Effect of strength grade on durability of concrete

Abstract

This study investigates the relationship between concrete strength grade and durability. Four concrete mixtures were proportioned with water-to-binder (W/B) ratios of 0.45, 0.50, 0.55, and 0.60, while a superplasticizer was used to achieve comparable workability among the mixtures. The properties of the concrete samples such as slump, compressive strength, water absorption, drying shrinkage, chloride ion penetration resistance, and ultrasonic pulse velocity (UPV) were evaluated in accordance with the relevant testing standards. The experimental results show that an increase in the W/B ratio resulted in a significant reduction in compressive strength, accompanied by increases in water absorption, drying shrinkage, and chloride ion penetration. In contrast, the UPV decreased with increasing W/B ratio, indicating a reduction in the compactness and integrity of the concrete microstructure. Correlation analysis revealed a clear inverse relationship between compressive strength and the evaluated durability indicators. The findings provide valuable experimental evidence for optimizing the W/B ratio to achieve a balanced performance in terms of both mechanical strength and long-term durability, thereby supporting the design and production of durable concrete structures.