EBJ-200B Bridge Expansion Joint Binder
Seamless Joint is a combination of an elastomer modified binder, and a carefully selected aggregate. The joint is constructed in-situ and is a hot process.
EBJ-200B bridge expansion joint binder is a special blend of bitumen, polymers, fillers and a surface active agent, formulated to combine good fluidity at process temperatures with low temperature flexibility and ambient temperature slump control. It is delivered to site in bags in its solid state, where it is heated in a special pre-heater to its normal application temperature in accordance with the manufacturer鈥檚 recommendations.
The stone is a single-size aggregate preferably from the Basalt, Gritstone, Gabbro or Granite groups. For the standard joint the aggregate size is 20mm. In special cases other sizes may be specified, e.g. a 14mm size in shallow joints. The use of single-size aggregate enables a high binder content to be reached and ensures a constant ratio of stone, important to give the optimum combination of flexibility and load bearing capacity.
The stone is cleaned, sized and bagged for dispatch to site. Immediately prior to use it is further cleaned by being rotated in a perforated drum mixer whilst being heated by hot compressed air to a working temperature range of 150掳C 鈥?190掳C.
All joints extend the full depth of the asphalt road surfacing and waterproof membrane down to the deck concrete. In certain instances, the engineer may decide that a rebate may be created in the concrete, to increase the depth of the joint to the required dimension.
For gaps up to 30mm wide, an aluminum flashing strip spans the gap to prevent stone entering the gap during joint construction or under the punching action of subsequent traffic. For gaps over 30mm wide, a steel plate is used which also serves to distribute wheel loads across the gap.
The joint develops a very strong bond to the concrete and to the vertical faces of the adjacent asphalt.
Installation Procedures
鈥?Remove the asphalt surfacing to the desired width by saw cutting and jack hammering. The asphalt should be completely removed to expose the deck. A clean join to the asphalt is essential. Any waterproofing membrane should be removed.
鈥?Clean out the recess and the expansion gap and prepare with a ESUN hot compressed air lance, as this warms the surrounding surfaces.
鈥?Caulk the expansion gap using thermal foam.
鈥?Tank the recess with hot EBJ-200B bridge expansion joint binder to seal the joint and improve adhesion of the joint to the asphalt.
鈥?Install the aluminum strip or steel plate over the gap.
鈥?Pour stone heated to 150掳C 鈥?190掳C into the joint to a maximum depth of 40 mm, but not less than 20mm. The layer should then be flooded with binder heated to the correct temperature. This process should be repeated until the joint is within 25mm 卤5mm of the surface.
鈥?Apply the Seamless Joint pre-mix layer.
鈥?Compact using a compactor or vibrating roller.
鈥?Seal the surface using EBJ-200B bridge expansion joint binder.
Seamless Joint is an asphaltic plug bridge expansion joint approved by the China Department of Transport and other road authorities around the world. It has the following movement capabilities:
Horizontal: +/-25mm; Vertical: 3mm total.
1. Binder
The binder used in the construction of an asphaltic plug joint must have the following characteristics:
- remain flexible in cold conditions
- be stable in hot conditions
- be flow resistant
The following tests should be carried out by an approved laboratory at the temperatures stated, and a certificate of compliance issued in not less than 12 months before the start of the contract:
A. Extension Test
B. Softening Point Test
C. Flow Resistance Test
Details of methods and test limits are available from the ESUN Technical Department.
2. Stone
The stone will be a single-sized 20mm aggregate. It shall be a clean, dry stone, pre-bagged to avoid contamination. It shall be a stone with a polished stone value of 60, and a maximum flakiness index of 25.
Technical Specifications
Softening point: 鈩?/p>鈮?5鈮?3鈮?3
Low temperature tensile-0鈩?pass-7鈩?pass-15鈩?pass
Cone penetration at 25鈩? dmm鈮?0鈮?5鈮?00
Flow value (60鈩? 5h/mm)鈮?鈮?鈮?
Elastic recovery: mm30锝?040锝?0鈮?0
Tensile adhesion: %鈮?00鈮?00鈮?00
Ductility: mm鈮?50鈮?00鈮?50
鈥?nbsp;High softening point, low flow value; no flow at 60 鈩? with strong rutting resistance at high temperatures.
鈥?nbsp;Good ductility at high temperature is better for resisting the widening of bridge joints caused by low temperature contraction.
鈥?nbsp;Good low temperature interfacial adhesion. Due to special additives, EBJ-200 binders offer better adhesion because of the physical riveting and chemical cross linking with bridge interfaces.
鈥?nbsp;High elastic recovery can better meet the bridge expansion and contraction.
Working Procedure at Site
Break outClean
CaulkTack & Seal
Place plateFill with mixture
CompactSurface treatmentChina Bridge Expansion Joint