GAM GBM Expansion Joints

Approach Ramp to the Tsing Ma bridge in Hong Kong – The largest combined road and rail bridge in the world – showing a GBM 195 Expansion Joint.


Honel single seal expansion joints are suitable for concrete, steel, and composite bridges. They are designed to accommodate movements both perpendicular and parallel to the centre-line of the joint.

The joint profiles are normally designed to follow the contour of the structure, i.e. slopes, kerbs, etc. Honel will be pleased to advise on specific details.

Materials used in the manufacture of single seal expansion joints:

Seals . . . . . . . . . . . . .EPDM or Neoprene Rubber

Edge profiles . . . . . . Steel to BS 4360 Grade 43A or equivalent

Anchors . . . . . . . . . . .Mild steel


The edge profiles incorporate a proven seal retention detail, with studs or anchor loops welded at intervals to suit structural requirements.

The standard seals are capable of a movement capacity of 80mm. Alternative seals catering for larger movement capacities are available for use where larger maximum gaps are permitted. The relevant national code should be consulted regarding maximum allowable gaps.

Corrosion Protection:

All exposed steel surfaces are hot – dip galvanised to BS5493 : 1977 and SABS 763 to 140 microns nominal thickness.


Type GAM160 – GAM640 :

Multi-element joints are available from 2 seal up to 8 seal. Each intermediate beam is rigidly connected to a support beam positioned at of 1600 mm along the length of the joint.

The support beams are mounted on sliding bearings in housings at each side of the joint. Stability is assured by preloaded elastomeric bearings positioned immediately above the sliding bearings supports, applying a downward force on the support beams.

Equalisation of the seal movement and absorption of breaking and traction forces is effected by elastomeric springs between edge profiles and support beams and between the support beams themselves.


This type of multi seal expansion joint is also manufactured. It is similar to the GAM range of joints with the exception of the mechanical linkage system connecting the edge and support beams together. This system is employed for the equalisation of the seal movement and absorption of braking and traction forces.

Design Capabilities:

Honel has always been in the forefront of technological advancement in the design and manufacture of structural bearings and expansion joints.

We have a staff of specialists trained to evaluate customers requirements and to prepare designs for our product range utilising sophisticated computer software which can accurately predict operating conditions in the field.

Our theoretical approach is backed up by extensive testing of new and existing designs, many of which are tailored to suit the arduous operating conditions encountered both in South Africa and abroad.

Komatie River Bridge showing the GAM400 (5 seal) Expansion joints