Effect of recycled concrete fine powder after calcination on the properties of autoclaved aerated concrete

Autor: Yang Deng, Li Wu
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Case Studies in Construction Materials, Vol 20, Iss , Pp e02961- (2024)
Druh dokumentu: article
ISSN: 2214-5095
DOI: 10.1016/j.cscm.2024.e02961
Popis: The recycled concrete fine powder (RFP) after calcination activation not only contains active powder with potential hydration characteristics, but also may cause the limestone contained in the fine powder to form calcium oxide. The effects of TRFP-750 and TRFP-850(RFP calcined at 750 ℃ and 850 ℃) replacing calcium oxide on the preparation and properties of autoclaved aerated concrete (AAC) were investigated in this study. The results showed that when 60% of calcium oxide in quicklime is replaced by TRFP-750 and TRFP-850, AAC with strength greater than 2.5 MPa and density less than 550 kg/m3 can be prepared. The dosage of TRFP will degrade the gas-foaming performance of AAC due to the decrease in temperature and alkalinity of the slurry. At the same content, AAC with TRFP-850 had higher gas-foaming rate due to more free calcium oxide. When the TRFP content is the same, TRFP-850 also leads to a higher compressive strength than the AAC containing TRFP-750. Tobermorite with better crystallinity and the increase of tobermorite content are the main reasons for the higher strength of AAC.
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