Chloride Egypt Drainage Waterproofing
Drainage channels at Chloride Egypt were lined with hot-spray polyurea in 2020.
01 · Project overview
What is this project?
Industrial drainage is a long concrete trough that nobody visits until it leaks into a foundation. At Chloride Egypt the channels turn corners, drop into outlets, and carry whatever the plant washes down them.
In 2020 those channels were lined with pure polyurea. Nile City applied the work. A drain is almost all detail and very little flat area, so the membrane has to be one that likes a corner.
| Place | Chloride Egypt |
|---|---|
| Year | 2020 |
| Scope | Drainage channels |
| System | Hot-spray pure polyurea |
| Applicator | Nile City |
02 · The challenge
What did this structure ask of the membrane?
Wash-down water sits in the invert. A rigid coat cracks at the change of direction. A sheet lining wants laps, and a lap in a drain is a place to peel. The lining has to stick, and it has to be continuous from the channel into the outlet.
03 · The solution
Which Krypton system was trusted here?
Sprayed polyurea is the practical answer on that shape. Polyurea Rayston is put on hot, at high pressure, and it gels in about four seconds, so it stays on the wall of a channel instead of running to the bottom. The same film lines the outlet.
04 · Application
How is this system built?
Concrete is prepared before any resin goes down. Polyurea Rayston, Krypton’s hot-spray pure polyurea, wants a support that is flat, compact and cohesive. Pull-off strength should be at least 1.4 N/mm2. Cracks are cut out and filled first. High-pressure sand or abrasion opens the pores, and the dust is vacuumed off. Moisture in the concrete must sit under 4 percent. Concrete temperature belongs between 10 and 40 degrees C, and the air should be under 85 percent relative humidity. If damp is suspected behind the slab, two coats of epoxy primer go on, the second one blinded with quartz sand. Metal is cleaned and primed with a polyurethane primer. That bond is what stops a blister when the structure heats up.
A drain carries dirty water, cleaners and the odd splash of chemical. Corners and outlets take the wear. The lining has to stick, and it has to turn those corners without a joint of its own.
Spraying is hot and fast. Both components are brought to about 25 to 30 degrees C before they are loaded. In the machine they run hotter: about 65 degrees C on the resin, 75 degrees C on the isocyanate, and 65 degrees C in the hose. Pressure at the gun is at least 140 bar. The usual build is 1.5 to 2.0 kg/m2, which leaves a film about 1.5 to 2 mm thick. Gel time is about 4 seconds at 25 degrees C. The surface is tack-free in a matter of seconds, not hours. Hardness climbs from roughly 28 Shore A at five minutes to about 88 Shore A after four days. One pass should make the thickness. Where a corner needs a second pass, it should follow within about two hours.
Speed is the practical gift on a crowded site. Upstands, outlets and internal corners can be closed before the next trade arrives. The film itself is elastic. Typical elongation is 324 percent and tensile strength is 16.2 MPa, with tear strength around 69 N/mm. It bridges cracks instead of snapping when concrete moves.
A drain lining has to shrug off dirty water, not just rain. Chemical testing puts Polyurea Rayston in class II against 25 percent salt and class III against hydrogen sulphide and 10 percent sulphuric acid. That is product data, and it is why the film belongs in a channel that sees wash-down as well as storm water. Water uptake is very low, about 0.002 kg/m2 per square-root hour. The resin is aromatic, but a channel is rarely a matter of colour. The product carries CE marking to EN 1504-2 and European Technical Assessment 16/0148.
Polyurea Rayston technical data sheet
After the spray, the invert and the outlets are the job. A channel that is thick on the flat and thin at the bend will leak at the bend. The film has to turn the corner at the same build, and the outlet has to be inside the film. Let the hardness climb before wash-down water is sent down it. Hours for a light touch, days for a full cure. A drain does not get a second easy visit once the plant is running.
05 · Results
What does a job like this ask us to stand behind?
The channel has to carry its water inside the lining, not through the concrete under a factory floor. That is the line this spray is there to hold.
06 · Products
Which products carry this duty?
Polyurea Rayston
Hot-spray pure polyurea. Typical build 1.5 to 2 mm. Elongation 324 percent. Root resistance tested to CEN/TS 14416.
07 · FAQ
Frequently asked questions
How fast does the polyurea set?
Polyurea Rayston gels in about 4 seconds at 25 degrees C and is tack-free in seconds. Full hardness still takes days.
Will it bridge a crack?
Typical elongation is 324 percent and tensile strength is 16.2 MPa. The film is meant to stretch with the concrete, or with a metal panel, instead of tearing at the movement.
Will wash-down water attack it?
The datasheet puts the film in class II against 25 percent salt and class III against hydrogen sulphide and 10 percent sulphuric acid. Outlets still have to be sprayed in, not left as a joint.
Does sunlight damage it?
Colour can shift because the resin is aromatic. Strength stays. An aliphatic topcoat is added where the film remains in the sun.
What moisture can the concrete have?
Support moisture should be under 4 percent, with concrete between 10 and 40 degrees C. Wetter concrete gets an epoxy primer blinded with quartz.