Today, we all talk about epoxy flooring for industrial floors. However, when a simple question is put up like “What is a concrete floor?”, often it is observed that even experienced professionals find it difficult to come up with a simple answer and rather start answering the question structurally. When it comes to resin flooring, structural definition of floor may not be the most apt one.
An Industrial Floor can be defined as a working surface and a trafficked area for people, machinery, products, and vehicular traffic. It is important for an industrial floor to be durable enough to withstand all loads and movements. Hence, its designing, load calculations, and selection of construction material should be done considering the final usage.
While industrial floors are made of reinforced concrete; these are laid with resin topping above the RCC surface. It is important, therefore, to ensure how the concrete floor is casted. Though water is highly friendly for green concrete, it is not desirable during efficient resin topping. Proper slip membrane and vapour barrier are of utmost importance for casting a sustainable resin floor.
Why Sustainability is Important
The sustainability of an industrial flooring is important for the following reasons:
- The HSE Factor: Health, safety and environment are directly related to floors for the workers in any industry. If the floor is not well maintained, it may cause accidents.
- Hygiene Factor: If the workplace does not bring a sense of good hygiene to the workers, then their output will get affected.
- Business Volume: Floors that are durable and sustainable will reduce unwanted shutdown of the factory / shopfloor and help increase its productivity thus enhancing business volume.
Pre-installation: The first aspect that comes to mind for any kind of resin topping during pre-installation is the moisture. The presence of moisture of more than the permissible (5%) limit in concrete is not desirable, but the rising dampness is more horrifying for resin floors as it may cause water entrapment between the concrete floor and the resin topping (bubbles). This eventually weakens the bond between the concrete floor and the resin topping causing the floor topping to peel off from the surface.
To resist the rising dampness to seep through the concrete surface, installation of a vapour barrier is recommended. Vapor barrier should be made of 300GSM HDPE/LDPE sheet. HDPE chemistry is vital for vapour barrier, as it should not get damaged during rebar handling over it.
Pre-installation is a good concreting practice. If the floor is not cast properly, then it will not sustain for long. Good concreting involves correct Concrete Pouring, Levelling, Curing, and Joint Cutting.
Concrete pouring: Nowadays, concrete is not only the mixture of sand, cement, aggregate and water, but a lot of chemicals have been introduced to improve its quality and performance. Hence, pouring of concrete in case of mass concreting, needs to be highly precise to avoid unwanted issues like segregation, honeycombing, etc.
Concrete levelling: In case resin topping is to be done, the floor must first be levelled for better execution of the system. Nowadays, the double rider power trowel is a common equipment for levelling.
Concrete curing: As a part of cement chemistry, curing is the most important factor for the strength and durability of a concrete floor. Curing of concrete floor is very easy: it can be done using the conventional ponding method; or by spraying curing compound; or by covering the concrete surface with a plastic sheet.
Joint Cutting: Joints in concrete floor need to be cut open properly within maximum 48 hours of concrete casting. When the construction joints are not cut at the right time, the floor tends to develop unwanted cracks. Construction joints need to be cut up to one-third depth of the floor thickness and filled with rigid material (in case of resin flooring application). This will help the epoxy/PU floor to be more sustainable and long-lasting.
Construction joints are considered non-moving joints and hence, can be filled with rigid materials. Expansion joints are considered as moving joints and hence, they need to be filled with flexible sealants. The width and depth ration as shown in the figure below need to be maintained in case of sealant for expansion joints. The Movement Accommodation Factor (MAF) of the sealant should be between 20-25%, which is sufficient for durability.
Post-installation of resin topping involves the following:
Curing time: Any resin floor of whatever chemistry installed at the work area needs to be properly cured before it is exposed to the challenges it has been installed for. For example, if one has installed a tough Polyurethane (PU) flooring at an assembly unit of an automobile plant, the floor will generally get exposed to heavy wear and tear and impact. If the PU floor is not given proper time for curing, and becomes exposed to the regular activity before the stipulated curing period, then it will not be sustainable and may even require redoing of the entire flooring, which will be waste of resources, time, asset, and the money spent.
Selection of system as per exposure condition
When making an industrial flooring, selection of the system/chemistry as per the exposure condition is very vital. In case of improper selection, the flooring may not serve its desired service life. For example, in a chemical plant, if the epoxy coating selected is not resistant to aggressive chemicals, then it will not be an effective solution for the industry. It could lead to a shutdown of the premises to re-install the entire flooring. Critical exposures include exposure to chemicals, impact, abrasion, and temperature.
Mechanical maintenance of floors is the maintenance of different vehicles that roll over the floor with certain load. Most industries have trolleys and forklifts, which could be manual or hydraulic. The type of wheels, condition of wheels and alignment of these vehicles must be well maintained, else the floor will develop tyre marks and reflect signs of damage.