Rights statement: This is the author’s version of a work that was accepted for publication in Cement and Concrete Composites. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Cement and Concrete Composites, 127, 2022 DOI: 10.1016/j.cemconcomp.2022.104407
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Phase dissolution and improving properties of completely decomposed granite through alkali fusion method
AU - Dassekpo, J.-B.M.
AU - Miao, L.
AU - Bai, J.
AU - Gong, Q.
AU - Shao, N.N.
AU - Dong, Z.
AU - Xing, F.
AU - Ye, J.
N1 - This is the author’s version of a work that was accepted for publication in Cement and Concrete Composites. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Cement and Concrete Composites, 127, 2022 DOI: 10.1016/j.cemconcomp.2022.104407
PY - 2022/3/31
Y1 - 2022/3/31
N2 - Low-reactive completely decomposed granite (CDG) was successfully synthesized by thermal activation with the addition of NaOH at low alkali/CDG mass ratio of 0.1/1. During alkali fusion, the degree of amorphicity of CDG rich in kaolinite (Al2Si2O5(OH)4) increased and a significant reduction of the peak intensities occurring between 20 and 45 (o2 theta) was observed. Reactivity analysis indicated that, initial CDG requires high molar NaOH to provide a proper dissolution, whereas fused CDG exhibits high reactivity (29Si = 555.57 ppm; 27Al = 223.73 ppm) at low NaOH concentration. Moreover, results from the setting time, varied between 15 and 45 min, indicating that alkali fusion is very effective for improving the dissolution of the fused CDG under Na2SiO3 solution. However, the setting time decreases as the reaction degree accelerates. FTIR analysis of the fused CDG presented lower wavenumber band of around 975 cm−1, confirming a decline of crystalline phases. In addition, SEM-EDS characterization and alkalinity analysis showed a compactness of the structure due to the liberation of enough sodium aluminosilicate gel. Finally, results from the mechanical test (4.75–39.55 MPa) and water solubility inferred that, by enhancing the reactivity of CDG by alkali fusion and by addition of up to 15% GGBS, CDG can be optimally recycled as an alternative source material to produce geopolymers.
AB - Low-reactive completely decomposed granite (CDG) was successfully synthesized by thermal activation with the addition of NaOH at low alkali/CDG mass ratio of 0.1/1. During alkali fusion, the degree of amorphicity of CDG rich in kaolinite (Al2Si2O5(OH)4) increased and a significant reduction of the peak intensities occurring between 20 and 45 (o2 theta) was observed. Reactivity analysis indicated that, initial CDG requires high molar NaOH to provide a proper dissolution, whereas fused CDG exhibits high reactivity (29Si = 555.57 ppm; 27Al = 223.73 ppm) at low NaOH concentration. Moreover, results from the setting time, varied between 15 and 45 min, indicating that alkali fusion is very effective for improving the dissolution of the fused CDG under Na2SiO3 solution. However, the setting time decreases as the reaction degree accelerates. FTIR analysis of the fused CDG presented lower wavenumber band of around 975 cm−1, confirming a decline of crystalline phases. In addition, SEM-EDS characterization and alkalinity analysis showed a compactness of the structure due to the liberation of enough sodium aluminosilicate gel. Finally, results from the mechanical test (4.75–39.55 MPa) and water solubility inferred that, by enhancing the reactivity of CDG by alkali fusion and by addition of up to 15% GGBS, CDG can be optimally recycled as an alternative source material to produce geopolymers.
KW - Alkali fusion
KW - Alkali-activated binder
KW - Completely decomposed granite
KW - Dissolution
KW - Reactivity
KW - Setting time
KW - Aluminum compounds
KW - Granite
KW - Kaolinite
KW - Silicon
KW - Sodium hydroxide
KW - Structure (composition)
KW - Fusion methods
KW - Phase dissolution
KW - Property
KW - Synthesised
KW - Thermal activation
U2 - 10.1016/j.cemconcomp.2022.104407
DO - 10.1016/j.cemconcomp.2022.104407
M3 - Journal article
VL - 127
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
SN - 0958-9465
M1 - 104407
ER -