CURRENT TRENDS IN INDUSTRIAL FLOORING

This paper presents the description of new trends of industrial flooring going on in the present sceneries, i.e., it comprises of materials used for construction of floor and design considerations.

Key Words: - Material of construction, Construction Equipments & Techniques, Resilient floor coverings, Flooring materials in market.

1. INTRODUCTION

Good quality industrial floors are sought by industries; Engineering, Electronics, Pharmaceuticals, Food processing& others. Deficiencies in the flooring will create hurdles in the production process, affecting the industry’s productivity.

The latest developments in industrial flooring are of having very much importance as good quality industrial floors are sought by industries. In India too the demand for better performing industrial floors has been acutely felt as some of the existing floors in many industries are showing signs of serious deficiencie’s. Therefore, urgency in upgrading the design, construction maintenance of the flooring system needs no emphasis. Use of conventional materials methods of construction that has characterized the existing flooring construction system needs to understand an immediate change for the better. To start with, the developments in technology materials in other parts of the world offer ample scope to guide our progress in this field.

2.DESIGN OF FLOORS

The technology of design &construction of industrial floors has advanced tremendously due to new materials new types of techniques of construction.

The various loads for industrial floorings are given below(From H.B.K of Building construction materials)

Table 1.Minimum Design Dead Loads

Material	Load Lb / ft²
Concretes, Stone aggregate, reinforced	150
Floor Finshes
Asphalt black 12 in	24
Cement 1 in	12
Hard Wood Flooring 7/8 in	4
Resident flooring ( Asphalt, Linolean)	2
Softwood sub flooring per inch thickness	3
Terrazzo 1 in	13
Wood Block 3 in	13
Floor Fill
Cinders per inch thickness	5
Cinders + Cement per inch thickness	9
Sand per inch thickness	8
Cock ( Insulating Materials) per inch thickness	0.8

From H.B.K of Building Construction Materials

Table 2 minimum Design Live Loads For Materials

Material	Load Lb / ft²
Asphalt	165
Cement + Portland , loose	90
Cement + Portland , set	183
Ciders, dry in bulk	45
Clay, dry	63
Clay, damp	110
Clay & Gravel, dry	100
Sand & Gravel, dry, loose	100
Sand & Gravel, dry, packed	110
Sand & Gravel, wet	120
Gravel, dry	104
Cement, Mortar	130
Sand, dry	90
Water, fresh	62.4
Water, Sea	64

Table 3 Live Loads : Concentrated Loads

Location	Load, lb
Elevation machine room ( 4 in² area)	300
Garages: Passenger Cars
Manual Parking (On 20 in² area)	2000
Mechanical Parking (Per wheel)	1500
Trucks, Buses (On 20 in² area) per wheel	16,000
Manufacturing:
Light	2000
Heavy	3000
Office floors ( On area 2.5 ft² )	2000

:

Table 4minimum Design Live Loads ( Impact Load Included)

Occupancy / Use	Load Lb / ft²
Garages:
Passenger Cars	50
Trucks & buses manufacturing & repairing area	250
Storage Warehouse:
Heavy	250
Light	125
Stores:
Retail:
Basement & First floor	100
Upper floors	75
Whole sale	125
Telephone Equipment rooms	80
Areas of public assembly, I floor lobbies	100
Conference & Card rooms	50
Offices	50

The technology of design comprises; -

· Materials Of Construction

· Design Considerations

· Construction Equipments & Techniques

· Joints

Materials Of Construction

Several varieties of materials are used nowadays of which the main material is concrete. When appearance is of not importance, it may serve as finished floor.

Ø Concrete

Concrete –the main material of construction has become a very versatile product with the incorporation of a verity of admixtures. Higher strength &lower abrasion resistance and special features can be obtained by proper choice of ingradients. The major addition has been the addition of polymers&fibres.

Polymers in concrete;

Polymers in concrete are of two types-

· Polymer modified concrete-are of 2 types

a) Polymer impregnated concrete

b) polymer cement concrete

· Polymer concrete

a) Polymer impregnated concrete

They are produced by the impregnation of precast hardned cement concrete with a monomer that after polymerization will become a solid polymer.The monomers usually used are methyl methacrylate,styrene,vinyl acetate&acrylo nitrile.The amount of monomer is limited by the amount of water and air that has occupied the total void space.Polymer impregnated concrete is produced by drying conventional concrete ,displacing air from open pores, saturating open porespaces by the diffusion of low viscosity monomer.

The main advantage of polymer impregnated concrete is that it improves the tensile, compressive&impact strength of concrete. It is alo durable and is having reduced permeability to water &salt solutions.

b) Polymer cement concrete

It is produced by replacing 10-15% of cement binder by a polymer. It

Consist of cement, aggregate, water, monomer&a catalyst.

The main disadvantage of this is that it gives only moderate improvement of strength &durability. In many cases materials poorer than ordinary concrete is obtained (because organic materials are incompatible with aqueous system and sometimes interfere with alkaline cement hydration process.)To avoid this, polymer cement concrete is improved by adding propolymers which will exhibit excellent bonding to steel reinforcement and to old concrete, good resistance to penetration of water, sulphates&chlorides.

B) Polymer concrete

They are also called synthetic resin concrete or resin concrete in which the binder phase is completely replaced by a synthetic organic polymer. It consists of monomer, hardner, catalyst&filler besides concrete. Plasticisers, fire retardants or fiber reinforcements may be used according to the flooring requirement.

· Fiber concrete

Main reason for the use of fiber concrete in construction industry is the growing interest to increase the toughness &tensile properties of the basic matrix. In industrial floors, polypropylene &steel fibers are mainly used with concrete. Incorporation of polypropylene fibres provide resistance to bleeding, cracking&settlement. Steel fibers can effectively transform the brittle unreinforced concrete into a ductile material by improving its properties in hardened state &by reducing the number size of cracks. They have tensile creep values 50 to 60% of those for normal concrete.

The greatest use of concrete floors is in shops, factories&warehouses. In such cases wear resistance is of most importance because many of these floors are subject to constant travel by trucks, fork lifts other heavy equipments. For heavy traffic silica, emery or iron particles are incorporated into the surface of concrete.Some of the fibre types and its applications are given inTable5.

Table 5 Fibre Types&Its Applications

Fibre Type	Applications
Glass	Used In Panels, Sewer Pipes, Wall Plaster For Concrete Block.
Steel	Used In Bridge Decks, Concrete Pipes, Airport Runways, Tunnel Lining.
Polypropylene	Used In Facing Panels.
Nylon	Used In Heavy Weight Coating For Under Water Pipe.
Asbestos	Used In Pipes, Insulating Materials, Sheets, Wall Lining.
Carbon	Corrugated Units For Floor Construction.

The surface may be textured slightly as smooth concrete is slippery when wet or oily. As concrete is always porous (it absorbs water other liquids) a varnish like the one concrete sealer is often used to seal the surface. Paints also perform a sealing function.

Ø Wood Flooring

Wood was once the most common type of flooring found in residences &in many industrial buildings. Wood is still used as a flooring material in small scale industries (in u.s, u.k) and is available in its new shapes.

In terms of shape or configuration,hard wood flooring is sold mainly as strip/plank/blocks and soft wood flooring is sold as decking/tongue groove flooring(Fig 1).

Strip flooring was the most popular form among hard wood flooring and it may be square edge or tongue & groove. The flooring is nailed at an angle through the tongue. It is usually installed unfinished then sanded finished in place. The common sizes available are ¾ inch, 2-¼ inch.

Plank flooring is similar to strip flooring except that pieces are parallel and wooden pegs are used instead of nails for fastening. Planks up to 8 inch wide are available.

In laminated block flooring(Fig 2), thick hard woods are laminated with grain running at right angles in alternate layers. Flooring is sold in in 9*9 inch tongue& groove blocks 15/32 inch thick. Size and spacings of wood joists(as per H.B.K Of Building Materials)are given in Table 6.

Table 6 Size&Spacing Of Wood Joists

Wood Joists Size	12 in Spacing	16 in Spacing
2 x 6	6	5
2 x 8	6	6
2 x 10	7	6
2 x 12	8	7
3 x 6	7	6
3 x 8	8	7
3 x 10	9	8
3 x 12	11	9
3 x14	12	10

Figure 1-solid wood decking (single tongue& groove)

Figure2-Laminateddecking

Ø Terrazzo

Terrazzo is another very old type of flooring, which has been improved by modern materials methods now. A terrazzo floor is improved by mixing colored marble chips into a matrix of Portland cement, Portland cement plastic mixture. The mixture is poured on to an underbed, leveled &ground to a smooth finish, exposing the colored aggregate.

Standard terrazzo uses Portland cement as the binder or matrix. It is poured over concrete floors, either directly on the floor or on a thin bed of sand or on a cement mortar underbed. Newer type of terrazzo uses plastic resins either mixed with Portland cement or serving as the matrix alone. Several different resins are used including epoxy, polyester or acrylics.

Three methods of casting in place Portland cement terrazzo atop structural concrete slabs are commonly used; sand cushion, bonded &monolithic

Sand cushion terrazzo (Fig.3) is used where structural movement that might injure the topping is anticipated from settlement, expansion, contraction or vibration. This topping is at least 3 in thick. First the underlying concrete slab is covered with a ¼ to ½ in bed of dry sand. Over this laid a membrane, then wire fabric reinforcing. The terrazzo under bed is laid to 5/8 in below the finished floor line. The thickness of topping plus under bed varies from 5/8 to 3 in. Narrow metal divider strips are laid in the under bed &leveled before the topping is poured. These strips aid in gauging the amount of grinding, localizing shrinkage stresses in the topping separating colors.

Bonded terrazzo(Fig.4) has a minimum thickness of 1 ¾ in. After the underlying concrete slab has thoroughly cleaned and soaked with water, the surface is slushed with neat Portland cement to ensure a good bond with terrazzo. Then the under bed is laid, dividerstrips are installed and terrazzo topping is placed.

Monolithic terrazzo(Fig.5) is constructed by placing a 5/8 in topping as an integral part of a concrete slab Terrazzo may be precast.

2.2 DESIGN CONSIDERATIONS: THE SUBSTRATA

Floor surfacing system is only as the integrity of the substrate to which it is applied. Before consideration is given to products, it is important to consider the substrate and how it will interact with the treatments.

(a) Moisture penetration

Many floor surfacing systems are water vapor barriers and it can trap water within the substrate. It is important to ensure that precautions are taken to prevent moisture penetration into new concrete slabs by using damp proof membrane. Moisture content is checked by thermo hygrometer. Existing slabs can be protected by moisture vapor permeable coating system or hot compressed air treatment.

(b) Strength of substrate

Inadequate strength can lead to floor problems due to impact damage on abrasion. Substrate possessing a concrete strength of less than 20N/mm is considered inadequate in most environments. Assessment of substrate can be done by using Schmidt hammer.

(c)Substrate surface contamination

It is usually associated with concrete where spillage of oil, chemicals or other forms of contamination may have occurred. If latency forms the top surface, a weak surface structure will be created, which must be removed. In areas of major surface irregularity or damage, especially pre blended material may be required which must be fast setting and strong.

(d)Electrical Properties

Most resin -based floors are electrical insulators and aids the generation of static electricity when people and vehicles present. For industries handling delicate electronic components/where potentially explosive materials are handled, or industries where explosive vapors are present (sparks resulting from accumulation of static electricity constitute a hazard.) static electricity turn out to be a serious hazard. In such situation, it is important to select floor capable of dissipating any electrical charges.

Electrical conductivity of flooring is improved by acetylene black (carbon) In ceramic, rubbers, vinyl floors the carbon is finely dispersed in material during manufacture; in black terrazzo, concrete terrazzo, carbon is dispersed in the dry powder mix.For linoleum flooring – brass seam connectors with projecting points are used for electrical intercoupling between sheets.For vinyl tiles – copper foil is placed between the adhesives.

(e) Tolerances

If the substrate is irregular, the floor surfacing system may not function well. So careful selection and specification of the type of the system is required, products capable of overcoming major surface irregularities may be chosen.

2.3 CONSTRUCTION EQUIPMENTS&TECHNIQUES

With the availability of construction equipments, techniques of constructing industrial floors have vastly improved. Large scale constructions with ready mix concrete using laser controlled equipments appear to be a common practice now in many countries. It is reported that construction rates of 40-50m3/hr are possible with the use of laser controlled equipment.

Fast track construction results in bespoke buildings being sold before they’re constructed. Floor must satisfy the exact requirements of clients&built in shortest possible time.

Hot weather concreting is done in large warehouse floor as concrete cure quickly during hot weather.

If the owner wants the interior of the facility to be bright with optional lighting and floor to be extremely durable, light reflective flooring is adopted. One such flooring is done in Atlanta Bonded Warehouse Corp (ABW) to improve the food handling facilities.

2.4 JOINTS

Industrial floors and concrete pavements are constructed generally to allow for the incidental early shrinkage of concrete. For this proper joints are placed in floors construction and proper maintenance of joint is another important thing in flooring. It is usually preferable to provide an isolation joint around the perimeter of the building as shown in figure (4).

Industrial floor joints require careful attention to avoid serious problems in the future. If treated incorrectly, joint arris collapse may occur, particularly in heavy trafficked areas, resulting in the loss of structural integrity. For UV resistance, fuel and fire resistance different breed of sealants must be opted. Joints at heavily trafficked areas, such as doorways across the perimeter of isolation joints need special treatment. For this either two stage joint sealing ( first immediately after sawing, with resealing carried out several months later after concrete has shrunk and building occupied) is done or steel angle nosing are incorporated.

3.0 RESILIENT FLOOR COVERINGS

They are the most diversified group of materials in the flooring field. The main component materials for these floors are asphalt, rubber, vinyl and cork.

Ø Asphalt Tiles:-

These tiles are intended for use on signal sub floors, such as smooth finished concrete, plywood, etc. The tiles can be satisfactorily installed on below grade concrete subject to slight moisture from the ground.

Asphalt tile is composed of mineral fibers, coloring pigments and filters. The mix is formed to a sheet under pressure cut to 9x9 inch or 12 x 12 inch standard tile, usually 1/8 or 3/16 inch thick. For dark colors the binder is Gilsonite asphalt; for intermediate and light colors, the binder is resins of cumarene indene type.

Properties:- Asphalt tile is water resistant, fairly easy to maintain, but is subject to damage by oils, acids, grease and petroleum solvents.

Ø Rubber Flooring

Flooring tile of rubber are made mainly of styrene Butadiene (SBR), a synthetic which has largely replaced natural rubber. The flooring also contains mineral pigments and mineral fillers such as zinc oxide, magnesium oxide and various clays.

Rubber flooring is solid in several forms, 9x9 inch, 12x12 inch tile being must popular. Thicknesses include 0.08 inch, 1/16 and 1/8 inch. Rubber flooring is applied with adhesive over any sound sub floor.

Ø Vinyl Flooring

Vinyl is a component of many different flooring materials but is the main ingredient of vinyl asbestos tile, solid vinyl tile, backed vinyl flooring. Vinyl flooring consists predominantly of poly vinyl chloride resin as binder, plasticizers, colorings pigments, fillers. Since vinyl resins are tough synthetic polymers, it can withstand heavy loads and yet is resilient and comfortable underfoot, it is practically unaffected by grease, fat oils or solvents.

Vinyl tiles are made in 3 forms.

(1) Vinyl Asbestos Tile:- They are most popular resilient flooring. It consists of asbestos fibers, fillers, pigments and poly vinyl chloride resin. They are made in 9x9 inch sequences, 1/16, 0.08, 3/32 and 1/8 inch thick.

(2) Solid Vinyl Tile: - They are made of vinyl resins, fillers, coloring agents. They are expensive but have great resiliency. They are available in 9x9 inch, 12x12 inch tiles, 1/16, 0.08, 3/32 and 1/8 inch thick.

(3) Backed Vinyl Tile:- They are available as sheets or tiles. In this type, a layer of vinyl applied to a backing of fabric, paper or asbestos fiber mat.

Ø Cork Tiles:

It comes from the bark of the cork oak, grows mainly in Spain, Portugal and other southern European countries. The tree bark is cleaned, chipped into particles of various sizes, then compacted with pressure and adhesives and phenolic or resin binders to form blocks. Tiles are sliced from blocks. They are the finished with wax.

Cork tile for flooring is available in 6x6 inch squares, thickness ranging from 1/8 to ½ inch. The greatest advantages of cork for the flooring are its resilience and insulating. Natural gum in the cork is sufficient to bind the particles.

It is used under machinery to leaden vibration and noise.

Ø Resin flooring for industrial use.

Certain industries require highly abrasion resistant floorings by the nature of work being performed in them. Such conditions can be met only by resin floorings. They are based on reactive resins such as epoxies or polyurethane.

Applications of Resins.

Resin floorings can be efficiently used in the following places:-

- where high abrasion resistance is desired

- where dust free environment is required

- Where hygienic environment of a very high degree is desired.

As they are characterized by being joint less, dust proof highly abrasion resistant etc, they are accordingly very useful for pharmaceutical industries, food processing units, hospitals and industries which use machines that demand dust free environment such as automotive and engineering industries. A special kind of resin flooring of anti static kind is used where conductive floorings are desired (Explosive units, Computer centre etc).

Properties of Resin

(a). Abrasion Resistance.

There is no resin flooring which is scratch proof. Resin flooring are not harder than saline particles which are prone to attach themselves under shoe and thus leads to scratches on the surface of flooring. So if one desires an absolutely scratch free flooring, as is common for the pharmaceutical and food industry, care should be taken to ensure that all the users walk on the flooring with shoes that are worn only indoors and no sharp objects are drawn on it. Wheels of trolleys used on such floorings should be either pneumatic or synthetic material with the edges rounded off.Since the resin flooring varies in thickness (from microns to 10 mm) the wear of the flooring depends on their thickness. Based on the thickness they are classified as floor coatings and floor screeds.

Based on the usage it can be said that the life of a resin flooring against abrasive wear I directly proportional to the thickness

(a). Resistance to Delamination

Performance parameter of flooring is based on its ability to resist delamination. Most failures of the resin floorings are due to delamination and not due to surface abrasion. The international norm for concrete surface moisture content for a floor to resist delaminationis 4 %. That is, a resin flooring with a moisture content of the concrete needs to be restricted only for the period during which the epoxy flooring or coating is applied and sets completely.

The major chemical types used in the floorings are shown in table (7)

TABLE 7 Major types of Resins &Its Characteristics

Chemical Types	General Characteristics
Acrylic Emulsions	Used in paint form as dust proofing treatment. Added to cement to provide floor topping with improved impermeability and flexibility
Ceramic Tiles	Good chemical resistance
Epoxy	-Coatings can be either solvent based or solvent free - Chemically resistant to alkalies and solvents, excellent abrasion and impact resistant.
Cement Composites	- Usually polymer modified for many applications - Coated to give sufficient chemical and abration resistance.
Poly Urethane	- Usually solvent containing - Good flexibility and overall chemical resistance
Silicates	- Floor Hardenss / dust proofers
Hybrid resins	- Combination of epoxy and polyurethanes - Excellent chemical and abrasion resistants

4.FLOORING MATERIALS IN MARKET

Ø Concrete Hardener for Industrial Floorings

Concrete hardness are non metallic. M/S Bauchemic Pvt Ltd are the chief manufacturer of concrete haerdners under the name “Dreitop Floor Hard”. It can be used in factories, workshops, park places, loading and unloading bays, warehouses etc.

Dreitop Floor Hard is a combination of natural hard aggregates graded to provide optimum surface density. Application is by dry shake process. Dreitop floor hard floor are abration resistant and antislip. They are resistant to oil spills, waterproof and antistatic.

Since the product is non-metallic, there are no problems of rusting and therefore application is suitable for normal traveling operations. The product being physiologically harmless can be used in industries like food packaging, pharmaceutical industry, dairies, flour mills.

Ø Nitoflor Hardtop

Nitoflor Hard top is formulated by Forsoc chemicals ltd, Bangalore. It is a floor topping used on fresh concrete floors soon after the surface water has evaporated. Two colors are available (a) Natural grey (b) Brick red.

The advantages of Nitoflor hard top are as follows:

- It contains special filler materials known for its very high surface hardness.

- Provides a hard abrasion- resistant surface.

- It is resistant to oils or grease, because of dense surface finish.

High strength:- Nito floor hardtop cubes cure is a final compressive strength of 700 kg/cm² , can takes high impact loads like trucks etc.

Non-metallic:- does not cause corrosion.

Early use : the floor may be opened to traffic after 7 days.

Ø Metallic Floor Hardner.

Contech chemicals, Ahmedabad manufacturee a metallic floor hardner under the brand name Ferricon. Ferricon is composed of specially processed, size graded, ductile iron particles combined with water dispersing agent and other chemicals.

Ferricon is used in factory floors, industrial floors, sunways etc which have to carry heavy loads and traffic. Iron particles resist the abrading action of heavy vehicles. Ferricon provides the following features:-

- Wear resistant

- Spark resistant

- Non dusting

- Water proof

- Easy to clean

- Non-slip

- Oil proof

Typical places where Ferricon is used include: industrial floors, godown floors, garage floors, workshop floors, concrete roads, runways, taxiways, dams etc.

CONCLUSION

A good quality flooring is provided in industries according to the factory environment, ie., a concrete floor is adequate if the factory conditions are dry, antistatic flooring may be provided in industries handling electronic components or industries where explosive materials are handled. Suitable flooring in Industries will enhance the speed of work.

With the availability of new techniques and instruments, conventional flooring has been improved by new materials of construction. In India too, the need for better performing industrial floors has been acutely felt nowadays.

ACKNOWLEDGEMENT

I here by take immence pleasure to express my sincere gratitude to Smt.P.P Umadevi, Lecturer,Department of Civil Engineering ,Palakkad for the valuable guidance and constant encouragement she has rendered as a seminar guide.Iwould also like to thank Dr.A.K Raji,Lecturer ,Staff in Charge of Seminar for her assistance during my seminar.Last but not the least,I thank one and all my friends whose contribution leads to completion of my seminar. I also thank Prof.T.Divakaran,Head Of The Department of Civil Engineering for his goodwill and encouragement extended to me.

Above all I thank God all mighty for his blessings.

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