Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 776-792 |
| Seitenumfang | 17 |
| Fachzeitschrift | Construction and Building Materials |
| Jahrgang | 163 |
| Frühes Online-Datum | 4 Jan. 2018 |
| Publikationsstatus | Veröffentlicht - 28 Feb. 2018 |
Abstract
Dicalcium phosphate dihydrate (DCPD) and hydroxyapatite (HAP) were prepared from oyster shell powder and phosphoric acid solution as raw materials using sol-gel process in order to study the influence of calcium phosphate compounds on the mechanical and microstructural properties of metakaolin-based geopolymer cements. The synthesized DCPD and HAP with molar ratio Ca/P equal to 1.00 and 1.65, respectively, were used as additives for replacement of metakaolin (0, 2, 4, 6, 8 and 10 wt%) and the resulting powders were used for producing geopolymer cements. The compressive strengths of geopolymer cements containing DCPD were in the range 40–48 MPa with increasing DCPD content, but when 10 wt% was used, the strength fell to 26 MPa. Similar results were obtained for HAP addition with a decrease of the compressive strength at 8 wt%. The ESEM images of geopolymers containing 4–10 wt% of HAP showed some non-reacted or partially reacted particles that do not well connect to the matrix. Samples of geopolymer with 4–8 wt% of DCPD present a lower number of unreacted particles and the matrix appeared denser than that of the control geopolymer cements. The use of calcium phosphate compounds such as brushite and hydroxyapatite led to the overall improvement in compressive strength and contribute to the densification of the structure of geopolymer cements. On the other hand, the addition of 4% of HAP and 10% of DCPD resulted in a large amount of hydroxyapatite and brushite, respectively in the systems. The matrix appear less dense indicating that a fraction of calcium phosphate addition at the aforementioned level was excessive.
ASJC Scopus Sachgebiete
- Ingenieurwesen (insg.)
- Tief- und Ingenieurbau
- Ingenieurwesen (insg.)
- Bauwesen
- Werkstoffwissenschaften (insg.)
- Allgemeine Materialwissenschaften
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in: Construction and Building Materials, Jahrgang 163, 28.02.2018, S. 776-792.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - The effects of synthesized calcium phosphate compounds on the mechanical and microstructural properties of metakaolin-based geopolymer cements
AU - Tchakouté, Hervé K.
AU - Fotio, Daniel
AU - Rüscher, Claus H.
AU - Authority, Elie
AU - Djobo, Jean N.Y.
AU - Bignozzi, Maria C.
AU - Leonelli, Cristina
N1 - © 2018 Elsevier Ltd. All rights reserved.
PY - 2018/2/28
Y1 - 2018/2/28
N2 - Dicalcium phosphate dihydrate (DCPD) and hydroxyapatite (HAP) were prepared from oyster shell powder and phosphoric acid solution as raw materials using sol-gel process in order to study the influence of calcium phosphate compounds on the mechanical and microstructural properties of metakaolin-based geopolymer cements. The synthesized DCPD and HAP with molar ratio Ca/P equal to 1.00 and 1.65, respectively, were used as additives for replacement of metakaolin (0, 2, 4, 6, 8 and 10 wt%) and the resulting powders were used for producing geopolymer cements. The compressive strengths of geopolymer cements containing DCPD were in the range 40–48 MPa with increasing DCPD content, but when 10 wt% was used, the strength fell to 26 MPa. Similar results were obtained for HAP addition with a decrease of the compressive strength at 8 wt%. The ESEM images of geopolymers containing 4–10 wt% of HAP showed some non-reacted or partially reacted particles that do not well connect to the matrix. Samples of geopolymer with 4–8 wt% of DCPD present a lower number of unreacted particles and the matrix appeared denser than that of the control geopolymer cements. The use of calcium phosphate compounds such as brushite and hydroxyapatite led to the overall improvement in compressive strength and contribute to the densification of the structure of geopolymer cements. On the other hand, the addition of 4% of HAP and 10% of DCPD resulted in a large amount of hydroxyapatite and brushite, respectively in the systems. The matrix appear less dense indicating that a fraction of calcium phosphate addition at the aforementioned level was excessive.
AB - Dicalcium phosphate dihydrate (DCPD) and hydroxyapatite (HAP) were prepared from oyster shell powder and phosphoric acid solution as raw materials using sol-gel process in order to study the influence of calcium phosphate compounds on the mechanical and microstructural properties of metakaolin-based geopolymer cements. The synthesized DCPD and HAP with molar ratio Ca/P equal to 1.00 and 1.65, respectively, were used as additives for replacement of metakaolin (0, 2, 4, 6, 8 and 10 wt%) and the resulting powders were used for producing geopolymer cements. The compressive strengths of geopolymer cements containing DCPD were in the range 40–48 MPa with increasing DCPD content, but when 10 wt% was used, the strength fell to 26 MPa. Similar results were obtained for HAP addition with a decrease of the compressive strength at 8 wt%. The ESEM images of geopolymers containing 4–10 wt% of HAP showed some non-reacted or partially reacted particles that do not well connect to the matrix. Samples of geopolymer with 4–8 wt% of DCPD present a lower number of unreacted particles and the matrix appeared denser than that of the control geopolymer cements. The use of calcium phosphate compounds such as brushite and hydroxyapatite led to the overall improvement in compressive strength and contribute to the densification of the structure of geopolymer cements. On the other hand, the addition of 4% of HAP and 10% of DCPD resulted in a large amount of hydroxyapatite and brushite, respectively in the systems. The matrix appear less dense indicating that a fraction of calcium phosphate addition at the aforementioned level was excessive.
KW - Brushite
KW - Compressive strength
KW - Geopolymer cements
KW - Hydroxyapatite
KW - Oyster shell
KW - Phosphoric acid solution
UR - http://www.scopus.com/inward/record.url?scp=85039710098&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2017.12.162
DO - 10.1016/j.conbuildmat.2017.12.162
M3 - Article
AN - SCOPUS:85039710098
VL - 163
SP - 776
EP - 792
JO - Construction and Building Materials
JF - Construction and Building Materials
SN - 0950-0618
ER -