Details
| Original language | English |
|---|---|
| Pages (from-to) | 21442-21450 |
| Number of pages | 9 |
| Journal | Ceramics international |
| Volume | 44 |
| Issue number | 17 |
| Early online date | 20 Aug 2018 |
| Publication status | Published - Dec 2018 |
| Externally published | Yes |
Abstract
This paper studies the alkali activation of iron-rich aluminosilicates (laterites). Three activating alkaline solutions were prepared from sodium hydroxide solution (8, 10 and 12 M) with sodium silicate (Na2SiO3) in order to obtain the sodium silicate solutions with moduli of SiO2/Na2O equal to 0.75, 0.92 and 1.04; H2O/Na2O = 9.78, 10.45 and 12.04. The effects of above-defined solutions on the setting time, physical and microstructural properties of geopolymer binders from calcined laterite (600 °C), containing metakaolinite, as the sole binder at room temperature are reported and discussed. A laterite from Eloumden and one from Odza were used. The synthesized products were labelled GPEL(i=1.04, 0.92 and 0.75) and GPOD(i=1.04, 0.92 and 0.75) series. The dry compressive strength measured after 7 and 28 days were 4–10 and 10–18 MPa, respectively. It was typically found that the geopolymer paste from sodium hydroxide with molar concentration 12 M and the molar ratio SiO2/Na2O of the silicate solution equal to 0.75 produced the highest compressive strength (~ 18 MPa). These samples also have a denser matrix. The dry bulk densities of both series increased with the decrease of silica moduli and were in the range 2.31–2.43 and 2.32–2.52 g/cm3 and the water absorptions were in the range of 8.21–11.40% and 7.23–13.03% for geopolymers GPEL and GPOD series, respectively. The setting time decreased with increasing molarity of NaOH solutions. The physicochemical properties and the mineralogy of both iron-rich aluminosilicates were influenced by the silicate modulus of activating solutions and the best compositions were achieved with characteristic SiO2/Na2O = 0.75 and H2O/Na2O = 9.78.
Keywords
- Compressive strength, Geopolymerization, Laterite, Microstructure, Silicate moduli
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Ceramics and Composites
- Chemical Engineering(all)
- Process Chemistry and Technology
- Materials Science(all)
- Surfaces, Coatings and Films
- Materials Science(all)
- Materials Chemistry
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Ceramics international, Vol. 44, No. 17, 12.2018, p. 21442-21450.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Effect of silicate modulus on the setting, mechanical strength and microstructure of iron-rich aluminosilicate (laterite) based-geopolymer cured at room temperature
AU - Kaze, Cyriaque Rodrigue
AU - Djobo, Jean Noel Yankwa
AU - Nana, Achile
AU - Tchakoute, Herve Kouamo
AU - Kamseu, Elie
AU - Melo, Uphie Chinje
AU - Leonelli, Cristina
AU - Rahier, Hubert
N1 - Funding Information: The authors are grateful to Ingessil S.r.l., Verona, Italy, for providing sodium silicate used in this study. This project received the contribution of The Academy of Science for the Third World TWAS through the financement 15-079RG/CHE/AF/AC_I to Dr. Elie Kamseu.
PY - 2018/12
Y1 - 2018/12
N2 - This paper studies the alkali activation of iron-rich aluminosilicates (laterites). Three activating alkaline solutions were prepared from sodium hydroxide solution (8, 10 and 12 M) with sodium silicate (Na2SiO3) in order to obtain the sodium silicate solutions with moduli of SiO2/Na2O equal to 0.75, 0.92 and 1.04; H2O/Na2O = 9.78, 10.45 and 12.04. The effects of above-defined solutions on the setting time, physical and microstructural properties of geopolymer binders from calcined laterite (600 °C), containing metakaolinite, as the sole binder at room temperature are reported and discussed. A laterite from Eloumden and one from Odza were used. The synthesized products were labelled GPEL(i=1.04, 0.92 and 0.75) and GPOD(i=1.04, 0.92 and 0.75) series. The dry compressive strength measured after 7 and 28 days were 4–10 and 10–18 MPa, respectively. It was typically found that the geopolymer paste from sodium hydroxide with molar concentration 12 M and the molar ratio SiO2/Na2O of the silicate solution equal to 0.75 produced the highest compressive strength (~ 18 MPa). These samples also have a denser matrix. The dry bulk densities of both series increased with the decrease of silica moduli and were in the range 2.31–2.43 and 2.32–2.52 g/cm3 and the water absorptions were in the range of 8.21–11.40% and 7.23–13.03% for geopolymers GPEL and GPOD series, respectively. The setting time decreased with increasing molarity of NaOH solutions. The physicochemical properties and the mineralogy of both iron-rich aluminosilicates were influenced by the silicate modulus of activating solutions and the best compositions were achieved with characteristic SiO2/Na2O = 0.75 and H2O/Na2O = 9.78.
AB - This paper studies the alkali activation of iron-rich aluminosilicates (laterites). Three activating alkaline solutions were prepared from sodium hydroxide solution (8, 10 and 12 M) with sodium silicate (Na2SiO3) in order to obtain the sodium silicate solutions with moduli of SiO2/Na2O equal to 0.75, 0.92 and 1.04; H2O/Na2O = 9.78, 10.45 and 12.04. The effects of above-defined solutions on the setting time, physical and microstructural properties of geopolymer binders from calcined laterite (600 °C), containing metakaolinite, as the sole binder at room temperature are reported and discussed. A laterite from Eloumden and one from Odza were used. The synthesized products were labelled GPEL(i=1.04, 0.92 and 0.75) and GPOD(i=1.04, 0.92 and 0.75) series. The dry compressive strength measured after 7 and 28 days were 4–10 and 10–18 MPa, respectively. It was typically found that the geopolymer paste from sodium hydroxide with molar concentration 12 M and the molar ratio SiO2/Na2O of the silicate solution equal to 0.75 produced the highest compressive strength (~ 18 MPa). These samples also have a denser matrix. The dry bulk densities of both series increased with the decrease of silica moduli and were in the range 2.31–2.43 and 2.32–2.52 g/cm3 and the water absorptions were in the range of 8.21–11.40% and 7.23–13.03% for geopolymers GPEL and GPOD series, respectively. The setting time decreased with increasing molarity of NaOH solutions. The physicochemical properties and the mineralogy of both iron-rich aluminosilicates were influenced by the silicate modulus of activating solutions and the best compositions were achieved with characteristic SiO2/Na2O = 0.75 and H2O/Na2O = 9.78.
KW - Compressive strength
KW - Geopolymerization
KW - Laterite
KW - Microstructure
KW - Silicate moduli
UR - http://www.scopus.com/inward/record.url?scp=85052753306&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2018.08.205
DO - 10.1016/j.ceramint.2018.08.205
M3 - Article
AN - SCOPUS:85052753306
VL - 44
SP - 21442
EP - 21450
JO - Ceramics international
JF - Ceramics international
SN - 0272-8842
IS - 17
ER -