Harnessing the bio-structure of corncobs: connecting morphology to mechanical attributes for sustainable building materials

The escalating global emphasis on sustainable construction and renewable materials has highlighted agricultural waste valorization as a critical research domain, particularly in response to the climate emergency. As the construction industry seeks alternative ecofriendly materials to mitigate environmental impact and expand affordable housing solutions, there is a pressing need to explore and evaluate suitable biomass resources in greater depth. Among these, corncob (CC) emerges as a significantly underutilized material with considerable potential for sustainable applications. Despite its abundance and promising properties, systematic understanding of the composition–structure–function relationships within CC anatomical fractions remains limited, impeding its optimal utilization in building and construction. This study employs a multi-analytical approach to investigate the intricate correlations between CC morphology, mechanical attributes, and chemical composition to establish its viability as a sustainable building material (SBM). The methodology integrated microscopic analysis (SEM–EDS), mechanical characterization, and chemical assays. Microscopy reveals differentiated ultrastructure that collectively confer balanced strength–ductility attributes. Elemental mapping demonstrated predominant carbon (64.73–67.74%) and oxygen (31.22–34.05%) composition, with strategic distributions of silicon (2.52%) and aluminum (0.69%) contributing to mechanical properties. Mechanical testing showed compressive strength (67.6 MPa) attributable to the lignocellulosic reinforcement grid resisting fractures. Comparatively, tensile testing indicates elasticity (Young’s modulus 191.19 MPa), exceeding most agricultural residues resulting from interfibrillar sliding mechanisms accommodating strains. Chemical analysis revealed optimal lignocellulosic composition complemented by functional additives (1% pectin, 4.21% resistant starch). Integrated morphological and mechanical characterization coupled with compositional mapping and the preliminary life cycle assessment substantiate cob waste as an economical bio-based substitute for mainstream building insulation, 3D printing, carbon sequestering, structural, and non-structural applications. The multi-level examination provides understanding of structure–function influences to direct processing interventions for customized material properties.