Chemically treated groundnut shell fibers for enhanced mechanical and blast performance of concrete.

Groundnut shell fiber, an agricultural byproduct rich in cellulose and lignin, offers potential as a sustainable reinforcement in high-performance concrete. This study investigates the effect of chemically treated groundnut shell fibers on the mechanical and blast performance of fiber-reinforced concrete (FRC). Fibers were subjected to alkali, silane, and acetylation treatments, followed by characterization through tensile testing, FTIR, and XRD analyses to evaluate structural and chemical modifications. The results demonstrated that NaOH treatment enhanced tensile strength and modulus of elasticity due to improved crystallinity and reduced fiber diameter. Concrete specimens incorporating fibers at varying dosages (0.5%, 1.0%, and 1.5% by weight of cement) were prepared and tested for compressive, split tensile, and flexural strengths. Findings revealed that untreated and pretreated fibers generally reduced strength, while post-treated fibers improved performance at optimized levels. The best outcomes were achieved at 0.5% post-treated fiber, showing approximately 10-11% improvement in compressive and tensile strengths compared to the control mix, with flexural strength optimized at 1.0%. Beyond these levels, fiber addition reduced performance due to poor dispersion and higher water absorption. Finite element blast simulations further indicated that treated fiber-reinforced panels exhibited improved stress distribution and reduced localized deformation compared to conventional concrete. Overall, the study highlights that chemically treated groundnut shell fibers can enhance the toughness and energy absorption capacity of concrete when used at optimum proportions. However, the blast resistance results are based on numerical modeling, and further large-scale experimental validation is required before structural application in high-impact environments.