How can industrial floors be properly cured?

Newly constructed industrial hall floors are primarily made of concrete. These are usually reinforced or unreinforced concrete slabs that are designed to be used as direct wearing surfaces to withstand mechanical loads. After placement, the concrete is smoothed to create a high-quality floor that meets both aesthetic demands and durability requirements. For successful production, careful planning of a consistent and well-thought-out curing concept is vital. The Emcoril Compact system from MC can be used to intermediate and finally cure industrial floors. What you need to consider is explained in our following MC-Pedia article.

According to the guideline "Concrete Industrial Floors" by the German Concrete and Construction Technology Association (DBV), an industrial floor is a concrete hall or outdoor surface used for manufacturing, handling, storing, or displaying goods. In the sense of this guideline, industrial floors are those that do not serve a load-bearing or bracing function according to DIN EN 1992-1-1. Instead, they are separated by movement joints from rising structural elements such as columns or pedestals. These floors are typically uncoated and serve as direct, moderately to heavily mechanically loaded wearing surfaces. High durability and aesthetics are generally expected as standard.

Concrete industrial floors – also referred to as smoothed concretes – are produced in four types: unreinforced, steel fibre-reinforced, rebar-reinforced, and hybrid (combination of rebar and steel fibres). During production, structural design follows DIN EN 1992-1 / Eurocode 2, and concrete mix design for durability follows DIN EN 206-1 and DIN 1045-2. For execution, DIN EN 13670 / DIN 1045-3 applies. Further details can be found in the DBV guideline “Concrete Industrial Floors”.

A professional design process is crucial for producing a smoothed concrete floor. This includes choosing the right concrete, its placement, and curing.

When planning, producing, operating, and maintaining an industrial floor, it is essential to understand the needs and expectations of the client or future users. Useful planning references can be found in the DBV guideline "Concrete Industrial Floors", the DIN 18205 “Requirements Planning in Construction,” and the DBV guideline “Quality of Planning.”

As standard, concrete for industrial floors is designed for a service life of 50 years under regular maintenance, based on exposure classes according to DIN EN 206-1 / DIN 1045-2 or DIN EN 1992-1. However, shorter lifespans are typical for industrial floors, so specific technical and economic requirements must be assessed case by case.

Levelling of an industrial floor

Guidance on the selection and composition of raw materials (aggregates, cement, admixtures, fibres, water) is provided in DIN EN 206-1 / DIN 1045-2 and the DBV guideline. Key parameters, supplemented by practical experience, include:

• Cement Content: DBV recommends 320–360 kg/m³. For exposure class XM (mechanical stress), the content should not exceed 360 kg/m³.
• Fines Content (0–0.125 mm): Recommended 360–400 kg/m³; total fine and very fine sand (0–0.25 mm) should not exceed 430 kg/m³. In practice, approx. 365 ± 10 kg/m³ has proven effective.
• Water Content: 180 kg/m³; 165–175 l/m³ is typical. Higher content leads to more bleeding, too little leads to insufficient bleeding.
• w/c Ratio: Recommended 0.45–0.55; practical value around 0.5 based on fines and water contents.
• Proper fine content and water levels are essential to avoid mortar accumulation on the surface. For hard aggregate broadcast, the concrete surface must remain moist enough for proper incorporation.
• Note: Air-entrained concrete (LP concrete) is unsuitable for smoothing, as trowelling destroys air pores in the top 3 mm, eliminating frost/de-icing salt resistance.

Placing concrete requires both technical knowledge and practical experience in surface finishing. Specialized contractors with years of practice typically perform this work. For indoor concreting, halls should ideally be enclosed to prevent drafts and excessive evaporation. Outdoor concreting requires consideration of weather effects. Otherwise, the surface may dry too quickly and crack. To prevent this, Emcoril Compact products are used.

Placement should be continuous in manageable strip lengths to ensure a "fresh-on-fresh" connection between sections. After placement, the concrete is compacted, levelled, and closed at the surface, usually with a float. Improper venting can lead to entrapped air below the surface, causing later bonding issues.

Drying-out conditions must be planned in advance during the laying period. If excessive drying is expected, to the extent that it is no longer possible to smooth or incorporate bedding in the event of step resistance, the drying of the surface can be reduced with an intermediate after-treatment. This agent must be able to be smoothed in later.

Concrete placement for an industrial floor

Immediately after surface closure, Emcoril Compact pro is applied as an intermediate curing agent and trowelling aid. It is sprayed using commercial pressure sprayers with a flat-jet nozzle (e.g. Mesto 8002) about 50 cm above the surface. Make sure the spray pattern is evenly distributed and milky white, with no drips, and that the specified dosing quantity of 150–200 g/m² is used. Emcoril Compact pro forms a film reducing surface evaporation, thus lowering the risk of rapid drying. This agent is only effective from placement to the point of step resistance (typically 3–5 hours depending on conditions). Concrete temperature significantly affects this. For example, at 20°C, this time might be 4 hours. Higher temps reduce this time, requiring earlier finishing; cooler temps extend it. Warm concrete can speed up curing in cold weather.

This means that in summer, the time required to achieve tread resistance is shorter. The smoothing process inevitably begins earlier. In winter, on the other hand, very long open times are to be expected at cool temperatures, even when using 42.5 R cements. Here, warm concrete can be used to shorten the time until the concrete is ready for foot traffic. Information on concreting in summer and winter can be found in the cement data sheet ‘Concreting at extreme temperatures’.

Application of the curing agent Emcoril Compact pro

Machine finishing requires the concrete to be step resistant and to bleed slightly (approx. 0.3–0.5 vol.%). In good conditions, bleeding water combined with the curing agent protects the surface. In poor conditions, the curing agent alone helps reduce drying.

At foot traffic readiness, the surface must still be moist enough for machine trowelling. For hard aggregate broadcasts, enough moisture must remain for bonding. Modern power trowels are then used for finishing.

After trowelling, the concrete surface must be effectively protected from drying. The previously applied Emcoril Compact pro has been worked into the surface and no longer forms a protective film. Therefore, it must be followed by final curing using Emcoril Compact top. This is also applied with a pressure sprayer and flat-jet nozzle (e.g. Mesto 8002) from about 50 cm height, forming an even, milky-white layer at 150–200 g/m². Curing duration follows DIN EN 13670 / DIN 1045-3. For exposure class XM, the double curing times from Table 5.NA must be applied.

The Emcoril Compact system, consisting of Emcoril Compact pro and Emcoril Compact top, carries the EMICODE seal. Sensitive lab testing (e.g. gas chromatography, mass spectrometry) confirms only trace amounts of volatile organic substances (VOCs) in the air. The products meet EMICODE® EC1PLUS— currently the highest standard technically achievable.

Using an intermediate curing agent as a temporary curing method during the laying phase and as a smoothing aid, followed by a final treatment, is a proven and suitable system for producing industrial floors. Thanks to the modern Emcoril Compact curing system and the practical experience of specialized contractors, it is technically possible to produce high-quality industrial concrete floors.