New Coal Char-Based Building Products: Manufacturing, Engineering Performance, and Techno-Economic Analysis for the USA Market

Abstract

Common building products, i.e., thin brick and stone veneer, add the look of brick walls or the enduring charm of natural stones into buildings and houses without imposing a substantial increase in structural load. This study investigates the mechanical strength, durability, and economic feasibility of producing innovative char-based thin bricks and stone veneers. The char-based thin brick vacuum treated with hydrophobic liquid exhibits water absorption rates within the 4–7% range, displays durability against 50 freeze–thaw (F-T) cycles, and maintains a saturation coefficient below 0.6. In contrast, commercial thin bricks have water absorption of 9–12%. Treated char-based stone veneer has water absorption of 5.3% and an average compressive strength of 19.2 MPa, maintains its structural integrity throughout 50 F-T cycles, and exhibits a negligible linear shrinkage of approximately 0.01%. In contrast, commercial stone veneers have water absorption of 10–16%. These engineering properties meet the criteria as per ASTM standards C1088 and C1670 for thin brick and stone veneer, respectively. A techno-economic study was preliminarily conducted to examine the potential cost efficiency and cash flow in manufacturing these char-based building products. The manufacturing cost of USD 25.83 is lower than the average market price of 64.65 USD/sq. m. for thin bricks. The manufacturing cost of USD 32.65 is lower than the average market price of 129.17 USD/sq. m. for stone veneers. These comparisons present a compelling economic advantage for their commercialization. This comprehensive study has demonstrated the advantages of sustainable char-based stone veneers and thin bricks regarding engineering performance and economic benefits.

New and Sustainable Coal Char-Based Paving Blocks for Roadway Applications

“…However, the requirement for water absorption can be barely achieved as the optimum mix design CH30-TL4 has a water absorption of 4.63% which is near 5%. The research studies conducted by Pandey et al [33] have shown char as a porous material and have a direct influence on increasing water absorption [33]. They reported water absorption in the range of 4-7% for treated samples in a mix design containing 40% char [33].…”

“…The research studies conducted by Pandey et al [33] have shown char as a porous material and have a direct influence on increasing water absorption [33]. They reported water absorption in the range of 4-7% for treated samples in a mix design containing 40% char [33]. So, paving blocks based on mix design CH30-T3 and CH30-TL3 can be used for light vehicular traffic areas.…”

“…Then dry mixing of these materials was carried out in a rotating mixer. Following the dry mixing, a predetermined quantity of water mixed with SP in a designated proportion was added to the dry mixture, and wet mixing was performed for another three minutes to obtain the blended mix as described by Pandey et al [33].…”

“…Yu et al [32] also showed the possibility of incorporating char alone without including natural aggregates in making high-strength bricks. Recently, Pandey et al [33] have shown the possibility of making char-based thin bricks and stone veneers with desired engineering properties, showcasing the economic feasibility of mass production. However, the feasibility of incorporating coal char into manufacturing paving blocks remains unknown and needs to be explored.…”

Ash Properties and Environmental Impact of Coal and Its Blend with Patent Fuel for Climate Sustainability

“…Coal ash and desulfurization gypsum are waste products of coal mines and coal-fired power plants. One possible solution is to use bottom ash and fly ash as a partial or complete substitute for natural aggregates [9,10]. These materials are obtained at a minimal cost and are byproducts of coal processing, which is a more sustainable alternative to the resource-intensive processes involved in mining and processing natural aggregates.…”