Phosphate-based geopolymer: Influence of municipal solid waste fly ash introduction on structure and compressive strength

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F23%3A00570921" target="_blank" >RIV/68378297:_____/23:00570921 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1016/j.ceramint.2023.04.042" target="_blank" >https://doi.org/10.1016/j.ceramint.2023.04.042</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ceramint.2023.04.042" target="_blank" >10.1016/j.ceramint.2023.04.042</a>

Result language

angličtina

Original language name

Phosphate-based geopolymer: Influence of municipal solid waste fly ash introduction on structure and compressive strength

Original language description

Materials resulting from incorporation of solid waste incineration fly ash into phosphate-based geopolymers, to partially replace metakaolin (up to 50% wt), were studied. X-ray diffraction, scanning electron microscopy, solidstate nuclear magnetic resonance spectroscopy and infrared spectroscopy were adopted to describe the mineralogical changes and the structural modifications of the geopolymer networks which impacted on the mechanical performance (compressive strength) of the materials. The results indicated that fly ash displays a different reactivity compared with metakaolin, behaving preferentially as a source of alkali that compete with the aluminosilicate metakaolin fraction by precipitating crystalline and amorphous phosphates. At 10 wt% of metakaolin substitution with fly ash, the extent and reticulation of the amorphous geopolymer matrix is preserved, and the mechanical properties are retained. At higher waste content (30–50% wt), the fast kinetics of the acid-base reactions involving the fly ash reactive phases prevail over the metakaolin dealumination, and the nature of the material shifts to an alkali-phosphate cement/phosphate-geopolymer composite. This behaviour, together with the development of porosity and presence of low-strength phases in the ash, led to a decline in the mechanical performance with increasing amount of substitution. All in all, this work provides fundamental information in the direction of a sustainable employment of phosphate-based geopolymers, which is limited by the relatively high cost of both metakaolin and phosphoric acid. Moreover, it indicates a recycling opportunity for this type of fly ash.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20501 - Materials engineering

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Ceramics International

ISSN

0272-8842

e-ISSN

1873-3956

Volume of the periodical

49

Issue of the periodical within the volume

13

Country of publishing house

GB - UNITED KINGDOM

Number of pages

11

Pages from-to

22149-22159

UT code for WoS article

001013288300001

EID of the result in the Scopus database

2-s2.0-85152418728