Carbon dioxide sequestration in mortars with excavated soil: Engineering performances and environmental benefits

Dwivedi, A and Gupta, S (2024) Carbon dioxide sequestration in mortars with excavated soil: Engineering performances and environmental benefits. In: Science of the Total Environment, 917 .

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Abstract

Globally, substantial volume of excavated soils is generated during construction and demolition activities, which can be utilized in the manufacturing stabilized earth-based construction materials. Furthermore, increasing amount of CO2 is being released into the environment from growing industrial operations that can sequestered in earth-based materials without compromising the engineering properties. This article attempts to explore the effect of CO2 sequestration through accelerated carbonation curing on engineering properties, micro-structure and phase composition of cement-lime stabilized soil mortars. Lateritic soil (clay content of 42 ) is used to replace 25 and 50 of natural sand by mass. The experimental findings demonstrate an increase in CO2 uptake by 15�23 and 33�40 due to addition of 25 and 50 soil respectively compared to control (0 soil). Precipitation of meta-stable calcium carbonates majorly contributes to the total CO2 uptake, accounting for 62�69 and 78�87 of the carbonates formed in 25 soil-mortars and 50 soil mortars. These are substantially higher compared to 40�50 in the case of control mixes. The mentioned finding is attributed to the formation of additional calcium-silicate-hydrate and calcium-aluminate-hydrate due to clay-lime reaction, that binds CO2 and precipitate meta-stable polymorphs of calcium carbonate. Addition of lime and carbon sequestration are found to substantially enhance 1-day strength of cement-soil and cement-lime-soil mortars by 31�36 , although no prominent effect at 7-day and 28-day marks are observed. Furthermore, capillary water absorption at 28-day age is reduced by 18�31 in lime-added cement-soil mortars compared to the ones without lime, that reduces moisture sensitivity of the mortars. Overall, the carbon sequestered mortars demonstrate satisfactory strength (20�37 MPa) and water absorption performance of the stabilized mortars for masonry applications, which will provide a promising means to manufacture low-carbon and more durable construction products. © 2024 Elsevier B.V.

Item Type:	Journal Article
Publication:	Science of the Total Environment
Publisher:	Elsevier B.V.
Additional Information:	The copyright for this article belongs toElsevier B.V.
Keywords:	Calcite; Calcium carbonate; Calcium silicate; Carbon dioxide; Carbonation; Hydrated lime; Hydrates; Hydration; Lime; Microstructure; Mortar; Precipitation (chemical); Silicate minerals; Sodium Aluminate; Soil cement; Soils, Carbon dioxide sequestration; Carbon sequestration; Cement-soil mortars; CO 2 uptake; Earth-based material; Engineering performance; Engineering properties; Meta-stable; Performance benefits; Soil engineering, Compressive strength, calcium carbonate; calcium oxide; calcium silicate; carbon dioxide; carbonic acid derivative, carbon dioxide; carbon sequestration; compressive strength; engineering; environmental impact; microstructure; mortar; soil, Article; carbon sequestration; chemical composition; compressive strength; controlled study; moisture; physical chemistry; porosity; precipitation; sand; soil analysis; structure analysis; water absorption; X ray diffraction
Department/Centre:	Division of Mechanical Sciences > Centre for Sustainable Technologies (formerly ASTRA)
Date Deposited:	04 Mar 2024 06:09
Last Modified:	04 Mar 2024 06:09
URI:	https://eprints.iisc.ac.in/id/eprint/84140

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