Steelflex® Strip Seals

Steelflex® Strip Seal Expansion Joint Systems have become the overwhelming choice of owners and specifying engineers around the world for accommodating up to five inches (127mm) of total structural movement. 

SYSTEM COMPONENTS

Cast-in-place Steelflex® Strip Seal Expansion Joint Systems consist of two proprietary components:  steel rail profiles and a matching neoprene sealing element.

Steel Rail Profiles
Steelflex® rail profiles are one-piece construction, manufactured using innovative hot rolled/non-machined and hot rolled/machined technology.  All proprietary steel rails are available in ASTM A36 or ASTM A588 steel grades.  Recent design improvements have eliminated all horizontal “legs” on the proprietary steel rail profiles to facilitate proper concrete placement during installation.  Independent field and laboratory testing has demonstrated that improperly consolidated concrete around the steel rail, anchorage, and/or reinforcement could lead to performance issues.  Anchorage of the proprietary steel rail profile into the deck concrete is the primary load carrying mechanism, and therefore, is critical to ensure long-term performance. 

Because it is field-proven, the Steelflex® SSCM2 rail profile has become widely accepted worldwide as an economical standard in the industry.  Other proprietary steel profiles are available to satisfy your specific project needs.     

Neoprene Sealing Elements
Selection of a neoprene strip seal sealing element is based on the maximum movement either perpendicular or parallel to the Steelflex® Strip Seal Joint Assembly.  To assist in your selection, the following table provides movement ranges for each sealing element type and the corresponding proprietary steel rail profile.  Information is also provided on the range of joint opening dimensions.  The preferred joint opening dimen-sions for sealing element installation is approximately 2.0 inches (51mm).  However, the preferred joint opening dimension for A2R-O and L2R-O seals is approximately 3.0 inches (76mm).

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All D.S. Brown Neoprene sealing elements are in-house designed and tested to provide a watertight seal at the connection to the Steelflex® rail profile.  Factory molded neoprene sealing element splices can also be produced to accommodate your specific project needs.
 

Delcrete™ Elastomeric Concrete

Since its introduction in 1983, the DELCRETE™ Elastomeric Concrete/Steelflex® Strip Seal Expansion Joint System has been utilized on hundreds of bridges worldwide as an alternative to more labor intensive, cast-in-place expansion joint rehabilitation solutions.  This expansion joint system also offers superior long-term performance when compared to various pourable joint solutions.

Components to this system include:  low profile SSA2 or SSE2 Steelflex® rail profiles and DELCRETE™ Elastomeric Concrete. 

DELCRETE™ Elastomeric Concrete is a pour-in-place, free-flowing, two-part polyurethane-based elastomeric concrete.  DELCRETE™ has been compounded to bond to a variety of surfaces including steel and concrete.

Design features of the industry’s premier elastomeric concrete: 

• Polyurethane chemistry

• Non-brittle over extreme temperature ranges

• Resistant to nearly all chemicals

• One hour cure time

• Permanent, long-term repair solution

Although initially developed for the bridge rehabilitation market, the outstanding performance record of  DELCRETE™ has resulted in bridge owners specifying DELCRETE™ Strip Seal Expansion Joint Systems for new bridge construction projects as well.  

Installation

Proper installation of DELCRETE™ is essential to ensure long-term performance.  Therefore, a D.S. Brown technical representative or a representative of its licensed applicator shall be present on the job site during all phases of the installation.

Basic installation considerations include:

• Minimum ambient and concrete substrate temperature: 45°F (7°C)

• Sandblast entire block out, including steel rail profile, followed by a compressed air sweep

• Block out area must be completely dry before installation

A comprehensive list of installation procedures is found in the D.S. Brown DELCRETE™ Strip Seal Expansion Joint System Installation Data Sheet.
 

Compression Joint Seals

In 1960 the D.S. Brown Company began designing and extruding the first generation of DELASTIC® Preformed Neoprene Compression Seals.  Since that time continuous improvements have been made to this versatile, cost-effective joint sealing solution.  To withstand the demanding requirements of bridge/highway installations, all DELASTIC® Preformed Compression Seals are extruded from neoprene (polychloroprene) compounds which satisfy the ASTM standard specification D3542 for Preformed Polychloroprene Elastomeric Joint Seals for Bridges.  In addition to highway and bridge applications, DELASTIC® Neoprene Compression Seals have also been used in spillways, dams, parking structures, stadium ramps and pedestrian overpasses.

Building Expansion Joints

For more information about BUILDING Expansion Joints

BEARING DEVICES

POT BEARING ASSEMBLIES

TYPICAL APPLICATIONS

Versiflex™ HLMR pot-style bearing assemblies are suitable at locations where low-profile, high-load bearing devices are suitable at locations where low-profile, high-load bearing devices are required.  Versiflex™ HLMR bearing assemblies are especially suited for curved or skewed bridges and other complex structures where the direction of rotation varies or cannot be precisely determined. 

DESIGN CRITERIA 

Required information for the proper design of a Versiflex™ HLMR bearing assembly includes:

• Vertical Load

• Horizontal Load

• Rotation

• Translational Movements

The plan area of a bearing assembly is usually controlled by the average vertical stress on the elastomeric disc.

Rotations of up to ±0.03 radians can be accommodated by Versiflex™ HLMR bearing assemblies.  Design rotation is a combination of the effects of live load and construction tolerances. 

The use of polytetrafluoroethylene (PTFE) as the low-friction sliding surface in bearing guide systems was previously the standard.  With the increased use of seismic design in the bridge industry, larger horizontal loads must pass through the bearing assembly’s guide system.  Alternative low-friction materials, which provide much highter allowable bearing pressures than PTFE, are recommended for cases where horizontal loads exceed 50 percent of the vertical design load. 

For curved bridge structures, the theoretical direction of movement is a chord projected from the mid-point of the deck at the expansion bearing line to the mid-point of the deck at a fixed bearing line.  Finite element analysis may also be used to determine a more precise movement direction.  All bearing assemblies at any pier or abutment line must be oriented in the same direction. 

TYPICAL APPLICATIONS 

For nearly 50 years, elastomeric bearing assemblies have been used in the construction of new bridges and the rehabilitation of existing structures.  Other applications include: buildings and arenas, shear-key bumpers, seismic isolation protection and vibration devices for machinery. 

GENERAL

VERSIFLEX™ elastomeric bearing assemblies are custom molded using neoprene or natural rubber and are categorized into three basic designs: non-reinforced, laminated and sliding bearing assemblies.  Rotation and displacement of elastomeric bearing devices are accommodated by deformation of the elastomer.  Bearing assemblies may be molded with holes, slots, skewed ends, clipped corners and/or sealing ribs and may also be circular in shape. 

SLIDE BEARINGS

For applications where horizontal displacements exceed ±2 inches (50 mm), sliding elastomeric bearing assemblies may provide an economical solution.  The addition of a low-friction sliding surface allows a standard laminated Elastomeric bearing device to accommodated unlimited horizontal displacement without increasing the height of the bearing assembly.

A slide bearing assembly consists of an upper and lower component.  The upper component consists of a steel load plate attached to the superstructure and a polished stainless steel sheet welded to the load plate.  The lower component consists of a low-friction PTFE sliding surface, steel backer plate, molded elastomer and bottom steel load plate.  All components of the bottom assembly are vulcanize-bonded during the molding process.  Slide bearing devices may be guided or free to move in any direction.

 

LAMINATED BEARINGS

The addition of internal steel plates (or laminates) increases the vertical load bearing capacity and the amount of horizontal deflection which can be accommodated by the bearing device.

Laminated bearing assemblies are molded to any shape or size.  The internal steel plates are vulcanize-bonded to alternating layers of elastomer during the molding process.  Laminated bearing assemblies may also be manufactured with top and/or bottom steel load plates which are also vulcanize-bonded.  An elastomer cover layer is necessary to protect the internal plates from the environment.
 

NON-REINFORCED DESIGN

Non-reinforced bearing devices are best specified when the load, rotation and horizontal deflection are minimal.  Top and/or bottom steel load plates can be vulcanize-bonded to the bearing device during the molding process.