Experimental investigation on mechanical and aging properties of novel high durability NR/EPDM blended rubber bearings

The durability of rubber materials is a critical factor influencing the long-term service performance of rubber bearings, and blending technology has been scientifically validated as an effective approach to significantly enhance the comprehensive performance characteristics of these materials. Plate rubber bearings are extensively utilized in bridge engineering, where durability issues are particularly prominent, leading to increased lifecycle costs of the bridge. To address this, the present study designed 10 distinct rubber blends by combining natural rubber (NR), known for its superior mechanical properties, with ethylene propylene diene monomer (EPDM) rubber, which exhibits excellent aging resistance. Through systematic testing of tensile strength, elongation, thermal aging resistance, and ozone aging resistance, three formulations—NR, NR/EPDM 8:2, and NR/EPDM 6:4—were selected for further evaluation. These formulations were used to fabricate 6 scaled and 15 full-scale rubber bearings, which subsequently underwent a series of rigorous experimental tests. The results demonstrate that the high-durability plate rubber bearings exhibit a shear modulus change rate less than 10 % after 72 h of accelerated aging at 100°C, and show no cracking after 336 h of exposure to high-concentration ozone (300 pphm). This study highlights the potential of blending technology to develop advanced rubber materials with enhanced performance for critical engineering applications.