Large movement expansion joints are best defined as those that provide support across the expansion void, without exceeding the code requirement of the 85 mm ULS unsupported gap.
Large movement expansion joints, particularly of the Modular type having movement capacities up to 2,000mm, require careful consideration as to the structural integrity of the bridge in this highly stressed area. Typical blockout depth is in the order 0f 400mm. Careful consideration is required early in the design process.
The most popular types of large movement Expansion Joints include the Modular type with movement range up to 2,000mm, Steel Finger Joints with movement range up to 600mm. Cast Aluminium Expansion Joints with movement range up to 300mm with each type having exhibiting unique operational characteristics.
For skew applications, cast aluminium finger joints, typically having a trigular shaped finger, can be ‘preset’ to provide for limited skew movements. Steel finger joints, typically with rectangular shaped fingere, can be manufactured to provide for very large shew movements.
This is achieved with special design features, such as cast aluminium or fabricated steel finger joints, which provide the bridging member spanning the structural gap. Finger Type Joints – which have relatively limited maximum movement range – can be set into a comparatively shallow blockout.
Expansion Bridge Joint Construction Step by Step
Credits on this video: EMSEAL Joint Systems, Ltd.