High-Resolution X-ray Diffraction and Fluorescence Microscopy Characterization of Alkali-Activated Slag-Metakaolin Binders

2013 ◽  
Vol 96 (6) ◽  
pp. 1951-1957 ◽  
Author(s):  
Susan A. Bernal ◽  
John L. Provis ◽  
Volker Rose ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
High Resolution ◽  
Fluorescence Microscopy ◽  
X Ray Diffraction ◽  
Alkali Activated Slag ◽  
X Ray ◽  
Activated Slag ◽  
Microscopy Characterization ◽  
Alkali Activated

scholarly journals Strength Development and Microstructure of Alkali-activated Slag-MgO in Air Curing Condition

2018 ◽  
Vol 186 ◽  
pp. 02003
Author(s):  
Chao-Lung Hwang ◽  
Duy-Hai Vo ◽  
Mitiku Damtie Yehualaw ◽  
Vu-An Tran
Keyword(s):  
Compressive Strength ◽  
Strength Development ◽  
X Ray Diffraction ◽  
Alkali Activated Slag ◽  
X Ray ◽  
Binder Ratio ◽  
Curing Condition ◽  
Activated Slag ◽  
Water To Binder Ratio ◽  
Alkali Activated

The aim of this study is to analysis the effect of MgO on strength development and microstructure of alkali-activated slag (AAS) in air curing condition. Four mixtures of AAS are prepared using different MgO content (0%, 5%, 10%, and 15 % by weight of slag) at water to binder ratio of 0.4. The flow, compressive strength, scanning electron microscopy, and X-ray diffraction are tested under relevant standards. The addition of MgO significantly accelerated the hydration rate of AAS. AAS with adding MgO tended to increase the compressive strength and to reduce the flow. The higher adding MgO content was associated with higher hydrotalcite-like phase (Ht) formation which improved the microstrure of AAS in the air curing condition.

scholarly journals Effects of CO2 Curing on Alkali-Activated Slag Paste Cured in Different Curing Conditions

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3513 ◽  
Author(s):  
Yubin Jun ◽  
Seong Ho Han ◽  
Tae Yong Shin ◽  
Jae Hong Kim
Keyword(s):  
Compressive Strength ◽  
Co2 Concentration ◽  
Strength Development ◽  
X Ray Diffraction ◽  
Curing Conditions ◽  
Alkali Activated Slag ◽  
X Ray ◽  
Compressive Strength Development ◽  
Activated Slag ◽  
Alkali Activated

The effect of CO2 curing on alkali-activated slag paste activated by a mixture of sodium hydroxide and sodium silicate solutions is reported in this paper. The paste samples after demolding were cured in three different curing environments as follows: (1) environmental chamber maintained at 85% relative humidity (RH) and 25 °C; (2) 3-bar CO2 pressure vessel; and (3) CO2 chamber maintained at 20% CO2 concentration, 70% RH and 25 °C. The hardened samples were then subjected to compressive strength measurement, X-ray diffraction analysis, and thermogravimetry. All curing conditions used in this study were beneficial for the strength development of the alkali-activated slag paste samples. Among the curing environments, the 20% CO2 chamber was the most effective on compressive strength development; this is attributed to the simultaneous supply of moisture and CO2 within the chamber. The results of X-ray diffraction and thermogravimetry show that the alkali-activated slag cured in the 20% CO2 chamber received a higher amount of calcium silicate hydrate (C-S-H), while calcite formed at an early age was consumed with time. C-S-H was formed by associating the calcite generated by CO2 curing with the silica gel dissolved from alkali-activated slag.

scholarly journals High-resolution characterization of the forbidden Si 200 and Si 222 reflections

2015 ◽  
Vol 48 (2) ◽  
pp. 528-532 ◽  
Author(s):  
Peter Zaumseil
Keyword(s):  
High Resolution ◽  
Angular Range ◽  
Angular Divergence ◽  
X Ray Diffraction ◽  
Multiple Diffraction ◽  
Diffraction Plane ◽  
X Ray ◽  
Sample Orientation ◽  
Plane Sample

The occurrence of the basis-forbidden Si 200 and Si 222 reflections in specular X-ray diffraction ω–2Θ scans is investigated in detail as a function of the in-plane sample orientation Φ. This is done for two different diffractometer types with low and high angular divergence perpendicular to the diffraction plane. It is shown that the reflections appear for well defined conditions as a result of multiple diffraction, and not only do the obtained peaks vary in intensity but additional features like shoulders or even subpeaks may occur within a 2Θ range of about ±2.5°. This has important consequences for the detection and verification of layer peaks in the corresponding angular range.

Characterization of alkali-activated slag paste containing dredged marine sediment

2016 ◽  
Vol 57 (51) ◽  
pp. 24688-24696 ◽  
Author(s):  
Jae-Ho Shim ◽  
Joo-Young Jeong ◽  
Jin-Young Park ◽  
Jin-Suk Ryu ◽  
Joo-Yang Park
Keyword(s):  
Marine Sediment ◽  
Alkali Activated Slag ◽  
Dredged Marine Sediment ◽  
Activated Slag ◽  
Alkali Activated

High Resolution X-Ray Diffraction Characterization of [111]B Oriented InGaAs/GaAs Mqw Structures

1997 ◽  
pp. 439-448 ◽  
Author(s):  
A. Sanz-Hervás ◽  
C. Villar ◽  
M. Aguilar ◽  
A. Sacedón ◽  
J. L. Sánchez-Rojas ◽  
...  
Keyword(s):  
High Resolution ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Mitigating the Drying Shrinkage and Autogenous Shrinkage of Alkali-Activated Slag by NaAlO2

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3499
Author(s):  
Bin Chen ◽  
Jun Wang ◽  
Jinyou Zhao
Keyword(s):  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Nitrogen Adsorption ◽  
Partial Substitution ◽  
Hydration Reaction ◽  
X Ray Diffraction ◽  
Na2o Content ◽  
Alkali Activated Slag ◽  
Activated Slag ◽  
Alkali Activated

The shrinkage of alkali-activated slag (AAS) is obviously higher than ordinary Portland cement, which limited its application in engineering. In this study, the effects of NaAlO2 in mitigating drying shrinkage and autogenous shrinkage of AAS were studied. To further understand the shrinkage mechanism, the hydration products and microstructures were studied by X-ray diffraction, scanning electron microscopy and nitrogen adsorption approaches. As the partial substitution rate of NaAlO2 for Na2SiO3 increased, the drying shrinkage and autogenous shrinkage reduced significantly. The addition of NaAlO2 could slow down the rate of hydration reaction and reduce the porosity, change the pore diameter and the composition of generated paste and cause more hydrotalcite and tetranatrolite generated—which contributed to reduced shrinkage. Additionally, raising the Na2O content rate caused obvious differences in drying shrinkage and autogenous shrinkage. As the Na2O content elevated, the drying shrinkage decreased and autogenous shrinkage increased. A high Na2O content would cause complete hydration reactions and provoke high autogenous shrinkage. However, incomplete hydration reactions left more water in the paste, and the evaporated water dramatically influenced drying shrinkage. The results indicate that addition of NaAlO2 could greatly mitigate the drying shrinkage and autogenous shrinkage of AAS.

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