Bentonite Waterstop Strips

Bentonite Waterstop Strips — Hydrophilic, Self-Sealing Waterbars for Concrete Joints

Short lead (1–2 lines — include primary keyword early)

Bentonite waterstop strips (also called hydrophilic waterstops, bentonite waterbars or swelling rubber strips) are composite butyl-rubber + sodium-bentonite products that swell on contact with water to create a reliable compression seal for construction and cold joints in below-grade structures.

Why choose Bentonite Waterstop Strips? (H2 — use long-tail keywords)

• Self-activating sealing: Swells on contact with water to form a tight compression seal — no external membranes required.
  

• Proven for cold joints & diaphragm walls: Designed for construction joints, precast segment joints, diaphragm walls, pipe penetrations and blindside applications.
  

• Durable composite formula: Butyl rubber carrier + high-purity sodium bentonite gives controllable swelling and dimensional stability.
  

• Cost-effective & fast to install: Coiled/strip format reduces labour and welding compared with PVC/metal waterstops.
  

Key features & performance

• Typical swelling ratio: 200%–400% (product dependent). Use higher-bentonite formulations for faster expansion.
  

• Swelling pressure / resistance: Many commercial products provide swelling pressure equivalent to resisting several bars (report examples show swelling pressure up to ~1.2–1.36 MPa in lab data).
  

• Temperature & durability: Stable under normal concreting temperature ranges; selected formulations tested for heat/low-temperature resistance.
  

• Formats & mounting: Coils, 1–3 m pre-cut strips, or factory-made profiles with adhesive or butyl backing for easy fixing.
  

Typical Applications

• Concrete construction joints (cold / day joints)

• Diaphragm walls & secant piles

• Precast segment joints (tunnel ring segments)

• Basement blindside waterproofing & slab joints

• Pipe and utility penetrations where a confined swelling seal is required.
  

Technical Data (Example product spec — publish exact numbers for each SKU)

Note: below is a representative data table — replace or augment with your factory test report / TDS for each SKU.

Installation Guide — quick steps

(Include “how to install bentonite waterstop strip for concrete joints” — high-value long-tail phrase)

1. Surface prep: Ensure concrete surface is clean, dry and free of loose laitance or form release agents.

2. Primer / adhesive (vertical surfaces): For vertical/overhead applications use manufacturer-recommended primer; allow tack time per TDS.
   

3. Mechanical fixing: Use concrete nails / clips every 200–300 mm for vertical or overhead installation; horizontal installations may rely on adhesive plus temporary weights.
   

4. Seams / joints: Butt joints are common; for continuous performance use manufacturer’s splice adhesive or vulcanizing method where required — do not cut bentonite core with scissors in a way that disrupts continuity.
   

5. Concrete cover: Maintain recommended cover (typically ≥ 70–80 mm) so the strip is confined and can exert sealing pressure during swelling.
   

6. Pouring window: Install immediately before the pour; follow product TDS for maximum allowable exposure time.

Comparison: Bentonite Waterstop vs PVC / Rubber Waterstop

• Bentonite (hydrophilic): Activates with water, simpler fixings, ideal for cold joints & blindside work; limited to confined joints (not for large movement joints).
  

• PVC / rubber (mechanical): Requires welding/splicing, better for large movement joints and where mechanical resilience under cyclic movement is required.
  

Packaging, Lead Time & MOQ (for B2B buyers)

• Standard packing: 20 m coil per carton (or custom lengths).

• MOQ: typically 1,000 m (negotiable for stock SKUs).

• Lead time: 2–4 weeks for standard sizes; OEM/custom profiles 4–6 weeks (confirm at PO).

• Certs & testing: We supply material test reports (TDS), swelling tests, and factory QC photos. (Adjust to your real terms.)

Downloadable Resources & Deliverables

• Product Technical Data Sheet (TDS) — PDF (recommended)

• Installation Manual / Quick Guide (PDF) — multilingual option for your site visitors

• Lab test report (swelling ratio & pressure) — on request

FAQ — targets high-intent long-tail searches

Q: What is a bentonite waterstop strip and how does it work?
A: A bentonite waterstop strip is a composite of bentonite clay and an elastomeric carrier (commonly butyl). When contacted by water, sodium bentonite swells to many times its dry volume to form a compression seal within a confined concrete joint.

Q: What swelling ratio should I specify for metro/tunnel projects?
A: Many projects specify products with 300%–400% swelling ability and proven swelling pressure; exact choice depends on confinement conditions and expected groundwater pressures. Always ask for lab swelling tests.

Q: Can bentonite waterstops handle hydrostatic pressure?
A: Yes — high-quality bentonite strips can resist significant water pressure when properly confined; manufacturers publish swelling pressure / impermeability test results (check TDS).

Q: Are bentonite waterstops suitable for saltwater/brackish conditions?
A: Some products are formulated for brackish/saltwater with modified bentonite systems — specify “saltwatergrade” if project has high salinity.

Q: How do I order samples and OEM labeling?
A: We provide free small samples for technical evaluation (shipping charged) and support OEM branding / customized packing for bulk orders — contact our sales team with project specs.