Fibres at the concrete plant: how does production integration work?

For concrete plants considering adding fibre reinforced mixtures to their range, the key question is: how do you integrate this into the existing production process? This article discusses the practical side of fibre dosing at the concrete plant.

Where in the process are fibres added?

Fibres are added during the mixing of the raw materials, together with or shortly after the aggregate, before final mixing with water and cement takes place. This distinguishes fibre addition from traditional reinforcement, which takes place as a separate process outside the plant (on site).

Dosing equipment

For regular use of fibres, concrete plants typically invest in dedicated dosing equipment, which can precisely measure and add the correct amount of fibre per batch. This is particularly relevant because:

• Too low a dosage does not deliver the desired effect (crack control, structural strength).

• Too high a dosage can lead to clogging of the dosing equipment and reduced workability.

For incidental use, fibres are also sometimes added manually, for example via pre-packaged bags with a fixed weight per batch — a method that requires less investment, but is less suitable for large-scale, continuous production.

Adjusting the mix design

Adding fibres often requires a slight adjustment to the rest of the mixture, particularly in the fine fraction (sand and filler content), to ensure optimal coating and bonding of the fibres. Concrete plants that work with fibres on a structural basis develop their own mix design adjustments per fibre type and dosage.

Ensuring homogeneous distribution

A good fibre does not settle or float out of the mixture and does not form balls during mixing. This depends both on the quality of the fibre itself and on the mixing settings (mixing time, mixing sequence) at the plant. For new fibre types, it is common to first make a trial mix and visually check for homogeneity, before a fibre is incorporated into the regular production process.

Quality control

For structural applications, it is common to check through sampling during production whether the correct dosage has actually ended up in the mixture — comparable to regular quality checks on, for example, the water-cement ratio and strength class of the concrete.

What does this mean for the plant's operations?

• Limited investment. For concrete with synthetic fibres, no drastic modification of the existing mixing equipment is generally needed, keeping the investment threshold low.

• Value added product. Fibres (steel fibres and synthetic fibres) are already offered by many plants as a so-called "value added product" alongside regular ready-mix concrete — an additional service that can contribute to customer loyalty and revenue.

• Building expertise as a competitive advantage. Plants that build up experience with various fibre types and dosages can distinguish themselves to contractors looking for a reliable partner for fibre reinforced concrete.

In conclusion

Integrating fibres into a concrete plant's production process requires well-considered dosing equipment, an adjusted mix design and careful quality control — but no drastic, costly modification of the existing production infrastructure.