Tarco bituminous expansion joints
Flexible, waterproof expansion joints.
A bituminous expansion joint is a surface section of special construction that not only transmits the load of vehicles’ wheels, but also compensates vertical and horizontal deformations caused by the expansion joint’s edge movement in the bridge construction.
This is the simplest, cheapest and quickest method of protecting expansion joint gaps in small- and medium-span bridges.
TARCO expansion joints prevent bridge surfaces from damage caused by thermal movement, vibrations and dislocations from span deflections. They also protect nearby areas from the pressure of rain water, anti-icers and other outside matter that comes from road surfaces and the insulation level.
TARCO expansion joints are applied directly to bridge constructions. They consist of fractured grit, from fractions of magmatic rocks and TARCOMASTIC binder, produced on the basis of modified asphalt with the addition of polymers, fillers and surface-active substances. The size of the expansion joint is selected individually for each structure.
Components of a TARCO expansion joint:
TARCO expansion joint channel – located in the surface, shaped like stairs with offsets, symmetrical to the expansion joint gap.
Stabilizer – aluminium or steel plate, protected against corrosion. Closes the expansion joint from above and supports its framework.
Membrane – PVC tape, resistant to high temperatures and characterized by a small friction coefficient.
TARCOMASTIC flooding mass – flexible mass based on bituminous substances, which is a filler-binder.
Grit – basaltic or granite aggregate of fraction from 11 mm to 25 mm thick. Acts as a framework for the filling.
Grit – aggregate of fraction from 2 mm to 5 mm thick (e.g. 2/4, 2/5), for the roughness of the expansion joint.
Polyurethane sealing profile – placed in the expansion joint gap to prevent the hot flooding mass in the joint channel from pouring out.
TARCO expansion joints are produced in the following sequence:
Preparation work (planning the expansion joint’s position, traffic organization etc),
Carving out the designed channel in the surface,
Cleaning the channel, drying it with hot, compressed air and sandblasting its surface,
Second cleaning of the sandblasted channel with compressed air,
Installation of muffs on shielding pipes located in the pavement, if needed,
Creating a drainage system at the insulation level (drains, drainage),
Securing the expansion joint gap with a spongy neoprene insert,
Spreading TARCOMASTIC flooding mass in the bottom of the channel,
Placing the stabilizer symmetrically along the expansion joint gap,
Further spreading of the flooding mass in the expansion joint gap and the stabilizer,
Application of PVC tape, symmetrically along the expansion joint gap,
Filling of the channel with, alternately, properly-heated flooding mass and hot
aggregate, so that the flooding mass covers the entire surface,
After thorough penetration of the aggregate (usually the following day), the last layer of the mass is poured in, and the aggregate is added,
Supplementing of kerbs and filling in gaps with flexible mass,
Reconstructing pavements over the expansion joint, in accordance with individual plan.
TARCO expansion joints should be constructed across the entire cross-section of the bridge, including the roadway and pavements. The construction of the pavement should allow for continuation of the channel cut into the roadway.
TARCO bituminous technology can also be used:
In transition zones between the surface and steel elements of other expansion devices,
In transition zones between the surface and modular expansion devices,
In transition zones between the bituminous surface and the concrete surface,
To ensure the safety of traffic driving over worn (broken) modular expansion devices,
To tighten the joints of roadway surfaces and pavements with kerbs,
TARCOMASTIC flooding mass can be used for flooding gaps near kerbs, inlets, drainage channels, and sewage run-offs situated close to kerbs and cornices.
Advantages of TARCO bituminous expansion joints:
Can be constructed in stages without closing a road,
Short construction time (10 – 20 m per day),
Easy to build into existing road structures (constructed in surface layers, without anchors); can be used in transport constructions of concrete, combined or steel superstructures, with bituminous, epoxide or concrete surfaces,
Inexpensive, quick and safe method of protecting structures from damage caused by leaking water and other harmful substances through expansion joint gaps,
Allow for renovation (replacement) of worn layers of roadway without the need to install a whole new expansion joint,
TARCO bituminous expansion joints have, for many years, worked well in practice, provided that materials of proper quality are used and that they are installed by qualified workers, in accordance with requirements.