Through years of experience in developing top-tier logistics and supply chain facilities, it's become evident that what seems like a simple flat concrete surface can often let us down.

In our previous article on industrial floors, we tackled one of the most pressing issues - floor joints, and explored solutions like the HCJ Co-Sinus Connect joints, which effectively eliminate historical problems associated with them. However, achieving a perfect industrial floor involves more than just addressing joint concerns. In this article, we delve into the requirements for a flawless industrial floor and share insights into achieving the best results.

The requirement for a perfect floor

A perfect industrial floor must meet several critical criteria:

• Load-Bearing Capacity: It should be capable of supporting both static loads (from racks and equipment within distribution centres or warehouses) and dynamic loads (created by moving machinery) without risk of failure.
• Level Tolerances: The floor should adhere to the level tolerances required for the specific operation it serves.
• Longevity: These qualities must be maintained throughout the floor's operational life, ensuring it stands the test of time.

 

Precision and Compliance in Industrial Construction

In the realm of industrial construction and design, precision and adherence to established standards are paramount. Whether you're constructing a warehouse, manufacturing facility, or distribution centre, the quality of the floor is integral to the safety, efficiency, and functionality of the workspace.

 

Understanding Floor Tolerances and Levels

To achieve an impeccable industrial floor, it's essential to understand floor tolerances and levels:

1. Flatness: Flatness relates to the evenness of a floor surface in a horizontal plane. In simpler terms, it gauges how smooth or uneven a floor appears. Irregularities in flatness can result in equipment mobility challenges, inefficient material handling, and safety hazards.
2. Levelness: Levelness pertains to the overall slope or tilt of the floor. A level floor ensures that liquids, materials, and machinery do not unintentionally move due to gravity.

 

Industry Standards and Codes

In the United Kingdom, the Concrete Society's "Technical Report 34 - Concrete Industrial Ground Floors" (TR34) stands as a widely recognized and comprehensive document for industrial concrete floors. It offers guidelines and recommendations covering various aspects:

• Floor Classes: TR34 categorizes floors based on expected usage, from lightly loaded to heavily loaded areas, each with specific tolerance requirements.
• Tolerance Categories: TR34 defines specific tolerance categories for flatness (FM1, FM2, FM3) and levelness (FL1, FL2, FL3).
• Measurement Methods: The document outlines precise methods for measuring flatness and levelness, including the use of straightedges and laser screeds.
• Remedial Work: TR34 provides guidance on addressing floor surface issues if they don't meet specified tolerances.
• Maintenance: It also offers recommendations for ongoing floor maintenance to ensure longevity and performance.

In the United States, the American Concrete Institute (ACI) provides guidelines and standards through documents like ACI 302.1R-15, "Guide for Concrete Floor and Slab Construction."

 

Importance of Compliance

Adhering to industry standards and codes such as TR34 or ACI 302.1R-15 is vital for several reasons:

• Safety: Level and flat floors reduce the risk of accidents, enhancing workplace safety.
• Operational Efficiency: Specified tolerances promote smooth material handling, efficient space utilization, and machinery operation.
• Longevity: Well-constructed and maintained floors have a longer service life, reducing the need for costly repairs or replacements.
• Cost Savings: Meeting tolerances and standards from the outset minimizes the need for expensive remedial work.

Industrial floor tolerances and levels are critical elements in industrial facility construction. Compliance with industry standards ensures that the floors meet specific performance criteria, leading to enhanced safety, operational efficiency, longevity, and cost savings. Prioritizing precision and compliance in floor construction lays a solid foundation for success in any industrial project.

The process commences with a deep understanding of the intended usage, marking the role as logistics consultants at the forefront of this crucial definition phase. This expertise encompasses a comprehensive grasp of planned operations, utilization requirements, and facility design nuances. It's imperative to recognize that architects or structural engineers alone cannot provide this level of insight. This input shapes critical elements such as load considerations, both dynamic and static, as well as precision requirements regarding tolerances, flatness, and levelness.

The specification process further entails stipulating the most suitable surface characteristics for the intended purpose, encompassing durability, dust prevention, and in certain instances, even colour considerations. An emerging international trend leans towards lighter floor hues to enhance workspace illumination, fostering a more favourable environment for workers and boosting overall productivity. Additionally, there might be a need to impose restrictions on joint placements to ensure they do not impede the layout of racking systems.

Specialized applications, where immobility is imperative, such as under automated operations, necessitate specific specifications. This extends to unique scenarios like installations within refrigerated environments, freezers, or specialized handling areas.

The subsequent phase centres on the technical design of the floor, a task entrusted to structural and civil engineers. However, the success of this stage hinges on experience, particularly an understanding of the intricacies and potential challenges that accompany these specific types of flooring projects. In practice, we collaborate closely with the engineers to guarantee the accurate application of standards such as TR34 or other pertinent codes.

Ultimately, the realization of an exemplary floor largely rests upon the expertise of the contractor. It's a stance I consistently maintain, advocating for the engagement of a specialist floor contractor well-versed in the intricacies of industrial flooring. While floor specifications and designs adhere to scientific principles, the actual construction process is an art form. Seasoned contractors bring invaluable experience, insights, and a nuanced understanding of the right supervision and techniques, all of which collectively contribute to the achievement of a superior floor.

In the initial stages of introducing large panel floor construction techniques, we often relied on overseas specialists to oversee these projects. However, as time has progressed, the local floor specialists have honed their expertise, acquiring state-of-the-art machinery that significantly enhances the quality of the final product. This transition has yielded more dependable and superior floors, reflective of the maturation of the local industry in this specialized field.

 

Common Problems Encountered

Apart from joint issues, industrial floors can suffer from various problems, including:

• Curling: The distortion of concrete slab edges or corners, leading to uneven surfaces, cracking, and operational disruptions.
• Cracking: The formation of cracks in the concrete, which can weaken the floor and pose safety risks.
• Rocking: Unwanted tilting or movement of concrete slabs, often related to curling, affecting floor stability.
• Delamination: Layers of the concrete surface separating or detaching from each other, compromising structural integrity.
• Non-Conforming Specifications: Deviations from specified load-bearing capacities, levelness, and flatness criteria.

 

Addressing Curling

Curling in concrete floors is a common challenge influenced by factors such as concrete mix design, curing methods, environmental conditions, and the presence of control joints or reinforcement. Mitigation strategies include proper curing, controlled environment curing (especially in enclosed spaces), and the use of reinforcement materials to minimize differential drying and shrinking.

 

Dealing with Delamination

Delamination is a structural issue where layers of the concrete surface detach. It can be caused by various factors, including poor adhesion, moisture intrusion, and surface contaminants. Addressing delamination often involves surface preparation, proper curing, and the use of appropriate repair materials like non-shrink epoxy.

 

Achieving the Perfect Floor

To achieve an impeccable industrial floor, consider the following steps:

Detailed Specification: Define usage, loads, tolerances, surface requirements, and even joint positions. Special applications like refrigerated or automated areas should also be specified.

Technical Design: Collaborate with structural and civil engineers with experience in industrial floors to design a floor that meets specifications.

Experienced Contractors: Engage specialized floor contractors with a track record in industrial floors, as floor construction is both science and art.

Concrete Supplier Selection: Choose a reliable concrete supplier capable of consistently delivering the specified concrete mix on time.

Concrete Mix Control: Collaborate with the supplier and engineer to ensure the mix accurately matches the specification.

Proper Groundwork: Prepare the subbase meticulously, ensuring it can withstand loads and is stable.

Timing and Process Control: Precise timing of each construction step is crucial, from the placement of the concrete to the application of surface hardeners.

Curing: Implement a controlled curing process to prevent differential drying, which can lead to curling.

 

Construction

Subsequently, meticulous attention is turned to preparing the subbase. Typically, a layer of G4 type stone is meticulously laid and manipulated to create a uniformly level working foundation. Following this, we introduce a layer of plastic sheeting to facilitate the concrete's controlled curing process while preventing untimely shrinkage. Finally, we proceed with pouring the concrete to the specified thickness.

Before the concrete can be poured, it's imperative that the building is sealed off. The nearest access point should be at a minimum distance of 100 meters from the concrete pouring site. This meticulous precaution plays a pivotal role in managing the curing process and serves as a potent preventive measure against the development of undesirable curling.

The subsequent step entails the setup of joints, anchoring them firmly to the subbase to prevent any displacement under the force of the incoming concrete. Precision is paramount in this task; the joints must exhibit perfect levelness and perpendicular to the floor surface. Any deviation from this precision could adversely impact joint performance, functionality, and the overall ease of navigation across the floor. The joint levels serve as the reference points guiding the floor's levelling process, playing a critical role in achieving the requisite flatness and levelness standards.

As the concrete is vibrated and meticulously worked into the space, ensuring the elimination of air gaps and the attainment of a homogenous mix becomes the priority. It's essential to exercise caution to prevent excessive vibrations, preventing larger stones from settling at the bottom and leaving only fines at the top, which would compromise the floor's strength.

The timing of each phase is of paramount significance, a facet well understood by experienced contractors. As the concrete is poured and vibrated, the curing process commences. To achieve the necessary level tolerance, laser screed machines become indispensable, especially for larger panel configurations. This technology supersedes the traditional straight-edge method, ensuring precision in achieving level surfaces. Following this, the surface hardener is introduced. In the past, this was a manual process involving individuals manually spreading the hardener and then power floating it. However, contemporary methods involve automatic machines equipped with booms designed to dispense precise quantities of the hardener.

Subsequently, the floor undergoes the power floating process, executed with ride-on machines that can be connected to laser technology for utmost accuracy. Timing here is critical, as the floor must have hardened sufficiently to prevent the power float from sinking while remaining workable enough to polish the surface. This meticulous timing ensures that the surface hardener penetrates the top layers, creating a gradient of hardness that effectively thwarts delamination.

The concluding step involves allowing the concrete to undergo proper curing. This necessitates rigorous control of the drying process to ensure that the top surface does not dry at a faster rate than the rest of the concrete, which could lead to uneven shrinkage and undesirable curling. Concrete requires a dedicated curing period to both cure and shrink.

Typically, the majority of shrinkage transpires during the initial few months, with a continued, albeit slower, rate of shrinkage over the subsequent 12 to 18 months. By the sixth month, approximately 90% of the shrinkage should be complete, with 70% to 80% achieved by the third month. For this reason, we strongly advise against loading the floor for the first three months, as premature loading can impede the natural movement and shrinkage of the concrete, potentially leading to cracking.

 

Handling Problems

Any issues that arise should be promptly addressed. Joints may require grinding and filling, while curling can often be corrected by grinding raised edges. Delamination may necessitate opening and filling with non-shrink epoxy. The key is to take action swiftly to prevent further damage.

 

Avoiding Pitfalls

Beware of trying to reduce floor thickness through additives. The primary concern should be achieving the desired floor quality, even if it requires additional investment in concrete.

In conclusion, building the perfect industrial floor involves meticulous planning, adherence to standards, and collaboration with experienced professionals at every stage. With the right team and attention to detail, you can create a floor that meets the highest standards of safety, efficiency, and longevity.

Don't prioritize short-term savings at the expense of long-term benefits. Investing in your floor will not only provide peace of mind but also yield significant returns in the future.