Mechanical and Microstructure Properties of Biochar-Based Mortar: An Internal Curing Agent for PCC

Abstract

In pursuing sustainability targets, the construction industry has witnessed significant efforts exerted on exploring new alternatives for raw materials. Such initiatives aim to alleviate concerns of overexploitation of natural resources leading to their depletion. On a different note, the disposal of municipal solid waste (MSW) has also become a major concern in some countries, such as the case of Lebanon, where illegal dumping continues to take its toll on the environment. Pyrolysis has been introduced as a biomass decomposition process of MSW and is considered an environmentally friendly process that can mitigate open dumping. However, pyrolysis produces significant amounts of biochar as a byproduct that in turn needs to be disposed of or treated. This research aims to investigate the viability of using biochar as a sustainable alternative material to sand in cementitious mortar composites. A thorough microscale physicochemical characterization of the biochar is conducted prior to its inclusion in mortar. Then, its incorporation as a partial replacement of sand in mortar is assessed at the mesoscale level, based on performance indices that included compressive strength and microstructure properties. Analysis of the experimental results are used to provide guidelines and recommendations as to the effective incorporation of biochar fraction in cementitious mortar.

Shielding Properties of Cement Composites Filled with Commercial Biochar

“…This behavior is similar to other cement composites [34]. The different behavior in terms of the frequency of the biochar composites with respect to plain cement composites can be attributed to the presence of entrapped water in the biochar [35].…”

Recent advancements in the use of biochar for cementitious applications: A review

“…The main rea son for this po si tion is that, based on some of the re viewed stud ies, biochar has some ma jor promis ing attrib utes for its adop tion as an ad mix ture in ce men ti tious ma te ri als. These in clude en hanced chem i cal sta bil ity, low con duc tiv ity, lim ited flam ma bil ity [ 88 ] as an in ter nal cur ing agent [ 89 ] and be cause of its car bon cap ture and stor age po ten tial.…”

Multifunctional Lightweight Mortars for Indoor Applications to Improve Comfort and Health of Occupants: Thermal Properties and Photocatalytic Efficiency

“…In this case, even though activated carbon is more porous, lighter, and therefore less mechanical resistant than sand, the mechanical strength of mortars is even greater than that of sand-based mortars, probably thanks to its surface roughness which improves the adhesion with the binder paste, guaranteeing an interlocking mechanism. This behavior was detected in other carbon-based materials with a porous surface that, acting as reservoirs, were able to provide a migration of water from their inside to the surrounding binder paste during the curing period, guaranteeing an optimum ITZ (Mrad and Chehab, 2019).…”