TY - JOUR

T1 - Influence of the synthetic calcium aluminate hydrate and the mixture of calcium aluminate and silicate hydrates on the compressive strengths and the microstructure of metakaolin-based geopolymer cements

AU - Moudio, A. M.N.

AU - Tchakouté, H. K.

AU - Ngnintedem, D. L.V.

AU - Andreola, F.

AU - Kamseu, E.

AU - Nanseu-Njiki, C. P.

AU - Leonelli, C.

AU - Rüscher, C. H.

N1 - Funding Information: This is a statement to certify that all authors have seen and approved the final version of the manuscript being submitted. They warrant that the article is the authors' original work, hasn't received prior publication and isn't under consideration for publication elsewhere. No potential conflict of interest was reported by the authors. This work was supported by the Alexander von Humboldt-Stiftung [KAM/1155741 GFHERMES-P]. A permission note is a statement that permission has been received to use any material in the manuscript such as figures etc. which isn't original content.Dr Herv? Tchakout? Kouamo gratefully acknowledges the Alexander von Humboldt-Stiftung for financial support this work under the grant N? KAM/1155741 GFHERMES-P. The authors would like to thank Dr Valerie Petrov for SEM observations.

PY - 2021/3/2

Y1 - 2021/3/2

N2 - The main goal of this study is to investigate the effects of the calcium aluminate hydrate (CA04) and the mixture of calcium aluminate and silicate hydrates (CA04 + CS04) on the compressive strengths and the microstructure of metakaolin-based geopolymer cements. Bauxite, rice husk and eggshells were calcined and mixed in proper amounts to prepare CA04 and CS04. Metakaolin has been substituted by 0, 5, 10, 15 and 20 wt% of CA04, 10 and 20 wt% of (CA04 + CS04) in the formulation of geopolymer cements. The clay-like solid materials were characterized by measuring their compressive strengths, the crystalline and amorphous phases were monitored using the X-ray diffractometry analysis, their microstructures were investigated using the scanning electron microscope and mercury intrusion porosimetry and the functional groups were studied using the infrared spectroscopy. The compressive strengths of geopolymer cements containing 0, 5, 10, 15 and 20 wt% of CA04 are 49.50, 57.17, 63.59, 38.79 and 35.05 MPa, respectively. Those containing 10 and 20 wt% of (CA04 + CS04) are 40.59 and 51.19 MPa, respectively. The average pore diameters of geopolymer cements containing 0, 10 and 20 wt% of CA04 are 11.80, 10.10, 12.20 nm, respectively. Whereas the one containing 20 wt% of (CA04 + CS04) is 10.80 nm. It appears that geopolymer cement with 10 wt% of CA04 and 20 wt% of (CA04 + CS04) have higher compressive strengths and lower average pore diameters. It was found that 10 and 20 wt% of CA04 and (CA04 + CS04), respectively, could be used as additives for the preparation of geopolymer cements with higher strength development.

AB - The main goal of this study is to investigate the effects of the calcium aluminate hydrate (CA04) and the mixture of calcium aluminate and silicate hydrates (CA04 + CS04) on the compressive strengths and the microstructure of metakaolin-based geopolymer cements. Bauxite, rice husk and eggshells were calcined and mixed in proper amounts to prepare CA04 and CS04. Metakaolin has been substituted by 0, 5, 10, 15 and 20 wt% of CA04, 10 and 20 wt% of (CA04 + CS04) in the formulation of geopolymer cements. The clay-like solid materials were characterized by measuring their compressive strengths, the crystalline and amorphous phases were monitored using the X-ray diffractometry analysis, their microstructures were investigated using the scanning electron microscope and mercury intrusion porosimetry and the functional groups were studied using the infrared spectroscopy. The compressive strengths of geopolymer cements containing 0, 5, 10, 15 and 20 wt% of CA04 are 49.50, 57.17, 63.59, 38.79 and 35.05 MPa, respectively. Those containing 10 and 20 wt% of (CA04 + CS04) are 40.59 and 51.19 MPa, respectively. The average pore diameters of geopolymer cements containing 0, 10 and 20 wt% of CA04 are 11.80, 10.10, 12.20 nm, respectively. Whereas the one containing 20 wt% of (CA04 + CS04) is 10.80 nm. It appears that geopolymer cement with 10 wt% of CA04 and 20 wt% of (CA04 + CS04) have higher compressive strengths and lower average pore diameters. It was found that 10 and 20 wt% of CA04 and (CA04 + CS04), respectively, could be used as additives for the preparation of geopolymer cements with higher strength development.

KW - Bauxite

KW - Calcium aluminate hydrate

KW - Eggshell

KW - Geopolymer cements

KW - Metakaolin

KW - Rice husk ash

UR - http://www.scopus.com/inward/record.url?scp=85101954869&partnerID=8YFLogxK

U2 - 10.1016/j.matchemphys.2021.124459

DO - 10.1016/j.matchemphys.2021.124459

M3 - Article

AN - SCOPUS:85101954869

VL - 264

JO - Materials chemistry and physics

JF - Materials chemistry and physics

SN - 0254-0584

M1 - 124459

ER -