TY - JOUR

T1 - Semi-Adiabatic Calorimetry to Determine the Temperature and the Time of the Formation of Faujasite and Geopolymer Gels in the Composites Prepared at Room Temperature and the Investigation of the Properties of the Hardened Composites

AU - Tchakouté, Hervé K.

AU - Melele, Sorelle J.K.

AU - Nanseu-Njiki, C. P.

AU - Rüscher, Claus H.

N1 - Funding Information: Dr. Hervé Tchakouté Kouamo gratefully acknowledges the Alexander von Humboldt-Stiftung for financial support this work under the grant N° KAM/1155741 GFHERMES-P .

PY - 2022/6

Y1 - 2022/6

N2 - This study seeks to investigate the time and the temperature of the formation of the composites faujasite-geopolymer gels in the reaction medium, and also study the compressive strengths and the microstructural properties of the hardened composites after curing at room temperature. Sodium waterglass from rice husk ash, incandescent and fluorescent bulbs known as low-value silica-rich wastes were used as hardeners for the preparation of the composites at room temperature. The X-ray patterns of the composites using sodium waterglass from incandescent and fluorescent bulbs indicate the reflection peaks of faujasite-Na and the broad hump structure belonging to the geopolymer networks. Whereas the one using sodium waterglass from rice husk ash shows only the broad hump structure. The semi-adiabatic results show that geopolymer gels are formed after 18 min at the temperature of the reaction medium of 38 °C in the composites when sodium waterglass from rice husk ash was used as a hardener. Whereas they are formed after 10 min at the temperature of the reaction medium of 34 and 43 °C in the composites using sodium waterglass from incandescent and fluorescent bulbs, respectively. Zeolite type faujasite-Na is formed after 72 and 40 min at the temperature of the system at 76 and 90 °C in the composites using sodium waterglass from incandescent and fluorescent bulbs, respectively. The increase in the temperature of the reaction medium leads to the crystallization of faujasite. The compressive strengths of the hardened composites using sodium waterglass from rice husk ash is higher (47.54 MPa) compared to those from the incandescent bulb (22.42 MPa) and the fluorescent bulb (12.53 MPa). It was found that faujasite-geopolymer composites could be obtained at non-hydrothermal condition using sodium waterglass from incandescent and fluorescent bulbs. It appears that the formation of faujasite in the structure of geopolymer cements decreases the compressive strength of the composites.

AB - This study seeks to investigate the time and the temperature of the formation of the composites faujasite-geopolymer gels in the reaction medium, and also study the compressive strengths and the microstructural properties of the hardened composites after curing at room temperature. Sodium waterglass from rice husk ash, incandescent and fluorescent bulbs known as low-value silica-rich wastes were used as hardeners for the preparation of the composites at room temperature. The X-ray patterns of the composites using sodium waterglass from incandescent and fluorescent bulbs indicate the reflection peaks of faujasite-Na and the broad hump structure belonging to the geopolymer networks. Whereas the one using sodium waterglass from rice husk ash shows only the broad hump structure. The semi-adiabatic results show that geopolymer gels are formed after 18 min at the temperature of the reaction medium of 38 °C in the composites when sodium waterglass from rice husk ash was used as a hardener. Whereas they are formed after 10 min at the temperature of the reaction medium of 34 and 43 °C in the composites using sodium waterglass from incandescent and fluorescent bulbs, respectively. Zeolite type faujasite-Na is formed after 72 and 40 min at the temperature of the system at 76 and 90 °C in the composites using sodium waterglass from incandescent and fluorescent bulbs, respectively. The increase in the temperature of the reaction medium leads to the crystallization of faujasite. The compressive strengths of the hardened composites using sodium waterglass from rice husk ash is higher (47.54 MPa) compared to those from the incandescent bulb (22.42 MPa) and the fluorescent bulb (12.53 MPa). It was found that faujasite-geopolymer composites could be obtained at non-hydrothermal condition using sodium waterglass from incandescent and fluorescent bulbs. It appears that the formation of faujasite in the structure of geopolymer cements decreases the compressive strength of the composites.

KW - Faujasite

KW - Fluorescent bulb

KW - Geopolymer materials

KW - Incandescent bulb

KW - Rice husk ash

KW - Semi-adiabatic

UR - http://www.scopus.com/inward/record.url?scp=85110810616&partnerID=8YFLogxK

U2 - 10.1007/s12633-021-01267-1

DO - 10.1007/s12633-021-01267-1

M3 - Article

AN - SCOPUS:85110810616

VL - 14

SP - 4669

EP - 4681

JO - Silicon

JF - Silicon

SN - 1876-990X

IS - 9

ER -