ESHAHYDROBENT | Water-swelling bentonite cord - waterstop

Expands by over 400 per cent on contact with water and seals the joint from the inside — no welding, no joints, unlike traditional PVC waterstops. A cord based on bentonite and butyl rubber to prevent water ingress through joints in plain or reinforced concrete.

Swelling is controlled: the material expands sufficiently to seal the joint without generating dangerous stresses in the structure. Water absorption exceeds 150% after 72 hours, with a cross-section of 19/25 mm and a base operating range from -15°C to +50°C.

The ARGYNET View

The real advantage is not the swelling — it is that it does not wash out.

Conventional bentonite is carried away by hydrostatic pressure and washes out of the joint, just when you need it most. Butyl rubber holds it firmly in place. And the material returns to its original form after repeated cycles of swelling and shrinkage — in other words, it works even in the tenth cycle of drying and rain, not just the first.

The second factor to consider on site: a minimum concrete cover of 80 mm. If the cord is placed too close to the surface, the expansion will cause flaking rather than sealing.