EMAGAZINE MARCH 2021 - Constrofacilitator
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eMAGAZINE
Constrofacilitator MARCH 2021 www.constrofacilitator.com
Knowledge and b2b portal for
construction and infrastructure
Volume-03 eM-03
FOLLOW US
WATERPROOFING
Water inltration can lead to damages such as insect infestation, mold and in worst cases
building failures. Waterproong the building before construction will avoid these
problems. Waterproong is very important as it helps keep your building dry. It helps
reduce humidity inside the house and thereby protects things inside your house from
damage caused due to humidity or water exposure. It is also important for the veracity of
the building. With time, waterproong as a concept has evolved and so have been the
types of membranes being used. The focus now is on faster solutions with long-term
benets.
In this edition of eMagazine, we have focused on waterproong membrane, tunnel
waterproong, basement waterproong and concrete deck waterproong. The wide
variety of waterproong options provides signicant advantages. Waterproong systems
can be installed indoors or out, depending on the level of water damage or owner
preference, allowing for a greater range of exibility and affordability
March 2021 • Constrofacilitator 2
Waterproofing membrane - Types
04
and Applications
Basement Waterproofing -
08
Causes, Methods & Membranes
Concrete Deck Waterproofing
12
membranes
Tunnel Waterproofing -
15
Components and Types
4 8
12 15
3 Constrofacilitator • March 2021
WATERPROOFING MEMBRANE
Waterproofing membrane - Types and
Applications
A
waterproofing mem- added to the concrete that will help the kind of membranes that come in
brane is a layer of make water ingress impenetrable as the form of liquid that can be sprayed
water-tight material well as making it easy to maintain. or brushed onto the surface. By spray-
that is laid onto a sur- ing, the liquid forms a monolithic mem-
face to prevent water Different types of waterproofing brane, with no laps, welds or seams.
leaks or damage. membrane Under these two broad categories, dif-
Waterproofing membranes generally ferent types of waterproofing mem-
consist of liquid applied or pre-formed Waterproofing membranes can be branes are available in the market,
sheet membranes. They can be broadly categorized as Sheet Based each of them is explained below.
adhered to or installed around the Membranes and Liquid Applied Water- Self-adhesive modified bituminous
foundations (like a structural slab) to proofing Membranes. Sheet-based membrane
prevent water penetration. Whether membranes come in the form of rolls.
it's to protect your building's basement These are unrolled and laid on a firm Self-adhesive modified bituminous
or roof, waterproofing will help stop surface. One of the most common membranes are composed of asphalt,
water from infiltrating your foundation sheet-based membranes is the bitumi- polymers, and tackifiers, and may con-
and protect your structure from water nous waterproofing membrane. Liquid tain mineral stabilizers. The products
damage. Waterproofing membrane is applied waterproofing membranes are may be reinforced with fiberglass, poly-
04 March 2021 • Constrofacilitator
WATERPROOFING MEMBRANE
of which indicates the proper material
heating. On the top side, the material is
covered by a polymer film.
EPDM membranes
It is a preformed elastomeric water-
proofing membrane made of high-
quality EPDM rubber. It exhibits high
tensile strength, elongation, tear
strength and is resistant to weathering,
ester, or a combination of the two. heat aging, ozone, UV rays, acids, alkalis
Products designed for exposure to the and oxygenated solvents. The installa-
elements are typically surfaced with tion is quick and more importantly,
mineral granules, coatings, films, or safe. Modern products come as a sin- Bituminous Membrane
other opaque surfacing. The self- gle component cementitious, polymer-
Hot melt liquid bituminous rubber
adhesive layer is protected with a modified non-reactive selective fiber-
blend structural waterproofing sys-
release film or paper, which is removed reinforced repair mortar to provide
tems with an interlaid reinforcement
during installation. Self-adhesive modi- excellent properties as well as resis-
can be used in roof and podium deck
fied bituminous membranes are gen- tance to corrosion and carbonation
applications to provide a seamless
erally packaged and stored in card- and shrinkage cracking. This can be
waterproofing membrane for high
board boxes or they are protected with applied in thickness from 10 mm to 40
green roofs and podiums, and are
opaque wrapping. mm in vertical and 25 mm in an over-
sometimes specified for winter applica-
head situation. It is suitable to apply by
Polymer-modified bitumen membrane tions as they can be laid at low temper-
hand trowel or by special mortar spray
atures.
The most widespread materials for the machine.
creation of the waterproofing layer are
the polymer-bitumen roll-fed sheet
membranes. These materials could
also be used as an underlay for pitched
roofs and as a vapor barrier. The mate-
rial withstands temperature fluctua-
tions and high mechanical loads pro-
viding long-term, reliable and effective
waterproofing. The polymer-modified
bitumen sheet membrane provides Polyurethane membrane
additional flow resistance that makes it Thermoplastic membrane
These products come with a fiber-
possible to use the material in a very
Thermoplastic roof membranes set enhanced one component water-
hot climate. On the bottom side, the
themselves apart from other commer- based polyurethane membrane that
material is covered by a polymer film
cial roofing systems. It is a blend of poly- has been designed for a range of
with special graphic elements, melting
propylene, ethylene-propylene and is waterproofing applications where the
often reinforced with polyester. Sheets
of TPO can contain UV absorbers,
colorants, flame retardants or other
add-ins to achieve required physical
properties. Often white, TPO sheets
can range in width from 6 to 12 feet
and have varying thicknesses, usually
40 to 100 mil. Thermoplastic mem-
branes can be less expensive than
other roofing options.
March 2021 • Constrofacilitator 05
WATERPROOFING MEMBRANE
membrane is to be covered over with proofing safety and installation effi- as there is no active release zone.
tiles, screeds, concrete beds, etc They ciency and are typically used for base- This can be addressed by installing
offer excellent adhesion properties ments or below-grade areas. a compressible foam rod to the
overbuilding substrates including con- perimeters, before placing the
Application of waterproofing mem-
crete, masonry, renders, cement sheet- screed. This is further compro-
brane
ing, wet area sheet surfaces and plas- mised when the required DFT is
terboard surfaces. Regardless of the scale, size, location or not achieved, reducing the mem-
type of building, waterproofing mem- brane elongation tolerance drasti-
Polypropylene Membrane
branes are an essential component cally.
It is a special waterproofing material necessary to protect the building's Ÿ Uneven film thickness is even
that is manufactured from Bitumen. structural integrity and its inhabitants. more prone to elongation failure.
They come in rolls. Each roll measures Its application areas include; Thicker coatings can restrict move-
10 metres by 1 metre and covers an ment, where thinner applied coat-
Ÿ Tanking/ basements ings will tear under minimal move-
area of 8.7 m². It is a very efficient and
durable waterproofing material used in Ÿ Flat Roofs (including Green Roofs) ment. This is why filleting is not as
most constructions. It is a common Ÿ Plant rooms successful as bond breaker sys-
waterproofing material used on con- Ÿ Podiums and balconies tems. An even DFT [ Dry Film
crete flat roofs. Apart from concrete Ÿ Retaining walls Thickness ] of coating, bonded to a
roofs and low-pitched roofs, other Ÿ Garden beds and planter boxes compatible joint sealant, is
areas of application are concrete gut- Ÿ Concrete water tanks restricted from stretching as the
ters, basements and retaining walls. Ÿ Containment and bunded areas uneven fillet section of sealant
allows free movement at the thin
Factors to consider for the water- points, and restricts movement at
proofing membrane application thicker fillet zones.
Oftentimes missing out on a small tech- Ÿ Most coating manufacturers
nical miss out might cause undesired require different ranges of mini-
results. Given below are few details mum DFTs [ Dry Film Thickness ]
that need to be addressed for the under different circumstances.
application of waterproofing mem- Internal wet areas may require a
branes. minimum DFT of 0.6 to 1mm for
wall applications and 1 to 1.5mm
Ÿ Coating materials need to be abra- for floors and horizontal surfaces.
sive resistant and accommodate Balconies and podiums may
PVC and TPO membrane building movement. Quite often require a minimum DFT at the
These are highly flexible sheet mem- this is misunderstood and range of 1.5 to 2mm, where lift
brane systems that protect any con- unbonded screeds are placed over pits, pools and planter boxes may
crete structure. It can be built as stan- membranes that are applied too require a minimum DFT up in the
dard single-layer compartment sys- thin, resulting in mechanical abra- ranges of 2 to 3mm, depending on
tems up to the active control system to sion. This mechanical abrasion is the coating material used.
meet the highest demands. They are akin to trying to wear through the Ÿ Low viscosity coatings must have
fully-bonded and offer high water- coating with a brick. Any thin at least 3 coats, where one cannot
spots, weak points or high spots achieve anything greater than
can wear through, forming rup- 0.5mm WFT, due to slump and
tures and blisters. souping of the coating. Even at
Ÿ Movement accommodation at 66% solids, we need to apply 3
bond breaker junctions is severely coats to achieve the 0.99mm
compromised when waterproof- (1mm) DFT required for floor and
ing is applied beneath a screed. horizontal surfaces.
The compacted screed restricts Ÿ Coating DFT[Dry Film Thickness ] is
the coating movement when paramount to achieving the opti-
releasing from the bond breaker,
06 March 2021 • Constrofacilitator
WATERPROOFING MEMBRANE
mum performance as required by
the manufacturer. Reduced coat-
ing thickness can result in abrasive
damage and reduces elongation
properties. Excessive thickness
may result in re-emulsification and
splitting during curing. Detailed
substrate preparation will ensure
even film thickness and perfor-
mance.
References:
prweb.com
sondhienterprises.com
polygomma.com
greenshield.co.in
sika.com
concretecareindia.com
bronco.co.in
sandexwaterproofing.com
Ultra-Water Resistant Surface
A
group of researchers from the ridging pattern will reduce the contact resistant coating, manufacturers might
Massachusetts Institute of Tech- time between water droplets and a sur- enable products to display superior
nology recently announced a face, it could hold great value in terms deicing properties. Similarly, ultra-
stunning breakthrough in the develop- of enhancing ice-resistance. Frozen water resistant fabrics would help pro-
ment of an exceedingly water-resistant water clinging to aircraft parts poses a tect people from exposure to the ele-
surface. Their research focused upon significant aviation issue in many situa- ments more effectively in some set-
repelling water droplets. They tions. By installing a more water- tings.
announced they had discovered a way
to increase exterior ridges in silicon in a
way that deflects water falling onto the
surface.
Their research could lead to the even-
tual production of very “hydrophobic”
i.e. water resistant garments and
mechanical and electronic parts. Ultra
hydrophobic (or superhydrophobic)
surfaces are highly hydrophobic, i.e.,
extremely difficult to wet. The contact
angles of a water droplet on an
ultrahydrophobic material exceed
150°.This is also referred to as the lotus
effect, after the superhydrophobic
leaves of the lotus plant. Since the fine
March 2021 • Constrofacilitator 07
BASEMENT WATERPROOFING
Basement Waterproofing -
Causes, Methods & Membranes
B
asement water ingress larly prone to wetness and moisture struction. When pockets of air are
can lead to problems of development. Water in the soil causes not removed, or the mixture is not
a s t r u c t u r e . U n d e r- hydrostatic pressure to be exerted allowed to cure properly, the con-
ground water and underneath basement floors and walls. crete can crack, which allows
Groundwater is the main This hydrostatic pressure can force water to force its way through the
source of water which water through cracks, which can cause wall.
will enter a basement. If the water table major structural damage as well as Ÿ Foundations (footings) are hori-
rises above the level of the basement mold, decay, and other moisture- zontal pads that define the perime-
floor water can enter the basement related problems. ter of foundation walls. When foot-
through the side wall. Basement water- ings are too narrow or are not laid
proofing thereby becomes important. It Causes of water ingress in basement deep enough, they are susceptible
involves techniques and materials to movement caused by soil ero-
used to prevent water from penetrating Water seepage in basement and crawl sion.
the basement of a structure. Water- spaces usually occurs over long peri- Ÿ Gutters and downspouts are used
proofing a basement that is below ods of time and can be caused by to catch rainwater as it falls and to
ground level can require the applica- numerous factors. discharge it away from houses
tion of sealant materials, the installation and buildings. When gutters are
of drains and sump pumps, and more. Ÿ Concrete is one of the most com- clogged or downspouts are bro-
The spaces of basements are particu- monly used materials in home con- ken, rainwater is absorbed by the
Constrofacilitator • March 2021 08
BASEMENT WATERPROOFING
Ÿ Buckling walls: Usually caused by Advantages of basement waterproof-
hydrostatic pressure. Walls ing
appear to be bowed inward.
Ÿ Better indoor environment
Ÿ Basement Floor Protection
Ÿ Prevention of basement flooding
Ÿ Protection to your sump pump
Ÿ Protection from structural damage
Ÿ Reduce Energy Costs
Different types of Basement water-
soil near the foundation, increas- proofing methods
ing hydrostatic pressure.
Ÿ Weeping tile is a porous plastic The choice of waterproofing system
drain pipe installed around the per- will depend on a number of factors
Ÿ Peeling paint: Water seeping such as the method & type of base-
imeter of the house. The main pur-
through walls may lead to bub- ment construction, the depth below
pose of external weeping tile is pre-
bling or peeling paint along base- ground, and the proposed end use.
venting water from getting into a
ment walls. Each situation is different, so it is
basement. However, these pipes
can become clogged or dam- important to have a good understand-
aged, which causes excess water ing of what waterproofing issues are
to put pressure on internal walls present. There are so many factors that
and basement floors. come into play when it comes to keep-
Ÿ Water build up inside window ing your basement. While each situa-
wells, after heavy rain or snow, can tion is different, the best policy is
lead to leaks through basement always prevention rather than repair.
window seams. Taking steps to waterproof your base-
Ÿ Ground saturation is another com- ment before water is present is sure to
mon form of basement leaks. yield the best results. The different
When the footing drain fails the types are discussed below.
ground around the basement can Ÿ Efflorescence: White, powdery
contain too much water and when residue found on basement walls Exterior basement waterproofing
the saturation point is met flooding near the floor.
can occur. The exterior basement waterproofing
method is designed to prevent water
Signs of basement water damage from causing any major structural dam-
age to the building, using polymers
Ÿ Cracked walls: Cracks may be hor- and membranes to coat the exterior
izontal, vertical, diagonal or stair- basement walls. Polymer-based prod-
stepped. Severe pressure or struc- ucts last for the lifetime of the building
tural damage is evident by widen- and are not affected by soil pH. Poly-
ing cracks. mer-based waterproofing materials
Ÿ Mold: Fungi that usually grow in can be sprayed directly onto a wall, are
damp, dark areas and can cause very fast curing, and are semi-flexible,
respiratory problems after pro- allowing for some movement of the sub-
longed exposure. strate.
09 Constrofacilitator • March 2021
Pre-engineered Roofing
BASEMENT WATERPROOFING
Interior basement waterproofing company, states like Michigan have a brane - It is used in the basement
lot of ground clay, which will absorb waterproofing. It is manufactured from
Interior basement waterproofing using and hold water, resulting in the flexing synthetic EPDM rubber. The EPDM rub-
coatings is effective where condensa- in basement foundation walls that can ber waterproofing membranes are
tion is the main source of wetness. It is cause cracking and subsequent leaks. techno-commercially much better than
also effective if the problem has minor substitutes.
dampness. Installing a backwater Waterproofing with Sealants and
valve is one of the most effective mea- Foundation crack injections
sures to save your basement. Installing
a drainage system is the most complex In poured concrete foundations,
solution for interior waterproofing. Sev- cracks and pipe penetrations are the
eral approaches and materials can be most common entry points for seep-
used. One proper solution is a French age. These openings can be sealed
drain with a sump pump installation, from the interior. Epoxies, which are
rubber walls, water weeping tiles, and a strong adhesives, or urethanes can be
drainage membrane. pressure injected into the openings,
thus penetrating the foundation Portland cement-based waterproofing
through to the exterior and cutting off membrane - This type of membrane
the path of the seepage. Interior seal- helps in resisting positive and negative
ers are good for preventing high atmo- pressure under 100m head in water
spheric humidity inside the basement retaining and below ground structures.
from absorbing into the porous
masonry and causing spalling. Interior
sealants are designed to ensure that
the atmospheric humidity level in the
basement stays low.
Waterproofing with drainage systems Foundation crack injections are used
when poured concrete foundations
A drainage system can help avoid crack either from a settlement or the
water buildup in your basement, mov- expansion and contraction of the con-
ing the water from the footers of the crete. Epoxy crack injections are typi-
house foundation and out below the cally used for structural purposes while Cement-based waterproofing mem-
basement floor. A common system for hydrophobic or hydrophilic polyure- brane - It is applied to a concrete sur-
draining water that has penetrated a thane injections are used to seal cracks face, the active chemicals combine
basement involves creating a channel to prevent penetration of moisture or with the free lime and moisture present
around the perimeter of the basement water. Injection sealing of the crack cav- in the capillary tract to form insoluble
alongside the foundation footers. A ity will address the problem and can be crystalline complexes. These crystals
French drain, PVC pipe, or a patented done from the inside with minimal dis- block the capillaries and minor shrink-
drainage system is installed in the ruption. age cracks in the concrete to prevent
newly-made channel. The installed any further water ingress.
drain is covered with new cement.
According to Rick Jacobs of Absolute
Waterproofing Solutions, a basement
waterproofing and foundation repair
Different types of basement water-
proofing membrane
Single-ply rubber waterproofing mem-
Constrofacilitator • October
March 2021
2020 10BASEMENT WATERPROOFING
Fiber reinforced waterproofing mem- Cell mesh membrane - This type of References:-
brane - It is a compound system con- membrane uses cell mesh that bonds
sisting of a rubberized bitumen emul- with freshly placed concrete which acts aquaguard.net,
sion with additives and a powder com- as a seal. This prevents water ingress. uswaterproofing.com,
ponent. The application is easy even It can be installed rapidly, with no need acculevel.com,
around details such as pipe penetra- for blinding concrete, priming, or pro- treehouseinternetgroup.com,
tions, inner and outer corners, wall- tection and can be trafficked immedi- washingtonpost.com,
floor junctions, etc. ately after application. archiexpo.it,
drybysuperior.com,
concretenetwork.com,
buildingenclosureonline.com,
aluminumconcreteforms.com,
wtrproof.com,
To read more about
waterproofing visit
www.constrofacilitator.com/
civil-products-services/
waterproofing/
Nano technology in waterproofing
I
n recent years, there has been an rally occur in some plant leaves, such oxidation, anti-icing, UV resistance,
increase in nanotechnology as the lotus leaf, and some insect high temperature resistant and also
research, and nanotechnology has wings. More about superhydrophobic resistant to chemical compounds. It
been incorporated into many applica- coatings. has self-cleaning capabilities when it
tions in everyday life. rains and can be used on a variety of
High hydrophobicity eco-friendly nano surfaces. Nano coatings do not
Nanotechnology is no longer just a coating can be applied onto objects to change the colour of the surface to
promising field of research. Many make them waterproof for the long- which they are applied. They are invisi-
nanotech solutions have made their term. The product is anti-corrosive or ble to the naked eye.
way into everyday life – one of the most
prominent being the use of ceramic
coating for waterproofing. Nano coat-
ing is hydrophobic (water repellent),
oleo phobic (oil repellent) surface layer
that repels water, oil, dirt, and other dry
particles. Superhydrophobic coatings
are used in dry surface application.
These naturally occur in some plant
leaves, such as the lotus leaf, and
some insect wings. Nano coating is
hydrophobic (water repellent), oleo
phobic (oil repellent) surface layer that
repels water, oil, dirt, and other dry par-
ticles.
Superhydrophobic coatings are used
in dry surface application. These natu-
11 Constrofacilitator • March 2021WATERPROOFING MEMBRANES
Concrete Deck Waterproofing membranes
Constrofacilitator • March 2021 12WATERPROOFING MEMBRANES
T
he concrete deck is prone to smooth. All grease, oil, wax, curing
water ingress, water may drip compounds, loose material, paint
through cracks or other sur- and any other contaminants must
faces, which may inevitably be removed, masonry surfaces
decay the surrounding area. must be pointed flush and surface
In the long run, this will be quite costly defects repaired. New concrete
to fix. In order to avoid this, and to keep must be cured for a minimum 28
your deck in the best shape, water- days.
proofing is key. Horizontal surfaces Ÿ External corners to be water-
exposed to the weather can be difficult proofed must be bevelled to structures to be overlaid with an
to waterproof. Inadequate slope can ensure a smooth transition of mem- asphalt concrete wearing course. It is
create areas of standing water. In colder brane from vertical to horizontal ideal for repair, maintenance, or new
climates, freeze/thaw cycles impose surfaces. construction applications.
additional challenges. Frequently, the
coating also has to stand up to foot traf- Deck waterproofing membranes Plastomeric waterproofing mem-
fic as well. brane
Urethane elastomeric waterproofing
The most common cause of a ceiling membrane These membranes are manufactured in
leak is a failure in the waterproof mem- advanced - under controlled conditions
brane or screed in the floor slab of the Urethane elastomeric membrane is by saturating and coating a robust rein-
upper floor apartment. The failure may both flexible and durable. This chemical forcement of synthetic non woven poly-
be because of natural deterioration of resistant, moisture cured, polyurethane ester carrier with a homogenous ther-
the waterproof membrane, material system is designed to expand and con- moplastic bituminous blend of distilled
damage or faulty construction / instal- tract with normal structural move- asphalt, modified with selected poly-
lation of the membrane. Whatever the ments. It has an aesthetically pleasing mer and inert fillers which gives the
cause, the membrane loses its water- monolithic surface that will not soften membrane its excellent properties of
proof properties and is no longer able in heat or become brittle in cold. With resistance to ageing, facilitates the ease
to prevent water from penetrating the the use of a catalyst the urethane deck- of application and adhesion and
porous concrete floor slab and seeping ing system can be accelerated to a two- accommodates structural movements.
into the lower part of that slab. day application. The coating system is These are designed as a cap-layer in
a waterproofing system that can be exposed membrane systems. They are
Waterproofing your deck also allows used on a wide range of applications. ideal for flat or sloped roofs, tiles on ter-
the concrete to be protected from natu- Installed and maintained properly, this races & for improved aesthetics.
ral foot traffic and the elements. When system will ensure years of waterproof-
you waterproof your deck, a special ing protection.
coating is added to the concrete that
will help make it impenetrable as well as
making it easy to maintain. One good
way to know that you need to resurface
and waterproof your concrete deck is if
there are multiple cracks in the deck.
Often, resurfacing your deck might not
be as expensive as you might think. Urethane waterproofing membrane
Since the actual foundation does not
need to be fixed, the top level of the It is a single component, a moisture-
deck is the only thing that is being cured elastomeric urethane water-
changed. Once the floor has been Polymeric waterproofing membrane proofing system designed for pedes-
resurfaced, it will not have any cracks or trian traffic. It is a monolithic system,
other signs of wear. It is shrink-resistant, heavy-duty, poly- designed to waterproof concrete and
propylene woven carrier fabric. The two plywood surfaces by excluding mois-
Preparation of waterproofing mem- components are laminated together ture penetration during low-
branes in decks under strictly controlled production pro- temperature exposure as well as high
cedures. It provides an excellent water- temperature, high humidity thermal
Ÿ All surfaces to be waterproofed proofing membrane for bridges, park- cycling. This waterproofing system has
must be firm, clean, dry, sound and ing decks or other vehicular traffic excellent adhesion, impact, and abra-
13 Constrofacilitator • March 2021WATERPROOFING MEMBRANES
many strong carbon-fluoride bonds.
The fluorine in a fluoropolymer is elec-
trically negative, which gives it the prop-
erty of not bonding easily with other
materials. That's what makes a fluoro-
polymer non-stick. Fluoropolymer coat-
ings have excellent non-stick properties
and reduce friction and resist corrosion.
They withstand very high temperatures,
as well. Fluoropolymers are insulators,
meaning they do not conduct electric-
ity. They do not absorb water, either.
Liquid Rubber Polyurethane water- between the membrane and substrate.
sion resistance while exhibiting supe- proofing membranes It is ideal for application on concrete
rior flexibility and weather resistance. decks, especially where surface profiles
It is a monolithic, fully-bonded, liquid- and the presence of services provided
New Halogen-Free Parylene water- based coating suitable for many water- detailing difficulties for the use of pre-
proofing membrane proofing and roofing applications. The formed membranes.
coating cures to form a rubber-like
New Halogen-Free Parylene coating elastomeric waterproof membrane and Advantages of concrete deck water-
offers manufacturers the same host of may be applied over many substrates, proofing membranes
beneficial properties that they have including asphalt, bitumen and con-
come to expect from the Parylene fam- crete. This is to apply, ultra-low VOC The modern membranes provide a
ily, but with improved barrier properties coating can be used to protect decks, wide array of advantages and products
over traditional halogen-free variants. It docks, outdoor walkways, floors and are now available with multiple advan-
is applied through a vapor deposition much more. Given the cured mem- tages, narrowed down are some of the
process that results in an ultra-thin, uni- brane's superior strength, waterproof common advantages of these prod-
form, pinhole-free conformal coating. properties and high adhesion to most ucts.
The thin film forms at a molecular level substrates.
to fully encapsulate components and Ÿ Tolerant to Damp Surfaces
devices, offering complete protection Ÿ Crack-bridging properties
and increased reliability of intricate, Ÿ Superior performance / Excellent
complex electronic devices. Adhesion
Ÿ Suitable for both Positive & Nega-
Fluoropolymer waterproofing mem- tive Water Pressure
brane Ÿ Seamless, reliable, user friendly
Ÿ Environmentally Friendly
A fluoropolymer is a polymer that is Ÿ Non-Toxic and Chloride Free
based in fluorocarbon and has strong Ÿ Suitable for use with Potable Water
carbon-fluoride bonds. fluoropolymer Ÿ Root resistant when reinforced
is a chemical compound that contains with Glass Fibre Mesh
Ÿ Anti-Carbonation and Electro-
Hybrid waterproofing membranes chemical Corrosion
Ÿ Reparability
Modern hybris coating includes poly-
mer-modified, polyurethane-asphalt References:
hybrid coating cures to form a tough
and highly-elastic membrane and pro- barrierdampproofing.com.au
vides durable and seamless water- creativityden.com
proofing protection for concrete sub- nimacochemicals.com
strates. When completely dry and fully scoop.it
bonded to the substrate, the coating purepoxy.com
forms an impervious continuous barrier spec-net.com.au
to eliminate the migration of water kamsons.com
Constrofacilitator • March 2021 14TUNNEL WATERPROOFING
Tunnel Waterproofing - Components and
Types
T
unnel waterproofing is one
challenging work under-
taken. This type of water-
proofing systems are faced
with very strict requirements
regarding durability, expo-
sure, sustainability, and
stress conditions. For waterproofing in tun-
nels or underground structures, it is impor-
tant to consider the entire system rather
than the individual waterproofing layers.
With respect to the durability of under-
ground structures, the ingress of water is
usually the most important factor to be con-
sidered. Some of the defects are intrinsic to
specific lining types but it can be stated that
deficient waterproofing is at the origin of
most problems. A problem that has
increased in urban tunnels is related to
chemically aggressive groundwater. For
such cases, considerations of chemical
interactions of pollutants with the water-
proofing system are of major importance.
15 March 2021 • Constrofacilitator
FebruaryTUNNEL WATERPROOFING
Components of tunnel waterproofing Different types of tunnel waterproofing sys-
tems
The basic design of waterproofing systems
in Tunnel construction is typically of two It Is essential to remember that waterproof-
types, namely Drained system and Pres- ing systems have to be selected and
sure system. The drained system allows the planned in order to represent the optimal
water to channelize and hence drain out of solution with regard to given requirements
the system, also commonly known as the pertaining to its intended use on one hand
Umbrella system. On the other side, the and technically & economically acceptable
pressure system holds the water behind the possibilities on the other. The key criteria in
membrane for a perpetual period. The selecting these systems are, hydrology con-
waterproofing membrane relies on various cept, permanent water table, the degree of
Spray applied waterproofing system
components that need to be compatible water tightness required, drained or
with each other and applied in the correct undrained concept, the height of water pres- mary and secondary linings. This offers
sequence to give a desired result. sure, the impacts and conditions during maintenance and repair benefits by pre-
construction etc. venting the movement of water either
Ÿ The basic support surface on which behind or, should it be breached, in front of
the layers of the proofing system are Hybrid waterproofing system the membrane. The application of the mem-
installed brane is very simple and can be executed
Ÿ The compensation layer, which makes Hybrid below-grade water-proofing mem- by a dry shotcrete machine. For the thin-
up for uneven substrates branes combine active polymer barrier tech- stream transport of powder to the nozzle,
Ÿ The drainage element which collects nology with conventional passive-bonded compressed air is needed.
and disposes of water on the rear side product technology. By incorporating multi-
of the waterproof layer ple barrier materials in a single waterproof- Sheet Membrane waterproofing system
Ÿ The sealing element or impermeable ing membrane, the new active polymer
layer generally includes a waterproof hybrid membranes compensate for the Sheet membrane systems are available in
membrane shortcomings of traditional materials. Rubber, Neoprene, high-density polyure-
Ÿ The protective layer that separates and thane, (HDPE) and combinations of rubber
protects the waterproof membrane The spray applied waterproofing system and HDPE. They are provided as rolls usu-
from the concrete casting filling mate- ally approximately 2-3 meters in width and
rial The spray applied waterproofing system in are self-adhered. During application, the roll
Ÿ The partitioning element that divides tunnels is used with single shell linings. The is laid out flipped over and the backing
surfaces into sections to help locate conditions of the application of this system removed. The sheet is placed onto the con-
leaks. are analyzed in terms of the deformation crete with the adhesive in contact with the
Ÿ The injection and control element and surface condition of the first layer of the concrete and pressed into place. The
enables the integrity of the sealed sur- shotcrete shell, water ingress and water sheets can be applied either as a blindside
faces and any resins injected into parti- pressure behind the waterproofing mem- waterproofing against sheet piling or a tem-
tioned sectors to be checked. brane. This method can bond to both the pri- porary support system or can be applied
after partial cure of the concrete.
Sheet Membrane waterproofing system
The epoxy Liner waterproofing system
These are two-component systems and
generally are produced in two formulations:
one for horizontal surfaces and one for verti-
cal surfaces. The difference is that the verti-
cal material is non-sag to better adhere to
the vertical surfaces. The formulations are
not interchangeable due to the requirement
Hybrid waterproofing system to have non-sag for vertical surfaces to
March 2021 • Constrofacilitator 16TUNNEL WATERPROOFING
develop the required thickness. Typical
installation of epoxy systems is performed
by spraying the epoxy.
PVC waterproofing membrane system
The double-layered system of PVC-P, in
combination with waterstop, injection
valves, hoses, a tunnel waterproofing sys-
tem can be divided and compartmentalised
into small independent watertight sections.
The tunnel/ structure is therefore divided
into manageable sections that can be
treated as individual entities. This system
allows us to test for water-tightness at loca-
tions suspected of accidental damage, or in
the case of leakage. Furthermore, the water
infiltrations would be limited to the single Crystalline waterproofing system
damaged section/compartment. Any dam- The product should be made up of virgin that will last for the life of the tunnel. These
age/leakage would remain localised, thus PVC compound and plasticized for long solutions are easy to use and do not require
rendering easy rectification, and thereby mit- term flexibility and durability. The mem- special weather conditions. This water-
igating one of the major concerns with tradi- brane shall be supplied with a signal layer, proofing system is designed for use in
tional PVC-P applications. This i.e. a thin sheet of different colour, bonded above- and below-grade applications,
compartmentalization forms this watertight to one side, which is intended to facilitate MasterLife 300 series admixtures react in
control by utilising the gap between the two the detection of damage. concrete to form non-soluble crystalline
waterproofing membrane layers. This gap hydration products in the capillary pores of
can be exploited to monitor the waterproof- Crystalline integral waterproofing system the concrete. These crystalline hydration
ing system sealing and allows for simple products effectively reduce the permeability
future repairs by resin injection.PVC-P twin Crystalline integral waterproofing solutions of concrete and seal the hairline cracks.
layer membrane is generally used as a protect the structural rebar from corrosion
waterproofing membrane, must be highly and provide a durable, leak-free solution Conclusion
durable and shall be judiciously selected.
A long service life of tunnel construction
requires durability of all components. A
major part in this context plays the water-
proofing layer and various components,
especially those which are supposed to
blend together. The designers, owners and
project managers should select the com-
plete system judiciously and understand in
detail the functioning of each component,
which together shall work in designed
period of life and not just the warranty
period.
References:
master-builders-solutions.com, sika.com,
tunnel-online.info, tunneltalk.com,
PVC waterproofing membrane system extruflex.com, prnewswire.com
17 March 2021 • ConstrofacilitatorWaterproofing membranes Waterproofing membranes are available in sheet form or liquid form. Liquid membranes are sprayed, rolled or trow- elled onto the concrete surface and cure to form a rubbery waterproof coating. Sheet membranes come in sheet form and are stuck to the concrete surface to provide a waterproof barrier preventing water intrusion into the structural ele- ments of a building or its finished spaces. Metropolitan Transportation Service (MTS) recently unveiled a new, high-efficiency wheel truing pit to keep rail cars rolling smoothly. On this project, an underfloor truing pit-with a metal milling machine-can simultaneously re- profile wheels of passenger or freight cars, while the wheel set is attached to the rolling stock. During excavation, the specifications outlined the depth of the pit to be almost three feet under the water table. When the general contractor began digging, water poured in quickly, filling the bottom of the hole. In order to finish the excavation, seven dewatering pumps were needed to drain the area and keep the water out. Original parameters specified installation of a waterproofing membrane. However, the project manager looked for a better solution to prevent water seepage through the concrete. The solution includes a range of crystalline products to treat all the con- crete for the footings, slab and walls of the truing pit. It also seals all the cold joints and helps to patch any remaining cracks and imperfections in the new structure. This reduces permeability by permanently sealing micro-cracks and this also helps protect the concrete against wa- ter penetration, even under high hydrostatic pressure. This is only one example. Construction materials continue to advance, enabling workers to build structures that are waterproof from the elements, ensuring a long-lasting struc- ture. Self-healing, water-repellent, spray-on coating Self-healing, water-repellent, spray-on coating developed at the University of Michigan is hundreds of times more durable than its counterparts. It could enable waterproofing of vehicles, clothing, rooftops and countless other sur- faces for which current waterproofing treatments are too fragile. It could also lower the resistance of ship hulls, a step that would reduce the fuel consumption of the massive vessels that transport 90 percent of the world’s cargo. The developers say the new concoction is a breakthrough in a field where decades of research have failed to produce a durable coating. While water-repellent finishes are available at present, they’re typically not strong enough for ap- plications like clothing or ship hulls. This discovery changes that. The coating is made of a mix of a material called “fluorinated polyurethane elastomer” and a specialized water- repellent molecule known as “F-POSS.” It can be easily sprayed onto virtually any surface and has a slightly rub- bery texture that makes it more resilient than its predecessors. If it is damaged, the coating can heal itself hundreds of times. It can bounce back “even after being abraded, scratched, burned, plasma-cleaned, flattened, sonicated and chemically attacked,” the researchers wrote in a paper recently published in ACS Applied Materials & Interfaces. In addition to recovering physically, the coating can heal itself chemically. If water-repellent F-POSS molecules are scraped from the surface, new molecules will naturally migrate there to replace them. That’s how the coating can re- new itself hundreds of times. Its healing ability is limited only by its thickness. March 2021 • Constrofacilitator 18
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