The Complete Guide to Trenchless Polyurea Pipe Rehabilitation

PART 3. Why Polyurea Suits Pipe Rehabilitation

3.1 Elongation and Flexibility — Resistance to Vibration and Ground Settlement

📌 Definition

Elongation refers to the percentage a material can stretch without breaking. Polyurea has an elongation rate of 400% to 450% depending on the grade.

Polyurea is unique in that it maintains concrete-level strength while simultaneously possessing a high elongation rate. Thanks to this flexibility, even if cracks appear in the concrete substrate, it does not break but follows the movement.

Pipelines are constantly undergoing subtle movements due to vibration, ground settlement, and temperature changes. Materials with low elongation cannot withstand these movements and crack, but polyurea follows the cracks, maintaining its waterproofing and structural performance. This flexibility and strength are even utilized as blast-protection measures in military facilities.

400~450%
Elongation
3.0N/mm²↑
Adhesion to Concrete
Richter 7.0
Waterproof Product Standard
Seismic Resistance Performance

3.2 Thickness Achievability

📌 Definition

Conventional coatings cover surfaces with a thickness of 1-2mm, forming a waterproof and anti-corrosion film. HIGHCOATIC's pipe lining is applied with a thickness of 19mm to 51mm, creating a new structural body inside the pipe.

This difference in thickness holds more significance than just a numerical value. While thin coatings of 1-2mm merely provide waterproofing and corrosion protection, 19-51mm linings form a separate structural body inside the pipe. In other words, it effectively creates a new pipe within the existing one.

Comparison of Conventional Coatings and HIGHCOATIC Pipe Linings

CategoryConventional CoatingHIGHCOATIC Pipe Lining
Thickness1~2mm19~51mm
RoleForms a waterproof and anti-corrosion filmForms a structural body inside the pipe, effectively creating a new pipe
Application MethodSpray, roller, or brush applicationExternal remote-controlled application via specially manufactured robots, unmanned

The reason such thickness can be achieved is due to its ultra-fast curing properties. Even when multiple layers are repeatedly sprayed in a short period, it cures in place without sagging, allowing thick structures to be built up quickly.

3.3 Chemical Resistance, Abrasion Resistance, and Corrosion Resistance

The interior of pipelines is constantly in contact with various substances such as water, gas, chemicals, and wastewater. Polyurea possesses the chemical resistance and abrasion resistance required in such environments.

Taber Abrasion Test Results — Abrasion Loss by Grade

Test StandardSTXTALLPPABG
ASTM D4060, CS-17 abrasion wheel8mg20mg35mg30mg25mg-
JIS K 5600-5-9, CS-10 abrasion wheel3mg14mg---3mg

Chemical Resistance Performance Test Results — Applicability by Grade, based on ASTM D3912

Chemical NameConcentrationSTXTLPPA
Hydrochloric Acid10%
Sulfuric Acid15%
Sulfuric Acid50%×××
Seawater-
Wastewater-
Diesel, Gasoline-
Sodium Hydroxide, Caustic Soda20%
Sodium Hydroxide, Caustic Soda50%-

● indicates recommended, ○ indicates conditionally recommended, and × indicates not recommended. Since the applicable chemicals and concentrations vary by grade, the product must be selected to match the substances transported by the pipeline. Detailed data for all 29 types of chemicals can be obtained by contacting HIGHCOATIC.

Shore D 80
Hardness · Abrasion Resistance
50%
Sulfuric Acid Concentration
Handled (depending on grade)

3.4 Eco-Friendliness and Suitability for Potable Water Facilities

Polyurea is a material with 0% volatile organic compounds (VOCs). It has minimal impact on worker safety and the surrounding environment.

📌 Certification Status

All HIGHCOATIC products have completed certification for use in potable water and food facilities by relevant authorities in the US, Singapore, Canada, China, and other countries. Among them, NUKOTE ST PW and Nukote IM 129 are compliant with ANSI/NSF 61, the US standard for materials in contact with drinking water. They also hold Class 1 flame retardancy certification according to ASTM E84 standards.

These certifications confirm that HIGHCOATIC's pipe linings can be safely applied to pipes that come into direct contact with drinking water, such as water supply pipes.

3.5 Application Speed

One of polyurea's greatest strengths is its curing speed. It cures within seconds to minutes after application, allowing for hundreds of square meters of application per day.

Within 10 seconds
Curing Time
30 minutes
Time until
vehicle traffic is possible after application
3-5 times
Waterproofing lifespan
compared to conventional epoxy/urethane

This application speed significantly reduces site occupation time and construction periods compared to methods like excavation-based replacement or CIPP, which require liner insertion and waiting for curing.

PART 3 Summary

  • High elongation allows it to withstand pipe vibrations and ground movements without cracking.
  • The ability to achieve thicknesses of 19-51mm goes beyond simple coating, forming a structural lining within the pipe.
  • Taber abrasion tests and data from 29 chemical resistance tests support its abrasion and chemical resistance.
  • With 0% VOCs and certification for potable water and food facilities, it can be safely applied to water supply pipes.
  • Ultra-fast curing within 10 seconds significantly shortens application time and construction periods.