator containing only sodium hydroxide, were cured at ambient temperature, and then placed in air for different numbers of days. The short- and long-term compressive strengths and shrinkage of fly ash-based AAM were measured and compared to one another. The effects of type of fly ash, alkali-equivalent content, GGBFs replace percentage, and ages on the compressive strengths and shrinkage of fly ash-based AAM were investigated. Even when different fly ash was used as the raw material for AAM, a similar compressive strength can be achieved by alkali-equivalent content, GGBFs replaces percentage. However, the performance of shrinkage due to different types of fly ash differed significantly.

scholarly journals Alkali-activated grouts based on slag-fly ash mixtures: From early-age characterization to long-term phase composition

2020 ◽  
Vol 260 ◽  
pp. 120510 ◽  
Author(s):  
Abdelilah Aboulayt ◽  
Faten Souayfan ◽  
Emmanuel Roziere ◽  
Reda Jaafri ◽  
Anass Cherki El Idrissi ◽  
...  
Keyword(s):  
Phase Composition ◽  
Fly Ash ◽  
Early Age ◽  
Alkali Activated

Properties of Materials from Activated Fly Ash from Fluidized Burning

2014 ◽  
Vol 1000 ◽  
pp. 338-341
Author(s):  
Jaromír Poláček ◽  
Rostislav Šulc
Keyword(s):  
Fly Ash ◽  
Chemical Properties ◽  
Accelerated Aging ◽  
Long Term Stability ◽  
Mechanical And Physical Properties ◽  
Properties Of Materials ◽  
Physical And Chemical ◽  
Alkali Activated

This article deals with the basic properties of materials based on alkali-activated fly ash which contains a portion of fly ash produced during fluid burning. The primary task of our research was characterization of physical and chemical properties of each type of fly ash and fly ash mixture. The new materials composed of fly ash mixture and fly ash may have the similar mechanical and physical properties. The work focused on findingan appropriate technological procedure, the optimum composition of mixtures. Long-term stability was simulated by means of accelerated aging of these materials.

scholarly journals Resistance of Soda Residue–Fly Ash Based Geopolymer Mortar to Acid and Sulfate Environments

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 785
Author(s):  
Xianhui Zhao ◽  
Haoyu Wang ◽  
Boyu Zhou ◽  
Han Gao ◽  
Yonghui Lin
Keyword(s):  
Fly Ash ◽  
Cement Mortar ◽  
Experimental Basis ◽  
Chemical Attack ◽  
Before And After ◽  
Infrared Spectrometer ◽  
Mechanical Performances ◽  
Mechanical Strengths ◽  
Scanning Electron

The early mechanical performances of low-calcium fly ash (FFA)-based geopolymer (FFA–GEO) mortar can be enhanced by soda residue (SR). However, the resistance of SR–FFA–GEO mortar to acid or sulfate environments is unclear, owing to the various inorganic calcium salts in SR. The aim of this study was to investigate the long-term mechanical strengths of up to 360 d and evaluate the resistance of SR–FFA–GEO mortar to 5% HCl and 5% Na2SO4 environments through the losses in compressive strength and mass. Scanning Electron Microscopy (SEM), Energy-Dispersive Spectroscopy (EDS) and Fourier Transform Infrared Spectrometer (FTIR) experiments were conducted for the SR–FFA–GEO mortars, both before and after chemical attack, to clarify the attack mechanism. The results show that the resistances of the SR–FFA–GEO mortar with 20% SR (namely M10) to 5% HCl and 5% Na2SO4 environments are superior to those of cement mortar. The environmental HCl reacts with the calcites in SR to produce CaCl2, CO2 and H2O to form more pores under HCl attack, and the environmental Na+ cations from Na2SO4 go into Si-O-Al network structure, to further enhance the strength of mortar under Na2SO4 attack. These results provide the experimental basis for the durability optimization of SR–FFA–GEO mortars.

scholarly journals Microstructure, Durability and Mechanical Properties of Mortars Prepared Using Ternary Binders with Addition of Slag, Fly Ash and Limestone

2021 ◽  
Vol 11 (14) ◽  
pp. 6388
Author(s):  
Javier Ibáñez-Gosálvez ◽  
Teresa Real-Herraiz ◽  
José Marcos Ortega
Keyword(s):  
Fly Ash ◽  
Mercury Intrusion Porosimetry ◽  
Mechanical Performance ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Cement Production ◽  
Mechanical Strengths ◽  
Furnace Slag

In order to improve the contribution to sustainability of cement production, several strategies have been developed, such as the incorporation of additions as clinker replacement. Regarding the production of commercial cements with additions, those made with binary binders are mostly produced. However, the use of ternary binders for manufacturing commercial cements is still very low, at least in Spain, and they could also be an adequate solution for producing eco-friendly cements. The objective of this research is to study the effects in the long term produced by ternary binders which combine the additions of blast furnace slag, fly ash and limestone in the microstructure, durability and mechanical performance of mortars, compared to mortars without additions and mortars made with binary binders. The ternary and binary binders accomplished the prescriptions for a cement type CEM II/B. The microstructure was characterized using mercury intrusion porosimetry, electrical resistivity and differential thermal analysis. Absorption after immersion, diffusion coefficient, mechanical strengths and ultrasonic pulse velocity were studied. The best performance was noted for ternary binder with both slag and fly ash, probably produced by the synergetic effects of slag hydration and fly ash pozzolanic reactions. These effects were more noticeable regarding the compressive strength.

scholarly journals Evaluation of short- and long-term properties of heat-cured alkali-activated fly ash concrete

2015 ◽  
Vol 67 (16) ◽  
pp. 897-905 ◽  
Author(s):  
Julia Shekhovtsova ◽  
Maxim Kovtun ◽  
Elsabe P. Kearsley
Keyword(s):  
Fly Ash ◽  
Fly Ash Concrete ◽  
Short And Long Term ◽  
Alkali Activated

Properties of Materials from Activated Fly Ash from Fluidized Burning

2014 ◽  
Vol 1054 ◽  
pp. 173-176 ◽  
Author(s):  
Jaromir Polacek ◽  
Rostislav Šulc
Keyword(s):  
Fly Ash ◽  
Chemical Properties ◽  
Accelerated Aging ◽  
Long Term Stability ◽  
Mechanical And Physical Properties ◽  
Properties Of Materials ◽  
Physical And Chemical ◽  
Alkali Activated ◽  
And Chemical Properties

This paper describes basic properties of materials composed of fly ash produced during fluid burning. This material is based on alkali-activated fly ash which contains a portion of fly ash produced during fluid burning. Firstly the physical and chemical properties was described for each type of fly ash and fly ash mixture. The new materials composed of fly ash mixture and fly ash may have the similar mechanical and physical properties. The work focused on findingan appropriate technological procedure, the optimum composition of mixtures. Long-term stability was simulated by means of accelerated aging of these materials.

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