Alkali-activated binders based on incinerator bottom ash combined with limestone-calcined clay or fly ash

2022 ◽  
Vol 320 ◽  
pp. 126306
Author(s):  
Jun Liu ◽  
Zhen Liang ◽  
Hesong Jin ◽  
Gediminas Kastiukas ◽  
Luping Tang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Bottom Ash ◽  
Calcined Clay ◽  
Alkali Activated Binders ◽  
Alkali Activated

scholarly journals Alkali-Activated Binders Using Bottom Ash from Waste-to-Energy Plants and Aluminium Recycling Waste

2021 ◽  
Vol 11 (9) ◽  
pp. 3840 ◽  
Author(s):  
Alex Maldonado-Alameda ◽  
Jofre Mañosa ◽  
Jessica Giro-Paloma ◽  
Joan Formosa ◽  
Josep Maria Chimenos
Keyword(s):  
Bottom Ash ◽  
Physicochemical Characterization ◽  
Waste To Energy ◽  
Promising Alternative ◽  
Leaching Potential ◽  
Aluminium Recycling ◽  
Alkaline Activator ◽  
Alkali Activated Binders ◽  
Energy Plants ◽  
Alkali Activated

Alkali-activated binders (AABs) stand out as a promising alternative to replace ordinary Portland cement (OPC) due to the possibility of using by-products and wastes in their manufacturing. This paper assessed the potential of weathered bottom ash (WBA) from waste-to-energy plants and PAVAL® (PV), a secondary aluminium recycling process by-product, as precursors of AABs. WBA and PV were mixed at weight ratios of 98/2, 95/5, and 90/10. A mixture of waterglass (WG) and NaOH at different concentrations (4 and 6 M) was used as the alkaline activator solution. The effects of increasing NaOH concentration and PV content were evaluated. Alkali-activated WBA/PV (AA-WBA/PV) binders were obtained. Selective chemical extractions and physicochemical characterization revealed the formation of C-S-H, C-A-S-H, and (N,C)-A-S-H gels. Increasing the NaOH concentration and PV content increased porosity and reduced compressive strength (25.63 to 12.07 MPa). The leaching potential of As and Sb from AA-WBA/PV exceeded the threshold for acceptance in landfills for non-hazardous waste.

scholarly journals Effect of CaSO4 Incorporation on Pore Structure and Drying Shrinkage of Alkali-Activated Binders

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1673 ◽  
Author(s):  
Hyeongmin Son ◽  
Sol Moi Park ◽  
Joon Ho Seo ◽  
Haeng Ki Lee
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Drying Shrinkage ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
Activated Slag ◽  
Capillary Tension ◽  
Alkali Activated Binders ◽  
Internal Pore Structure ◽  
Alkali Activated

This present study investigates the effects of CaSO4 incorporation on the pore structure and drying shrinkage of alkali-activated slag and fly ash. The slag and fly ash were activated at a 5:5 ratio by weighing with a sodium silicate. Thereafter, 0%, 5%, 10%, and 15% of CaSO4 were incorporated to investigate the changes in phase formation and internal pore structure. X-Ray Diffraction (XRD), thermogravimetry (TG)/derivative thermogravimetry (DTG), mercury intrusion porosimetry (MIP), nuclear magnetic resonance (NMR), and drying shrinkage tests were carried out to find the correlation between the pore structure and drying shrinkage of the specimens. The results showed that CaSO4 incorporation increased the formation of thenardite, and these phase changes affected the pore structure of the activated fly ash and slag. The increase in the CaSO4 content increased the pore distribution in the mesopore. As a result, the capillary tension and drying shrinkage decreased.

scholarly journals Leaching, carbonation and chloride ingress in reinforced alkali-activated fly ash mortars

2018 ◽  
Vol 199 ◽  
pp. 02025 ◽  
Author(s):  
Gregor J. G. Gluth ◽  
Petr Hlaváček ◽  
Steffi Reinemann ◽  
Gino Ebell ◽  
Jürgen Mietz
Keyword(s):  
Fly Ash ◽  
Visual Inspection ◽  
Electrochemical Behaviour ◽  
Transport Coefficients ◽  
Chloride Penetration ◽  
Chloride Ingress ◽  
Reaction Products ◽  
Steel Bars ◽  
Alkali Activated Binders ◽  
Alkali Activated

Alkali-activated fly ash mortars were studied with regard to durability-relevant transport coefficients and the electrochemical behaviour of embedded carbon steel bars on exposure of the mortars to leaching, carbonation and chloride penetration environments. The transport coefficients differed considerably between different formulations, being lowest for a mortar with BFS addition, but still acceptable for one of the purely fly ash-based mortars. Leaching over a period of ~300 days in de-ionized water did not lead to observable corrosion of the embedded steel, as shown by the electrochemical data and visual inspection of the steel. Exposure to 100 % CO2 atmosphere caused steel depassivation within approx. two weeks; in addition, indications of a deterioration of the mortar were observed. The results are discussed in the context of the different reaction products expected in highand low-Ca alkali-activated binders, and the alterations caused by leaching and carbonation.

Durability of Alkali-Activated Fly Ash/Slag Concrete

2017 ◽  
Vol 904 ◽  
pp. 157-161 ◽  
Author(s):  
Mao Chieh Chi ◽  
Hsian Chen ◽  
Tsai Lung Weng ◽  
Ran Huang ◽  
Yih Chang Wang
Keyword(s):  
Fly Ash ◽  
Total Charge ◽  
Test Results ◽  
Mass Ratio ◽  
Modulus Ratio ◽  
Granulated Blast Furnace Slag ◽  
Alkali Activated Binders ◽  
Furnace Slag ◽  
Alkali Activated ◽  
Better Than

This study investigated the durability of alkali-activated binders based on blends of fly ash (FA) and ground granulated blast furnace slag (GGBFS). Five fly ash-to-slag ratios of 100/0, 75/25, 50/50, 25/75, and 0/100 by mass were selected to produce alkali-activated fly ash/slag (AAFS) concrete. Sodium oxide (Na2O) concentrations of 6% and 8% of binder weight and activator modulus ratios (mass ratio of SiO2 to Na2O) of 0.8, 1.0, and 1.23 were used as alkaline activators. Test results show that the total charge passed of AAFS concrete is between 2500 and 4000 coulombs, higher than the comparable OPC concrete. However, AAFS concrete exposed to sulfate attack performed better than OPC concrete. Based on the results, 100% slag-based AAFS concrete with Na2O concentration of 8% and activator modulus ratio of 1.23 has the superior performances.

Influence of Curing Temperature on the Mechanical Properties of Alkali-Activated Bottom Ash Geopolymer Mortar

2011 ◽  
Vol 488-489 ◽  
pp. 198-201 ◽  
Author(s):  
Gum Sung Ryu ◽  
Si Hwan Kim ◽  
Kyung Taek Koh ◽  
Su Tae Kang ◽  
Jang Hwa Lee
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Power Plants ◽  
Bottom Ash ◽  
Basic Research ◽  
Molar Concentration ◽  
Curing Temperature ◽  
Active Research ◽  
Alkali Activated Concrete ◽  
Alkali Activated

The fabrication of Portland cement causes numerous problems accompanying the large exhaustion of gas. Even if fly ash, an industrial by-product produced in thermoelectric power plants, is recycled in concrete by partial replacing of cement, more than 50% remains still discharged in marine and ashore landfills and, continue to provoke environmental problems. Recently, active research has been dedicated to alkali-activated concrete that does not use cement as binder. This alkali-activated concrete as a cement zero concrete activated by alkali solution using bottom ash rich in Si and Al instead of cement is effective in reducing gas exhaustion. This study is a basic research for the fabrication of concrete without cement and using 100% of bottom ash among the industrial by-products. Therefore, the purposes are to develop cement zero concrete by evaluating the mechanical properties by age according to the change of the molar concentration and ratio (SH/SS) of the alkali-activator and the curing temperature, and to investigate the reaction mechanism. From the test results, the compressive strength increased with larger molar concentration and the optimal curing temperature was 60°C. In addition, the measurement of the leaching according to the molar concentration of fly ash having similar chemical composition showed that the leaching of Si4+ and Al3+ increased. Compared to 6M, the leached quantities of Si4+ and Al3+ were twice larger for 9M and 12M. The formation of gel at the surface of fly ash indicated that fly ash was more activated in higher alkaline environment.

Effect of Mechanical Activation on Properties of Alkali Activated Binders

2014 ◽  
Vol 1000 ◽  
pp. 67-70 ◽  
Author(s):  
Martin Sisol ◽  
Juraj Mosej ◽  
Miroslava Drabová ◽  
Ivan Brezani
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Mechanical Activation ◽  
Sodium Hydroxide ◽  
Water Glass ◽  
Fly Ashes ◽  
Alkali Activated Binders ◽  
Alkali Activated

Effect of mechanical activation of fly ashes on strength of alkali activated binders is investigated. Four different kinds of fly ashes are mechanically activated. The aim of mechanical activation is to increase the reactivity of fly ashes. Mechanically activated fly ash is used as an admixture to the untreated original fly ash in proportion of 0, 50, 75 and 100 %. Fly ashes are alkali activated with solutions containing sodium hydroxide and sodium water glass. Compressive and flexural strength is tested on hardened alkali activated binders.

scholarly journals Influence of Water Content on Mechanical Strength and Microstructure of Alkali-Activated Fly Ash/GGBFS Mortars Cured at Cold and Polar Regions

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 138 ◽  
Author(s):  
Xiaobin Wei ◽  
Feng Ming ◽  
Dongqing Li ◽  
Lei Chen ◽  
Yuhang Liu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Content ◽  
Negative Temperature ◽  
Polar Regions ◽  
Uniaxial Compression Strength ◽  
Influence Of Water ◽  
Strength And Durability ◽  
Alkali Activated Binders ◽  
Alkali Activated

Negative temperature curing is a very harmful factor for geopolymer mortar or concrete, which will decrease the strength and durability. The water in the geopolymer mixture may be frozen into ice, and the water content is a crucial factor. The purpose of this paper is to explore the influence of water content on the properties of alkali-activated binders mortar cured at −5 °C. Fly ash (FA) and ground granulated blast furnace slag (GGBFS) were used as binders. Three groups of experiments with different water content were carried out. The prepared samples were investigated through uniaxial compression strength test, Scanning electron microscopy (SEM), and X-ray diffraction (XRD) for the determination of their compressive strength, microstructural features, phase, and composition. The results indicated that, the compressive strength of samples basically maintained 25.78 MPa–27.10 MPa at an age of 28 days; for 90 days, the values reached 33.4 MPa–34.04 MPa. The results showed that lower water content is beneficial to improving the early strength of mortar at −5 °C curing condition, while it has little impact on long-term strength. These results may provide references for the design and construction of geopolymer concrete in cold regions.

Alkali Activated Binders Based on Biomass Bottom Ash and Silica By-Product Blends

2020 ◽  
Author(s):  
D. Vaičiukynienė ◽  
D. Nizevičienė ◽  
A. Kantautas ◽  
A. Kielė ◽  
V. Bocullo
Keyword(s):  
Bottom Ash ◽  
Alkali Activated Binders ◽  
Alkali Activated
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