MECHANICAL PROPERTIES OF CONCRETE MODIFIED WITH SODOM APPLE SAP (CALOTROPIS PROCERA) AS AN ADMIXTURE

This study investigates the strength and durability performance of concrete made with Sodom apple sap (Calotropis procera) as an admixture. The need for affordable and locally available admixtures in developing countries has prompted interest in bio-based alternatives in improving concrete properties. Using a Central Composite Design (CCD), the effects of water–cement ratio (0.45–0.55) and sap dosage (0.5–1.5%) on fresh and hardened properties of C25/30 concrete were evaluated. Tests conducted includes compressive strength, flexural strength, splitting tensile strength, density, and microstructure using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) Results show that optimal sap dosages (1.0%) improved density (23.85–24.45 kg/m³), compressive strength (up to 52 N/mm² at 90 days), flexural strength (up to 5.4 N/mm²), and tensile strength (up to 3.1 N/mm²). Over-dosage and high water–cement ratios slightly reduced performance due to increased organic interference in hydration. Findings from this study show that, Sodom apple sap is a strong potential as a sustainable and cost-effective admixture that enhances later-age strength and microstructural refinement. Findings support its suitability for structural concrete applications in line with Eurocode requirements.