ASSESSMENT OF CURING TECHNIQUES FOR GRANITE/GRAVEL COMPOSITE TO ENHANCE STRUCTURAL STRENGTH AND DURABILITY IN CONSTRUCTION

Abstract

Concrete remains the most widely used construction material, yet its performance is significantly influenced by aggregate type and curing technique. This study investigated the effects of varying granite–gravel combinations on the compressive strength and durability of concrete, with a focus on optimizing curing practices. The experimental process involved sieve analysis, water absorption tests, and preparation of concrete mixes incorporating granite and gravel in ratios ranging from 100/0 to 50/50 at a 1:2:4 mix proportion. Curing was carried out using air, water, and membrane methods, followed by compressive strength testing at 7, 14, and 28 days. Durability performance was assessed by immersing samples in saline solution (2.5% NaCl) for 28 and 56 days to simulate aggressive environments. Data were presented through comparative graphs and trend analysis across curing ages and methods. Results showed that increasing gravel content consistently reduced compressive strength, though mixes containing 10–20% gravel replacement still satisfied BS 8110 requirements for mass concrete ($≥15\text{ N/mm}^2$). Water curing produced the highest compressive strengths, followed by membrane curing, with air curing yielding the lowest results due to limited hydration across the curing ages. In NaCl environments, concrete gained early-age strength up to 28 days but declined at 56 days, indicating reduced long-term durability under saline exposure. In conclusion, it is recommended that granite–gravel blends not exceed 20% gravel replacement for structural use, and that water curing be adopted where possible to achieve optimal strength and durability.