Friction Behavior of PTFE Bridge Bearing Pads at Extreme Temperatures

Bridge structures are exposed to natural outdoor environments all year round, and bearing pads need to work stably in extreme high-temperature and extreme low-temperature environments. Temperature change has a decisive impact on the friction behavior of bridge bearing pads, and the fluctuation of friction coefficient will directly affect the displacement coordination, stress distribution and structural stability of bridge structures. Traditional bridge bearing materials have extremely unstable friction performance under extreme temperature conditions: rubber bearings harden and have increased friction at low temperatures, soften and creep at high temperatures, while plastic bearings are brittle and cracked at low temperatures and deformed at high temperatures, which seriously affects the normal operation of bridges. PTFE bridge bearing pads have extremely stable friction behavior in extreme temperature environments, which solves the industry problem of temperature-sensitive friction performance of traditional bearings PTFE SHEET.

In extreme high-temperature environments, the friction behavior of PTFE bridge bearing pads shows excellent stability. In summer high-temperature seasons, the surface temperature of bridge structures can reach more than 60°C, and the local temperature of bearing pads in closed structural space is higher. Most polymer materials will have decreased hardness, increased plasticity and increased friction coefficient under high-temperature conditions, resulting in unsmooth bridge sliding displacement and structural stress accumulation. High-purity PTFE materials maintain stable molecular structure and surface friction characteristics below 260°C, with no obvious change in friction coefficient, no thermal softening and no viscous friction failure. The stable high-temperature friction behavior ensures that the bridge can freely complete thermal expansion displacement in high-temperature environments and release structural internal stress in time.

In extreme low-temperature environments, PTFE bearing pads still maintain excellent flexible friction performance. In alpine regions and winter low-temperature weather, the ambient temperature can drop to minus tens of degrees Celsius. Traditional bearing materials are prone to low-temperature embrittlement, surface hardening and sharp increase of friction resistance, resulting in difficult bridge contraction displacement, structural cracking and bearing damage. PTFE materials have excellent low-temperature toughness, and will not brittle and crack at -200°C. The ultra-low temperature adaptive friction performance ensures that PTFE TUBE and sheet bearing components can still maintain flexible sliding and stable friction coefficient in extreme low-temperature environments, meeting the displacement coordination needs of bridge low-temperature contraction.

Professional extreme temperature friction test data shows that the friction coefficient fluctuation range of PTFE bridge bearing pads in the full temperature range of -180°C to 260°C is less than 5%, which is far lower than the 30% fluctuation range of traditional rubber and plastic bearings. This ultra-stable friction behavior enables PTFE bearings to adapt to global regional climate differences, whether it is high-temperature tropical regions, temperate seasonal temperature alternating regions or frigid alpine regions, they can maintain consistent working performance.

The stable extreme temperature friction behavior of PTFE bridge bearing pads greatly improves the environmental adaptability and operational reliability of bridge structures. It avoids various structural diseases caused by friction performance failure of bearings under extreme temperatures, such as bridge deck cracking, beam end damage, support compression deformation and structural residual stress. It provides a reliable technical guarantee for the long-term safe operation of bridge projects in complex climate environments and has become an important technical advantage of modern high-quality bridge bearing systems.