Utilizing crushed Choerospondias Axillaris seeds as a sustainable alternative to natural aggregate in concrete

The waste management of Choerospondias Axillaries Seed (CAS), originating from forests, markets, and factories, is a growing concern in Nepal. To address this, CAS was crushed and used in M20 concrete (water-to-cement ratio = 0.445 and cement: sand: coarse aggregate = 1: 1.363: 2.171) as a replacement for natural coarse aggregate (NCA) at varying proportions. The results showed a decrease in workability, density, and strengths with increasing water absorption as CAS replaced NCA. The 28-day compressive strength decreased by 4.4 %, 11.2 %, 28.4 %, 42.8 %, and 53.1 % at replacement levels of 0 %, 20 %, 40 %, 60 %, 80 %, and 100 %, respectively. The study suggests that up to 20 % CAS replacement can achieve the same concrete grade, with acceptable workability, flexural and tensile strengths, and water absorption. Higher replacement levels can be used for low-grade or non-structural concrete, contributing to CAS waste management and reducing NCA consumption, thus promoting sustainability and preventing environmental degradation.