Bolt connection performance post fire in steel bridges

Abstract

Fire events reduce the strength of the steel structure on the bridge and can cause collapse which results in losses, so it is necessary to consider the effects of fire when planning construction. Considering that the joints affect the performance of steel structures, the results of research on the performance of steel beams need to be augmented by testing the post-fire girder bridge bolt connection performance. Structural tests will be carried out on six specimens of bridge steel beam elements with high quality bolt connections in the center of the beam with sliding type bolt connections. Two control specimen beams were tested with shear loads without combustion. Two specimens with temperature of 700°C and 900°C with different torque bond variables. From the displacement control test using UTM on six specimens, it will be known the performance of each type of connection by evaluating changes in carrying capacity, stiffness, deflection capacity, ductility, and stress-strain capacity due to the influence of temperature acting during the fire process. The results can prove which type of bolt connection is better for use on bridges with fire risk.

Loss of Friction Force Due to High Temperature Effect on A325 Bolts with Proof Load on Steel Bridge

“…The test results show that the beam model with a center load of 38kN in the center of the span can withstand temperatures of 550°C for 120 minutes without significant reduction with a deflection of about 10 mm and is much larger than a similar specimen burning at the same temperature with a load of 19kN. Burning at a target temperature of 900°C for approximately 20 minutes showed that specimens with a load of 19kN experienced a very large deflection with a deflection of up to 150 mm, while specimens with a load of 38kN collapsed due to lateral flexural [3]. The above results are consistent with the test results numerical (Gunadi, 2016), which proves that at a temperature of 600°C, the beam's stiffness and flexural capacity has very significantly decreased.…”

“…At this temperature, the maximum stress that can be achieved is far below the yield stress of the material [4]. Another study is that the steel profile bolt joints that are burned and subjected to a flexural test with Universal Testing Machine (UTM) have been shown to reduce the plate friction force by 12%, thereby reducing the post-fire friction performance [5].…”

“…Therefore, research on the performance of steel joints is needed to support the post-fire structural steel performance results and the handling of reinforcement performance. [6]…”

“…Experimental testing and SEM showed the behavior and performance of the friction force on the bridge bolt connection post-fire. [6]…”