Concrete is a composite material made up of cement, aggregate, water and, where required, admixtures. When the mix composition changes, the performance of the product may also change. Our production mainly uses a method in which dry-consistency concrete is compacted in the mould. On request, production can be carried out with special concrete options suited to the project conditions.
Cement Content
If the project specifies a cement content, the request is assessed together with the target strength of the concrete and the conditions of use. Cement content is stated in kg/m³; on its own, it does not define the concrete class or its durability.
Sulphate-Resisting Cement
Sulphate attack can lead to expansion and deterioration as a result of interactions with the binder components of the concrete. The severity of the attack depends on the composition of the environment and the properties of the concrete.
The selection of a binder suitable for sulphate exposure is considered together with measures such as low permeability, adequate compaction and curing. Sulphate-resisting cement alone does not provide protection against acid attack or against all chemicals.
Fibre-Reinforced Concrete
Depending on their type and design, fibres can contribute to crack control and to post-cracking load-bearing performance. The properties, dosage and distribution of the fibre used and the concrete mix are assessed together.
- Steel fibre: can contribute to post-cracking load transfer and toughness; it can be used together with reinforcement or, in applications verified by design and testing, in place of reinforcement.
- Synthetic fibre: microfibres are considered mainly for early-age crack control, and macrofibres for post-cracking performance in suitable designs.
- Glass fibre: for cement-based elements, alkali-resistant types suitable for this use are selected.
- Basalt and carbon fibre: for special performance requirements, these are assessed together with material compatibility and test results.
The fibre used in our products is mainly steel fibre. The appropriate fibre type and quantity are determined according to the product's cross-section, loads, manufacturability and target performance.
Reactive Powder Concrete
Reactive powder concrete, with its fine-grained constituents, low water/binder ratio and dense particle packing, is a special type of concrete aimed at high performance. Its strength and durability properties are determined by the mix and the production conditions.
In the Telecom, Fibre Optic and PTT Manholes Group, reactive powder concrete is used for the fibre optic covers of the Fibre Optic Manhole Base Sets (400×400 and 600×600 mm). This mix is preferred because the cover must both carry the load passing over it and remain thin and portable.
On request, production with reactive powder concrete can also be considered for other products with thin sections where high strength is expected.
Colour, Minerals and Texture in Landscape Elements
In landscape elements, concrete is not only the load-bearing material but also the visible surface; the mix can be adapted as much for appearance as for strength.
- Colour: this is achieved by using pigments or by changing the cement itself. An element produced with white cement gives a much lighter and more vivid colour than one made with grey cement. An additive is not always required for colour; sometimes choosing the right cement is enough.
- Minerals and texture: changing the aggregate changes the character of the surface. By using mineral-based stone and coloured aggregates, a range of results can be achieved, from an exposed-aggregate appearance to a mosaic texture.
Colour and texture requirements are finalised using a sample; the approved sample becomes the reference for series production.
Chemical Admixtures
Chemical admixtures are used for specific purposes, such as workability and production conditions. In our production, the choice of admixture is considered to the extent required by the mix and the product; suitability is determined through production and performance checks.