Arandara, et al (2024) Evaluation of coconut shell biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More on recycled aggregate concrete through petrographic studies. Construction and Building Materials. https://doi.org/10.1016/j.conbuildmat.2024.136342

In a recent study published in the journal Construction and Building Materials, researchers explored the effectiveness of Coconut Shell Biochar (CSB) in mitigating the Alkali-Silica Reaction (ASR) in Recycled Aggregate Concrete (RAC). This reaction is a significant concern in concrete recycling, where the interaction of alkalis from cement and reactive silica from aggregates can lead to structural damage.

The study focuses on tropical regions like Sri Lanka, where the availability of coconut shells makes CSB a cost-effective and sustainable option. Researchers conducted petrographic analyses, which include microscopic examinations and Scanning Electron Microscopy (SEM) observations, to understand the interactions within CSB-modified RAC.

Their findings suggest promising outcomes for using CSB in concrete. For instance, concrete samples containing CSB showed improved mechanical properties, such as compressive strength (25.4 MPa), split-tensile strength (2.5 MPa), and flexural strength (4.1 MPa) after 28 days. These enhancements indicate that CSB can effectively reduce the detrimental alterations and chemical reactions typically associated with ASR.

The incorporation of CSB not only helps in controlling specific chemical reactions but also in adsorbing secondary materials, particularly finer particles of biochar showing high potential. This use of biochar aligns with circular economic models in the construction industry, which aim to reduce the use of virgin materials and decrease the environmental impact of building activities.

This study marks a significant step towards sustainable construction practices, highlighting the potential of biochar as a viable solution to one of the industry’s pressing challenges. Further research could provide deeper insights into optimizing CSB content in concrete mixtures to fully harness its benefits.