Influence of Environmental Factors and Aggregates on Concrete Elasticity: Ultrasonic and Strength Testing

Abstract

This study investigates the effects of recycled aggregates (RAs), temperature, humidity, and freeze–thaw cycles on the modulus of elasticity in concrete, using a comparative approach between ultrasonic pulse velocity (UPV) and compressive strength tests. A range of RA proportions (0%, 25%, 50%, 75%, and 100%) was explored. These mixes were subjected to environmental conditions, including temperatures of 25, 0, and −18°C in both dry and wet states, to assess their impact on the mechanical properties of concrete rigorously. The findings reveal that the modulus of elasticity decreases by up to 35% with higher recycled content and more severe environmental exposure, with significant variations observed under different temperatures (25, 0, and −18°C) and moisture conditions. Notably, samples with 25% recycled content maintained higher elasticity, suggesting an optimal threshold for incorporating recycled materials. The study also validates using UPV as a nondestructive method to efficiently evaluate concrete’s structural integrity. These insights advocate for the tailored use of RA concrete (RAC) in construction, enhancing durability and sustainability in varying climatic conditions. This research contributes to the development of concrete formulations that are both durable and environmentally adaptive, promoting sustainable construction practices.