Turning sandstone clay into supplementary cementitious material: activation and pozzolanic reactivity evaluation

Cao, Yubin and Wang, Yanru and Zhang, Zuhua and Ma, Yuwei and Wang, Hao (2021) Turning sandstone clay into supplementary cementitious material: activation and pozzolanic reactivity evaluation. Composites Part B: Engineering, 223:109137. pp. 1-12. ISSN 1359-8368


Abstract

The present paper explores the methods of transforming low grade kaolinitic clay, sandstone clay, into supplementary cementitious material (SCM). The sandstone clay is the waste product in the sand manufacturing from sandstone mineral. Thermal calcination at 600–900 °C was applied to activate the initial sandstone clay. Microstructure characterization was then carried out on the obtained activated sandstone clays (ASCs) to study the microstructure and chemical changes during the thermal activation. The pozzolanic reactivity of ASCs were assessed by direct methods (isothermal calorimetry test and lime consumption test) and indirect method (strength measurement of ASC blended mortar). The compressive strength of the ASCs blended cement based mortar showed that ASCs possessed high pozzolanic reactivity through the dehydroxylation and the alternation of Al and Si coordination environments during thermal activation. Agglomeration occurred after the sandstone clay calcination, however the particle size was reduced. Even at a short time calcination for 1 h, the pozzolanic reactivity of ASCs improved as the calcination temperature increased from 600 to 900 °C. Mortar strength test results confirmed that the ASCs with a fineness similar to OPC, can be used as high quality SCMs. Further isothermal calorimetry results indicated that ASCs not only contributed to pozzolanic reaction but also had a good filler effect in the early hydration stage due to the existence of micro-quartz.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 17 Jan 2022 23:24
Last Modified: 19 Jan 2022 02:32
Uncontrolled Keywords: Dehydroxylation; Kaolinitic sandstone clay; Lime consumption; Mortar strength test; Pozzolanic reactivity; Supplementary cementitious material; Thermal activation
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
Fields of Research (2020): 40 ENGINEERING > 4005 Civil engineering > 400505 Construction materials
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9699 Other Environment > 969999 Environment not elsewhere classified
Socio-Economic Objectives (2020): 18 ENVIRONMENTAL MANAGEMENT > 1899 Other environmental management > 189999 Other environmental management not elsewhere classified
Identification Number or DOI: https://doi.org/10.1016/j.compositesb.2021.109137
URI: http://eprints.usq.edu.au/id/eprint/45492

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