Watertight—the tensionless silicone bellows is installed just below the deck surface. This ensures watertightness is achieved at the deck surface.
Unlike liquid-applied sealants, compression seals, and inflated seals, the BEJS System does not rely on adhesion in tension. Instead the material is precompressed in the factory ensuring that the spring energy of compression is always pushing back on the substrate.
BEJS is not like other foam-based (EVA) expansion joints. BEJS is supplied precompressed to less than the joint size. It is held in compression by its packaging. When released it expands. BEJS, properly sized, is never in tension in the joint. This is the key to its performance.
BEJS is coated at a width that exceeds the maximum expected joint opening. Expansion is faster when hot and slower when cold.
Older technologies don’t perform to the standards of BEJS. Liquid sealants and asphaltic plugs fail in extension due to tensile stresses at the bondline or within the system. Closed-cell foams (EVA-types), rubber compression seals, and inflated seals all fail from tensile stresses at their bond lines after compression set takes place.
Non-Invasive Anchoring—there are no hard metal-to-concrete connections as those found in systems with embedded pins, anchors, screws, bolts or tracks, trays or rails. Instead, BEJS is locked to the joint faces by means of the 1) backpressure of the foam; 2) the epoxy adhesive; and 3) the injected silicone sealant band at the joint face to foam and silicone bellows interface.
Continuity of Seal—as in all EMSEAL expansion joint systems, continuity of seal through changes in plane and direction is an essential performance differentiator. Details for watertight, field-fabricated transitions from deck to wall, at curbs, sidewalks, parapets, tees, and crosses are available with the BEJS System.
Aesthetics & Versatility—Both sticks and reels are supplied with a standard bellows surface color of black (gray and other custom colors are also available). They feature uniform bellows appearance, fuel resistance, and an enhanced ability to handle variations in joint size are among other system features.
Installation—Fast, easy, and can be staged to preserve partial traffic flow. Under average conditions and temperatures, BEJS provides a driveable surface within an hour of installation.
- BEJS sticks and reels are produced by coating an impregnated cellular foam with AASHTO-approved, Pecora 301 highway-grade silicone.
- The expanding foam is cellular polyurethane foam impregnated with a water-based acrylic.
- The silicone external facing is factory applied to the foam at a width greater than maximum joint extension and is cured before final compression.
- Silicone application and curing takes place in a factory-controlled environment. In contrast to field-applied liquid sealant and backer rod installations, no movement takes place during curing that can cause deformation or stresses in the material.
- When compressed, a bellows is created in the coating. As joint movement occurs the bellows simply folds and unfolds free of tension on the bond line, and virtually free of tensile stresses in the silicone material. Sizes 1/2-inch (12mm) through 1 1/4-inch (35mm) have a single-curve convex bellows; sizes from 1 1/2-inch (40mm) through 4-inches (100mm) have a dual-curve convex bellows.
- The foam provides a resilient backing to the silicone coating, making the system capable of resisting reasonable transient point loads.
- BEJS SYSTEM is supplied in sticks [6.56 LF (2m) shrink-wrapped lengths] or reels [12 LF (3.65m) wrapped reels] depending on its width. It is precompressed to less than the joint size for easy insertion. After removal from the shrink-wrap and hard board restraining packaging, it expands gradually.
- Substrates must be parallel, plumb and capable of resisting approx. 2.5 psi backpressure from the foam.
- Fuel Resistance: Silicone sealant is not degraded by contact with fuel. Some swelling of the material will normally occur, but it will return to its original shape upon evaporation of the fuel.
Transitions and Terminations
(US Patent 9,200,437, Patent Pending)
Factory-Fabricated Terminations and Transitions—in all EMSEAL expansion joint systems, continuity of seal through changes in plane and direction is an essential performance differentiator.
BEJS is manufactured in straight-run sticks which can be joined in the field to EMSEAL’s patented “Universal-90” Transitions and Terminations.
These factory-fabricated single-piece 90-degree units have a 12-inch long leg and a 6-inch vertical piece on each end of the elbow. The Universal-90’s are symmetrically coated on both sides. This allows them to be installed as an upturn or as a downturn. Either leg can be trimmed in the field to connect to straight run material or to another Universal-90 when going, for example, up and over a curb and/or parapet.
Universal-90 terminations end, on the 6-inch leg, in a 45o sealed and mitered end. This allows termination as a stand alone upturn in a parapet wall or provides a surface against to which a wall joint system can be married. Flipped over, the Universal-90 termination unit can be alternatively installed as downturn termination where a joint runs off the bridge deck. In this use, the sealed, mitered end provides a drip edge for drainage of water off the joint.
In addition to guaranteeing a continuous waterproof coating, EMSEAL’s “Universal-90’s” allow for much faster and secure installation by eliminating field cutting or notching and bending at angles.