Mirafi HP570 applications, specifications and selection considerations
What Mirafi HP570 is used for
Mirafi HP570 is a high-performance woven polypropylene geotextile used where a project requires separation, filtration and reinforcement from one geosynthetic layer. Public product literature from Solmax and TenCate describes it as a high-tenacity woven fabric for stabilization and soil reinforcement applications, including roads, railways, embankments and other aggregate-supported structures. In practical design terms, it is not selected only because it is a strong fabric. It is selected when the detail must keep aggregate and subgrade soils from mixing, maintain water movement through the section and add tensile restraint that helps distribute loads over weak or variable soils.
Project teams checking “mirafi hp570” are usually looking for technical fit: whether the product is woven or nonwoven, how its published strength and hydraulic values compare with a specification, and where it may belong in a civil works detail. This article focuses on those application and selection questions. For related textile application topics, visit the Applications section.
Published specifications and what they mean
Product data sheets should be checked before procurement because manufacturers can update values, roll sizes and approval status. The table below summarizes commonly published Mirafi HP570 values from Solmax and TenCate technical literature. These values are useful specification references, but they do not replace project design or agency requirements.
| Property | Test method | Published value | Why it matters |
|---|---|---|---|
| Material and structure | Product description | High-tenacity polypropylene yarns woven into a stable network | Supports dimensional stability, separation and tensile reinforcement under aggregate layers. |
| Wide-width tensile strength at ultimate | ASTM D4595 | 4,800 lb/ft, or 70.0 kN/m, in both machine and cross-machine directions | Indicates high tensile capacity for reinforcement and survivability, especially in demanding installation conditions. |
| Tensile strength at 5 percent strain | ASTM D4595 | 2,400 lb/ft, or 35.0 kN/m, MD; 3,000 lb/ft, or 43.8 kN/m, CD | Helps engineers consider serviceability, deformation control and directionality, not only ultimate strength. |
| Flow rate | ASTM D4491 | 30 gal/min/ft2, or 1,222 L/min/m2 | Shows water flow capacity normal to the plane of the fabric under the test condition. |
| Permittivity | ASTM D4491 | 0.50 sec-1 | Supports filtration and drainage checks when the fabric is placed between soil and aggregate. |
| Apparent opening size | ASTM D4751 | U.S. Sieve 30, approximately 0.60 mm | Must be compared with site soil gradation to reduce the risk of piping, clogging or excessive soil migration. |
The tensile numbers often receive the most attention, but the hydraulic numbers should not be treated as secondary. A stabilization geotextile may underperform if it has adequate strength but allows fines to migrate, clogs too quickly or does not match the drainage assumptions of the section. Apparent opening size, permittivity and flow rate should be reviewed against the soil gradation, groundwater condition and aggregate gradation specified by the engineer.
Directionality also needs attention. The published ultimate tensile value is balanced in both directions, while the 5 percent strain values are not identical. If the design assumes a primary load direction, the plans should still show the required roll orientation. On bridge abutments, embankment toes and reinforced soil sections, orientation and connection details can be as important as the product name.
Main application areas
Unpaved roads, access roads and haul roads
Mirafi HP570 is commonly considered where construction traffic or service traffic must pass over weak subgrade soils. In an unpaved road section, the geotextile is normally placed between the prepared subgrade and the aggregate base. Its separation function reduces aggregate contamination by fines. Its filtration function allows water movement while limiting soil migration. Its reinforcement function helps distribute wheel loads and reduce rutting potential when the aggregate layer is properly designed and compacted.
The fabric alone does not make a weak road stable. Aggregate thickness, subgrade strength, moisture condition, traffic loading, compaction and drainage still control performance. The geotextile is one component in the road system. When used correctly, it can help preserve aggregate quality and improve constructability over soils that would otherwise pump, rut or mix with the base course.
Paved roads, parking areas and working platforms
For paved road bases, industrial yards, temporary work platforms and parking areas, a high-performance woven geotextile may be considered where the pavement structure needs subgrade stabilization below the aggregate base. This is different from a paving fabric used within asphalt layers. Mirafi HP570 belongs to the stabilization and soil reinforcement family, so its typical position is beneath aggregate rather than between asphalt lifts.
The distinction matters because a geotextile placed in the wrong layer may not deliver the intended benefit. A woven stabilization fabric under aggregate addresses aggregate-soil interaction. A paving interlayer is used for asphalt cracking, waterproofing or bond-related functions. Engineers and contractors should confirm the intended function before substituting one fabric type for another.
Railways, embankments and soft foundation work
Railway and embankment applications can involve repeated loading, high aggregate stresses and difficult subgrade conditions. A woven geotextile with high tensile capacity may be evaluated for separation and reinforcement beneath ballast, subballast, working mats or embankment fill. The same selection logic applies: the fabric must match the loading, subgrade, aggregate and hydraulic conditions.
Soft foundation work often adds design questions such as settlement, global stability, creep, staged construction and drainage paths. In these cases, published tensile strength is only the starting point. Designers usually apply reduction factors for installation damage, creep and durability to estimate allowable long-term design strength. Project-specific calculations remain necessary.
GRS-IBS bridge and abutment details
Geosynthetic Reinforced Soil Integrated Bridge System projects use closely spaced layers of compacted granular fill and geosynthetic reinforcement to create a composite mass. Federal Highway Administration guidance describes the use of wrapped geotextile layers in approach and foundation zones to help confine granular fill and manage transitions near bridge beams. Solmax has also published a Rock County, Minnesota case study in which Mirafi HP570 was used to encapsulate compacted gravel as part of an abutment base system.
That type of case study is useful as an application example, but it should not be read as universal design approval. Bridge abutments require engineering checks for bearing, sliding, settlement, reinforcement spacing, facing details, drainage and construction sequencing. If Mirafi HP570 is referenced in a bridge detail, the project drawings and specifications should define layer spacing, overlap or seam requirements, orientation, fill gradation and compaction criteria.
How Mirafi HP570 compares with adjacent geosynthetic choices
A common source of confusion is the difference between woven geotextiles, nonwoven geotextiles and geogrids. Mirafi HP570 is a woven geotextile. It provides high tensile strength while also serving separation and filtration functions. Nonwoven geotextiles are often selected where cushioning, filtration and drainage are more important than high tensile reinforcement. Geogrids provide strong aggregate interlock and reinforcement, but they generally do not provide continuous separation or filtration, so a geotextile may still be needed with them in some soil conditions.
Within the Mirafi HP-Series, HP570 sits among products with different strength and hydraulic profiles. Lower-strength grades may suit lighter stabilization needs, while higher-strength grades may be evaluated where design loads, installation stresses or reinforcement requirements increase. The correct choice depends on design calculations and project specifications, not on a simple “stronger is always better” rule. A stronger fabric can still be unsuitable if its opening size, permittivity, seam behavior or agency approval does not match the project. See also: Coatings.
It is also important not to confuse structural geotextiles with landscape fabrics. Landscape fabrics may look similar to non-specialists, but they are not designed or tested for the same construction stresses, tensile requirements or civil engineering functions. For road bases, working platforms and reinforced soil applications, substitution should be controlled by the engineer of record or the agency specification.
Selection checks before specifying or substituting
Before specifying Mirafi HP570 or approving it as an equal, the reviewer should confirm the intended function. Is the fabric expected to provide separation only, separation plus filtration, reinforcement, or a combination of all three? A product that satisfies one function may not satisfy another.
- Confirm soil compatibility. Apparent opening size and permittivity should be reviewed against soil gradation and water conditions. Fine silts, gap-graded soils and high groundwater conditions may require extra attention.
- Check strength basis. Published wide-width tensile strength is not the same as allowable long-term design strength. Reduction factors may be needed for creep, installation damage, seams and durability.
- Verify agency acceptance. Some transportation agencies maintain approved product lists. Approval can vary by state, application and specification category.
- Review installation survivability. Aggregate angularity, drop height, construction equipment and initial lift thickness can damage fabric if not controlled.
- Confirm roll layout and direction. Machine direction and cross-machine direction should align with the project’s reinforcement assumptions.
- Avoid unsupported substitutions. A geogrid, a nonwoven geotextile and a woven stabilization geotextile may each be correct in different details, but they are not automatically interchangeable.
Environmental exposure is another practical issue. According to product literature, polypropylene geotextiles are commonly used in civil construction and resist many naturally encountered chemicals, acids and alkalis. However, prolonged uncovered ultraviolet exposure, unusual chemical environments or high-temperature applications should be reviewed against current manufacturer guidance.
Installation and quality control considerations
Good installation often determines whether a geotextile performs as intended. The subgrade should be prepared to the specified grade, with sharp objects, deep ruts and unsuitable soft pockets addressed before placement. The fabric should be placed smoothly, without excessive wrinkles, and should not be dragged over rough surfaces in a way that causes abrasion or tears.
Overlap, seam and repair requirements should come from the project specification or manufacturer guidance. On weak subgrades, larger overlaps or sewn seams may be required to prevent separation during aggregate placement. On reinforced soil details, seams and connections can affect load transfer, so they should not be improvised in the field.
Aggregate placement should protect the fabric. Contractors commonly place the first aggregate lift by end dumping and spreading forward so trucks do not travel directly on the exposed geotextile. Heavy equipment should normally operate on a sufficient aggregate cover layer, and turning movements should be minimized until the section is stable. If tears, punctures or displaced overlaps are observed, repairs should be made before the area is covered permanently.
Quality control should include roll identification, product certificates, visual inspection, weather and exposure checks, seam inspection where applicable, and confirmation that the delivered material matches the specification. For public works, documentation may also need to show compliance with the relevant agency’s geotextile category and approved product requirements.
Frequently asked questions
Is Mirafi HP570 woven or nonwoven?
Mirafi HP570 is a woven polypropylene geotextile. Public product descriptions identify it as a high-tenacity woven fabric designed for stabilization and soil reinforcement applications.
What is the main purpose of Mirafi HP570?
Its main purpose is to combine separation, filtration and reinforcement beneath aggregate or within reinforced soil systems. Typical applications include road bases, access roads, embankments, working platforms and some bridge approach or abutment details.
Can Mirafi HP570 replace geogrid?
Not automatically. A woven geotextile and a geogrid reinforce soil in different ways. A geogrid relies heavily on aggregate interlock, while a woven geotextile provides a continuous fabric layer with separation and filtration. Substitution should be based on project design requirements.
Is Mirafi HP570 suitable for drainage?
It has published hydraulic properties, including flow rate, permittivity and apparent opening size, but drainage suitability depends on the soil and aggregate around it. It should not be selected for drainage solely by product name.
What should be verified before ordering?
Verify the latest technical data sheet, agency approval status, roll size, seam or overlap requirements, required strength direction, soil compatibility and installation requirements. Product availability and approvals can change, so the latest project documents should control the final decision.
