Crack Initiation
Shrinkage, restraint and tensile stresses can exceed the tensile capacity of concrete, initiating cracks within the matrix.
MACRO SYNTHETIC FIBER REINFORCEMENT
PP Twisted Bundle Fiber
Engineered Reinforcement for Crack Control & Concrete Toughness
POLYVIA™ PP Twisted Bundle Fiber is an engineered polypropylene macro synthetic fiber designed for distributed reinforcement, crack bridging and improved toughness in concrete.
Suitable for industrial floors, pavements, precast concrete, shotcrete, tunneling and infrastructure applications.
3D Distributed Reinforcement
Twisted fiber bundles provide multidirectional reinforcement throughout the concrete matrix.
Effective Crack Bridging
Macro fibers bridge developing cracks and help control crack opening after cracking.
Improved Toughness
Improves energy absorption and helps maintain concrete integrity under mechanical loading.
Non-Corrosive Reinforcement
Polypropylene fibers do not rust, supporting durable reinforcement in concrete environments.
PRODUCT SNAPSHOT
What Is PP Twisted Bundle Fiber?
PP Twisted Bundle Fiber is an engineered polypropylene macro synthetic fiber with a twisted bundle structure, designed for distributed reinforcement in concrete.
During mixing, the fiber bundles separate and disperse throughout the matrix, helping bridge cracks, transfer stress and improve toughness and post-crack performance.
Product Name
PP Twisted Bundle Fiber
Fiber Material
100% Polypropylene
CAS No.
9003-07-0
Fiber Geometry
Twisted Bundle / Macro Synthetic Fiber
Available Lengths
40 / 50 / 56mm or customized
Tensile Strength
≥500 MPa
Main Function
3D Reinforcement / Crack Bridging / Toughness Improvement
Key Advantages
Non-Corrosive / Alkali Resistant / Distributed Reinforcement
Applications
Industrial Floors / Pavements / Precast / Shotcrete / Tunnels / Concrete Structures
CONCRETE REINFORCEMENT CHALLENGES
WHEN CONCRETE CRACKS, INTEGRITY BEGINS TO CHANGE
Concrete performs strongly in compression, but tensile stresses, shrinkage and repeated loading can initiate and propagate cracks.
The challenge is not simply whether concrete cracks — but how cracking develops and how effectively the matrix maintains integrity after cracking begins.
Crack Propagation
Once formed, cracks can widen and propagate under continued tensile, flexural or repeated loading.
Brittle Post-Crack Response
Plain concrete has limited post-crack capacity and can rapidly lose continuity and integrity as cracks open under load.
Durability Exposure
Open cracks can provide pathways for water and aggressive substances, potentially affecting long-term concrete durability.
Distributed fiber reinforcement bridges developing cracks throughout the concrete matrix, helping control crack opening and support toughness and post-crack integrity.
SELECT THE RIGHT FIBER LENGTH
Available in multiple lengths to support different concrete reinforcement requirements.
| Fiber Length | Selection Focus | Typical Applications | Selection Guidance |
|---|---|---|---|
| 40 mm | Balanced Dispersion | General Concrete / Precast / Pavements | For applications prioritizing fiber distribution and practical mixing performance |
| 50 mm | Balanced Reinforcement | Industrial Floors / Pavements / Precast | Balanced option for fiber engagement, toughness and overall reinforcement performance |
| 56 mm | Enhanced Crack Bridging | Heavy-Duty Floors / Pavements / Shotcrete | For demanding applications requiring greater fiber engagement and post-crack performance |
| Custom Length | Project-Specific | Application Dependent | Fiber length can be evaluated according to concrete mix design and project requirements |
Engineering Note: Fiber length should not be selected independently. Aggregate size, concrete workability, mixing and pumping conditions, fiber dosage and target performance should be evaluated together.
HOW PP TWISTED BUNDLE FIBER WORKS
From fiber dispersion to crack bridging, reinforcement develops throughout the concrete matrix.
Bundle Opening & Dispersion
The twisted bundles progressively open during mixing, allowing individual fibers to separate and distribute throughout the fresh concrete matrix.
3D Fiber Distribution
Dispersed fibers become randomly oriented throughout the concrete volume, creating multidirectional reinforcement across multiple potential crack planes.
Crack Bridging
As cracks develop, fibers crossing the crack plane engage with the surrounding matrix and transfer tensile stress across the opening.
Post-Crack Reinforcement
After matrix cracking begins, engaged fibers continue bridging crack faces, helping control crack opening and maintain concrete integrity under continued loading.
Fiber geometry, dispersion, dosage and matrix interaction work together to determine crack-bridging efficiency and the resulting reinforcement performance.
TECHNICAL DATA
| Property | Specification |
|---|---|
| Material | 100% Polypropylene |
| Appearance | White / Grey Twisted Bundle Fiber |
| Density, g/cm³ | 0.91-0.98 |
| Equivalent Diameter, mm | 0.60 ± 0.05 |
| Length, mm | 40 / 50 / 56 / Customized |
| Tensile Strength, MPa | ≥ 500 |
| Elastic Modulus, MPa | > 4,500 |
| Elongation at Break, % | 20 ± 5 |
| Melting Point, °C | 160–170 |
| Chemical Resistance | Excellent Resistance to Acids & Alkalis |
APPLICATIONS
INDUSTRIAL & STRUCTURAL CONCRETE
Industrial Floors & Slabs
For warehouse floors, factory floors, logistics facilities and heavy-duty slabs requiring improved crack control, toughness and performance under service loading.
Concrete Pavements
For roads, yards, parking areas and other concrete pavements exposed to traffic, repeated loading and demanding service conditions.
Precast Concrete
For pipes, panels, drainage components and other precast products where distributed fiber reinforcement can support crack control and component integrity.
Building & Structural Concrete
For slabs, roofs, basements, foundations and other concrete elements requiring multidirectional reinforcement and improved resistance to crack development.
INFRASTRUCTURE & SPECIALIZED CONCRETE
Shotcrete & Tunneling
For tunnels, underground structures and sprayed-concrete systems where fiber reinforcement supports crack control, toughness and post-crack performance.
Marine & Coastal Concrete
For ports, coastal structures and marine concrete applications requiring improved crack control, toughness and long-term durability.
Bridge Decks & Infrastructure
For bridge decks and civil infrastructure exposed to repeated loading and demanding service conditions where crack control and long-term performance are important.
Hydraulic & Water-Retaining Structures
For channels, reservoirs, pools and other hydraulic concrete applications where controlling crack development can contribute to structural integrity and durability.
PERFORMANCE BENEFITS
PERFORMANCE BEYOND CRACK CONTROL
Distributed macro synthetic reinforcement supports toughness, crack control and post-crack performance throughout the concrete matrix.
Crack Control
Help control crack opening and propagation through distributed fiber bridging across developing crack planes.
Enhanced Toughness
Improve energy absorption and support a less brittle response as the concrete matrix cracks and deforms.
Post-Crack Performance
Fibers remain engaged across opened cracks, helping maintain matrix integrity and continued stress transfer after cracking.
Impact Resistance
Improve resistance to localized damage under impact and other dynamic loading conditions.
Fatigue Performance
Support concrete integrity under repeated loading by helping control progressive crack development.
Flexural Performance
Support behavior under bending through fiber bridging and continued load transfer across developing cracks.
Performance depends on fiber length, dosage, concrete mix design, fiber dispersion, curing conditions and project-specific requirements.
CONCRETE SYSTEM COMPATIBILITY
Fiber performance depends on the complete concrete system
Fiber Performance Depends on the Complete Concrete System
PP Twisted Bundle Fiber performance is governed by the complete concrete system—from fiber selection and mix design to dispersion, placement and final reinforcement performance.
The optimum fiber system should provide effective dispersion, crack bridging and post-crack reinforcement while maintaining the required workability, pumping and placement performance.
Fiber Length & Dosage
Fiber length and dosage influence fiber population, distribution and engagement across potential crack planes.
Concrete Matrix
Matrix properties influence fiber–concrete interaction, crack development and post-crack behavior.
Aggregate Grading
Aggregate size and grading affect concrete workability, fiber distribution and placement performance.
Water-to-Binder Ratio
Water-to-binder ratio influences rheology, matrix properties and the overall response of fiber-reinforced concrete.
PCE & Admixtures
A compatible PCE Superplasticizer can support water reduction and workability where required, helping maintain effective fiber dispersion and placement.
Mixing Conditions
Mixing sequence, time and energy influence bundle opening, fiber separation and uniform distribution throughout the concrete.
Pumping & Placement
Pumping, placing and finishing conditions should be considered to maintain workability and consistent fiber distribution.
Performance Target
Fiber selection should reflect the required crack control, toughness, post-crack behavior and project-specific performance targets.
PERFORMANCE-BASED FIBER SELECTION
Match Fiber Reinforcement to the Required Concrete Performance
Selecting PP twisted bundle fiber should start with the required concrete performance—not fiber length alone. The appropriate fiber configuration and dosage depend on the reinforcement target, concrete mix, application method and service conditions.
| Performance Target | Reinforcement Objective | Key Selection Factors |
|---|---|---|
| Crack Control | Control crack development and limit propagation | Fiber distribution · Dosage · Mix compatibility |
| Post-Crack Performance | Maintain reinforcement after matrix cracking | Fiber geometry · Anchorage · Fiber content |
| Flexural Toughness | Improve energy absorption and deformation capacity | Fiber length · Bond · Dosage |
| Industrial Flooring | Provide distributed reinforcement across concrete slabs | Loading · Slab design · Fiber dosage |
| Shotcrete & Tunneling | Support toughness and post-crack integrity | Dispersion · Pumpability · Energy absorption |
| Precast Concrete | Support crack control during handling and service | Fiber distribution · Concrete workability |
| Durability-Focused Systems | Provide non-corrosive distributed reinforcement | Exposure conditions · Reinforcement requirements |
Selection Note:
Fiber length and dosage should be determined according to the required performance, concrete mix design, construction conditions and applicable project requirements. Final selection should be verified against the target performance of the concrete system.
TECHNICAL SUPPORT
Safety Data Sheet (TDS)
Key specifications and technical information.
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Safety Data Sheet (SDS)
Handling, storage and safety information.
Request SDS ↓
Application Guide
Practical guidance for product use and application.
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Certificate of Analysis (COA)
Batch-specific quality and specification results.
Request COA ↓FREQUENTLY ASKED QUESTIONS
What is PP Twisted Bundle Fiber? +
PP Twisted Bundle Fiber is a polypropylene macro synthetic fiber designed to provide distributed reinforcement in concrete. Its twisted bundle structure opens during mixing, allowing fibers to disperse throughout the concrete matrix and contribute to crack control, toughness and durability.
What is the difference between PP Twisted Bundle Fiber and ordinary PP Fiber? +
Ordinary fine PP fibers are commonly used primarily for plastic shrinkage and early-age crack control.
PP Twisted Bundle Fiber uses a longer macro fiber geometry designed to provide reinforcement across developing cracks and contribute to hardened-concrete toughness and post-crack behavior.
How does PP Twisted Bundle Fiber reinforce concrete? +
During mixing, the twisted bundles open and fibers distribute throughout the concrete. Randomly oriented fibers form multidirectional reinforcement and can bridge developing cracks, helping transfer stress and control crack propagation.
Which fiber length should I use — 40 mm, 50 mm or 56 mm? +
Fiber length should be selected according to the concrete mix, aggregate size, application, mixing and pumping conditions, required dosage and reinforcement target.
POLYVIA can support fiber-length selection based on the specific application.
What is the recommended dosage? +
For general crack-control applications, 1.0–1.5 kg/m³ can be used as a recommended starting range.
For applications requiring enhanced reinforcement performance, 3–6 kg/m³ can be evaluated.
Final dosage should be confirmed through concrete trials and project requirements.
Can PP Twisted Bundle Fiber be used with PCE superplasticizer? +
Yes. PP Twisted Bundle Fiber can be used in concrete systems containing PCE superplasticizers.
Because fiber addition can influence fresh-concrete rheology and workability, the complete concrete formulation should be evaluated to achieve suitable dispersion, pumping, placement and finishing performance.
Does PP Twisted Bundle Fiber affect concrete workability? +
Macro fiber addition can influence concrete rheology and apparent workability, particularly as fiber dosage increases.
Appropriate aggregate grading, PCE selection, mix design and mixing procedure can help achieve the required balance between fiber reinforcement and construction performance.
Can PP Twisted Bundle Fiber replace steel mesh or steel fiber? +
PP Twisted Bundle Fiber may serve as an alternative to certain conventional secondary reinforcement systems in suitable applications.
However, replacement of welded wire mesh, steel fiber or other reinforcement should be determined through engineering evaluation, required concrete performance and applicable project/design requirements.
From Fiber Selection to Concrete Performance
Not Sure Which Fiber Fits Your Concrete? Share your concrete application, mix design, aggregate size and target performance. Our technical team can help evaluate fiber length, dosage and mix compatibility for your project.
FROM FIBER SELECTION TO CONCRETE PERFORMANCE