New coal char-based bricks: Effects of curing temperature, humidity, pressing pressure, and addition of superplasticizer on the physical, mechanical, and thermal properties

Journal Article · 04 October 2023 · Case Studies in Construction Materials

DOI: https://doi.org/10.1016/j.cscm.2023.e02529 · OSTI ID:2279157

Yu, Hua ^[1]; Ng, Kam  ^[1]; Lau, Chooikim ^[1]

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1. University of Wyoming, Laramie, WY (United States)

Coal char, as a sustainable and eco-friendly material, holds significant potential for use in new construction materials, specifically, coal char-based bricks. This study employed the pre-pressing method to create char bricks containing high char content of 70%. The impact of various curing temperatures (20, 40, 60 °C), humidity levels (15% and 90%), and pressing pressures (3.5, 7, and 10 MPa) on the density, X-ray diffraction, compressive strength, and thermal conductivity of char-based samples were examined. The addition of superplasticizer and the performance of char bricks were assessed by comparing them to traditional clay bricks and corresponding standards. The study discovers that the temperature of 40 °C enhances the early 7-day strength of char brick samples, while the highest 28-day strength is observed in char bricks at a temperature of 20 °C and humidity of 90%. Compared to conventional clay bricks (with density of 1.9 g/cm3, thermal conductivity of 0.39-0.63 W/mK, compressive strength of 10-20 MPa), the proposed char bricks exhibit lower density (~0.8 g/cm³), lower thermal conductivity (0.26-0.35 W/mK), and good performance in compressive strength (up to 15 MPa). Lastly, coal char-based bricks with high char content demonstrate significant advantages over traditional clay bricks, making them a sustainable and environmentally friendly building material option.

• Research Organization: Univ. of Wyoming, Laramie, WY (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy and Carbon Management (FECM)
• Grant/Contract Number: FE0031996
• OSTI ID: 2279157
• Journal Information: Case Studies in Construction Materials, Vol. 19; ISSN 2214-5095
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English