THE IMPACT OF CENTRIFUGATION ON THE DURABILITY OF REINFORCED CONCRETE

Abstract

The durability of reinforced concrete structures is a critical factor in ensuring the safety and reliability of infrastructure, primarily determined by its resistance to reinforcement corrosion and environmental degradation. This article investigates the impact of the centrifugation manufacturing process on the long-term performance of concrete poles in Lithuania's electrical grid. The research employs a comparative analysis of spun-cast (centrifuged) and vibrated concrete structures with service lives ranging from 3 to 52 years. Research methods include visual inspection, crack width measurement, and non-destructive testing of compressive strength using the Schmidt hammer (rebound index) according to LST EN 12504-2. The results indicate that the centrifugation process creates a high-density concrete matrix with a lower water-to-cement (W/C) ratio, particularly in the outer protective layer. Findings show that centrifuged poles exhibit significantly higher durability, maintaining an average compressive strength of 37,45 MPa after 52 years, compared to 31,38 MPa for vibrated concrete after 50 years. Furthermore, centrifuged structures showed high resistance to carbonation and only minor longitudinal micro-cracks (<0.02 mm), whereas vibrated structures displayed advanced degradation and reinforcement exposure. The study concludes that the unique structural density achieved through centrifugation ensures superior reliability and a residual service life exceeding standard design projections.