2. What is Asbestos
WHAT IS ASBESTOS ?
Asbestos is a naturally occurring mineral -
found in underground rock formations
There are two different varieties of asbestos
(i)Chrysotile variety and
(ii)Amphibole variety
Only Chrysotile (white asbestos) variety is in production and use for the past
two decades.
Asbestos-containing material (ACM)
•Any material, object, product or debris that contains asbestos.
•Can take several physical ‘forms’ depending on its method of manufacture and
application
Chrysotile asbestos
3. What is Asbestos
WHAT ARE ASBESTOS-CEMENT (AC) PRODUCTS
AC products are made with a mix of
• Chrysotile fibres - about 8-9%
• Cement - about 40%
• Fly Ash - about 30%
• The rest being wood pulp and water.
Over 90% of asbestos fiber imports of India go in to AC sheet and pipe
production
AC Sheets - most cost effective, easy-to-install, strong and durable roofing
material
• Used for warehouses, factories, low-cost housing
• Weather-proof and corrosion resistant, these sheets are practically
ageless and maintenance free
Asbestos fibers
4. What is Asbestos
AC sheets for roof coveringVinyl floor tiles Toilet partitioning External wall sheeting
Can take several physical ‘forms’ depending on its method of
manufacture and application
Asbestos used
•Most useful and versatile industrial raw materials nature
has gifted to mankind.
•Different asbestos-based products possess different
merits, but in every case asbestos is employed because of its
unique combination of properties in one single material
5. What is Asbestos
What is CORK
Cork is a versatile raw material used for multiple applications, from wine
bottles to Building Materials to Aeronautics
• Lightweight material,
• Elastic and flexible
• Impermeable to gases or liquids
• Imperishable
• Good electric insulator,
• Thermal, sound and vibration insulator
• Dielectric material.
Cork Oak bark (quercus suber)
6. What is Asbestos
Characteristics of CORK
•Renewable and 100% natural raw material
•Unlimited durability without losing its properties
•Completely recyclable
•Excellent dimensional stability (even when subject to
wide thermal variation)
•Density: 110-120 kg/m3
•Thermal conductivity coefficient 0.038/0.40 W/mk
•Low energy consumption (93% cork, 7% electricity)
7. What is Asbestos
Uses in Buildings and other civil construction works:
• Thermal insulation,
• Vibration insulation,
• Acoustic correction,
• Floor covering,
• Wall covering,
• False ceilings, and
• Expansion joints.
Varnished cork tiles can be used for flooring,
as an alternative for linoleum, stone or
ceramic tiles
Thermo plastic Composite Samples
8. What is Asbestos
What is FELT
Felt is a textile that is produced by matting, condensing and
pressing fibers together.
WOOL FELT SHEETS
Different types -
•Industrial
•Technical
•Designer and craft applications
•While some types of felt are very
soft, some are tough enough to form
construction materials
Made from –
•Natural fibers such as wool or
•Synthetic fibers such as acrylic
9. What is Asbestos
Tar Felt
•Waterproofing,
•Damp-proofing of roofs,
• Basements, and terraces
Features:
•High strength
•Proper seam integrity
•Easy maintenance
Tar Felt roll
Advantages:
•Rot proof
•Proven waterproofing
•Easy to apply, repair and maintain
•Dimensional stability with adequate flexibility to adopt all
types of contours
10. What is Asbestos
What is MICA
A natural occurring mineral that is based on a collection of
silicate minerals and composed of varying amounts of
potassium + iron + aluminum + magnesium and water
ROCK WITH MICA
•Mica can resist nearly all
mediums like chemicals, acids,
gasses, alkalis, and oils
•India produces estimated 90 %
of the world`s mica
11. What is Asbestos
Uses of Mica
•Paints
•Electrical industry
•Toothpaste and cosmetics
•Insulator
Other uses - joint cement, as a dusting agent, in
lubricants, and in plastics, roofing, rubber, and
welding rods
12. What is Asbestos
What is ADHESIVE?
Substance applied to the surfaces of materials that
binds them together and resists separation
Adhesive outside a tube
Adhesive = Glue
Raw materials = Naturally occurring
and synthetic
13. What is Asbestos
Four main requirements for Adhesive
•Wet the surfaces
•Adhere to the surfaces
•Develop strength
•Remain stable
Adhesives have a long list of
uses..
Industrial Use + Commercial Use + Household
use
14. What is Asbestos
What is BAKELITE?
•Bakelite is an early Plastic
•One of the first plastics made from synthetic
components
•It will not burn. It will not melt.
•In liquid form, it is a varnish. Jellied, it is a
glue
Used in - pipe stems, fountain pens, billiard
balls, telephone fixtures, castanets, radiator caps,
etc..
MATERIAL OF A THOUSAND
15. What is Asbestos
What is CHINACLAY?
•Rocks that are rich in kaolinite are known as kaolin
or china clay
•Kaolinite is one of the most common minerals
•Soft, Earthy, usually white
mineral
•One of the purest of the clays
•Easily molded, have a fine
texture, and are white when fired
16. What is Asbestos
Uses of CHINACLAY
In Ceramics (main component in Porcelain)
In Toothpaste
Light diffusing material in white incandescent Light
bulbs
In Cosmetics
In Paints
In Rubber for its semi-reinforcing properties
In Adhesives
In the production of common smoking pipes
As Whitewash in traditional stone masonry homes
As adsorbents in water and wastewater treatment
17. What is Asbestos
Top 5 fire resistant materials used by builders
•Bricks
•Fire Resistant Glass
•Concrete
•Plaster
•Gypsum
18. What is Asbestos
Bricks
•High endurance to heat and temperature
•Exceptional compressive strength and high
durability
•Fire resistant withstanding between one to 4 hours.Features
Aesthetic Appeal
Thermal & Acoustic Insulation
Zero Maintenance Cost
Fire Resistance
Flexible in Application
Economic sustainability
Brick Cleanliness is so much that it
doesn't even require plastering.
19. What is Asbestos
Properties
•Strength
•Aesthetic appeal
•Porosity
•Fire Resistance
•Sound Insulation
•Thermal Insulation
•Wear resistance
•Efflorescence
•Flexibility in Application
•Durability
20. What is Asbestos
Fire Resistant Glass
•high energy absorption rate
•four times as stronger than a normal glass window
Wired glass: wire mesh inlaid
in the glass to prevent it from
shattering and breaking out
under stress or when exposed
to high temperatures.
21. What is Asbestos
Concrete
•Most common building Material
•Fire resistant
•Non combustible
•has low thermal conductivity
•Used to reinforce and protect
steel structures from fire
•Concrete is popular as a roofing
material because of its strong fire
resistance properties
22. What is Asbestos
Plaster
•also known as Stucco
•string resistance to heat and fire
•made up on Portland cement,
sand and lime
•Roof overhangs are protected
using plaster coatings to make them
safe and fire resistant.
•Used as both artistic and
structural purposes
•one of the best materials for
boxing in hazardous eaves.
23. What is Asbestos
Gypsum
•also known as dry-walls
•Consists of a layer of gypsum sandwiched
between two sheets of paper
•Fire resistant material
•Multiple layers of gypsum to get
enhancement in the physical strength
•Gypsum board has a
noncombustible core that contains
chemically combined water (in
calcium sulfate).
Editor's Notes
Building material is any material which is used for construction purposes. Many naturally occurring substances, such as clay, rocks, sand, and wood, even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacture of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, insulation, plumbing, and roofing work. They provide the make-up of habitats and structures including homes
1. WHAT IS ASBESTOS ?
Asbestos is a naturally occurring mineral found in underground rock formations. For commercial purposes, it is recovered by mining and rock crushing. Fine fibres, invisible to the eye, are present in the air and water in every region of the globe. Hence, all of us may be inhaling and also ingesting them through drinking water every day. There are two different varieties of asbestos (i) Chrysotile variety and (ii) Amphibole variety. Amphibole variety comprises of Crocidolite, Amosite, Tremolite, etc. Only Chrysotile variety is in production and use for the past two decades.
Only Chrysotile variety (white asbestos) is in commercial use now. Indian asbestoscement sheet and pipe manufacturers import all their requirements of chrysotile fibres from Canada, Brazil, Russia, Zimbabwe and Kazakhstan for production of AC sheets and pipes. Chrysotile asbestos is also mined in India in very small and insignificant quantities which are of no consequence or relevance to our asbestos-cement production. The other varieties of asbestos known as amphiboles (crocidolite, amosite, tremolite, etc) which were considered rather unsafe, have been prohibited all over the world including in India. Wherever asbestos is produced or used in products, only Chrysotile variety is permitted now.
Chrysotile asbestos fibre, (composed mainly of magnesium and silica), is a great reinforcing agent. While its tensile strength is greater than steel, it has other rare and highly valued fire-retardant, chemical-resistant and heat-insulating qualities. In fact it is a magic mineral.
WHAT ARE ASBESTOS-CEMENT (AC) PRODUCTS ?
AC products are made with a mix of chrysotile fibres (about 8-9%), cement (about 40%), Fly Ash (about 30%), the rest being wood pulp and water. Over 90% of asbestos fibre imports of India go in to AC sheet and pipe production.
AC Sheets have been used in India for over 70 years. Being weather-proof and corrosion resistant, these sheets are practically ageless and maintenance free, whereas metal sheets corrode and deteriorate with age and exposure. (See chart for comparison).
AC Sheets have also proven to be the most cost effective, easy-to-install, strong and durable roofing material for warehouses, factories, low-cost housing, and practically any structure needing a roof. Apart from India, Russia, China, Thailand, Brazil are some of the largest users of AC Sheets.
AC sheets and pipes, being corrosion and erosion-free, once properly laid and jointed, need no maintenance or replacement. They are also very cost effective
AC products, which consume low energy in manufacture and do not in any way deplete the natural resources, meet the needs of the country in its developing economy in the context of rapidly rising population and limited resources.
AC products are manufactured under (ISI) licence strictly conforming to the standards of Bureau of Indian Standards. IS 459/1992 for Corrugated Roofing Sheets, IS 2098/1997 for Building Boards, IS 2096/ 1992 for Flat Sheets and IS 1626 (Part III)/ 1994 for Roofing Accessories. AC Pressure Pipes are covered by IS 1592/1989.
Why is asbestos used?
Asbestos is one of the most useful and versatile industrial raw materials nature has gifted to mankind. It is a fibrous mineral used in many different products. Different asbestos-based products possess different merits, but in every case asbestos is employed because of its unique combination of properties in one single material. Research has yet to develop a single substitute material technically equivalent to Chrysotile in many of its applications. Over the years, some alternate materials in combination have been developed as substitutes for specific applications but studies are yet to be conducted to state that these substitute materials are health-wise safe and commercially and economically viable.
Cork's elasticity, combined with its near-impermeability, makes it the perfect material for making bottle stoppers, floor tiles, insulation sheets, bulletin boards and other similar products
Lightness:
Cork is light, and floats on water. For several thousand years, this was its most obvious and well known characteristic. Since ancient times, cork has been used for fishing tackle.
Elasticity and Resilience:
Cork’s cell membranes are highly flexible, making it compressible and elastic. This means that it returns to its original shape after being subjected to pressure.
Impermeability:
The presence of suberin (a complex mixture of fatty acids and heavy organic alcohol) makes cork impermeable to both liquids and gases. As a result, it does not rot, making it one of the best insulants available.
Insulation and fireretardant qualities:
The value of cork is further enhanced by its low conductivity to heat, sound or vibrations. This is because the gaseous components contained in cork are enclosed in small impermeable compartments, isolated from each other by a moisture resistant substance.
In comparison to any other natural substance, this makes cork one of the best insulants, both thermal and acoustic. Cork is also a natural fire retardant: it burns without a flame and does not emit toxic gases during combustion.
Wear resistant:
Cork is extremely wear resistant, and has a high friction coefficient. Thanks to its honeycomb structure, its resistance to impact or friction is greater than that of other hard surfaces.
Hypoallergenic properties:
As cork does not absorb dust, it helps protect against allergies and does not pose a risk to asthma sufferers. It also possesses an inalterable constitution which guarantees efficiency
Lightness:
Cork is light, and floats on water. For several thousand years, this was its most obvious and well known characteristic. Since ancient times, cork has been used for fishing tackle.
Elasticity and Resilience:
Cork’s cell membranes are highly flexible, making it compressible and elastic. This means that it returns to its original shape after being subjected to pressure.
Impermeability:
The presence of suberin (a complex mixture of fatty acids and heavy organic alcohol) makes cork impermeable to both liquids and gases. As a result, it does not rot, making it one of the best insulants available.
Insulation and fireretardant qualities:
The value of cork is further enhanced by its low conductivity to heat, sound or vibrations. This is because the gaseous components contained in cork are enclosed in small impermeable compartments, isolated from each other by a moisture resistant substance.
In comparison to any other natural substance, this makes cork one of the best insulants, both thermal and acoustic. Cork is also a natural fire retardant: it burns without a flame and does not emit toxic gases during combustion.
Wear resistant:
Cork is extremely wear resistant, and has a high friction coefficient. Thanks to its honeycomb structure, its resistance to impact or friction is greater than that of other hard surfaces.
Hypoallergenic properties:
As cork does not absorb dust, it helps protect against allergies and does not pose a risk to asthma sufferers. It also possesses an inalterable constitution which guarantees efficiency
Tar Felt Rolls that find a vast usage in waterproofing, damp-proofing of roofs, basements, and terraces. Offering strong construction and high bonding capacity, tar felt rolls are widely used in construction purposes. These tar felt rolls can be availed at industry leading rates.
Features:
High strength
Proper seam integrity
Easy maintenance
Application:Tar Felt - BH are recommended respectively for above and below ground waterproofing applications as per IS code of practice IS: 1346/76 and IS: 1609/76 respectively. They are suitable for application on various types of surfaces such as concrete, corrugated asbestos / GI sheet, timber, shell / folded plates, etc. TarFelt BH is a proven waterproofing materials for application on silos, grain godowns, warehouses, wagons, trams, buses, etc.
Advantages:
Rot proof
Proven waterproofing first generation membrane and offers impermeability to water
Easy to apply, repair and maintain
Dimensional stability with adequate flexibility to adopt all types of contours
A natural occurring mineral that is based on a collection of silicate minerals and composed of varying amounts of potassium, iron, aluminum, magnesium and water is Mica. It is found having thin-sheet like or plate-like structure with various composition and physical properties. Mica forms flat six-sided monoclinic crystals along with an extraordinary split in the direction of larger surfaces. This allows the mineral to be easily cleaved into optically flat films. High in silica, this stone has the extensive capacity to remain elastic and tough even at high temperatures. This helps the people to handle and work with the stone in those places with high and humid temperatures.
It is used in paints as a pigment extender and also helps to brighten the tone of colored pigments
In the electrical industry the same as thermal insulation, and electrical insulators in electronic equipment
Its shiny and glittery appearance makes it ultimate for toothpaste and cosmetics
The high thermal resistance allows it to be used as an insulator in various electronics
It is used in paints as a pigment extender and also helps to brighten the tone of colored pigments
In the electrical industry the same as thermal insulation, and electrical insulators in electronic equipment
Its shiny and glittery appearance makes it ultimate for toothpaste and cosmetics
The high thermal resistance allows it to be used as an insulator in various electronics
There are three main theories of adhesion:
adsorption, electrical and diffusion.
The two main types of adhesives are natural and synthetic. Natural adhesives come from a variety of animal and vegetable sources. Synthetic adhesives are compounded from simple chemicals.
It must "wet" the surfaces - that is it must flow out over the surfaces that are being
bonded, displacing all air and other contaminates that are present.
•
It must adhere to the surfaces - That is
after flowing over the whole surface area it
must start to adhere and stay in position and become "tacky".
•
It must develop strength - The material must now change its structure to become
strong or non-tacky but still adherent.
•
It must remain stable - The material must remain unaffected by age, environmental
conditions and other factors as long as the bond is required.
Kaolin is used (or was used in the past):
in ceramics (it is generally the main component in porcelain)
in toothpaste
as a light diffusing material in white incandescent light bulbs
in cosmetics
as paint to extend titanium dioxide (TiO2) and modify gloss levels
for its semi-reinforcing properties in rubber
in adhesives to modify rheology[16]
in the production of common smoking pipes in Europe and Asia
in organic farming, as a spray applied to crops to deter insect damage, and in the case of apples, to prevent sun scald
as whitewash in traditional stone masonry homes in Nepal (the most common method is to paint the upper part with white kaolin clay and the middle with red clay; the red clay may extend to the bottom, or the bottom may be painted black)
as a filler in Edison Diamond Discs[17]
as an indicator in radiological dating since kaolinite can contain very small traces of uranium and thorium
to soothe an upset stomach, similar to the way parrots (and later, humans) in South America originally used it[18] (more recently, industrially-produced kaolinite preparations were common for treatment of diarrhea; the most common of these was kaopectate, which abandoned the use of kaolin in favor of attapulgite and then (in the United States) bismuth subsalicylate (the active ingredient in Pepto-Bismol))
for facial masks or soap[19]
as adsorbents in water and wastewater treatmen
Top five fire resistant materials that are used by builders to make sure the building is fire resistant and safe for residential use.
Bricks: Bricks are the intrinsic part and parcel of each home and what’s more they are fire resistant. Bricks are made in fire kilns and have a high endurance to heat and temperature. While it is true that a single brick is much more fire resistant than a wall because of the use of cement, sand and mortar. A wall still provides adequate protection from fire, depending on the thickness of the wall during construction. A brick wall is rated as fire resistant withstanding fires between one to 4 hours.
PropertiesBricks are made from clay by burning it at high temperatures. The action of heat gives rise to a sintering process that causes the clay particles to fuse and develops extremely strong ceramic bonds in the burnt clay bodies. Such bonds are highly stable. As a result, bricks can withstand the severe weathering actions and are inert to almost all normal chemical attacks.StrengthClay Bricks are well-known for their high compressive strength. Their compressive strength depends on :
The raw materials used
The manufacturing process
The shape and size
Bricks made by a de-aerated extruder and fired to sufficiently high temperature can easily withstand a compressive pressure exceeding 28 N/mm2 (4,000 psi). They are suitable for almost all structural building applications
Aesthetic appealClay Brick possesses the natural and pleasant colors of burnt clay. Its color formation is achieved through a complicate physical chemical reaction during the firing process. In contrast to color of stained body, brick color is permanent and will not be faded during weathering process. Different clay compositions, firing temperatures or kiln atmosphere can lead to different colors of the burnt products. By proper control of these factors, bricks can be made to exhibit endless variety of natural and attractive colors.Besides its richness in color, bricks can be made to various textures. It is the combination of color and texture that gives brick such distinctive feature which is everlasting, and mellows with age. In view of the high cost to maintain the appearance of a building, the unique features of brick become an unparalleled advantage to housing design.
PorosityPorosity is an important characteristic of brick. In contrast to other molded or pre-cast building materials, the porosity of brick is attributed to its fine capillaries. By virtue of the capillary effect, the rate of moisture transport in the brick is ten times faster than in other building materials. Moisture is released during day-time and re-absorbed during night-time. The ability to release and re-absorb moisture (a "breathing" process) by capillary effect is one of the most useful properties of brick, helping it to regulate the temperature and humidity of atmosphere in a house. This distinctive property makes brick an admirable building material, particularly suitable for houses in the tropics. On the other hand, all porous materials are susceptible to chemical attacks and liable to contamination from weathering agents like rain, running water and polluted air. Porosity of building material is an important factor to consider in respect of its performance and applications.Experiment results show that bricks with water absorption rate at 8% are 10 times more durable in resisting salt attack than that with water absorption rate at 20%. Well burnt brick has a normal water absorption rate less than 10% in contrast to that of concrete block and cement mortar exceeding 15%. This explains why brick walls require comparatively minimum maintenance in the course of time.To mitigate the adverse effects but at the same time retain the advantages associated with porosity, the rate of water absorption of facing bricks for masonry brickwork should preferably be maintained around 10%.A rarely known property of brick is its Initial Rate of Absorption (IRA). It is in fact the initial rate of absorption that plays a key role in affecting the strength of bond between bricks and mortar during bricklaying. High value of IRA tends to remove excessive water from the mortar rapidly and thus hampers the proper hydration of cement. Experiments show that an increase of IRA from 2 kg/m2/min to 4 kg/m2/min reduces the strength of brickwork by 50%. Generally, bricks with IRA exceeding 2 kg/m2/min will give rise to difficulties in laying, using common cement mortars. Modern brick extruder with de-airing action produces denser brick with lower IRA.
Fire ResistanceBrick is inherent with excellent fire resistance. 100 mm brickwork with 12.5 mm normal plastering will provide a fire-resistance of 2 hours and 200 mm non-plastered brickwork will give a maximum rating of 6 hours for non-load bearing purposes. Brick can support considerable load even when heated to 1000oC in contrast to concrete wall at only up to 450oC due to loss of water of hydration.It is a fact that the non-combustibility of brick helps to promote its use in building houses against fire. There have been numerous examples in the past that people chose to use bricks for their houses after a devastating fire that burned down the whole city. Perhaps the most famous instance is the great London Fire in 1666, after which the rebuilding was largely done, if not entirely, in brick.
Sound InsulationBrick wall shows good insulation property due to its dense structure. The sound insulation of brickwork is generally 45 decibels for a 4-1/2 in. thickness and 50 decibels for a 9-in. thickness for the frequency range of 200 to 2,000 Hz.
Thermal InsulationClay Brick generally exhibits better thermal insulation property than other building materials like concrete. Perforation can improve the thermal insulation property of bricks to some extent. Besides, the mass and moisture of bricks help to keep the temperature inside the house relatively constant. In other words, bricks absorb and release heat slowly, and thus keep the house cool during daytime and warm during nighttime.Energy saving of a brick house is remarkable. A study commissioned by the Brick Institute of America had demonstrated that a brick house can save energy up to 30% when compared to that built of wood.
Wear resistanceThe wear resistance of a substance depends on its particulate bonds. Clay Bricks show high wear resistance because of its extremely strong ceramic bonds formed by the effect of heat at high temperature.
EfflorescenceEfflorescence is a phenomenon that can make soluble slats, dissolved in water, to be easily carried, deposited and gradually accumulated on brick surfaces to form an unsightly scum. The soluble salts may be originated from the raw material of bricks. But in most cases, efflorescence is caused by salts from the external sources such as ground water, contaminated atmosphere, mortar ingredients and other materials, which are in contact with the bricks.
Flexibility in ApplicationsClay Brick is used for an extremely wide range of applications in an equally extensive range of building and engineering structures. In particular, it can be used for load bearing structures, which simplifies the construction process so as to save materials, time and labor. Besides, Clay Brick can be made into a convenient shape and size, facilitating the construction work. It is very flexible and handy in various applications almost everywhere.
DurabilityClay Brick is extremely durable and perhaps, it is behind the most durable man-made structural building materials so far. There has been numerous ancient brick-building standing for centuries as a testimony of the endurance of burnt-clay brick.
Windows can be a potential fire hazard due to the popular use of wooden frames and glass material. Replacing normal glass window by a fire resistant glass can bring own the fire hazard potential of window substantially. A normal window glass can easily break during a fire allowing the flames to enter the interiors of the house easily. Fire resistant glasses uses dual paneled glasses which have a high energy absorption rate making it four times as stronger than a normal glass window. Wooden framing may be a potential fire hazard and replacing wood frames to PVC or steel frames along with the use of a fire resistant glass will ensure almost foolproof protection from fire.
Wired glass is a type of glass into which a wire mesh is embedded during production
Concrete: Concrete plays an intrinsic role in all construction related work. Concrete is not only fire resistant but is also non combustible due to its low thermal conductivity. Concrete due to its intrinsic fire resistant properties is used to reinforce and protect steel structures from fire. Concrete is popular as a roofing material because of its strong fire resistance properties.
Plaster: Plaster also known as “stucco” is a commonly used material in construction activity known for its string resistance to heat and fire. Plaster is made up on Portland cement, sand and lime and can be used to cover any structure to provide artistic coverage as well as fire resistance coverage. Roof overhangs are protected using plaster coatings to make them safe and fire resistant.
Gypsum: Gypsum is another commonly used fire resistant material used in construction activity. Many structural materials are attached underneath with gypsum sheeting to prevent any fire hazards and to achieve good fire resistant ratings. Gypsum boards also known as “dry-walls” are also chemically treated to enhance the fire fighting abilities of gypsum. Builders used multiple layers of gypsum coating on gypsum boards to make sure their fire resistance properties of the underlying physical structure gets enhanced.