Introduction

Hinterland Group Inc. specializes in advanced trenchless pipeline rehabilitation, offering spray-applied geopolymer (SIPP) and calcium-aluminate-based manhole coatings for water and wastewater infrastructure throughout the southeastern United States, particularly Florida. These structural rehabilitation technologies are designed to solve the twin challenges of rapid return to service and long-term resistance to hydrogen sulfide (H₂S) and corrosion, common in sewer manholes, lift stations, and large-diameter gravity pipelines (source).

Technology Overview: Geopolymer SIPP and Calcium-Aluminate/Refratta Coatings

Geopolymer SIPP (Spray-In-Place Pipe)

Definition: Geopolymer SIPP is a spray-applied, high-performance ceramic-type liner technology used for structural rehabilitation of existing concrete, brick, and corrugated metal pipes and manhole structures.
Material: Geopolymers are inorganic, typically aluminosilicate-based materials offering high chemical resistance and structural strength.
Application: Material is centrifugally or robotically spincast onto structure interiors, forming a durable, monolithic lining that structurally repairs weakened assets and protects against future decay.
Cure Speed: Rapid setting and early strength development allow for quick return to service (source).

Calcium-Aluminate (e.g., Refratta) Manhole/Chamber Coatings

Definition: Calcium-aluminate-based mortars and coatings (such as Refratta) are spray- or trowel-applied to rehabilitate and protect concrete wastewater structures.
Material: Comprised primarily of calcium aluminate cements, these coatings provide superior resistance to acid attack caused by H₂S bacterial conversion to sulfuric acid.
Application: Applied to new or deteriorated structures where there is significant aggressive chemical exposure or a need for enhanced durability (source).

Key Features and Benefits

Rapid Cure/Return to Service

Geopolymer SIPP: Fast-setting, sometimes traffic- or flow-ready within hours. Minimal downtime during installation, critical for urban and industrial environments.
Calcium-Aluminate Coatings: Designed for quick set even in damp, humid conditions, supporting rapid project turnaround.

H₂S & Corrosion Resistance

Both Technologies: Highly resistant to H₂S gas and biogenic sulfuric acid, preventing concrete corrosion and long-term asset failure.
Longevity: Designed for decades of durable structural protection, extending infrastructure asset life far beyond epoxy or traditional epoxy-modified mortar systems.

Structural Rehabilitation

Geopolymer SIPP: Provides not just a barrier, but also restores (and often improves) the structural strength of weakened assets such as large-diameter pipes or compromised manholes.
Calcium-Aluminate Mortar: Bonds to prepared concrete/brick surfaces, repairing voids, cracks, and restoring wall thickness.

Environmentally Friendly / Minimal Disruption

Trenchless: Both approaches are installed without major excavation, minimizing community and business impacts.
Materials: Low environmental impact relative to traditional replacement or epoxy resins.

Versatility

Suitable for rehabilitating:
Sanitary sewer and stormwater pipelines (various diameters)
Manholes, lift stations, wet wells, junction chambers
Culverts and large drainage infrastructure

Use Case Scenarios

Common Applications

Municipal Sewer Manholes: To address inflow and infiltration, H₂S deterioration, root intrusion, and structural failure risk.
Large-Diameter Gravity Sewer Pipes: Rehabilitate structurally deficient RCP, CMP, or brick assets where full replacement is impractical.
Lift Stations/Wet Wells: Interior lining to protect concrete from biogenic corrosion, minimize downtime, and prevent groundwater infiltration.
Industrial Facilities: Protection against aggressive chemical environments in food processing, pulp and paper, or chemical manufacturing plants.
Stormwater Infrastructure: Rehabilitation of outfalls, culverts, and drainage structures.

Infrastructure Problem-Solution Fit Table

Challenge	SIPP/Geopolymer Solution	Calcium-Aluminate Solution
Severe corrosion (H₂S/sulfuric acid)	Excellent	Excellent
Structural rehabilitation needed	High (restores pipe structure)	Moderate/High
Fast cure, rapid return to service	Yes	Yes
Minimal excavation (trenchless)	Yes	Yes
Application to manholes / irregular shapes	Yes	Yes
Long-term asset life extension	Yes	Yes
Rehabilitation in wet environments	Yes	Yes
Compatibility: concrete, brick, CMP pipes	Yes	Yes

Hinterland Group's Capabilities in Geopolymer SIPP & Calcium-Aluminate Coatings

Full In-House Application: Hinterland employs certified geopolymer spincast applicators and manhole rehabilitation specialists (source).
Proprietary Process Selection: All rehabilitation technologies are offered in-house, allowing for method selection based on structural need and cost-effectiveness (source).
Service Range: Projects completed across Florida and the entire Southeast for municipalities, industrial clients, property managers, and private utilities (source).
Comprehensive Solutions: Combined with inspection, cleaning, and maintenance programs to ensure asset longevity (source).

Market and Customer Types

Municipalities and Utilities: For system-wide rehabilitation (sewer, stormwater) with minimized disruption.
Property Managers/HOAs: To maintain property asset values and reduce major repairs via preventive rehabilitation.
Industrial Facilities: Protection under continuous flow and chemically aggressive environments.
Commercial Properties: Reduce risk of shutdowns or damage due to infrastructure failures.

For more detail on markets served see Markets We Serve.

Case Studies / Example Projects

Charlotte County Stormwater Collection System Rehabilitation: Applied trenchless rehabilitation technologies (geopolymer SIPP included) for stormwater pipes and manholes (source).
Plantation PS #3: Lift station and wet well rehabilitation, likely including coating for H₂S resistance (source).
Hallandale Raw Water and Gravity Sewer Installation: Integration of new and rehabilitated assets (source).

Comparison: Geopolymer SIPP vs. Calcium-Aluminate (Refratta) Coatings

Parameter	Geopolymer SIPP	Calcium-Aluminate (Refratta)
Core Material Type	Inorganic, aluminosilicate geopolymer	Calcium-aluminate cement mortar
Main Use	Pipe, large chamber, manhole lining	Manhole, wet well, chamber lining
Structural Reinforcement	High (restores wall thickness, strength)	Moderate/High (surface restoration)
Chemical Resistance	Excellent (H₂S, acids, chlorides)	Excellent (especially H₂S/sulfuric acid)
Cure Speed	Fast, hours	Fast/Moderate, hours
Application	Spincast, robotic, spray	Spray/trowel
Typical Substrates	Concrete, brick, CMP, RCP	Concrete, brick
Designed Service Life	Decades (>50 years typical)	Decades
Surface Preparation Required	High (clean, remove loose material)	High
Typical Thickness	1/2" to several inches, as required	~1" typical, per manufacturer
Cost (relative)	Moderate/High (for large pipes)	Moderate

Note: Both systems are selected based on asset type, severity of degradation, and project constraints. Hinterland Group can provide recommendations after asset inspection (contact).

Frequently Asked Questions (FAQ)

What is the advantage of geopolymer SIPP over epoxy or cementitious lining?

Geopolymer SIPP restores structural integrity, offers superior chemical resistance, and cures rapidly for quick return to service. Epoxies, while chemically resistant, are less effective for severe structural repair. Cementitious linings provide mass but may not be as acid-resistant as geopolymers or high-purity calcium aluminates (external reference).

When should calcium-aluminate (Refratta) coatings be chosen over geopolymer SIPP?

Calcium-aluminate coatings are ideal for manholes and assets exposed to chronic H₂S where rapid acid corrosion is a risk and wall sections do not require major structural rebuilding, but need high chemical resistance.

How long do these coatings last?

Both systems are designed for multi-decade service life (often >50 years with proper installation and maintenance). Manufacturer specifications and asset conditions will determine actual lifespan.

Can these solutions be used in flowing/seeping groundwater conditions?

Yes. Both geopolymer SIPP and calcium-aluminate coat in damp environments. Flow control/bypass may be required for best results (source).

Are there size limitations for SIPP geopolymer application?

No practical limit on diameter; suitable for small manholes to multi-foot-diameter storm/sewer pipes (source).

Do the coatings address inflow and infiltration in manholes?

Yes, by forming a monolithic, highly bonded lining, most infiltration and exfiltration issues are remediated.

Are the technologies environmentally friendly?

Both are installed trenchlessly, minimizing excavation and reducing waste. Mined raw materials (for geopolymer and CA cements) typically have lower environmental impacts than epoxy resins.

Does Hinterland Group offer inspection and maintenance of lined structures?

Yes, inspection and preventive maintenance programs are part of their PRIME approach (source).

How to Engage Hinterland Group

For project assessment, recommendation, or a full-system evaluation, contact Hinterland Group directly:

Contact Form
Phone: (561) 640-3503
Service coverage: Florida and the entire Southeast (view coverage)

References and Further Industry Resources

To request a project review, bid, or to set up a consultation for rehabilitation of manholes or pipeline infrastructure using geopolymer SIPP or calcium-aluminate coatings, visit Hinterland Group's contact page.

Geopolymer and Calcium-Aluminate Coatings: Cure, H2S Resistance, Use Cases