Fibres at the concrete plant: ordering and production integration

A concrete batching plant mixes and delivers ready-mix concrete — including mixes with fibre reinforcement. When ordering, you specify the number of cubic metres, the strength and exposure class, the fibre type and the dosage (steel fibre typically 25–50 kg/m³); the plant blends the fibres into the mix during production. For the plant itself, that integration requires only a modest investment.

What does a concrete batching plant do?

A batching plant produces ready-mix concrete: a fresh mixture of cement, water, sand, gravel and any admixtures, composed to a fixed mix design per strength and exposure class. The mix is delivered ready to pour — hence the term ready-mixed concrete — and driven to site by truck mixer, typically 8 to 12 m³ per load. Because fresh concrete remains workable for only a limited time after production (as a rule of thumb one and a half to two hours, depending on temperature and any retarders), the driving distance between plant and project is a hard planning factor.

For fibre-reinforced concrete, the plant is the logical place to add the reinforcement: the fibres are weighed and mixed under controlled conditions, with the same process monitoring as the rest of the mix design. That fundamentally distinguishes fibre reinforcement from traditional reinforcement, which is tied and placed on site as a separate work stage.

Fixed plant or mobile batching plant?

Alongside the fixed plant there is the mobile batching plant: a relocatable mixing installation set up on or near the project. That option is mainly of interest for large, continuous offtake (think infrastructure projects running to thousands of cubic metres) or on locations with no batching plant nearby, where the driving time would jeopardise workability. For a mobile plant the same applies: dosing fibres is perfectly feasible, provided the process includes a weighing point at which the fibres are measured out per batch.

For regular projects, a fixed plant within roughly 30 to 45 minutes' driving distance is the starting point. If you are looking for a batching plant nearby that can supply fibre-reinforced concrete, ask explicitly about experience with your fibre type — not every plant keeps every fibre in stock, but virtually every plant can blend in supplied fibres to specification.

Ordering fibre-reinforced ready-mix concrete: what to specify

Ordering ready-mix concrete with fibres differs from a regular order on only one point: you specify the fibre reinforcement just as precisely as the strength class. The plant needs:

• Quantity in m³ — length × width × thickness plus a 5–10% margin; the calculator works this out for you together with the fibre dosage.

• Strength class and exposure class — for example C20/25 XC1 for an indoor floor, as advised by your structural engineer.

• Fibre type and dosage — brand, type and kg/m³. The usual ranges per fibre type are set out in the dosage guidelines for concrete fibres: steel fibre 25–50 kg/m³, synthetic macro fibre 2–6 kg/m³, micro fibre 0.6–1.0 kg/m³.

• Consistency class — with fibre concrete often one class softer (for example F4/F5) for good workability.

• Placement method — pump, skip or chute, so the plant can tailor the mix accordingly.

On cost, allow indicatively (2026 price level) €110–€165 per m³ for the concrete itself, plus a fibre surcharge that runs up to around €45 per m³ for steel fibre and is usually lower for synthetic fibre. A full breakdown is given in what does fibre-reinforced concrete cost? The complete journey from order to curing — including drying times and a pour plan — is covered step by step in the complete guide to pouring fibre-reinforced concrete.

Pumping ready-mix concrete: does that work with fibres?

Yes. Placing ready-mix concrete by pump works well with fibre concrete: both steel fibres and synthetic macro fibres are pumpable, provided dosage and consistency are matched to each other. In practice that means a slightly softer consistency and a hose diameter of at least 100 mm; synthetic fibres are the least critical thanks to their low weight. State in your order that you will be pumping — the plant will then tune the mix and fibre length accordingly, and you avoid blockages at reducers.

Choosing a concrete supplier for fibre work

Not every concrete supplier has the same level of experience with fibres. When choosing, look at three points: demonstrable references with your fibre type, a dosing solution that actually delivers the specified kg/m³, and certified production so the mix design is assured. Also ask whether the plant includes the fibre's CE declaration of performance (to EN 14889) with the delivery ticket — for structural work, the structural engineer will want to see that documentation. What else to look for on the fibre side of the chain is covered in how to choose a fibre reinforcement supplier.

Where in the process does the plant add fibres?

Fibres are added while the raw materials are being mixed, together with or shortly after the aggregate, before the final mixing with water and cement. That way the fibres are rubbed apart between sand and gravel and distribute themselves through the entire volume. If dosing only happens at the truck mixer — which occurs with smaller quantities or top-up deliveries — extra mixing time is needed: as a rule of thumb four to five minutes at full mixing speed, so the mix makes enough revolutions before it is poured.

The moment of addition matters because it directly determines homogeneity. A fibre added too late, or tipped in all at once too quickly, can ball up; a fibre that travels along with the aggregate distributes itself almost automatically.

Dosing: from pre-packed bags to a dosing installation

For the plant, the key question is how the correct quantity of fibre reliably gets into the mixer per batch. Accurate dosing is no formality:

• Too low a dosage fails to deliver the intended effect (crack control, structural residual strength) — and that cannot be corrected afterwards.

• Too high a dosage can clog the dosing installation and reduce the workability of the mix.

For occasional use, manual dosing via pre-packed bags with a fixed weight per batch is sufficient — an approach that requires virtually no investment. Macro fibres such as TwistR are supplied ready-packed per bag, so one or a few bags per m³ deliver the intended dosage directly; the same applies to micro fibres such as Promicro at 0.6–1.0 kg/m³.

For structural production, plants invest in a dosing installation that automatically weighs and feeds per batch. Indicatively (2026 price level, depending on capacity and fibre type): a semi-automatic fibre doser with weighing unit from around €10,000–€25,000, a fully automatic dosing line linked to the mixing control system around €25,000–€75,000. For concrete with synthetic fibres, no major modification of the existing mixing installation is usually needed — keeping the investment threshold low, certainly set against the margin on a more specialised product.

Mix design and homogeneous mixing

Adding fibres often calls for a slight adjustment of the rest of the mix, especially in the fines (sand and filler content), to ensure optimum coating and bonding of the fibres. Plants that work with fibres structurally therefore develop their own mix design variants per fibre type and dosage — including the slightly softer consistency that finishers ask for with fibre concrete.

A good fibre neither sinks nor floats out of the mix and does not form balls during mixing. That depends on the fibre itself and on the mixing settings (mixing time, mixing sequence). The delivery form helps here: glued steel fibres such as the MPZG HT+ 35/0.55 are held together in compact strips with water-soluble glue, dose as small packets and only come apart during mixing — distributing more evenly than loose fibres and preventing balling at high aspect ratios.

For new fibre types, a trial mix is the standard: mix first, check visually for homogeneity and workability, and only then include it in the regular production programme.

Quality control on the fibre dosage

For structural applications, plants use spot checks during production to verify that the specified dosage is actually in the mix — for example by washing out a sample of fresh concrete and weighing the recovered fibres. That is comparable to the regular checks on water-cement ratio and strength class, and it ties in with the documentation duty: the fibre's performance per dosage is recorded in the CE documentation to EN 14889, and the structural residual strength of the mix is determined to EN 14651.

For buyers, this is the verifiable difference between "there are fibres in it" and an assured reinforcement function: for structural work, always ask for the dosing record on the delivery ticket.

What does fibre-reinforced concrete deliver for the plant?

Within the applications and target groups of fibre reinforcement, the batching plant is a link that wins on both sides: the buyer gets reinforcement without steel fixing, the plant a product with more margin. In concrete terms:

• Value added product — steel and synthetic fibres are offered by many plants as an addition to their regular ready-mix concrete: an extra service that contributes to customer retention and revenue per cubic metre.

• Modest investment — certainly for synthetic fibres the threshold is low: pre-packed bags to start with, a dosing installation once the volume justifies it.

• Knowledge advantage — plants that build up experience with fibre types, mix design adjustments and dosages stand out to contractors looking for a reliable partner for fibre-reinforced concrete. That knowledge is harder to copy than a per-cubic-metre price.

Ordering fibres for your plant or project

If you are starting out with fibre-reinforced ready-mix as a plant, begin with one or two proven fibre types and a trial mix per mix design. The technical specifications per fibre — dosages, performance classes and CE documentation — are bundled in the datasheets. If you want to know which dosage suits a specific mix design and application, request dosing advice for your mix design: you will receive advice per fibre type, including a delivery form (bulk, big bag or pre-packed bags) matched to your dosing method.