20.500.12556/DiRROS-21107 Rapid immobilisation of chemical reactions in alkali-activated materials using solely microwave irradiation Efflorescence, a time-dependent and water-driven phenomenon, is a major concern inalkali-activated materials (AAMs), impacting their practical use and preservation in a time-frozen state for post-characterisation. Although a method for stopping chemical reactions in conventional cements exists, it is time-consuming and not chemical-free. Therefore, this study explored the effects of low-power microwave-induced dehydration on efflorescence, mechanical performance, and structural integrity in AAMs, to create an alternative and more “user-friendly” dehydration method. For this purpose, several mixtures based on secondary raw (slag, fly ash, glass wool, and rock wool) and non-waste (metakaolin) materials were activated with a commercial Na-silicate solution in ratios that promoted or prevented efflorescence. Characterisation techniques, including Fourier-transform infrared spectroscopy and X-ray diffraction, showed that microwave dehydration effectively removed water without altering crystallinity, while mercury intrusion porosimetry and compressive strength tests confirmed increased porosity. In addition to being an efficient, time-saving, and solvent-free manner of stopping the reactions in AAMs, microwave irradiation emerged as an innovative, chemical-free method for evaluating curing finalisation and engineering foams in a stage when all other existing methods fail. However, the artificially provoked efflorescence in aged dehydrated AAMs connected the slipperiness of AAM with the instant extraction of Na, which raised the need for further research into alternative alkali replacements to evaluate the practical use of AAM. materials chemistry alkali-activated materials geopolymers slag fly ash rock wool glass wool metakaolin microwave irradiation dehydration stopping chemical reactions efflorescence kemija materialov alkalijsko aktivirani materiali geopolimeri žlindra elektrofiltrski pepel kamena volna steklena volna metakaolin mikrovalovno obsevanje dehidracija zaustavljanje kemijskih reakcij rast soli true false true MDPI AG Angleški jezik Slovenski jezik © 2024 by the authors. Neznano 2024-12-23 11:02:22 2024-12-23 11:18:21 2024-12-24 03:35:46 0000-00-00 00:00:00 2024 0 0 str. 1-30 iss. 12, [article no.] 1219 Vol. 14 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2024-11-29 54 2075-163X 10.3390/min14121219 217643779 https://www.mdpi.com/2075-163X/14/12/1219 1 020d377e-c115-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=29919 http://hdl.handle.net/20.500.12556/DiRROS-20199 1 035ef49b-c115-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=29920 RAZ_Tesovnik_Anze_2024.pdf RAZ_Tesovnik_Anze_2024.pdf 1 C8BB23FE3A42B17D8F776F1631CCEB80 31104b01e57ca969d4fcf363f319b15475fcdafaa6f0efe085aff4cfce7d64df 2df0692b-c117-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=29921 Zavod za gradbeništvo Slovenije Dehydration with microwave irradiation 0 0 0