Installation of bentonite cord

Bentonite cord is a profile that swells upon contact with water. It is used for sealing joints of concreting breaks (cold, working), communication inputs and sealing shuttering holes in concrete.

Depending on the purpose, there are different types of bentonite cord, respectively, and a different installation method.

Bentonite cord of rectangular cross-section can be of different sizes and is used to seal cold joints in concrete (foundations, floor-wall connection, wells, reservoirs, pools, etc.):

• Bentonite cord 10x20 mm – used for sealing cold joints, with a concrete structure thickness from 80 mm to 150 mm.
• Bentonite cord 15x25 mm – used for sealing cold joints, with a concrete structure thickness from 150 mm to 250 mm.
• Bentonite cord 20x30 mm – used for sealing cold joints, with a concrete structure thickness from 250 mm to 400 mm, as well as in structures that are subject to high groundwater pressure or very deep occurrence.

Installation of bentonite cord:

The surface on which the bentonite cord will be laid should be smooth, without potholes and cracks, thoroughly cleaned of dirt, dust, construction debris. There should be no standing water, but a slightly damp base is allowed.
The bentonite cord is laid on a flat and clean surface so that the distance from the edge to the harness is at least 30 mm from the side of the expected water pressure.

In the case when the reinforcement comes out of the concrete part, a bentonite cord is laid between the reinforcement projections. If the thickness of the concrete structure is more than 400 mm, a bentonite cord measuring 20 * 30 is laid in two contours, on both sides of the insulated seam, at a distance of at least 50 mm from the edge of the concrete.
The connection between each other is made with an overlap of 50 mm or joint to joint, but, at the same time, the ends of both sides must be forked by 100 mm and woven together.
The bentonite cord is fixed using a special mounting grid or fixed with dowels, sealant, glue or mastic.
After that, you can start pouring the next part of concrete (foundations, pools, reservoirs, etc.), or laying reinforced concrete structures (wells, septic tanks, etc.).

Bentonite cord 5x20 mm is the minimum cross–section, which is used only for sealing places of passage of engineering communications: engineering networks of water supply, sewerage, centralized heating, etc.

Installation of bentonite cord for sealing the inputs of communications:

• In case of non-new construction (repair, restoration, restoration): embroider the abutment around the pipe to the foundation. And also treat the concrete surface with penetrating waterproofing.
• Clean the pipe from dirt, dust and construction debris.
• Wrap the bentonite cord around the pipe or sleeve being laid several times (at least 2)
• Fix the cord with glue, sealant or wire.
• Seal the inlets with a cement-based non-shrink repair compound.
• After solidification of the repair compound, treat the surface with a coating or penetrating waterproofing.

Round bentonite cord d-22 mm - used for sealing holes in concrete.

During the concreting of structural elements, for the correct shape, construction formwork is used. The formwork panels are tightened with metal anchors (tie screw, anchor rod, stud) and fixed with nuts, while the anchor itself is inserted into a plastic pipe so that it can be easily reached after the concrete has hardened. After removing the formwork, the tube remains in the concrete body, and since plastic and concrete do not create a single whole, this place very often becomes the cause of active water leaks. In order to seal these holes, a round bentonite cord is used.

Installation of a round bentonite cord:

• Drill a plastic tube out of the concrete body, at least 180 mm deep.
• Clean the hole from dust, dirt, oil, construction debris. A slightly damp base is allowed.
• Insert a bentonite cord of round cross-section, 22 mm in diameter into the hole. The length of the bentonite cord depends on the thickness of the concrete structure and is approximately 5-8 cm.
• After that, the hole is sealed with a non-shrink repair compound on a cement-based thixotropic type.
• The sealed hole, after solidification of the repair compound, as well as in a radius of 20-30 mm, should be treated with penetrating waterproofing.