The Load-Bearing Efficiency of Reinforced Concrete Bridge Structures Strengthened with Fiber Reinforced Polymer (FRP)

Abstract

Due to increasing economic and social development, there is a rising demand for transportation infrastructure. At the same time, many existing bridges have been in service for decades and now require strengthening and rehabilitation to ensure structural safety and performance. This study focuses on evaluating the load-carrying capacity of bridges through full-scale bridge load testing to determine their dynamic characteristics and structural responses before and after strengthening. Carbon Fiber Reinforced Polymer (CFRP) and Aramid Fiber Reinforced Polymer (AFRP) materials are applied to enhance the structural performance of the bridges. The selected bridge types are Plank Girder and Slab-on-Girder systems, which are commonly used in Thailand. Sensors such as displacement transducers, strain gauges, and accelerometers are installed to measure deflection, strain, and vibration responses. The results indicate that structural strengthening significantly reduces overall strain and deflection in the bridges. In terms of dynamic performance, the natural frequencies of the bridges remain nearly unchanged, suggesting that the strengthening does not negatively affect structural stability. The use of CFRP and AFRP sheets improves the distribution of bending moments and enhances the loadbearing capacity of the structures. These findings confirm the effectiveness of fiber-reinforced polymer materials in improving bridge performance without compromising their stability.