To fix fiber balling with glued steel fibres, first slow the fibre feed, confirm the mixer is not overloaded, and check that the concrete mix can disperse the fibres. Add fibres gradually into a moving, well-proportioned mix, then allow sufficient mixing for the glued bundles to separate. If balls continue to form, review the addition sequence, aggregate grading, workability, fibre dosage, and product condition before changing the mix or adding water.
Please visit our website for more information on this topic.
Glued bundles are intended to make steel fibres easier to handle and feed; the adhesive holds fibres together before mixing and is expected to release during mixing. A persistent ball is a sign that the fibres are not dispersing effectively under the particular production conditions. I recommend changing one factor at a time in a controlled trial so the cause—and the effective correction—can be identified.
Fiber balling occurs when multiple fibres remain entangled or bundled instead of dispersing through the concrete. The cause is often a combination of feeding, mixing, and mix-design conditions rather than a single defective component. Glued fibres can reduce loose-fibre handling problems, but they still require suitable mixing energy and a practical addition method.
Dumping a large quantity of fibres into one spot can create a dense cluster that the mixer struggles to separate. Adding fibres too quickly, feeding them before the aggregates and cementitious materials are adequately mixed, or operating an overloaded mixer can also limit dispersion. Worn or poorly maintained mixing components may further reduce the mixing action.
A mix that is too stiff or has an unsuitable balance of fine and coarse aggregate may not flow around the fibres effectively. High fibre dosage can increase the challenge of dispersion, particularly if the mix proportions and mixing procedure were not designed for that dosage. The appropriate correction depends on the full mix design, so a balling issue should not be treated by adding water automatically.
Check whether the clumps appear during fibre feeding, remain visible in the mixer, or are found only during discharge or placement. Note the batch size, fibre dosage, mixing sequence, feed method, and any recent material or equipment changes. This record helps distinguish a feeding problem from a mix-design or equipment problem.
Inspect the packaging and fibres for moisture exposure, damage, or compaction during storage and handling. Confirm that the feed equipment releases the product consistently rather than delivering intermittent surges. Follow the product supplier’s handling instructions, because bundle design and recommended use can vary by product.
Feed fibres gradually into the moving mix, spreading the feed across the mixer where the equipment allows. As an illustrative controlled trial—not a universal operating specification—compare feeding over 60 seconds with feeding over 120 seconds while keeping the other batch conditions unchanged. Do not pour an entire bag or bundle into one location unless the product and mixer instructions specifically permit that method.
Check the sequence recommended for the concrete mix and the fibre product. In many production processes, the base mix is brought together before fibres are introduced, but the correct sequence depends on the mixer, materials, and supplier instructions. If the sequence is appropriate, test a modest extension of mixing after fibre addition and inspect the result before making a larger change.
You will get efficient and thoughtful service from BEKA.
For a trial log, record post-addition mixing time in seconds or minutes, rather than relying on operator impressions such as “mixed longer.” For example, compare inspection after an additional 30-second interval with the existing cycle, then proceed only if the trial remains within production and quality requirements. This is a test method, not a guaranteed mixing-time recommendation.
Verify that the batch matches the approved mix design and that the actual fibre quantity is being weighed and added accurately. Record dosage in kilograms per cubic metre (kg/m³), along with the batch volume and measured workability using the project’s specified method. If the mix is outside its approved workability range, consult the mix designer about an approved adjustment rather than adding unmeasured water.
Also review aggregate grading and the proportions of fine and coarse materials. A mix that does not provide sufficient mobility or paste volume for the specified fibre content may require technical review. Any mix-design revision should be validated against the project’s performance and placement requirements.
| Observation | Possible factor to investigate | Practical next check |
|---|---|---|
| Balls form as fibres enter the mixer | Fast or concentrated feeding | Slow the feed and distribute it more evenly |
| Fibres remain clumped after mixing | Mixing sequence, duration, loading, or workability | Review the sequence and conduct a controlled mixing trial |
| Balling occurs only at higher dosage | Dosage or mix design not suited to the production process | Confirm the specified dosage and consult the mix designer |
| Results vary between batches | Inconsistent feed, batching, materials, or equipment condition | Compare batch records and inspect feeding and mixer operation |
Use a written batching procedure that defines the fibre dosage, addition point, feed method, and mixing sequence. Train operators to use a steady feed and to report unusual clumps rather than compensating with unapproved water or extra material. Keep batch records so that changes in aggregate supply, admixture, equipment, or fibre lot can be compared with dispersion results.
Before full-scale production, verify proposed changes in a controlled trial that reflects the intended materials and equipment. One practical pilot might use a 0.5 m³ batch where that volume is compatible with the mixer and project procedures; it is an example, not a required trial size. Inspect representative samples and document fibre distribution using the project’s agreed acceptance method.
Contact the supplier if fibres arrive damaged or damp, if the supplied product differs from the approved specification, or if balling persists after feeding and mixing have been checked. Share the fibre type and dosage, batch volume, mixer type, addition sequence, feed duration, mixing time, and observations from the trial. These details help the supplier assess whether product handling, fibre selection, or production guidance needs further review.
At BEKA, we can review the product information and process details provided by the buyer and discuss whether the selected glued steel fibre and handling approach appear suitable for the stated application. The final mix design and acceptance criteria should remain under the control of the project’s concrete technologist or engineer. For a useful technical discussion, include the required fibre specification, target dosage, mixer details, and a clear description or photograph of the clumps.
The most effective first response to fiber balling is to identify when the clumps form, then check feeding, mixer loading, sequence, mixing time, workability, and dosage systematically. Start with a slower, more distributed feed and make controlled changes one at a time. Record the results, follow product instructions, and consult the mix designer before altering water content or approved mix proportions.
If balling continues, share the batch and process details with your fibre supplier and technical team before scaling up production. BEKA can help review the fibre product information and discuss practical next steps for evaluating glued steel fibres in your application. This approach supports a clearer diagnosis while keeping mix performance and project requirements at the centre of the decision.
Are you interested in learning more about How to Fix Fiber Balling Issues When Using Glued Steel Fibres? Contact us today to secure an expert consultation!