Waterstop Tie Rod

A Waterstop Tie Rod(also called Waterproof Tie Rod or Sealing Tie Rod)is a specialized fastener system used in water-retaining concrete structures(e.g.,basements,reservoirs,tunnels)to simultaneously resist concrete pressure during pouring and prevent water leakage through formwork penetration points.It integrates a traditional tie rod with a waterproofing mechanism,ensuring structural integrity and long-term impermeability.

Design&Components

Central Waterstop Element:

A steel plate(e.g.,50×50×3mm)welded to the rod’s midpoint,or hydrophobic seals(e.g.,rubber/polymer washers)embedded along its length.

Creates a labyrinthine path blocking water migration through concrete.

Threaded Rod:

High-tensile steel(Q235/Q345),typically hot-dip galvanized or epoxy-coated for corrosion resistance.

Diameters:M12–M20;lengths customized for wall thickness.

End Assemblies:

Nuts&Washers:Tightened against formwork to withstand concrete lateral pressure(e.g.,60–90 kN/m²).

PVC Sleeves(optional):Allow rod extraction for reuse in non-critical applications.

Variants:

One-Piece Design:Traditional rod with fixed waterstop,permanently embedded.

Three-Piece System:Removable outer rods+sealed inner segment,reducing material waste and improving surface finish.

Working Principle

During concrete pouring,the rod’s tensile strength counters formwork deformation.Post-curing,the waterstop:

Physically blocks water via extended seepage paths around the plate.

Chemically expands(if hydrophilic seals are used)to plug micro-cracks between rod and concrete.

Applications

Watertight Structures:Basement walls,sewage tanks,swimming pools.

Civil Infrastructure:Tunnels,bridges,retaining walls.

Industrial Projects:Nuclear plants,water treatment facilities.

Installation Process

Drill holes through formwork at designed spacing(e.g.,400–600mm).

Insert the rod with waterstop centered in the wall thickness.

Secure ends with nuts/washers;torque to specifications(e.g.,40–60 N·m).

After concrete curing,cut exposed ends and seal with waterproof mortar.

Advantages

Dual Function:Combines structural support and waterproofing.

Durability:Corrosion-resistant materials ensure decades of service.

Adaptability:Compatible with poured walls,slabs,and curved surfaces.

Cost Savings:Reduces post-construction leak remediation expenses.

Technical Standards

ASTM A615:Steel reinforcement specifications.

EN 1992-3:Design rules for liquid-retaining structures.

ISO 9001:Quality management in manufacturing.

Challenges&Solutions

Corrosion Risk:Use stainless steel or galvanized rods in chloride-rich environments.

Improper Sealing:Ensure waterstop is centered;seal rod ends with hydraulic cement.

Load Miscalculation:Engineer spacing/diameter based on concrete pressure charts.

Innovations

Smart Waterstops:Embedded sensors monitor seal integrity and stress.

Biodegradable Sleeves:Eco-friendly alternatives to PVC for temporary applications.

Conclusion

The Waterstop Tie Rod is a critical innovation in concrete technology,addressing both structural and waterproofing needs in modern construction.Its robust design,compliance with international standards,and adaptability to complex projects make it indispensable for engineers prioritizing durability and sustainability.Proper installation and material selection are key to achieving a leak-free,resilient structure.