Effect of Bamboo Biochar as a Supplementary Cement on the Mechanical Properties of Concrete

Abstract

Bamboo processing industries produce a significant amount of waste mainly in the form of lignocellulosic materials. Much of this waste remains underutilised and is often disposed of through open burning or landfilling, placing unnecessary strain on the environment. At the same time, cement-based materials are among the largest contributors to carbon emissions due to their energy-intensive production processes. Given the prominence of Gigantochloa scortechinii as a commercial bamboo species in Malaysia and across ASEAN countries, this study explores the potential use of biochar derived from this species and assesses its influence on both short-term and long-term mechanical properties of biochar-enhanced composites, with the aim of reducing carbon emissions and industrial waste. In this study, bamboo biochar produced from Gigantochloa scortechinii sourced from Tadom Hill Resorts was ground and incorporated into concrete mixtures. Seven different mixes were prepared: one control mix without biochar and six mixes containing between 5 wt% and 10 wt% biochar. The results indicated that the mix with 9 wt% biochar delivered the best performance, achieving a 7% increase in compressive strength and a 47% increase in flexural strength after 7 days of curing. At 28 days, the 9 wt% mixture remained optimal, recording a compressive strength of 30.88 N/mm2 and a flexural strength of 14.8 kN/mm2.