Disaster management and seismic retrofitting

Disaster Management and
Seismic Retrofitting
Dr K M Soni
Chief Engineer, CPWD, Mumbai

Major Disasters Worldwide
4th July 2017 Disaster management 2
Sl.
No.
Name of Event Year Country and
Region
Fatalities in the
known history
1 Earthquake 1556 China, Shaanxi 830000
2 Earthquake 1731 China 100000
3 Cyclone 1737 India, Calcutta 300000
4 Yellow River flood 1887 China 9,00,000-20,00,000
5 Messina Earthquake 1908 Italy 123000
6 Earthquake 1920 China, Gansu 235000
7 Great Kanto Earthquake 1923 Japan 142000
8 Great Chinese Famine
1958-1961 China
1958-1961 China 150,00,000-
430,00,000
9 Bhola Cyclone 1970 West Bengal,
India & B/desh
5,00,000
10 Tangshan Earthquake 1976 China 2,42,419

HAITI’S E/Q, 12.1.2010; DEATHS-3,16,000; MAGNITUDE:7
34th July 2017 Disaster management

TANGSHAN, CHINA, 27.7.1976; DEATHS-242,769; MAG. 7.5

SUMATRA E/Q, 26.12.2004
DEATHS;2,27,898
MAG. 9.1

Haiyuan, china
e/q 16.12.1920
Deaths; 2,00,000
Mag. 7.8

Kanto, e/q, Japan; 1.9.1923
Deaths-1,42,800
Magnitude: 7.9

Pakistan e/q, 18.10.2005
Deaths; 86000
Mag-7.6

Iran e/q, 20.6.1990
Deaths-50,000
Mag. 7.4

Gujarat e/q, 26.1.2001
Deaths-20,085, Mag. 7.6

Latur, india e/q 29.3.1993
Deaths – 9748
Mag. 6.2

NEPAL EARTHQUAKE
12
2015, Magnitude: 7.9, deaths over 5000

AFGHANISTAN EARTHQUAKE
14
26th October, 2015

Disasters in India
• Natural disasters
– Earthquakes
– Floods
– Cyclones
– Tsunamis
– Droughts
– Landslides
• Man made disasters
– Road/Rail accidents
– Chemical disasters
4th July 2017 15Disaster management

Major Disasters in India

S. No. Name of Event Year State & Area Fatalities
1. Floods October 2014 Jammu & Kashmir
2.
Cyclone Hud
Hud
September
2014
Andhra Pradesh &
Odisha
3. Odisha Floods October 2013 Odisha 21
4. Andhra Floods October 2013 Andhra Pradesh 53
5.
Cyclone Phailin October 2013 Odisha and Andhra
Pradesh
23
6.
Floods/Landslid
es
June 2013 Uttarakhand and
Himachal Pradesh
4,094
7.
Cyclone
Mahasen
May 2013 Tamil Nadu 08
8. Cyclone Nilam October 2012 Tamil Nadu 65
9.
Uttarakhand
Floods
Aug – Sep
2012
Uttarkashi,
Rudraprayag and
Bageshwar
52
10.
Assam Floods July – Aug
2012
Assam ---

11.
Cyclone Thane December
2011
Tamil Nadu,
Puducherry
47
12.
Sikkim Earthquake September
2011
Sikkim, West Bengal,
Bihar
60
13.
Odisha Floods September
2011
19 Districts of Odisha 45
14.
Sikkim Earthquake 2011 North Eastern India
with epicenter near
Nepal Border and
Sikkim
97 people died (75 in
Sikkim)
15. Cloudburst 2010 Leh, Ladakh in J&K 257 people died
16. Drought 2009
252 Districts in 10
States
-----
17.
Krishna
Floods
2009
Andhra Pradesh,
Karnataka
300 people died
18. Kosi Floods 2008 North Bihar
527 deaths, 19,323
livestock perished,
2,23,000 houses
damaged, 3.3 million
persons affected
19. Cyclone Nisha 2008 Tamil Nadu 204 deaths
20. Maharashtra Floods July 2005 Maharashtra State
1094 deaths
167 injured
54 missing

21. Kashmir 2005
Mostly Pakistan,
Partially Kashmir
1400 deaths in Kashmir (86,000
deaths in total)
22. Tsunami 2004
Coastline of Tamil Nadu,
Kerala, Andhra Pradesh,
Pondicherry and
Andaman and Nicobar
Islands of India
10,749 deaths
5,640 persons missing
2.79 million people affected
11,827 hectares of crops damaged
300,000 fisher folk lost their
livelihood
23.
Gujarat
Earthquake
2001
Rapar, Bhuj, Bhachau,
Anjar, Ahmedabad and
Surat in Gujarat State
13,805 deaths
6.3 million people affected
24.
Orissa Super
Cyclone
1999 Orissa Over 10,000 deaths
25. Cyclone 1996 Andhra Pradesh
1,000 people died, 5,80,000 housed
destroyed, Rs. 20.26 billion
estimated damage
26.
Latur
Earthquake
1993
Latur, Marathwada
region of Maharashtra
7,928 people died
30,000 injured
967 people died, 435,000 acres of
land affected
28. Drought 1987 15 States 300 million people affected
10,000 deaths
hundreds of thousands homeless
40,000 cattle deaths4th July 2017 19Disaster management

Cascading Effect
• Earthquake
• Tsunami
• Fire
• Nuclear disaster
• Floods
• And so on...

Road Accidents

Vulnerability Profile

Of the 7,516 km long
coastline, close to 5,700
km (@76%) is prone to
cyclones and tsunamis.

58.6 per cent of the
landmass is prone to
earthquakes of moderate
to very high intensity.

Over 40 million hectares
(12 % of land) is prone to
floods and river erosion.

Disaster Management Act
On 23 December 2005, the Government of
India enacted the Disaster Management Act,
which envisaged the creation of National
Disaster Management Authority (NDMA),
headed by the Prime Minister, and State
Disaster Management Authorities (SDMAs)
headed by respective Chief Ministers, to
spearhead and implement a holistic and
integrated approach to Disaster Management
in India.

Functions & Responsibilities
• Lay down policies on disaster management ;
• Approve the National Plan;
• Approve plans prepared by the Ministries or Departments of the Government of
India in accordance with the National Plan;
• Lay down guidelines to be followed by the State Authorities in drawing up the
State Plan;
• Lay down guidelines to be followed by the different Ministries or Departments of
the Government of India for the Purpose of integrating the measures for
prevention of disaster or the mitigation of its effects in their development plans
and projects;
• Coordinate the enforcement and implementation of the policy and plans for
disaster management;
• Recommend provision of funds for the purpose of mitigation;
• Provide such support to other countries affected by major disasters as may be
determined by the Central Government;
• Take such other measures for the prevention of disaster, or the mitigation, or
preparedness and capacity building for dealing with threatening disaster
situations or disasters as it may consider necessary;
• Lay down broad policies and guidelines for the functioning of the National
Institute of Disaster Management.

Themes of the policy
• Community-based disaster management,
including last mile integration of the policy,
plans and execution.
• Capacity development in all related areas.
• Consolidation of past initiatives and best
practices.
• Cooperation with agencies at the national,
regional and international levels.
• Compliance and coordination to generate a
multi-sectoral synergy.

Disaster Management Cycle

Prevention and Mitigation
&
Capacity Building

Disaster Management

Prepare

Capacity Building
to deal with new works to deal with
disasters, retrofitting and
repair/rehabilitation

Damage/poor maintenance enhances
risk of damage/collapse of structures
during disasters

Types of Damages
• Damages could include both Structural and Non-Structural
• Non structural damage could include:
• Plaster,
• Panel/filler walls, parapets
• Doors, windows, window glass panes etc
• Dislocation of civil services like water supply, gas, drainage pipes and
electrical conduits/wiring
• Disturbed Roofing Tiles
• Flooring at ground level, etc
• Structural damage could cover
• Foundation system
• Load bearing walls
• RCC beams/columns
• Roofing
• Lintels over door/windows, etc

Sequence of Operation
• Removal of Hazardous Components
• Propping & Supporting, wherever required
• Condition Survey to Determine Rehabilitation
• Evaluate Damage to each Structural
Component
• Restoration and strengthening
– Appropriate Structural Repair Method
– Non structural repairs covering civil &
electrical items
• Finish the Repaired Structure

Structural Damage Assessment
• Important to conduct ‘Condition Survey’
– Determining rehabilitability i/c part demolition
– Whether building to be got vacated for repairs?
– Detailed damage assessment and determining residual
strength.
– Details of temporary support arrangement to avoid further
distress under normal loads

Repairs, Rehabilitation and Retrofitting
• In New Building, the extra Cost of Seismic
Resistant features is nominal (i.e. 2% to 5% of
structure’s cost)
• In Existing Building, the seismic retrofitting is
costlier (i.e. 5 to 15% of structure’s cost)
• Structural Repairs of Corrosion distressed
structures are also costlier
• Replacement of structure is still more costly
• A Balanced View is required to be taken before
deciding upon the various options

Repair & retrofitting Vs
Reconstruction
• As a thumb rule, repair/ strengthening is
resorted, if its overall cost is less than 30%
of the cost of reconstruction
• Replacement/reconstruction is, generally
avoided due to
– Preservation of Historical Architecture
– Maintaining functional social and cultural
environment

Classification of Repair Materials
• Based on its Application
– Surface Preparation
– Rust Removers / Converters
– Passivators for Reinforcement Protection
– Bonding Agents
– Structural Repair Materials
– Injection Grouts
– Joint Sealants
– Protective Surface Coatings

Cement Concrete/Mortar as
Repair Material
• Cement Concretes/Mortars are the natural
Repair Materials for RCC structures but not
favoured due to inherent undesirable
properties like:
– Drying shrinkage
– Slow Setting
– Low Workability
– Prolonged Curing requirements
– Permeability

Repair Sequence for Corrosion Damaged &
Spalled cover Concrete
1. Surface Preparation
• Loose and carbonated concrete removal all-
around reinforcement
2. Fix Shear Connectors, if required
3. Apply bonding layer over Substrate concrete
4. Apply Passivating Coat over Steel
Reinforcement
5. Apply repair – Cement based repairs or
– Resin based repairs, or
– Sprayed concrete (shotcrete)

Jacketing of
RCC Column

REHABILITATION AND SEISMIC
RETROFITTING

EARTHQUAKES
• EARTHQUAKES DO NOT KILL BUT IT IS THE BUILDINGS
WHICH KILL
• NEARLY 5,00,000 EARTHQUAKES OCCUR EVERY YEAR
• ABOUT 1,00,000 ARE FELT
• Minor earthquakes occur nearly constantly around
the world in places like California and Alaska in the
U.S., as well as in Mexico, Guatemala, Chile, Peru,
Indonesia, Iran, China, Pakistan, Portugal, Turkey,
New Zealand, Greece, Italy, India and Japan, but
earthquakes can occur almost anywhere.

CASUALTIES
• LARGE NUMBER OF CASUALTIES OCCUR IN
DEVEOPING COUNTRIES. REASONS MAY BE;
– INADEQUATE DESIGN
– POOR CONSTRUCTION AND MAINTENANCE
– LACK OF RESOURCES
– INADEQUATE KNOWLEDGE
– INADEQUATE AWARENESS
– INADEQUATE TRAINING
– INADEQUATE SAFETY IMPLEMENTATION

77
CAUSES OF FAILURE OF MASONRY
BUILDINGS
 POOR QUALITY OF MORTAR
 IRREGULARITY IN PLANE AND VERTICAL
DIRECTION
 NO PROVISION OF BANDS
 NO THOROUGH STONES
 HEAVY MASS CONCENTRATION AT ROOF LEVEL
 UNSYMMETRICAL BUILDINGS AND FULL
OPENINGS
 UNCONFINED WALL CORNERS
 INADEQUATELY DESIGNED CANTILEVER
ELEMENTS
77

CAUSES OF FAILURE OF RCC
BUILDINGS
• SOFT STOREY (ONE IN WHICH LATERAL STIFFNESS IS LESS
THAN 70% OF THAT IN THE STOREY IMMEDIATELY ABOVE
OR LESS THAN 80% OF THE COMBINED STIFFNESS OF
THREE STOREYS ABOVE)
• POOR DETAILING OF BEAM COLUMN JUNCTIONS
• PROVISION OF FLOATING COLUMNS
• PLAN AND MASS IRREGULARITY
• INADEQUATE FOUNDATION
• POUNDING OF BUILDINGS
• INADEQUATE DESIGN AND DETAILING
• INADEQUATE CONNECTVITY LIKE ISOLATED STAIRCASES
AND WATER TANKS NOT PROPERLY ANCHORED

87
NORMALLY STRUCTURES REQUIRING
REPAIR AND REHABILITATION ARE
MORE SUSCEPTIBLE TO DAMAGE,
HENCE REPAIR AND REHABILITATION
IS VERY IMPORTANT
87

CAUSES OF DETERIORATION OF
RCC
• PENETRATION OF WATER/CHEMICALS
LEADING TO CARBONATION, CHLORIDE
INGRESS, LEACHING, SULPHATE ATTACK,
ALKALI SILICA REACTION ETC LEADING TO
CORROSION IN THE REINFORCEMENT

MAIN REASON OF PENETRATION OF
WATER
• POROSITY OF CONCRETE

PRECAUTIONS TAKEN TO PREVENT
POROSITY
• ADEQUATE STRENGTH OF CONCRETE
• PROPER COMPACTION
• WATER PROOFING ON ROOF
• PLASTER ON CONCRETE
• WATER PROOFING PAINTS ON EXPOSED
PLASTERED SURFACE

CAUSES OF DETERIORATION OF
CONCRETE
• AGING OF STRUCTURE
• POOR QUALITY
– POOR QUALITY OF TESTING/INVESTIGATION
– POOR QUALITY OF DESIGN
– POOR QUALITY OF EXECUTION IN TERMS OF
MATERIALS/COMPACTION/PAINTS/COVER/RCC
– POOR QUALITY OF MAINTENANCE

SELECTION OF MATERIALS FOR
REHABILITATION/ RETROFITTING
• TECHNICAL REQUIREMENTS
• COST
• AVAILABILITY
• EXPERT’S ADVICE
• IMPORTANCE OF THE STRUCTURE
• BALANCE LIFE OF THE STRUCTURE
• TOXICITY OF THE MATERIAL
• AESTHETIC CONSIDERATION

REHABILITATION METHODS
• SAND BLASTING FOR REMOVAL OF CORROSION AND
APPLYING A COAT TO RETARD CORROSION
• BINDING/ADDING OF ADDITIONAL
REINFORCEMENT/CONCRETE
• WELDING
• ANCHORING TO THE EXISTING MEMBERS THROUGH
SHEAR KEYS OR ANCHORS
• SHOTCRETING
• PLATE BONDING
• JACKETING
• FIBRE WRAPPING

PROCEDURE
• REMOVAL OF LOOSE MATERIALS/RUST
• PROVIDING PROTECTIVE LAYER/COATING
• PROVIDING BONDING COAT BETWEEN OLD
AND NEW MATERIAL/SURFACES
• PROVIDING STEEL
MEMBERS/WELDING/ANCHORS/ SHEAR KEYS
TO ENSURE MONOLITHIC ACTION

RETROFITTING IN RCC
COLUMNS/BEAMS/SLABS
• PLATE BONDING
• FIBRE WRAP TECHNIQUES THROUGH GLASS
FIBRES/CARBON FIBRES
• RCC JACKETING
• NEW CASTING
• GUNITING/SHOTCRETING

RCC Jacketing

Carbon Fibre Wrapping

Carbon Fibre
Wrapping

Glass Fibre Reinforcement Wrapping

MS Plate Wrapping

MASONRY STRUCTURES

VULNERABILITY
• BRICK/STONE MASONRY STRUCTURES ARE
MORE VULNERABLE AND THEN POORLY
CONSTRUCTED/REPAIRED?
• DISASTER= VULNERABILITY X HAZARD
• BRICK STRUCTURES ARE MORE IN THE COUNTRY
• SO WE NEED SAFE BRICK MASONRY
STRUCTURES
• IF NOT, WE NEED TO MAKE THEM SAFE BY
RETROFITTING.

SEISMIC STRENGTHENING/ RETROFITTING
 THE TECHNIQUE TO UPGRADE THE STRUCTURE
FOR EARTHQUAKE RESISTANCE TO THE LEVEL
OF PRESENT DAY CODAL REQUIREMENTS
HAVING ORIGINAL STRUCTURAL INADEQUACY
OR INADEQUACY DUE TO MATERIAL
DEGRADATION OVER TIME OR DUE TO
ALTERATIONS CARRIED OUT DURING ITS USE
OVER THE YEARS

SEISMIC STRENGTHENING
 MAIN PURPOSE OF SEISMIC STRENGTHEING IS
TO UPGRADE/PROVIDE THE SEISMIC
RESISTANCE ON A BUILDING SO THAT IT
BECOMES SAFER UNDER EARTHQUAKE
OCCURANCES
 AVOIDING THE POSSIBILITY OF BRITTLE MODES
OF FAILURE BY PROPER REINFORCEMENT AND
CONNECTION OF RESISTING MEMBERS

IS CODES
 CODES
◦ IS 13935 (JUNE 2009) – GUIDELINES FOR REPAIR,
RESTORATION, CONDITION ASSESSMENT AND
SEISMIC STRENGTHEING OF MASONRY BUILDINGS

GENERAL PROVISIONS REQUIRED IN
MASONRY BUILDINGS
 PLINTH BAND
 LINTEL BAND
 ROOF SLAB/ROOF BAND
 CORNER REINFORCEMENT
 BRICK WORK IN CEMENT MORTAR OF
1:6
 RESTRICTED OPENINGS
 ADEQUATE FOUNDATION

SELECTION OF MATERIALS AND
TECHNIQUES FOR RETROFITTING
 CEMENT
 STEEL
◦ BOLTS, RODS, ANGLES, BEAMS, CHANNELS,
EXPANDED METAL, WELDED WIRE FABRIC
 ADMIXTURES TO IMPROVE NON-SHRINKAGE
(GROUTS CONSISING POLYMER, NON-SHRINK
CEMENT AND SPECIAL SANDS), BOND (EPOXY
RESINS) ETC.

114
114

SEQUENCE OF RETROFITTING
 REPAIR/REHABILITATION
 ALL CRACKS SHOULD BE FULLY REPAIRED
◦ PRESSURE INJECTION OF NON-SHRINK CEMENT
POLYMER GROUT FOR 0.5 TO 5 MM CRACKS
◦ REPAIR BY EXPANSIVE CEMENT MORTAR, QUICK
SETTING CEMENT, ADDL. SHEAR OR FLEXURAL
REINFORCEMENT, STEEL MESH, STEEL RODS

REPAIR/STRENGTHENING OF WALLS
 BY GROUTING (CEMENT WATER MIXTURE OR
POLYMERIC MORTAR)
 BY ADDITION OF VERTICAL REINFORCEMENT
CONCRETE COVERINGS ON THE TWO SIDES OF THE
WALL
 BY PRESTRESSING WALL

HORIZONTAL SEISMIC BELTS
 TO BE PROVIDED
◦ ON ALL WALLS
◦ ON BOTH THE FACES
◦ JUST ABOVE THE LINTEL
◦ BELOW ROOF
◦ BELOW FLOOR
◦ IN CASE OF RCC SLAB ROOF BELT NOT REQUIRED
◦ NOT REQUIRED AT PLINTH LEVEL UNLESS PLINTH
HEIGHT IS MORE THAN 900 MM

ON ALL WALLS
ON BOTH THE FACES
ABOVELINTEL

SEISMIC BELTS AROUND
DOOR/WINDOW OPENINGS
 IN CATEGORY “D” AND “E” BUILDINGS
 MESH OF GAUGE 10 WITH 8 WIRES IN VERTICAL
DIRECTION SPACED AT 25 MM IN A BELT WIDTH OF
200MM OR
 GAUGE 13 WITH 10 WIRES IN VERTICAL DIRECTION
SPACED AT 25 MM IN A BELT WIDTH OF 250MM (IN
CAT. C BUILDINGS ALSO)

AROUND OPENINGS

VERTICAL SEISMIC BELTS AT CORNERS
 AT THE CORNERS OF ROOMS
 JUNCTIONS OF THE WALLS
 WIDTH ON EACH SIDE OF THE CORNER
TO BE KEPT 25 MM EXTRA TO THE
WIDTH OF THE MESH
 REIFORCEMENT TO BE STARTED BELOW
300 MM BELOW PLINTH LEVEL

128
AT EXTERNAL CORNERS

VERTICAL REINFORCEMENT
AT INSIDE CORNER

ROOFS CONSISTING OF STEEL JOISTS FLAT OR SEGMENTAL ARCHES MUST
HAVE HORIZONTAL TIES HOLDING THE JOISTS HORIZONTALLY IN EACH ARCH
SPAN SO AS TO PREVENT SPREADING OF JOISTS

ANCHORS
 MECHANICAL ANCHORS
 CHEMICAL ANCHORS

136
PROCEDURE OF ANCHORING

SPECIFICATIO
NS FOR
HORIZONTAL
SEISMIC BELT
SPEC. FOR
VERITICAL
REINFORCEM
ENT

Additional steps
• Repair and rehabilitation to be carried out prior
to retrofitting.
• At the external corners, on each face of the wall,
the width of the mesh for corner reinforcement
may be kept as minimum 250 mm on each wall
so that it covers minimum one brick.
• The mesh reinforcement at the corners may be
kept minimum 300 mm below ground level

Contd.
• Mesh reinforcement used should be galvanized steel
and anti rusting paint should be applied on the cut
points to prevent corrosion.
• MS washers used on wire mesh should be painted
with anti corrosive paint. In the present case, M.S.
washers of size 50X50X5 mm were used to anchor the
mesh reinforcement.
• Since it was not possible to provide roof belt of mesh
of required width in central portion due to segmental
arch construction and ventilators provided near the
top portion, MS flat belt was provided.

•The anchors are to be inserted into the
hole after the grout is inserted within gel
time, which is given 4 minutes for
temperature of 30 degree Celsius and 6
minutes for 20 degree Celsius for the
anchors and chemical grout used from Hilti
India Private Limited.

•In the inside corner reinforcement,
a prefabricated MS piece was used
having two holes, one used for
inserting into the bar which can be
adjusted at any position and other
end used for inserting anchor.
Chemical anchoring was done
thereafter.
Anchoring on wire mesh should be
in staggered (zig-zag) manner.

151
TRAINING, SKILL UPGRADATION AND
COMPETENCE DEVELOPMENT
• STAKEHOLDERS
– POLICY MAKERS
– TRAINERS
– PARTICIPANTS
– IMPLEMENTERS
POLICY MAKERS
TRAINERS
PARTICIPANTS
IMPLEMENTERS
151

Item 1
• Providing and fixing 250 mm wide or required
size seismic belt for retrofitting with 12 gauge
(2.64 mm dia) galvanized iron welded mesh
with 25 mm spacing of wire on walls at
required height (inside and out side the
building ) fixed in position with headed nails at
required distance complete as per direction of
Engineer-in-charge. (Cut end of wire mesh to
be painted with NitoZinc Primer)

Item 2
• Providing and fixing stainless steel anchors of 8 mm dia
(HAS-EM8 x 80 / 14) of HILTI or equivalent on GI wire
mesh at required distance in staggered position i/c
drilling of 10 mm dia hole with HILTI hammer drill
machine TE-6S or equivalent and cleaning of hole by
brush and blow out pump. Anchors shall be fixed by
resin and hardener pack of HILTI make HY-150/330/2R
or equivalent (35 holes per tube of 330 ml) chemical.
Mesh will be fixed with MS washer of size 50x50x5 mm
painted with NitoZinc primer (FOSROC) on top of the
mesh with anchor screwed with nut complete as per
direction of Engineer- in- charge.

Item 3
• Painting on galvanized iron / steel work such
as M.S. angle, flat, cold twisted bars with
Protective / Bond coats i.e NitoZinc (FOSROC)
primer of approved brand and manufacture as
per direction of Engineer-in-charge.(Surface
area of steel work shall be measured for
payment)

Item 4
• Providing and Fixing steel reinforcement bar 10
mm dia for seismic strengthening of building at
inside corner i/c fixing with M.S. cleat 50x50x6
mm size having 2 holes. The reinforcement bar
shall pass through one hole and other hole shall
be used for anchoring into brick / CC wall.
(The payment for steel reinforcement, Anchor &
grouting at floor and roof shall be paid for
separately)

Item 5
• Providing and fixing seismic band for seismic
strengthening of size 50x5 mm flat iron
section at required level including making
necessary holes not more than 75 cm apart
and keeping in position with nails and finally
fixing with Anchors ( Payments for Anchors &
its fixing shall be made separately).

Item 6
• 28 mm thick Acrylic modified cement
mortar/micro concrete band at required level
with mix 1:1:2 (1 cement : 1 coarse sand : 2
graded stone aggregate 6 mm & down nominal
size) in two coats admixed with polymer
modified compound (Armourcrete / Tapecrete) @
10% of cement (by weight) used area and
including slurry coat of Acrylic cement @ 2.2 kg /
sqm mixed with polymer modified compound
(Armourcrete/ Tapecrete) @ 10% of cement used
and finished smooth complete (top layer will be
of 12 mm plaster).

Photos and References have been taken from various web sites.
Their contribution is gratefully acknowledged)

Disaster management and seismic retrofitting

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