Bonded Multistrand Post-Tensioning

Bonded Multistrand Post-Tensioning Systems

Extensively used in bridge and transportation structures, bonded multistrand post-tensioning systems have also been successfully applied to commercial building construction. A single multistrand tendon can hold up to fifty-five 0.5″ or 0.6″ strands encased in PT-Plus™ plastic or steel duct and is fully bonded using a high-performance grout.

When bonded multistrand post-tensioning systems are used for large structural members, such as beams and transfer girders, design advantages include increased span lengths and load-carrying capacity and reduced deflection. Additionally, because the strands are stressed simultaneously, less labor is required resulting in cost savings.

multistrand anchorage

VSL 2C Whitetext

STRUCTURAL TECHNOLOGIES is the exclusive manufacturer of VSL post-tensioning products and construction systems in the United States. Our manufacturing facilities in the United States are certified by PTI’s Plant Certification Program to ensure the highest quality fabrication of materials.

multistrand anchorage close
Multistrand Anchorages

Our multistrand systems are tailored to meet a variety of unique project specifications, including:

  • Encapsulated for optimum corrosion protection
  • Couplers to connect tendons that are already installed
  • Inspectable for post-grouting inspection
  • Electrically Isolated to eliminate corrosion or monitor tendon integrity
  • Loops where there is no access to the dead-end
post tensioning duct
Sheathing & Corrosion Protection

PT-PLUS™ is our proprietary duct system, utilizing corrugated plastic duct and couplers that are designed for easy installation and provide positive sealed mechanical connections for increased durability. Advantages of the PT-PLUS™ system include:

  • Enhanced corrosion protection
  • Improved tendon fatigue resistance
  • Reduced sensitivity to stray electric currents
  • Reduced tendon friction
  • Electrical isolation when used with special anchorages
  • Airtight / Watertight
grout mixer vsl
Installation Support

Our highly trained field leadership provides expertise in all areas of post-tensioning installation services– including stressing and grouting operations. Our technicians are certified by the Post-Tensioning Institute (PTI) and American Segmental Bridge Institute (ASBI) for quality installation. They are also available to provide on-site training and supervision or to install systems and perform stressing and grouting services as needed. We also provide installation equipment that is expertly maintained and calibrated by skilled mechanics prior to jobsite delivery.

How Stressing Works

The unique feature of our P-T system is its special wedge locking procedure. The wedges always remain in contact with the strands during the stressing operation. As the pressure in the jack is released, the wedges automatically seat into the conical holes of the anchor head.

stage one post tensioning stressing

1) Placing of anchor head and wedges

phase 2 post tensioning

2) Positioning of jack

phase 3 post tensioning

3) Stressing

phase 4 post tensioning stressing

4) Seating of wedges

VSL Bonded Multistrand Products

Post Tensioning: Anchorages
ProductDescriptionTechnical Data
ECIFor 7, 12, or 19 strandsPDF
KMultistrand CouplerPDF
AFDead-End Anchorage for limited accessPDF
Post Tensioning: Ducts
ProductDescriptionTechnical Data
PT-PLUS™Proprietary plastic duct and coupler systemPDF
Post Tensioning: Strand Properties
ProductDescriptionTechnical Data
StrandPost-tensioning strand and tendon propertiesPDF
Post Tensioning: Equipment
ProductDescriptionTechnical Data
Stressing EquipmentBlock out dimensions, clearance requirements, and stressing jack dataPDF

Post-Tensioning Engineering Support

Post-Tensioning Expertise

STRUCTURAL TECHNOLOGIES’ post-tensioning specialists are committed to bringing innovation to complex projects. Our in-house design professionals have extensive experience in structural design and are active members of technical organizations such as the Post Tensioning Institute (PTI) and the American Concrete Institute (ACI).

Post-Tensioning Team Leader

Read more about our products and applications on our post-tensioning solution builder page

john cringler headshot
Design-Assist & Engineered Product Support

• Investigation Support
• Solution Development
• Budget Development
• Specification Assistance
• Constructability Consulting
• Application Engineering
• Quality Control Programs
• Project-Specific Design-Assist


• Preliminary Designs
• Feasibility Studies
• Budget Development
• Optimization of Structural Geometry
• Specification Development


• P-T System Selection
• Customized P-T System Design
• P-T Element Design & Detailing Support
• Integrated Shop Drawings & Building Information Modeling (BIM)
• Quality Control Plan Development


• P-T System Installation Support
• Project Coordination
• Manufacturing & Material Supply
• Equipment Rental
• Safety Planning