Rubber is an important engineering material that is highly stretchy and abrasion resistant. It can be molded into various shapes and has properties like elasticity, thermal contraction, and durability. Rubber is widely used in construction, including as an adhesive, coating, fiber, and electrical insulator. It has applications in concrete, tiles, bearings, pipes, roofing, and sound insulation. The process of obtaining natural rubber involves tapping latex from rubber trees, purifying it, and coagulating it. There are also various types of synthetic rubber with different chemical resistance properties used in construction.

1. RUBBER IN CONSTRUCTION INDUSTRY
INTRODUCTION
• Rubber is very important engineering material for any nation the
most one being tire industry.
• India is the fifth largest natural rubber producing country in the
world after Malaysia, Indonesia, Thailand and Sri Lanka.
• Rubber is a highly stretchy, abrasion resistant material that's
commonly molded into various shapes.
• Rubber also known as elastomers are high polymers having a
unique property of undergoing large deformation under load and
returning to their original shape and dimension on
its removal owing to lengthening and shortening of the springs of
spring polymeric chains
• The upstretched rubber molecule is amorphous in stretching the
molecules in it get partially aligned to one another. On releasing the
stress chain regains its orginal coiled state.
• It is widely used and has applications in countless components and
household items.
• The commercial use of rubber came into existence with the
discovery of process known as the vulcanization in year 1836 by
Good Year.
RUBBER PROPERTIES
Elasticity: The molecular structure of rubber material
allows them to return to their normal shape after being
compressed or stretched.
Thermal contraction: While most materials expand when
heated, rubber contracts.
Durability: Most rubbers are highly durable, resisting
damage and degradation from abrasive and tearing forces
impact, low temperatures, and water.
RUBBER CHEMICAL PROPERTIES
•Rubber is water repellent and resistant to alkalies and
weak acids.
•Rubber is elastic in nature
•It is tough
•It is impermeable
•It has good adhesiveness
•It is resistant to electricity
•All these properties make it useful as :an adhesive,
coating composition, a fiber, a molding compound, and an
electrical insulator.
RUBBER APPLICATION
•It is used as a polymer mortar to improve its bonding
and waterproofing qualities.
•It is directly used in concrete for making polymer concrete.
•Rubber tiles are used for resilient floors which are made from
natural and synthetic rubber as the basic ingredient.
•A synthetic rubber Neoprene is widely used for bearings
of bridges ,handrail bearing pads ,pads between steel beam ,girders,
grates, columns ,etc..
•Natural and synthetic is used to make many products used in the
building industry like plasticized PVC pipes are made by the
addition of rubber.
• It is used in many various types of glue-like Fevicol , to add
superior adhesion.
•Also used in windows, pipes, roofing, expansion joints, and also
for sound insulation.

2. NATURAL RUBBER
• Consists of basic material latex, dispersion of isoprene
which polymerizes to form long coiled chain of
polyisoprene. It's made from sap occurring in cells of
various parts of plants such as HAVEA
BRASILIANSIS & GAUYILE.
• Latex is obtained by making incisions in bark of
rubber tree allowing sap to flow out. It's collected and
diluted to contain 15-20% of rubber and then stained
to remove any dirt.
Plantation:
• The rubber trees are planted. They start oozing outafter a period of
about 5 to 7 years and continue to ooze out for a life to about 30
yrs.
• A normal rubber tree gives about 10N to 50N of dry rubber per
year.
Tapping Latex:
• A vertical groove about 600mm long is made in the rubber tree by
means of a pointed knife at a height of about 1m from the ground
level.
• The vertical groove is connected of slanting grooves inclined
upward.
• An earthenware pot is attached at the lower end of vertical groove
to collect the latex that oozes out of the tree.
• The latex from the pot is taken by the tapper everyday or every
alternate day and at the time, the grooves are slightly widened.
The care should taken to see that the grooves do not penetrate
beyond the cambium layer of the tree.
Purification:
• The impurities such as leaves ,sand ,debris ,etc are
removed.
Coagulation:
• The latex then converted into a massive form by the
process of coagulation.
• The coagulant usually adopted is weak acetic acid.
• The addition of coagulant converts latex into curd like
form.
• It is then pass through rollers.
CREPE RUBBER
• Produced by coagulating rubber in presence of retarder like
sodium bisulphate.
• Then passed between rollers of creping machine where most of
serum is squeezed out and a sheet of resembling crepe is formed
SMOKED RUBBER
• Produced by pouring diluted latex into tanks having sides with
vertical grooves .Diluted formic or acetic acid is added and
stirred.
• Partition plates are inserted and left for 16 hours. Slabs formed
are removed and passed through series of rollers with decreasing
clearance.
The process of obtaining Natural Rubber is carried out in
following four stages.
• plantation
• Tapping Latex
• Purification
• Coagulation.

3. Synthetic Rubber
• The term synthetic or artificial rubber was conceived through research and
development as a polymer which could be used to replace the natural rubber.
• The real beginning of a synthetic rubber industry started in USA, Germany and other
foreign countries.
TYPES OF SYNTHETIC RUBBER
STYRENE BUTADIENE (SBR)
• Originally developed as a low cost substitute for natural rubber
• Good water resistance and abrasion resistance
• Poor weathering resistance, but can overcome with specific raw materials
• Not recommended for contact with oils and solvents
• Not used with concentrated acids or alkalis
• Maximum continuous operating temperature is about 225° F
BUTYL
• Very good resistance to most gases including air
• highly resistant to ozone and weathering
• Abrasion resistance close to natural rubber and good for concentrated acids and alkalis
• Not recommended for petroleum product exposure
• Maximum continuous operating temperature is about 300°F
EPDM
• Exceptional resistance to weathering and ozone
• Excellent resistance to water, most gases, steam, and heat aging
• Good for exposure to concentrated acids and alkalis, but not recommended for
exposure to oils and solvents
• Maximum continuous operating temperature is about 350°F
FKM(VITON)
• High cost, but high performance material
• Outstanding resistance to most chemicals, oils and solvents
• Good oxidation and ozone resistance
• Maximum continuous operating temperature is about 650°F
• "Viton" is a trademark of DuPont and signifies material produced by DuPont
NITRILE (BUNA)
• Much better oil and solvent resistance compared to either natural rubber or
Neoprene
• Recommended for most oil field applications
• Can be formulated for use at low temperatures
• Good compression set and abrasion resistance, but poor weathering resistance
• Can be used with concentrated acids and alkalis but there are better
alternatives
• Maximum continuous operating temperature is about 275°F
NEOPRENE (CHLOROPRENE)
• Good general purpose rubber with properties close to natural rubber, but is
synthetically produced
• Better resistance to oils and solvents compared to natural rubber but similar
low compression set
• Can be compounded for flame resistance
• Good weathering resistance
• Poorer low temperature performance compared to natural rubber
• Maximum continuous operating temperature is about 275°F

4. ASBESTOS IN CONSTRUCTION INDUSTRY
INTRODUCTION
• Asbestos is a naturally occurring silicate material.
• It is used in building constructions generally mixed with cement
concrete.
• Asbestos was nicknamed "the magic mineral" because its unique
chemical composition and physical properties made it suitable for use
in thousands of products
• It acts as a thermal insulator (to keep heat in and cold out).
• It is fireproof and corrosion resistant.
• It was commonly used in wall and ceiling paneling, roofing and floor
tiles.
• There are six types, all which are composed of long and thin
fibrous crystals: each fiber being composed of
many microscopic "fibrils" that can be released into
the atmosphere by abrasion and other processes.
• Large-scale mining of asbestos began at the end of the 19th century.
• Inhalation of asbestos fibers can lead to various dangerous lung
conditions including mesothelioma, asbestosis and lung cancer.
• Use of asbestos is now considered as a serious health and safety
hazard.
PHYSICAL PROPERTIES
• Excellent electrical insulator.
• Highly fire resistant.
• Excellent thermal insulator (heat stability and acoustic
insulation)
• Resistant to chemical and biological breakdown.
• High tensile strength.
• High flexibility.
• High adsorption capacity.
CHEMICAL PROPERTIES
•It is a hydrous magnesium silicate.
•Its chemical composition is Mg3Si2O5(OH)4.
•Asbestos is divided into two types based on its chemical
properties:
•Serpentine : includes mineral chrysolites, magnesium
silicate and possesses long, flexible crystalline fibers which
are capable of being woven.
•Amphibole: includes mineral amosite, crocidolite,
tremolite, anthophyllite and actinolite, and form
crystalline fibers that are substantially more brittle than
serpentine asbestos. It is more limited in being fabricated.
This group can form a variety of polymeric
structures through the Si-O-Si bond.
APPLICATION
•Used in floor tiles, road signs, insulating mattresses, cement building
materials, pipework lagging, fire resistant insulation boards, sprayed fire-
proofing products, water and sewage pipes, gas masks, friction materials
for vehicle brakes and clutches, lifts and machinery.
•Boilers and pipework were lagged with asbestos products in hospitals,
power stations and throughout heavy industry.
•Asbestos insulation products were popular in the shipbuilding and railway
industries and in the dockyards etc.
•The Royal Yacht Britannia, built in 1952, was riddled with asbestos
insulation which was stripped out upon discovery in 1980.
•Sprayed asbestos insulation containing crocidolite was used in the roof
space of the House of Commons Chamber; linings of the ventilation ducts in
the House of Commons were insulated with chrysotile (white asbestos).
•Other asbestos-containing materials used in British buildings
were: insulation partition boards, ropes and yarns, cloth, millboard and
paper, asbestos cement sheets, textured coating, mastics, sealants, putties,
adhesives, wall plugging compound, and much more.
DIFFERENT
FORMS OF
ASBETOS
TYPES OF AMPHIBOLE ASBESTOS
SERPENTINE
ASBESTOS

5. MANUFACTURING PROCESS
HEALTH HARAZARDS OF ASBESTOS
• All types of asbestos can cause severe lung infections like
mesothelioma, asbestosis (fibrosis of the lungs), lung cancer, ovarian
cancer and cancer of the larynx.
• Exposure to asbestos occurs through inhalation of fibers present in
the air in the working environment, ambient air in the vicinity
of factories handling asbestos, or indoor air in housing and
buildings containing crumbling asbestos materials.
• Amphiboles pose a greater health hazard than chrysolite asbestos.
• The duration and degree of exposure to asbestos can decide
the severity of the hazard caused by it.
• Studies show that some asbestos-induced lung cancers only occur
when the exposure is above a certain level of concentration. Below
that threshold, there is no statistical increase in lung cancer over that
found in the general population.
MANUFACTURE OF ASBESTOS AS A MATERIAL MANUFACTURE OF ASBESTOS FOR
THE TEXTILE INDUSTRY
ELIMINATION OF ASBESTOS
Elimination of asbestos related diseases should take
place through the following public heath actions:
• Stop the use of all types of asbestos.
• Replace asbestos with safer materials;
develop economic and technological mechanisms
to stimulate its replacement.
• Taking measures to prevent exposure to asbestos,
even while removal of asbestos (abatement).
• Improving early diagnosis, treatment, social and
medical rehabilitation of asbestos related disease
and establishing registries of people with past
and/or current exposure to asbestos.