Concrete for your project

• Transit-mix concrete
• Ready-mix concrete
• Fresh concrete
• Screed concrete
• Cement screed
• Anhydrite screed
• Exposed concrete
• WU (waterproof) concrete
• Steel-fibre-reinforced concrete
• Structural concrete
• Bridge concrete
• Road concrete
• Self-compacting concrete (SCC)
• Easily compactable concrete (SDC)
• Lightweight concrete
• Heavyweight concrete
• Recycled concrete
• Drainage concrete
• FB BLOCK
• Backfill material
• Cement slurries

Compressive strength is one of the most important properties of concrete. Based on its compressive strength, which is measured using a specific method, concrete is classified into different strength classes. The letter C in the designation stands for concrete. As part of the harmonisation of European standards, concrete strength classes have been standardised across Europe in the current generation of standards.

• C12/15: lightweight foundations, non-load-bearing structural elements
• C20/25: floor slabs, foundations
• C25/30: load-bearing structural elements, slabs
• C30/37: higher loads, civil engineering
• C35/45: bridges, traffic areas
• C50/60: high-performance applications

A key property of fresh concrete is its consistency. In concrete technology, consistency describes the workability, compactability, pumpability and placeability of concrete. Fresh concrete is classified into consistency classes using different testing methods. At roxit, we use the flow spread classes F1–F6 for our tests:

• F1: flow spread ≤ 340 mm – stiff
• F2: flow spread 350–410 mm – plastic
• F3: flow spread 420–480 mm – soft
• F4: flow spread 490–550 mm – very soft
• F5: flow spread 560–620 mm – flowable
• F6: flow spread 630–700 mm – highly flowable

Concrete properties are determined according to exposure classes XC, XD, XF, XA and XS, as specified in EN 206 and national regulations. Exposure classes categorise the environmental conditions concrete will face, and concrete cover and after-treatment requirements are adjusted accordingly to meet the requirements of the relevant exposure class.

• Sand
• Gravel/crushed stone
• Cement matrix
• Additives (superplasticisers, retarders, accelerators)
• Admixtures (fly ash, slag)

Formulations are developed using technical expertise and validated through laboratory testing.

• Concrete resistant to freeze-thaw cycles and de-icing salts
• Low-chloride concrete formulations
• Heavyweight concrete for radiation shielding
• WU (waterproof) concrete for white tank construction
• Self-compacting concrete (SCC)
• Easily compactable concrete (SDC)

roxit supplies transit-mix concrete for general building and civil engineering applications, produced in compliance with applicable standards and technical regulations. It covers all standard strength, consistency and exposure classes and is suitable for load-bearing and non-load-bearing structural elements, including foundations, slabs, columns, walls and floor slabs. Production, delivery and quality assurance are carried out following clearly defined requirements. 

The right choice depends on the type of construction work involved (foundations, floor slabs, columns, etc.) and the specific requirements of your project. If you don’t have all the details to hand, we can offer a brief consultation to help you select the right product and avoid costly mistakes.

Ideally, concrete should be ordered 1 to 2 days in advance. At a minimum, orders must be placed one day before the planned pour date. Delivery usually takes place within 24 hours, depending on the required volume and project location. We also offer pumping services tailored to your site conditions to ensure fast and efficient concrete placement. If a concrete pump is required, we recommend placing the order 2 to 3 days before the scheduled pour. Short-notice deliveries will be accommodated whenever possible following consultation with our dispatch team.

The basic formula for calculating the required volume of concrete is length × width × height = m³. If a concrete pump will be used, we generally recommend ordering an additional 0.5 m³ to ensure sufficient material is available on site. The price is determined by several factors: concrete grade, quantity, transport distance and additional services (pumping services, admixtures). We provide fast, transparent quotations, tailored to the specific requirements of each individual project.

Access to your construction site must be suitable for lorries with a gross vehicle weight of 40 tonnes. Sufficient space must be provided for setting up the concrete pump and accommodating any additional delivery lorries. You must also ensure there is space available for cleaning the concrete chute(s) and, where applicable, flushing out the pump hopper after the pour. 

Yes, because concrete is sensitive to temperature. At temperatures below 5 °C, it sets much more slowly and can be damaged by frost. In hot weather, it dries too quickly and cracks can form. Mild weather is ideal for placing concrete.

Yes, but only with appropriate precautions. Light rain is typically not a major problem. However, excess rainfall ca:

• wash away the surface
• weaken the top layer of the concrete
• result in an uneven surface finish

Solution: Cover the concrete (tarpaulin or plastic sheeting) and protect freshly concreted surfaces. At temperatures below 5 °C, the chemical reaction that causes the concrete to set slows down significantly. In frosty conditions, water within the concrete can freeze and cause permanent structural damage.
Solutions:

• Use R cement (r = rapid, i.e. fast-setting)
• Use warm concrete
  • Keep the subgrade frost-free
  • Cover the concrete surface thoroughly and insulate it

Yes. Follow-up treatment begins immediately after the concrete has been poured. The concrete needs to be

• protected from sunlight, wind, heat and frost
• kept moist or covered with plastic sheeting

Why? Concrete does not set by drying out, but through a chemical reaction. Without sufficient moisture, it cracks.

On average, concrete placement and compaction must be completed within 105 minutes of the initial addition of water at the plant (see the delivery note and the time listed under “Start of loading”). Environmental conditions such as hot or cold weather, can affect the setting process of the concrete. Admixtures can be added to extend the placement window. Please specify this requirement when placing your concrete order. Important: If the concrete appears dry, DO NOT simply add water. Adding water will weaken the concrete, cause it to crack more readily and reduce its overall service life.

If a concrete order need to be cancelled, for example due to weather conditions, please contact our dispatch department at the earliest opportunity. Please note that cancellations may incur charge. Any changes to the scheduled concrete placement time must be agreed with our dispatch department in advance.

It is important that you order the right type of concrete for your specific application. Not all concrete is the same. Foundations or floor slabs, for example, require a different type of concrete than indoor or outdoor areas. If in doubt, simply tell us how the concrete will be used when placing your order and we will select the right concrete for you.

Never add cement or any other binder to the concrete. Instead, leave the concrete as it is and follow the proper after-treatment procedures (keep the concrete moist, cover it, and carefully finish the surface). You should also verify that concrete was ordered correctly (too “runny” consistency). If the concrete is still in the mixer, contact the concrete plant immediately so the consistency can be professionally adjusted.

A retarder slows down slows down cement hydration – the chemical reaction between cement and water. As a result, the concrete remains workable for longer, making it easier to transport and place. This is particularly beneficial in high ambient temperatures, where transport distances are long, during unexpected jobsite delays, or when large concrete pours cannot be completed in a short timeframe.

All technical information is provided for general reference purposes only. Project-specific requirements, structural engineering specification and the agreed technical delivery conditions always take precedence. For project-specific quotations and orders, please use the location map or contact our team directly.