Evolution of Extruded Expansion Joint Seals

Multi-cell Neoprene extrusion installed into epoxy “lubricating adhesive” applied to joint face.

Anchoring system reliant on adhesive in tension – weakest way to use adhesive
Must be force-compressed (squeezed) in the joint
Limited movement: Max. joint size limited by relaxed width of seal. Min joint size limited by complex internal webbing.
Compression set: permanent loss of ability to exert backpressure against substrate – substrate pulls away from seal
Rigid “box” structure combined with poor anchoring system cannot handle vertical differential deflection (up and down) movement.
Neoprene thermoplastic rubber extrusion cannot be heat-welded. Terminations and transitions in plane and direction as well as repairs must be glued. Glue dries out over time.

Double or single barrier Neoprene thermoset rubber extrusion with joint face-applied epoxy “adhesive-in-tension” anchoring system
Seal is inflated during installation to improve bond.

Anchoring system reliant on adhesive in tension – the weakest way to use adhesive.
Approx. 18 square inches of adhesive in tension per foot of joint.
Bond line stressed by: peeling action during up and down vertical deflection; gravel and sand forced by tires into epoxy-to-seal interface; and standard tension from lateral movement
Does not protect joint edge. Blockouts with elastomeric header required to waterproof joint edges and prevent cracking and spalling
Durable terminations, transitions and repairs difficult. Neoprene thermoset rubber extrusion cannot be heat-welded. Terminations and transitions in plane and direction as well as repairs must be glued. Glue is not UV stable and dries out over time.
Poor extrusion tolerances of Neoprene yields excessive bulk at flexural nodes in gland, inhibiting movement and excessively stressing epoxy bond.
Dependent on extremely smooth joint face. Relies on epoxy to fill irregularities.

Blockout-anchored multi-cell extrusion with integral punched flanges encapsulated in elastomeric concrete nosing material.

Superior anchoring system to compression seal and inflated seal.
Elastomeric concrete nosing encapsulates punched flanges, mechanically anchoring seal using adhesive in shear – strongest way to use adhesive.
Over 45 square inches of adhesive in shear per foot of seal.
Not affected by minor irregularities in joint face.

Limited movement. Max. joint size limited by relaxed width of seal. Min joint size limited by complex interior webbing.
Rigid “box” structure inhibits vertical differential deflection (up and down) movement capabilities.
When retrofitting joint-face adhered technologies, requires cutting of blockouts. In new construction, blockouts can be formed.

Double-Barrier Santoprene thermoplastic rubber extrusion with integral punched flanges encapsulated in elastomeric concrete nosing material.

Latest evolution of gland design. Combines high-movement of double barrier inflated seal with integral flanges for secure blockout mounting.
Elastomeric concrete nosing encapsulates punched flanges, mechanically anchoring seal using adhesive in shear – the strongest way to use adhesive.
Weldabilty of thermoplastic-rubber extrusion allows for continuity of seal through changes in plane and direction and offers repairability.
Over 45 square inches of adhesive in shear per foot of seal.
Not affected by minor irregularities in joint face.

When retrofitting joint-face adhered technologies, requires cutting of blockouts. In new construction, blockouts can be formed.