Waterstop Bolt

1.Basic Definition&Primary Function

A Waterstop Bolt(also known as a Sealing Bolt45 or Grout Stopper is a specialized mechanical fastener specifically engineered for waterproofing applications in concrete structures.Its core function is to prevent the passage of water through concrete walls or slabs where penetrating bolts or tie rods are used,effectively creating a watertight barrier.

These bolts are crucial components in structures where resisting water infiltration is paramount to maintaining structural integrity and dryness,such as in basements,underground constructions,water tanks,swimming pools,tunnels,and sewage treatment facilities.

2.Key Features&Design Characteristics

Waterstop bolts possess several distinguishing features:

Integral Waterstop Element:The most defining feature is an integral waterstop or sealing ring.This is often a central steel washer(stop ring) or a rubber/PVC sealing(gasket) fixed to the bolt shaft.This element disrupts the potential path of water along the bolt.

High-Strength Material:Typically manufactured from high-strength steel or stainless steel to withstand the significant tensile stresses encountered during concrete pouring and to resist corrosion in damp environments.

Common Configurations:

One-Piece Design:Traditional style where the entire bolt,with its central waterstop,is permanently cast into the concrete.

Three-Piece Retractable Design:A newer design gaining popularity.It consists of a short inner segment with the waterstop and two removable outer rods.After concrete curing,the outer rods are detached and reused,leaving only the inner segment embedded.This saves material and reduces costs.

3.How It Works/Operational Principle

The waterproofing mechanism is primarily mechanical:

Installation:The waterstop bolt is inserted through formwork and serves as a tie rod,holding the forms together at the correct spacing against the fluid pressure of wet concrete.

Embedment:The bolt is permanently cast into the concrete structure.

Barrier Creation:The critical component—the waterstop washer or sealing ring—is embedded within the concrete mass.It acts as a physical barrier,significantly lengthening the seepage path for water.Any water attempting to migrate along the interface between the bolt shank and the concrete is blocked by this ring,preventing it from reaching the other side.

Additional Sealing(Sometimes Used):In some applications,special sealants or waterproofing coatings might be applied around the bolt ends at the concrete surface for added protection.

4.Primary Applications

Waterstop bolts are indispensable in:

Below-Grade Structures:Basement walls,foundations,underground parking garages.

Water Retaining Structures:Reservoirs,swimming pools,water treatment tanks,sewage containment pits.

Civil Infrastructure:Tunnels,subways,culverts,bridge abutments where waterproofing is critical.

Other Structures:Dams,lift shafts,and any concrete structure requiring protection against pressurzed water or moisture ingress.