Jointseal Tape LT
Hydro-expansive waterstop joint based on sodium bentonite and special polymer binders with delayed expansion
Drykos® Jointseal Tape LT is a preformed hydro-expansive waterstop joint with delayed expansion, specifically designed for sealing construction joints in concrete structures, masonry, and foundations where a permanent airtight seal against water infiltration and a delayed activation of the expansion process are required.
The product consists of a high-performance mixture of natural sodium bentonite, hydro-expansive rubber, and special aggregating polymers, coated with a special temporary protective film. This coating controls the onset of expansion, delaying it for approximately 6–7 days after casting, which is the time necessary for the concrete to fully develop its initial strength. This “Long Time” technology of the Drykos® Jointseal Tape LT waterstop avoids any interference with the setting and curing phases of fresh concrete, eliminating the risk of premature pressure on the unhardened conglomerate.
During the initial stages following the pour, the surface protective film prevents immediate hydration of the hydro-expansive component, keeping the strip dimensionally stable. Once the protection period has passed, the coating progressively dissolves, allowing the swelling process to activate. Expansion therefore occurs when the concrete has already developed adequate mechanical characteristics, allowing Drykos® Jointseal Tape LT to perform its sealing action under conditions of full confinement and structural safety.
It is supplied with a rectangular cross-section of 25 × 20 mm in 5 m rolls.
Features
Main features
- Delayed and controlled volumetric expansion
- Activation of expansion after approximately 6-7 days
- External protective film with timed dissolution
- High dimensional stability in the initial phase
- Optimal adaptation under confinement
- Permanent airtight seal of the construction joint
Fields of application
- Horizontal and vertical construction joints
- Construction joints in structural works
- Foundations and thick floor slabs
- Massive pours
- Retaining walls and underground structures
- Tanks, reservoirs, and hydraulic works
- Tunnels and underground infrastructure
- High technical responsibility structures
Technical specifications
Packaging
Color
Black.
Appearance
Compact strip.
Storage
12 months from production date.
Storage conditions
Store correctly in the original, sealed, and intact packaging, protected from moisture, frost, and direct sunlight, preferably at temperatures between +5°C and +35°C. Unsuitable storage conditions may compromise the rheological performance of the material.
Application data
Theoretical consumption
1 m per linear meter
Application temperatures (substrate and environment)
Minimum -20°C | Maximum +50°C
Application info
Substrate preparation
At the time of application, the concrete substrate must be solid, compact, and free of loose parts.
Before installation, it is necessary to remove cement laitance, dust, processing debris, and any residues from casting operations to ensure proper adhesion of the strip to the substrate.
Drykos® Jointseal Tape LT can also be applied to slightly damp surfaces, provided there is no standing water or ongoing washout phenomena.
Application
Drykos® Jointseal Tape LT must be positioned manually along the intended line of the construction joint, ensuring the continuity of the strip and its perfect adhesion to the substrate.
Fixing can be carried out by bonding with the specific Drykos® Sealflex N adhesive cartridge or by mechanical nailing, using steel nails equipped with washers, with a fixing point approximately every 20–25 cm.
Joints between different sections of the strip must be made by simply butting the ends together for a minimum length of 5 cm, avoiding overlaps that could compromise the regularity of the expansion.
In particularly demanding application conditions or in the presence of irregular surfaces, the specific Drykos® Jointnet LT containment cage is available, made of galvanized steel wire and supplied in 1 m profiles. The cage must be fixed to the substrate by nailing, ensuring effective confinement of the strip.
Correct positioning of the waterstop must ensure a minimum concrete cover of 8 cm on both sides, a necessary condition to contain and counteract the expansive action generated by the hydration of the bentonite. Similarly, any formwork spacers must be placed at a distance of no less than 8 cm from the bentonite strip.
Other indications
- However, it is recommended to carefully check the condition of the strip before pouring concrete in cases of: intense weather events with prolonged immersion of the material; exposure to atmospheric agents for several days before the pour; environments characterized by high humidity, persistent fog, or standing water in direct contact with the strip.
- The product must not be used on surfaces heavily contaminated by aggressive substances such as acids or solvents. In such conditions, it is necessary to thoroughly clean the substrate and evaluate application suitability in advance.
- Do not install the strip in the absence of adequate confinement
- Not suitable for structural joints or expansion joints
- Reinforcement spacers must be placed at an adequate distance from the strip so as not to interfere with the correct expansion of the material
- For anything not covered, contact Technical Support at +39 0171 1874992 or write to [email protected]
Technical performance
Environment and safety
Safety
The product is classified as an article and, in accordance with Regulation (EC) No. 1907/2006 (REACH), does not require the preparation of a Safety Data Sheet. During handling and use, it is nonetheless recommended to use appropriate personal protective equipment, such as gloves and protective goggles, and to comply with the safety procedures established at the workplace.
Use
Product for professional use.