| HS Code | 307801 |
| Material | 100% virgin polypropylene |
| Fibre Type | Monofilament |
| Colour | Natural / white |
| Length | 12 mm |
| Diameter | 0.032 mm |
| Aspect Ratio | 375 |
| Density | 0.91 g/cm³ |
| Melting Point | 160-170 °C |
| Ignition Point | > 400 °C |
| Tensile Strength | 350-400 MPa |
| Elastic Modulus | 3.5-4.0 GPa |
| Elongation At Break | 15-20% |
| Water Absorption | Nil / <0.1% |
| Alkali Resistance | Excellent |
| Acid Resistance | Excellent |
| Recommended Dosage | 0.6-1.8 kg/m³ |
As an accredited SikaFiber 12 - Polypropylene Fiber for Concrete factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SikaFiber 12 packaging: 600 g bags, supplied 20 bags per carton, totaling 12 kg per carton. |
| Container Loading (20′ FCL) | Container Loading (20′ FCL): SikaFiber 12 polypropylene fiber for concrete, palletized, shrink-wrapped, and securely braced inside a 20-foot FCL container. |
| Shipping | SikaFiber 12 is shipped in moisture-resistant bags or boxes, palletized and shrink-wrapped. It is non-hazardous and not classified as dangerous goods for transport. Keep dry and away from ignition sources. Standard handling and PPE apply; avoid dust generation. No special shipping labels or placards are required. |
| Storage | Store SikaFiber 12 in a cool, dry, well-ventilated area using original, sealed packaging. Protect from moisture, direct sunlight, heat, and ignition sources. Stack pallets securely off the ground; avoid puncturing bags or generating dust. Keep away from incompatible materials. Follow good housekeeping and local regulations. Use first-in, first-out. Typical shelf life is 24 months when stored properly. |
| Shelf Life | Shelf life: 24 months from production when stored correctly in original, unopened packaging, dry, protected from moisture and direct sunlight. |
In high-tolerance slab-on-grade construction where laser screeding controls FF/FL profiles, SikaFiber 12 is batched at 0.6–1.0 kg/m³ as a micro-reinforcement to interrupt bleed-water channel continuity and inhibit plastic shrinkage cracking during the initial 6 h evaporation window. The fibre is supplied as a 12 mm polypropylene monofilament with density 0.91 g/cm³ and negligible water absorption, so batching by weight requires no moisture correction. The EU/EEA compliance path is CE marking under EN 14889-2:2006 Annex ZA, which requires declared values for fibre length, diameter, tensile strength, and alkali resistance; North American specifications use ASTM C1116/C1116M-23 Type III synthetic fibre classification. Floor placement is assigned under ACI 302.1R-15 and Concrete Society TR34, which address joint-free slab performance but do not permit fibre substitution for doweled contraction joints or structural reinforcement. In production, the fibre is introduced in a twin-shaft compulsory mixer with a rated batch capacity of 1.0–1.5 m³ after coarse aggregate and before water, allowing 30–45 s of dry predispersion before cement paste forms; free-fall drum mixers show greater agglomeration risk when fibres are dumped onto charged static surfaces. The mixed concrete is placed at slump 120–160 mm by laser screed and power trowel lines. The fibre does not alter the specified saw-cut timing, but it can reduce early crack survey defects in slabs exposed to wind speeds above 3.0 m/s and relative humidity below 40%, the range in which ACI 305R-10 evaporation nomographs typically predict high plastic-shrinkage potential. End products include distribution-centre floor slabs, cold-storage decks, automotive trim-and-assembly aisles, and high-bay racking slabs.
Fire test data for high-strength segmental linings indicate that 12 mm polypropylene monofilaments create a pressure-relief pathway when the polymer softens at approximately 160–170 °C and leaves microchannels for water vapour escape before pore pressure exceeds the tensile capacity of the concrete matrix. Under ISO 834-1:1999 and EN 1992-1-2:2004 fire scenarios, spalling control is evaluated by temperature rise, mass loss, and deformation criteria rather than by a single fibre dosage; RILEM TC 256-SPF programmes indicate that dosages below 1.2 kg/m³ are frequently insufficient for concretes above 60 MPa with moisture contents above 4% by mass. The batching range for tunnel segments is typically 1.5–3.0 kg/m³, with the upper bound used in high-binder silica-fume mixes and the lower bound in wet-cast segments where surface finish is critical. In production, the fibre is added at the central batching plant under high-shear mixer energy, then the segment mould is filled by skip or hopper and compacted on high-frequency external vibrators at 50–150 Hz; steam curing at 50–80 °C remains below the softening threshold and therefore does not destroy the future spalling function. End products include TBM tunnel lining segments, shaft linings, cross-passage blocks, and cut-and-cover roof units.
Production failures in this segment occur when the fibre is added at the tail end of the batching cycle instead of at the beginning; free-fall drum mixing produces fibre balls that remain intact after steam curing and appear as surface defects on the segment extrados. In counter-current high-shear mixers, the fibre is metered by screw or vibratory feeder over the aggregate stream to avoid static clumping, and the total mixing time after fibre addition is maintained at 60–90 s. Formulation adjustments for fire-spalling control must account for accelerator, superplasticizer, and air-entrainment interactions; polycarboxylate ether superplasticizers with high charge density do not degrade the polypropylene melt-channel formation because the fibre is dispersed before hydration begins, but overdosing air entrainment can create additional interconnected voids that change the pressure-relief threshold. Published data for this specific product configuration at dosages above 3.0 kg/m³ in 70 MPa steam-cured wet-cast concrete is limited; project-specific ISO 834-1 testing is required for fire-safety qualification rather than extrapolation from lower-grade concretes.
Operationally, wet-mix sprayed concrete shifts from a predictable pumpable mix to a line-blockage risk when fibre dosage exceeds 1.2 kg/m³ in a 50 mm internal-diameter delivery line, because the monofilaments increase paste yield stress and can accumulate at 45° elbow bends after the pump. The governing sprayed-concrete specification is EN 14487-1:2005 with the EFNARC 1996 European Specification for Sprayed Concrete; fibre conformity remains under EN 14889-2:2006, and end-use exposure classes are assigned under EN 206:2013+A2:2021. The formulation window is 0.9–1.2 kg/m³ for wet-mix tunnel support, balancing plastic shrinkage control against pumpability; higher dosages are occasionally used for spalling-critical permanent linings but require wider hose diameters or reduced pumping distance. Production-scale equipment consists of a positive-displacement concrete pump with 60 m³/h nominal output, a wet-mix nozzle injecting air at 7–14 m³/min, and an alkali-free accelerator dosing unit delivering 4–8% by weight of binder; the nozzle is held at 90° to the substrate to maintain rebound below 15%. Fibre-related blockages are typically observed when a line is restarted after a prolonged standby period without a reverse pump pulse; the pump outlet pressure rise can reach 5–10 bar before the line can be cleared.
At the nozzle, the in-place fibre dosage differs from the batched dosage because rebound removes fibre and matrix at different rates; continuous build thickness above 15 cm without adequate accelerator can lead to sloughing, and the fibre contribution is limited to crack suppression rather than green tensile strength. Storage in unopened bags at relative humidity above 60% may cause fibre clumping during dosing; the material should be kept in dry, covered storage and added to the mixer without tearing open multiple bags simultaneously. The process converts the dosed wet mix into NATM (New Austrian Tunnelling Method) tunnel support shells, rock slope stabilisation layers, permanent single-shell linings, and temporary access adits in aggressive groundwater where steel-fibre corrosion is a documented limitation.
A counter-current pan mixer with a star rotor imposes a distinct addition sequence for SikaFiber 12 that determines whether the fibre disperses as individual filaments or forms low-energy agglomerates that later appear on architectural surface finishes. The relevant precast concrete standards are EN 13369:2018 for common rules and EN 14889-2:2006 for fibre conformity; North American projects may additionally specify ASTM C1116/C1116M-23 Type III synthetic fibre. Dosage in conventional precast is usually 0.6–1.0 kg/m³, with the lower end used for thin-walled wet-cast panels and the upper end for vibration-intensive dry-cast pipe and manhole products where green strength prevents demoulding cracks. The production process requires fibre charging through a dosing hopper after 30–45 s of dry aggregate blending but before water and superplasticizer make the paste phase adhesive; in high-speed planetary mixers, adding the fibre simultaneously with cement often leads to static-charge clumping on mixer walls and requires a scrapedown cycle. After mixing, the concrete is cast into steel or polyurethane moulds and compacted by external vibrators operating below 150 Hz; fibre-related surface blemishes are more likely in acid-etched or polished architectural panels and can be reduced by using the lower end of the dosage window and by avoiding direct trowelling over wet fibre ends. Typical end products include cable troughs, utility vaults, retaining wall panels, non-structural cladding elements, drainage channels, and concrete pipe where the fibre acts as a plastic-shrinkage crack inhibitor and does not replace steel reinforcement required for load capacity.
For bonded and unbonded cementitious screeds, SikaFiber 12 is charged at 0.5–0.9 kg/m³ and mixed in a forced-action paddle mixer to control early plastic cracking; the applicable screed standard is EN 13813:2002, with fibre conformity under EN 14889-2:2006, and the material is placed by mixing pump or hopper-fed flood screeding to produce residential levelling courses, underfloor-heating cover slabs, and repair patches in which surface fibre visibility is accepted where a bonded floorcovering is later applied. The fibre is not a substitute for mesh reinforcement in unbonded screeds over compressible insulation, and it does not alter the drying time required before moisture-sensitive floor coverings are installed.
Once the evaporation rate measured by a sling psychrometer exceeds 1.0 kg/m²/h, the plastic shrinkage cracking window in slipform paving becomes the controlling placement variable, and the early-age crack-bridging function of SikaFiber 12 is specified relative to that measurement. The reference test for restricted plastic shrinkage is ASTM C1579-21; pavement design falls under ACI 330R-08 and, in European practice, EN 13877-2 for concrete pavements, while the fibre itself is qualified under EN 14889-2:2006 and ASTM C1116/C1116M-23. The field dosage range for pavement and external hardstanding concrete is 0.9–1.2 kg/m³, with the higher value applied to high-wind, low-humidity placements and to transverse joint bays over 4.5 m in width. Production uses central-mix or truck-mix concrete with a slipform paver placing at 0.5–1.5 m/min; the fibre is added at the plant to guarantee distribution before discharge, because adding at the paver hopper creates concentration streaks. Saw-cut depth and timing remain a function of aggregate type and concrete temperature, not fibre content; the sawing window is typically 4–12 h after final set. End products include container yards, truck courts, toll plazas, agricultural access roads, and maintenance aprons where the fibre contributes only to plastic and early-age crack width reduction; it provides no increase in flexural capacity or load transfer at joints and therefore must not be used to increase joint spacing.
Competitive SikaFiber 12 - Polypropylene Fiber for Concrete prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8618112911328 or mail to sales1@liwei-chem.com.
We will respond to you as soon as possible.
Tel: +8618112911328
Email: sales1@liwei-chem.com
Flexible payment, competitive price, premium service - Inquire now!
SikaFiber 12 is a monofilament polypropylene fibre supplied as secondary reinforcement for concrete. The product is specified for control of plastic shrinkage cracking in slabs on grade, pavements, precast elements, and wet-mix shotcrete. It is classified as a Type III synthetic fibre under ASTM C1116/C1116M-10a and is CE marked under EN 14889-2:2006 as a Class I polymer fibre. The fibre is manufactured from virgin polypropylene and is packaged in pre-weighed, water-soluble bags for direct addition to the batch mixer.
Physical data reported by the manufacturer include a nominal fibre length of 12 mm, a circular monofilament cross-section, and a specific gravity of 0.91. The material has a melting point in the range of 160 °C to 170 °C and is chemically stable in the alkaline pore solution of Portland cement concrete, which typically exhibits pH 12.5 to 13.5. The fibre does not corrode, does not absorb mixing water, and does not participate in alkali-silica reaction. These characteristics differentiate it from steel fibres and from non-alkali-resistant glass fibres in environments where surface exposure or chloride ingress is a concern.
Mechanical properties are consistent with low-modulus synthetic fibres. Manufacturer documentation lists tensile strength between 300 MPa and 400 MPa, elongation at break between 25 % and 60 %, and an elastic modulus near 3.5 GPa to 4.0 GPa. The fibre is not a structural reinforcement replacement. It is intended to reduce crack width during the plastic and early hardening phases, before the matrix develops sufficient tensile capacity. For post-crack flexural reinforcement, macro-synthetic or steel fibres with higher residual strength classifications are required.
The practical dosage window for SikaFiber 12 is bounded at the lower end by crack-control efficacy and at the upper end by workability and finishability. Manufacturer-recommended addition is 0.6 kg/m³ to 0.9 kg/m³. At 0.3 kg/m³, fibre count per cubic metre is approximately 40 million to 50 million filaments, which may be insufficient to reduce plastic shrinkage crack width under rapid-evaporation conditions. At 1.8 kg/m³ or above, field batching reports from ready-mix plants indicate increased risk of fibre balling, non-uniform distribution, and surface fuzzing after power trowelling.
Fibre count is a more meaningful measure than mass dosage. For a 12 mm monofilament with a diameter of approximately 30 µm, the mass per filament is approximately 7.7 × 10⁻⁶ g. At 0.9 kg/m³, the dosage corresponds to roughly 120 million individual fibres per cubic metre. This population provides a three-dimensional network during the plastic phase, when segregation, bleed-water accumulation, and finishing traffic induce localised tensile strain. The low specific gravity of 0.91 requires sufficient mixing energy to overcome the tendency of filaments to float near the surface in high-slump concrete.
Batching sequence modifies dispersion. Plant-level trials with twin-shaft compulsory mixers indicate that adding the pre-weighed bag after aggregate charging but before water and admixture introduction reduces clumping. Mixing for 5 min to 7 min at 12 rpm to 18 rpm in central mixers, or 70 to 100 revolutions in truck mixers at maximum charging speed, is generally sufficient for uniform distribution. Shortening mixing time to 30 revolutions has been associated with visible fibre clusters in discharge samples, particularly in mixes with dense aggregate and water-to-cementitious ratio below 0.35.
Compatibility with polycarboxylate ether superplasticizers, naphthalene formaldehyde condensates, and air-entraining admixtures is generally acceptable. Simultaneous addition of fibre and powdered admixtures can generate local dry pockets; batch operators should add fibre separately from silica fume and high-range water reducers. Pumping trials with 50 mm and 65 mm internal-diameter boom lines have shown no fibre-induced blockages at dosages up to 1.2 kg/m³ when the mix is properly dispersed. At dosages near 1.5 kg/m³, the interaction between polypropylene filaments and entrained air voids may reduce air content by 0.5 to 1.0 percentage points; therefore, air-entraining admixture demand should be re-verified using ASTM C231 or EN 12350-7. Published data for this specific configuration is limited, so site-specific trial batches are recommended before production.
Field comparisons between SikaFiber 12 and fibrillated polypropylene fibres show different finishing behaviour. Fibrillated fibres are produced as slit films that may open into a net-like structure during mixing. This increases specific surface area but can produce a hairy surface if the slab is overworked. The monofilament geometry of SikaFiber 12 tends to remain discrete and is less likely to protrude after machine trowelling, although blade angle and dwell time still govern final surface quality.
| Property | SikaFiber 12 | Fibrillated micro-polypropylene | Hooked-end steel fibre |
|---|---|---|---|
| Fibre class | Type III synthetic | Type III synthetic | Type I steel fibre |
| Length | 12 mm | 6 mm to 20 mm | 35 mm to 60 mm |
| Equivalent diameter or width | approximately 0.03 mm | 0.02 mm to 0.10 mm tape | 0.5 mm to 1.0 mm wire |
| Specific gravity | 0.91 | 0.91 | 7.85 |
| Elastic modulus | 3.5 GPa to 4.0 GPa | 3.5 GPa to 4.0 GPa | 200 GPa to 210 GPa |
| Typical dosage | 0.6 kg/m³ to 0.9 kg/m³ | 0.6 kg/m³ to 0.9 kg/m³ | 15 kg/m³ to 60 kg/m³ |
| Primary technical function | Plastic shrinkage crack control | Plastic shrinkage crack control | Post-crack flexural capacity |
| Corrosion and chemical risk | None | None | Corrosion at exposed surfaces unless stainless |
Steel fibre dosages are typically 15 kg/m³ to 60 kg/m³ and are selected from notched beam performance classes under EN 14651 or ASTM C1609/C1609M. SikaFiber 12 is not assigned a post-crack residual strength class for structural design because its low elastic modulus does not provide the same crack-bridging stiffness after matrix cracking. In contrast, macro-synthetic fibres with an equivalent diameter greater than 0.3 mm and lengths of 30 mm to 60 mm may be used in ground-supported slabs where EN 14889-2 Class II or ASTM C1116 Type III synthetic macrofibre performance is specified.
The following table summarises physical characteristics and conformity references relevant to specification review. Values are taken from manufacturer-declared technical data and applicable classification standards. Batch-specific declarations should be confirmed against the current Declaration of Performance for the production facility and lot.
| Property or designation | Value or classification | Standard, test method, or source |
|---|---|---|
| Fibre type | Monofilament polypropylene | Manufacturer technical specification |
| Nominal length | 12 mm | Manufacturer technical specification |
| Specific gravity | 0.91 | ASTM D792 or ISO 1183-1:2019 |
| Tensile strength | 300 MPa to 400 MPa | ASTM D2256/D2256M-21 |
| Elongation at break | 25 % to 60 % | ASTM D2256/D2256M-21 |
| Elastic modulus | 3.5 GPa to 4.0 GPa | ASTM D2256/D2256M-21 |
| Melting point | 160 °C to 170 °C | ASTM D3418 or ISO 3146 |
| ASTM classification | Type III synthetic fibre | ASTM C1116/C1116M-10a |
| European polymer fibre class | Class I micro-synthetic fibre | EN 14889-2:2006 |
| Comparative plastic shrinkage test | Evaluated at 0.6 kg/m³ to 0.9 kg/m³ | ASTM C1579-06 |
Manufacturer-declared values are batch-specific. The values in the table should be verified against the current product technical data sheet for the local production source. Published data for this specific configuration is limited where the product is used outside the declared dosage range or in concrete with admixture systems not covered by the manufacturer’s compatibility testing.
Because SikaFiber 12 is a micro-synthetic fibre, its primary differentiation from steel fibre is not strength but compatibility with corrosion-sensitive environments. Steel fibres can provide substantial post-crack residual strength, but they require careful embedment to avoid surface staining and may complicate recycling of returned concrete. SikaFiber 12 does not introduce metallic contamination, does not rust, and can be used in exposed pavement and precast surfaces where a uniform colour is required. However, it does not substitute for welded wire reinforcement or steel fibre in structural sections designed for flexural capacity after cracking.
Compared with fibrillated polypropylene fibres, the monofilament cross-section of SikaFiber 12 produces a lower specific surface area per filament but distributes as discrete filaments more rapidly in high-shear mixing. Fibrillated fibre bundles can open into high-aspect-ratio networks that reduce plastic shrinkage cracks effectively but may create more visible surface fibre at the trowelled slab surface. The monofilament configuration is generally associated with less fibre show-through in hard-trowelled finishes, provided the finishing sequence is not delayed beyond normal bleed-water clearance.
Compared with alkali-resistant glass fibres, polypropylene is inherently stable in high-pH cement pore solution. Glass fibres require zirconium oxide content to resist alkaline attack, and processing damage during mixing can reduce their reinforcing efficiency. SikaFiber 12 is not subject to alkaline dissolution and does not require special cement chemistry. Its low modulus and high elongation, however, mean that it cannot provide the same crack-opening resistance as well-bonded alkali-resistant glass in thin-section fibre-cement products.
For cast-in-place slabs that will receive a hard-trowel finish, the finishing operation should be adjusted to avoid overworking the surface. Because SikaFiber 12 has low density and low modulus, it does not alter hydration heat flow significantly, but filament ends can be exposed if the surface is overworked. Field reports from flatwork contractors indicate best results when floating and trowelling follow normal timing and bleed-water disappearance, with no added delay. Machine trowel blade angles above 15° to 20° during the final pass may expose fibres at the surface. Overworking should be avoided.
Precast applications include architectural panels, non-load-bearing elements, and utility structures. In these applications, fibre addition at 0.6 kg/m³ has been used to reduce edge chipping during demolding. Because the fibres are hydrophobic, they do not increase water demand. The product does not replace corner bars, lifting inserts, or primary reinforcement. Structural design must follow the applicable provisions of ACI 318 or EN 1992-1-1 for anchorage and load transfer.
Wet-mix shotcrete applications can include SikaFiber 12 at 0.6 kg/m³ to 0.9 kg/m³ for plastic shrinkage crack control before the sprayed concrete develops significant tensile capacity. The 12 mm fibre length is compatible with standard wet-mix nozzles, but published data for this specific configuration is limited. Nozzle-builder trials are required to confirm rebound and encapsulation. The material does not replace welded wire mesh, lattice girders, or rock bolts in structural tunnel linings.
