Highway bridges in coastal areas are seriously affected by the marine environment, while most of the existing test methods for bridge-reinforced concrete beams considering both corrosion and fatigue factors are carried out in an alternating manner, which cannot reflect the actual service conditions of the bridge structure. This paper focuses on an experimental study of the coupled influence of reinforcement corrosion and fatigue loading in reinforced concrete T-shaped beams. A novel loading test device that can realize the corrosion–fatigue coupling effect is designed, and then six reinforced concrete T-shaped beams are fabricated and tested. For the corrosion–fatigue coupling test beams, the variation law of beam cracks, failure modes, steel strain development law, load-deflection relationship, and fatigue life are analyzed and compared with that of the simple fatigue test beams. The test results show that the cracks of the test beam develop continuously with the fatigue loading times under the corrosion–fatigue coupling environment. The fatigue failure modes are all brittle fractures of the main steel bars, which present the shape of uneven oblique section tearing. The new testing device and approach can provide direct insights into the interaction of reinforcement corrosion and cyclic loading on the fatigue behavior of T-shaped RC beams, which can be further used to understand the long-term performance of bridge structures under complex marine environments.

Bridges are a critical component of transportation infrastructure, playing a vital role in connectivity. The safe operation of bridges demands significant resource and capital investment, particularly as the operation phase is the most extended period in a bridge’s life cycle. Therefore, the efficient allocation of resources and funds is crucial for the maintenance and repair of bridges. This study addresses the need to predict changes in bridge condition over time. The commonly used state-based Markov chain method for bridge condition rating prediction is straightforward but limited by its assumptions of homogeneity and memorylessness. To improve upon this, we propose a novel method that integrates an Elman neural network with a Markov chain to predict the bridge condition rating. Initially, the ReliefF algorithm conducts a sensitivity analysis on bridge features to obtain the importance ranking of these features that affect the bridge condition. Next, six significant features are selected for data classification: bridge age, average daily truck traffic volume, material type, skew angle between bridges and roads, bridge deck structure type, and bridge type. The Elman neural network is then trained to train a prediction model for bridge condition ratings using the classified data, which can predict the condition levels of bridges. The Markov chain’s transition probability matrix is derived using a genetic algorithm to match the deterioration curve predicted by the Elman neural network. This proposed method, when applied to actual bridge data, demonstrates its effectiveness as evidenced by the condition rating of an actual bridge.

Cracks, water seepage and other damage often occurred in the hinge joints of the fabricated hollow slab bridge and affect the transverse integrity of the bridge. In order to solve these problems, a new type prefabricated I-girder is proposed, the girder is connected crosswise through wet joints, and the distributed bars extending from the flange are firmly connected in the wet joints. The wet joint has replaced the hinge joint in the traditional hollow slab structure. Through the static load test of the three-piece fabricated I-section slab girder model, the overall mechanical behavior and the transverse distribution of the load in the fabricated I-section slab girder bridge are studied. Then the dynamic characteristics and overall mechanical properties of the traditional hollow slab girder bridge and the fabricated I-girder bridge with equivalent section was analyzed by MIDAS, consider the influence of shallow hinge joints, middle hinge joints and deep hinge joints. The experimental results are compared with the numerical analysis results, the results show that, under the condition of equivalent section, the overall flexural stiffness and torsional stiffness of the fabricated I-section slab girder structure are greater than that of the traditional hollow slab structure, and the transverse distribution of the load is more uniform, the fabricated I-section slab girder structure has better mechanical performance.