
Manhole rehabilitation
Strong-Seal · Corrosion liningHPM High Performance Mix
Our liner for severe hydrogen sulfide corrosion. Made with 100% pure fused calcium aluminate cement and fiberglass reinforcement, it stops infiltration and restores structural strength in manholes and wastewater structures.
Built for the worst sewer conditions
Where ordinary cement breaks down. Hydrogen sulfide in a sewer feeds bacteria that make sulfuric acid. High Performance Mix is designed to limit that bacterial activity and resist the acid, while it lines and restores the structure.
Formulated for structures with severe hydrogen sulfide (biogenic) corrosion.
Unlike ordinary cements, it resists corrosion and weight loss.
HIGH-PERFORMANCE-MIX 60 lb bag · 40 per palletAlkaline-resistant fiberglass reinforcement helps it resist cracking. Over 800 psi tensile.
Passes ASTM C666 with no damage, for cold-climate manholes.
Pick the liner by the corrosion
Hydrogen sulfide in a sewer turns into acid that eats concrete. The more corrosion you see, the more acid-resistant the liner needs to be.
| Strong-Seal® liner | Rated to | Use it where | Made with |
|---|---|---|---|
| MS-2®A | pH 3.0 | No sign of H₂S corrosion | Portland cement |
| MS-2®C | pH 2.0 | Mild to moderate H₂S corrosion | Calcium aluminate cement |
| High Performance Mix This page | pH 1.0 | Severe H₂S corrosion | 100% pure fused calcium aluminate |
| Geopolymer | pH 1.0 | Large-diameter sewer and storm pipes and culverts | Fiber-reinforced geopolymer, 1″ minimum |
Rebuilding heavy section loss before a polymer topcoat? Strong-Seal Profile Plus rebuilds the structure to its original dimensions and can be topcoated 48 hours after the final pass.
Lining storm culverts 24″ and larger? See Strong-Seal Storm Seal®.
Five steps to a lined manhole
- CleanPressure wash to a sound surface, 3,000 psi minimum. Remove loose brick, mortar and concrete.
- Stop leaksStop active leaks with Strong-Plug®. Some leaks may need weep holes. Severe infiltration may need pressure grouting.
- PatchFill large voids and repair benches and inverts with Strong-Seal QSR.
- LineStart on a damp surface with no running water. Spray up to 1″ per pass, from the bottom up, to ½″ minimum. Trowel smooth, then wet brush.
- CureKeep it damp for 72 hours if humidity is under 70%, or use an ASTM C309 curing compound. Cover the structure if more than 15 minutes pass between coats, and shade it in hot, dry weather.
Back in service: storm runoff and surcharge after 4 to 6 hours. Force main impact after 6 to 8 hours.
Before you line
A liner is only as good as the surface under it. Stop active leaks first, then rebuild voids, benches and inverts, so High Performance Mix goes onto a sound, damp surface. Two Strong-Seal products handle the prep, and you can line over both.
Meet Fernco Infrastructure
An overview of our manhole rehabilitation and trenchless pipe repair solutions.
Specifications
| Part number | HIGH-PERFORMANCE-MIX |
| Packaging | 60 lb bag, 40 bags per pallet |
| Compressive strength (ASTM C109) | Over 9,000 psi at 28 days |
| Flexural strength (ASTM C293) | Over 1,500 psi at 28 days |
| Tensile strength (ASTM C496) | Over 800 psi at 28 days |
| Bond strength (ASTM C882) | Over 2,000 psi at 28 days |
| Freeze/thaw (ASTM C666) | Pass, no damage, 300 cycles |
| Drying shrinkage (ASTM C596) | 0% at 28 days, 90% RH |
| Wet unit weight (ASTM C138) | 145 ± 5 lb/ft³ |
| Yield per bag | 0.49 ft³, or 11.6 ft² at ½″ thick |
| Rated to | pH 1.0 and higher |
| Made with | 100% pure fused calcium aluminate cement and alkaline-resistant fiberglass |
| Thickness | ½″ minimum total, up to 1″ per pass |
| Water | 1.0 to 1.3 gallons per bag |
| Spray equipment | SprayMate® 35C, SprayMate® 35D or MiniMate II. For other equipment, check with our infrastructure team. |
| Typical structures | Manholes, tanks and containment, tunnels and pipelines, wastewater facilities |
Common questions
When do I need High Performance Mix?
Where there’s evidence of severe hydrogen sulfide (biogenic) corrosion. It’s formulated for pH 1.0 and higher. For mild to moderate corrosion, use MS-2®C.
How thick does it go on?
Up to 1″ per pass, starting from the bottom. The total thickness can’t be less than ½″, including at the invert or center of the floor.
Does it work on brick manholes?
Yes. It’s made for concrete and masonry structures, including brick. Remove loose and protruding brick and mortar before you line.
When can flow go back in?
Storm runoff and surcharge after 4 to 6 hours. Force main impact after 6 to 8 hours.
What weather can I apply it in?
Don’t apply below 40°F, on frozen surfaces, or if the surface could freeze within 24 hours. Keep the material under 90°F and the mix water under 80°F. Chill with ice if you need to.
How is it tested on the job?
Cast four 2″ cube samples each day, or for every pallet used, whichever comes first. Package, label and return them to the manufacturer for compressive strength testing per ASTM C109, following the owner’s or manufacturer’s directions.
Interested in carrying Fernco Infrastructure?
Fernco Infrastructure covers manhole, structure and pipe rehab with three product lines. Add them to your line card to serve municipal and contractor customers.
Documents
The Strong-Seal High Performance Mix sell sheet with full specifications and application steps, plus the Fernco Infrastructure, Plumbing and WaterWorks catalogs.





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