48 The Masterbuilder - September 2012 • www.masterbuilder.co.in

An Insight into Slip Resistance Floor through Anti Slip Floor Coatings

Slip resistance of floors and pavements is a measure of the ability of a surface to resist accidental slipping by pedestrians – in dry or wet conditions. There is

an expectation that surfaces will provide adequate slip resistance and this is increasingly being incorporated into regulations. Polished concrete floors is a generic term that describes a variety of exposed decorative concrete flooring

options often having a highly polished or gloss surface finish. With the increasing popularity of these types of finishes the issue of providing adequate slip resistance has become an important consideration. Various companies are doing extensive research in this area and have come up with wide range of anti-slip floor solutions. However all are not cost effective, like flooring option that involves anti-slip tiles

Sonjoy Deb, B.Tech,’Civil’

Associate Editor

“Slippery floors are a hazard to any business. Add wet conditions or potential spills and you’ve multiplied the risk to employees, equipment and customers. Non slip floor coating can help make flooring safer, regardless of what might get spilled. Slip resistant floor coatings can be used in a wide variety of places to offer more traction and stability.”

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will prove to be very expensive. This made construction agencies to find out a cost effective and aesthetic anti-slip treatment for floors. The result of this is various types of anti-slip coating materials. The best part of such materials is it can use the base cement concrete floors and some products can even give very attractive looks. Several con-struction projects where mass movement of pedestrian is involved like malls, hospitals, airports, schools are now adopting this technique.

Factors Influencing Slip Resistance

Pedestrian slip resistance is a complex subject, where the likelihood of a slip is a function of a variety of factors such as the surface (type and texture), the environmental conditions, and the individual users (their physical condition and footwear). The reasons for accidental falls on concrete surfaces can be divided into four categories:

(A) External factors: These are essentially hazards such as stepping (vertical displacement)at footpath cracks and other slab joints, slippery floor surfaces and slopes. These can be minimised through good design and installation practices, good cleaning and maintenance practices, safety audits, remedial policies, and mandatory legislation. Footwear may be considered an external factor, since inappropriate or excessively worn footwear maybe the prime cause of an accident.

(B) Internal factors: These include voluntary and involuntary responses of people to environmental factors such as distractions. Responses may also be influenced by stress, fatigue, medicinal and recreational drugs, and also by the person’s mood and the degree of preoccupation (which may be influenced by the nature of the activity being under-taken –carrying, pushing, rushing), and whether it imposes a temporary functional limitation, e.g. obscured vision or impaired balance.

(C) Environmental factors: These include lighting conditions, contamination of the surface (by water or other materials) and slopes. The risks can be minimised by good design practices (lower gradients, less glare) and staff training (response to spills, replacement of light bulbs).

(D) Pathological factors: These include ageing, impaired vision, physical disabilities, instantaneous health conditions (eg stroke, heartattack), and diseases (eg Parkinson’s disease).

Measuring Slip Resistance

While the surface roughness can be measured, the two common methods used to assess wet slip resistance are the wet pendulum test, which measures the frictional force offered by simulating a foot moving over a water-contaminated surface, and the ramp test, which determines the maximum gradient at which a person can just traverse

the surface, either barefoot (wet barefoot test) or in shoes (oil-wet test).

1. Wet Pendulum Test- This test (BS 7976: 1- 3 2002) is generally used in the laboratory for classifying the wet slip resistance of new flooring (pedestrian surface) materials. However, as the test instrument is portable Figure 1, it can also be used on site to assess the slip resistance of existing floors and pavements (BS 7976: 1- 3 2002).The instrument has a rubber slider attached to a spring-loaded foot at the end of a pendulum arm (leg). The pendulum arm is released from a horizontal position, allowing it to swing so that the slider contacts the wet pedestrian surface over a set distance of 126 mm. The extent to which the pendulum fails to reach its release height on the over swing is used as a measurement of the slip resistance. The reading on the scale is the Pendulum Test Value (PTV).BS 7976 has 3 parts, BS 7976-1 describes specification. BS 7976-2 describes preparation of sliders prior to testing, pre-test checks, testing procedure, temperature correction and essential information for reporting. BS 7976-3 describes the calibration method.

Figure 1: Wet pendulum test apparatus

PTV Range Slip Potential

0 to 24 High

25 to 35 Moderate

36+ Low

2. Ramp Tests- These tests use human subjects to sub-jectively assess the slip resistance of pedestrian surfaces under closely controlled conditions. The subjects walk forwards and backwards on a ramp Figure 2 while the operator progressively increases the angle of inclination, until the subjects reach the ‘zone of insecurity’ where they either experience slipping or sense that they will fall if the

Health and Safety Executive (HSE) classifies PTV’s as Follows

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Figure 2: A ramp test being conducted

Figure 3: Anti-Slip Coating on Concrete

angle is further increased. The angles of inclination reached are used to assess the friction characteristics of the test surface. The test is not intended to provide guidance on the angle of ramps for which a particular classification is suitable.

There are two principal test methods under ramp test viz. wet barefoot test and the oil-wet test.

Achieving the desired Slip Resistance through Anti Slip Coatings

When specifying the slip resistance of polished concrete

surfaces, an optimization of appearance and required slip resistance needs to be made. For example, high gloss finishes may not achieve the required slip resistance for some applications. It is therefore important to consider the slip resistance offered by the combination of finish, texture and sealer (if present) so that the slip resistance and finish requirements can be realistically specified and achieved. The advice of a hard-flooring specialist may be sought regarding the appropriate combination of finish, texture and sealer for the slip resistance performance required. Concrete surface coating materials are playing a vital &cost effective role in this process. Refer Figure 3 for a slip resistance surface through Anti Slip coatings.

Type of Anti Slip Coating materials

Certain types of paint can lend a non slip function, they include an extra set of grit to be sprinkled as the paint dries, adding traction. There are two available types of anti-slip coating materials viz. Epoxy Resin Coatings and Polyurethane Coatings. Micro etching treatments is another way for achieving anti-slip characteristics in concrete floors. When applied, such treatment create millions of microscopic grooves and indents that provide slip resistance when the concrete is wet.

About Resin Coatings-A super hard non slip epoxy Resin coating that quickly cures to a slip resistant surface with a rough grit that is easy to use. It requires no tools for mixing of chemicals & provide a safe non-skid surface. This unique aerosol contains special synthetic grit with no sharp edges and it is available in several Non-Slip paint colors. Its needed to be spray painted on almost any hard surface and may need to be re-applied as needed. Aerosol paint leaves surface like a diving board surface. A slip-resistant, epoxy non slip coating that cures to a hard, flat, textured finish is designed for interior and exterior use on concrete and other surfaces where a slip-resistant finish is desired.

About Polyurethane Coatings- The Anti-Slip Polyurethane Floor Paint is a hard wearing polyurethane single pack paint designed to seal and color concrete floors. The product uses a high quality resin system with a fine textured finish so providing anti-slip properties for pedestrian traffic areas. Petrol and oil resistant, this product is ideal for general walkways, factory and garage floors and has excellent durability.

Surface Preparation

Poor surface preparation is the major cause of floor coatings failures. Using correct surface preparation methods and equipment is essential to secure the cleanliness and surface profile necessary for the good adhesion and performance of floor coating systems. Concrete and primed concrete surfaces must be clean and dry and free of contaminants

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such as dust, dirt, grease, or oil. It is important that a suitable moisture barrier is in place for slabs on-grade. If a moisture barrier is not in place, seasonal variations in ground moisture can cause excessive hydrostatic pressure regardless of results measured prior to coating application. There are two types of surface, i. New/Bare concrete and ii. Previously painted concrete.

Methodology Adopted in Anti-Slip Coating of Concrete

The anti-slip aggregate can be applied in many different ways. There are two principal ways, however. Firstly, the aggregate can be added to the paint solution and it will then be an integral part of the paint when applied to the floor. The other option is to first apply paint to the floor and then spread the aggregate evenly over the paint in the quantity required. Depending on the situation, a second coat of paint is then normally applied over this aggregate finish to seal it and give color. Whichever methodology is used, this new anti-slip floor coating will enhance safety for pedestrians, and it is also useful where to give extra traction on slopes and ramps for forklift trucks etc.

The best anti-slip characteristics are obtained when the product is rolled. It is recommended to use a smooth napless solvent resistant roller on smooth surfaces. For irregular surfaces it is advised to use an adhesive/bristle core roller or short nap roller.

1. Pour a “strip” of coat on the concrete surface.

2. Roll in one direction only by pulling material toward applicators direction in slow straight strokes.

Use a modest amount of downward pressure. It is important that the rolled profile expose the maximum amount of non-slip aggregate. If aggregate is not properly exposed, the coating may become slippery when wet. Do not over-roll or press down too heavily. It is important to ensure that coating is even without any thick puddles. If applied too heavily the coating may not cure properly.

Health and safety aspects

These coating materials should not come into contact with skin and eyes or be swallowed. Ensure adequate ventilation and avoid inhalation of vapours. Some people are sensitive

Figure 4: Application of Anti-Slip coatings over various types of concrete floors.

Figure 5: Al GhanimGarrage in Kuwait

Figure 6: Tawaren Commercial Center, Riyadh, KSA

to resins, hardeners and solvents. Wear suitable protective clothing, gloves, and eye protection. If working in confined areas, suitable respiratory protective equipment must be used. The use of barrier creams provide additional skin protection. In case of contact with skin, rinse with plenty of clean water, then cleanse with soap and water. In case of contact with eyes, rinse immediately with plenty of clean water and seek medical advice. If swallowed, seek medical attention immediately do not induce vomiting.

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Figure 7: Guangzhou International Finance Center, Guangzhou, China

Figure 8: This 10,000 m2 unit Factory was sprayed with this recycled coating material.

Figure 9: Application stages of recycled glass based coating material on concrete floor.

Examples of some specific areas of Application

Figure 4 shows application of Anti Slip coatings in Parking places and shopping complexes.

Example 1: Al Ghanim Garage, Kuwait - The World’s largest car repair garage, 31,000sq m of anti-slip coating application.

Example 2: Tawaren Commercial Center, Riyadh, KSA. 7,000 sq m of anti-slip coating application.

Example 3: Guangzhou International Finance Center, Guangzhou, China. 25,000 sq m of coating area in the parking place.

Green Concept

“Putting back what we take out” is a sense which every human being should have in his heart. In the anti-slip coating technology various companies are carrying out research to make it a more sustainable and green concept. In this a very recent research is invention of a coating material with 100% recycled glass added to the binder which is nontoxic, environmentally friendly and water based. This can be sprayed on in a single application to create a relatively smooth textured and stone like finish which gives anti-slip behavior to concrete floors. The product is of low maintenance and readily acceptable for all kinds of commercial, industrial or home building. It comes in avariety of colours and can be sprayed on new and old surfaces that need a decorative finish. Unlike paint or cement based renders and even epoxy that tends to fade, the crystals

are completely colour coated on all sides. Added to this, the crystals filter out the U/V to the underlying sides thus adding to the remarkable longevity of colour retention and even thermal property. Refer Figure 8 and 9 for the application of this coating material on concrete surface.

Conclusion

Anti-Slip floor coating is an emerging cost effective concept in construction industry. The concept will find a very wide spread application owing to its cost effectiveness and ability to provide aesthetic and colorful surfaces. The other major advantage of this product is that it uses the concrete floor as base. Implementation of green/sustainable concept on this material will make it more popular amongst other other products in this domain. Numerous researches is going on in its technological evolution. However specific standards needs to be put on place to have a stringent control on its production, application and lifespan.

Reference

- http://ppgamercoatus.ppgpmc.com/products/pdf/SFT-600-PDS_AI.pdf

- http://www.business.com/human-resources/non-slip-floor-coating/

- http://www.interstateproducts.com/nonslipproducts.htm- http://www.noskidding.com/ns_50378.htm- http://www.newventureproducts.co.uk/documents/PU_Anti_

Slip_Floor_Paint.pdf- http://ppgamercoatus.ppgpmc.com/products/pdf/SFT-600-

PDS_AI.pdf- http://www.arconsupplies.co.uk/pdfs/protective_coatings/

nitoflor%20fc130.pdf- http://www.robexfloorcoatings.co.uk/UserFiles/Technical%20

Data%20Sheets/Non-SlipConcreteFloorPaint.pdf- http://www.vubasupplies.co.uk/paints-coatings/slip-resistant/

non-abrasive-anti-slip-paint.html- http://www.nonslipcoating.com/concrete.htm- http://www.wayout.com.au/downloads/Eco_Crystal.pdf

Floor Coatings Anti Slip