Presentation on Conservation of Modern Architecture and Restoration of Cement Concrete Structures prepared by Prof. Er. Jagjit Singh Ghuman, Coordinator and Principal Investigator, CCA Conservation Research Project, Formerly Chief Town Planner and Head T&CP Dept., Govt. of Punjab in International Conference: Concrete Action 2014 organised by Chandigarh College of Architecture on 3rd-4th April, 2014.

1. CONCRETE ACTION 2014
Prof. Er. Jagjit Singh Ghuman
Coordinator and Principal Investigator,
CCA Conservation Research Project
Formerly Chief Town Planner and Head
T&CP Dept., Govt. of Punjab
Conservation of Modern Architecture
Restoration of Cement Concrete Structures
Truthfulness of Material and Construction Code
Grading and Restoration of Surface Textures
Exposed Concrete Façade of Heritage Building
Prof. Prafulla T. Janbade
Asst. Prof. Architecture
and Principal Investigator,
CCA Research Cell
Chandigarh College of Architecture

2. CITY LEGACY / OVERVIEW
Chandigarh City is a symbol of India’s freedom, an expression of citizen’s
faith in its development, i.e. “Urban Form, Architecture, City Landscape”, to
sustain its legacy / heritage buildings for the future generations.
The study “Truthfulness of Material and Construction Code”, quantify and
qualify norms, standards, code of practices for concrete structures in the
construction industry.
The study of Corbusier’s Concrete, “Grading and Restoration of Surface
Textures” covers the demonstration exercise undertaken for conservation
and effective treatment of exposed concrete surface texture of a roof in a
faculty room in CCA Building Chandigarh.
The study / demonstration exercise on conservation, repair, restoration of
“altered or damaged concrete façade of Heritage Buildings” in the City
Centre / CCA Building in Chandigarh.
The study / demonstration exercise aim to protect / restore its architectural
heritage sustain a healthy work-living environment and ensure a distinct
quality of life to its citizen.

3. Ancient or pre-historic concrete used a)
Pozzolan, a siliceous aluminous material
from volcanic ash, b) quicklime obtained
by heating limestone, mixed with sand and
grit / gravel.
Modern Cement Concrete in the
construction industry was revived by
James Parker, a clergyman in 1780’s and
developed as Portland Cement by Joseph
Aspdin (1779-1855) of UK in 1824.
Portland Cement gets the name from its
resemblance (on hardening) to the famous
limestone, obtained from quarries on the
Isle of Portland in UK.
It is made from finely pulverized alumina
(form of aluminum oxide occurring
naturally), limestone, iron oxide, magnesia,
and silica burnt together in a kiln.
TRUTHFULNESS OF MATERIAL AND CONSTRUCTION
CODE
or cement mortar for stone or brick laying

4. TYPE-PROPERTIES OF MODERN CEMENT
“Portland Cement” is by far the most common type of cement, generally
used around the world, often referred to as OPC used as mortar in masonry
or cement concrete in the construction industry.
•Natural or Geo-polymer Cement
•Energetically Modified Cement (EMC)
Portland Cement Blends, these are available as inter-ground mixtures of
Portland Cement with similar formulation with different ingredients at the
concrete mixing plant, namely;
Non-Portland Hydraulic Cements, ground granulated blast furnace slag is
not hydraulic on its own, but is "activated" by addition of alkalis, most
economically using lime.
•Slag-Lime Cement
•Super Sulfated Cement
•Calcium Sulfoaluminate Cement
• Portland Blast Furnace Cement
• Portland Pozzolan Cement
• Portland Silica Fume Cement
• Expansive Cement
• White Blended Cement
• Finely Ground Cement

5. GRADING OF CEMENT AND CONCRETE
Indian Standard Code for grading of cement and concrete in the
construction industry is given for:
•Type and Properties of cement, sand and gravel
•Design , composition and proportioning mix
•Compressive strength for structural stability
•Workability of graded cement concrete, laying and formwork
•Structural’s durability Compaction by use of vibrators
•Time schedule for curing and removal of formwork
DETERIORATION OF CEMENT CONCRETE
STRUCTURES
Damage of exposed cement concrete due to environmental changes, its
scanning-mapping to maintain permanent record / data, its restoration,
maintenance and upkeep is a major concern of physical planners, architects
and engineers.
•Environmental causes, climate and weathering action, air and water
pollution, effect of pH value, carbonation, corrosion of reinforced steel.

6. SCANNING, MAPPING OF DAMAGED CONCRETE
STRUCTURES
Diagnosis of deterioration / damage, required for assessing the quantum of
repair / rehabilitation necessary, is made by the following methods:
• Identifying symptoms by visual observations, The symptoms which
indicate active corrosion of the embedded steel include appearance of red
stains on the surface; splitting and spalling of concrete cover exposing
reinforcement; appearance of parallel cracks along the reinforcement,
embedded pipe fitting etc. and, cleavage planes showing the separation of
concrete from the bars.
• Damage can also be assessed by non-destructive methods, The Non-
destructive Evaluation Testing Methods now available include the
Ultrasonic pulse velocity test; Rebound hammer test; Half-cell potential
mapping method; Electrical resistivity measuring method; permeability
test; chloride test; water test; petrography and carbonation test.
•Scanning and mapping techniques, CorroMap and Core Test

7. Conservation of cement concrete
begins with the assessment of
the extent of structural damage
in buildings. Findings of the
study of “Truthfulness of
material and construction code”
helps to build this relationship.
Patch work repair of exposed
concrete surfaces, invariably do
not match with the surface
texture. Changes effected due to
faulty repair and treatment of
exposed concrete surface texture
need to be restored.
Avoid mismatch of exposed
concrete surface texture of
buildings in the city landscape.
CONSERVATION OF CEMENT CONCRETE
STRUCTURES

8. GRADING AND RESTORATION OF SURFACE
TEXTURES
The CCA Research Cell study covers, in-depth investigation of the exposed
cement concrete structures and surfaces in buildings. It also aims to identify
options-alternatives for preventive treatment of the controlled building
façade and the exposed cement concrete roof surface of the CCA Building to
restore its healthy texture, namely:
• Truthfulness of material and construction code
• Grading-Restoration of Corbusier’s Concrete: Demonstration Exercise,
i.Study the CCA building structure, develop skills & techniques for
conservation of exposed cc surface texture.
ii.Application of silicon, polymer or petroleum based products to ensure
sustainable maintenance of the concrete surface texture.
GRADING AND RESTORATION OF SURFACE
TEXTURES
The physical condition and characteristics of exposed cement concrete
structure and surface texture was carried out for the listed heritage
buildings in Chandigarh.

9. Cement Concrete Building Structure and Architectural
Controlled Façade
(Exposed Concrete Surface Texture)
External
Exp. c.c.
Facade
Internal
Exposed
Concrete
Gross
Exposed
Concrete
Damaged
Concrete
Structure
(in m2
)
Damaged Untreated
Surface Texture
(in m2
)
(m2
) (m2
) (m2
) Area % age Area % age
Capitol Complex 158938.93 635755.73 794694.67 8025.00 1.01% 794694.67 100%
Assembly Building 34690.20 138760.80 173451.00 2601.77 1.50% 173451.00 100%
Secretariat Building 40471.90 161887.60 202359.50 2428.31 1.20% 202359.50 100%
High Court Building 25439.48 101757.92 127197.40 1526.37 1.20% 127197.40 100%
Hall of Shadows Building 289.09 1156.34 1445.43 17.35 1.20% 1445.43 100%
Geometric Hill 231.27 925.07 1156.34 5.78 0.50% 1156.34 100%
Open Concrete Pavement 57817.00 231268.00 289085.00 1445.43 0.50% 289085.00 100%
City Centre, Sector-17 92507.20 370028.80 462536.00 11346.59 2.45% 462536.00 100%
SCO Concrete Façade 52035.30 208141.20 260176.50 7805.30 3.00% 260176.50 100%
Govt. Buildings Concrete Façade 11563.40 46253.60 57817.00 1734.51 3.00% 57817.00 100%
Office and Hotel Complex 28908.50 115634.00 144542.50 1806.78 1.25% 144542.50 100%
Museum and Arts College, Sector-10 40471.90 161887.60 202359.50 3237.75 1.60% 202359.50 100%
College of Architecture, Sector-12 1156.34 4625.36 5781.7 109.85 1.90% 5781.7 100%
PGI Campus, Sector-12 46253.60 185014.40 231268.00 3700.29 1.60% 231268.00 100%
Punjab University Campus, Sector-12 2890.85 11563.40 14454.25 231.27 1.60% 14454.25 100%
Administrative Block 2312.68 9250.72 11563.40 185.01 1.60% 11563.40 100%
Gandhi Bhawan 578.17 2312.68 2890.85 46.25 1.60% 2890.85 100%
Punjab, UT and other Govt. Off. Bldg. Façade, Sector-10 46253.60 185014.40 231268.00 3700.29 1.60% 231268.00 100%
SCO Bldg. Concrete Façade, MM, Sector-9 37002.88 148011.52 185014.40 4255.33 2.30% 185014.40 100%
Physical assessment of the area of external exposed façade and the concrete surface texture of cement
concrete building structures in Chandigarh City Landscape.

10. Physical assessment and grading of exposed cement concrete surface texture
(Table 1) show that the damage of concrete structures in the Capitol
Complex is approximately 1.62% as compared to private owned concrete
buildings in Sector-17 (2.04%) and along Madhya Marg Sector-9 (2.3%).
The damage of exposed concrete surface texture is predominantly due to
structural alterations and faulty repair of the building façade.
Grading of surface texture for sustainable restoration of concrete structures
is as follows:
ST 1: Glossy shiny, lustrous bright silver grey or beige colour.
ST 2: Soft, fine to touch in silver grey colour partial change in colour
of concrete surface texture due to carbonation etc.
ST 3: Smooth free from irregular surface particles, in steel or
processed wood shuttering or moulding with carbonation and change
in concrete surface texture colour.
ST 4: Coarse medium or small granular surface, with surface voids,
carbonation, change in concrete surface colour.
ST 5: Course rough or large granular surface, generally seen in rough
wood shuttering, carbonation and total change in concrete surface
texture colour.

11. RESTORATION OF CONCRETE SURFACE TEXTURES
The restoration, maintenance and upkeep of exposed concrete surface is
generally carried-out by;
• Dry or Wet Process: cleaning the Cement Concrete surface infested
with dust and cobwebs, etc. with water and brush.
• Optional, use mechanical or manual dry or wet process i.e. air or sand
blasting, or steel or coir fibre brush for cleaning the concrete surface to
remove carbonation.
• Mechanical or manual process i.e. compressed air pump with a spray
gun to dry and clean the Concrete Surface.
• Protect & treat: all concrete surfaces with silicon or polymer based
product or petroleum based product i.e. a mixture of sulphur free Diesel
(low lubricant) 50% + Kerosene (absence of olefin lubricant) 40% + 10%
household insecticide-disinfectant (by volume) with a 4” paint brush or a
compressed air pump spray gun.
• Ensure fire and other safety requirements: including use of silicone
hand gloves, face mask, protective glasses etc. when treating or applying the
aforesaid indigenously prepared mixture.
• Allow free flow of air & ventilation: in the room or interior portion of
the building before occupying it

12. CONSERVATION OF CCA BUILDING:
DEMONSTRATION EXERCISE

14. Graded Surface
Texture
Recommended Cleaning
Process
Surface
Treatment
ST 1: Glossy,
lustrous silver grey
or beige colour.
Dusting , cleaning with soft
cotton fibre dry mopper and
clean portable water without
any additives
Clear wax or petroleum jell,
polish mix with diesel or
kerosene
ST 2: Soft, fine to
touch in silver grey
colour
Coir or soft brush dry process
with nylon sponge and water
without any additives
Petroleum base proportionate
mix with insecticide
ST 3: Smooth free
from irregular
surface voids or
particles
Coir or soft brush dry process
with nylon sponge and water
without any additives
Petroleum base proportionate
mix with insecticide
ST 4: Coarse
medium or small
granular surface,
with surface voids
Wire brush, low pressure sand
or water blasting mechanical
process or wet process
Petroleum base proportionate
mix with insecticide
ST 5: Course rough
or large granular
surface voids
Wire brush, low pressure sand
or water blasting mechanical
process or wet process
Petroleum base proportionate
mix with insecticide
Recommended effective cleaning and treatment process for exposed cement
concrete graded surface texture.

15. HERITAGE BUILDINGS: SEC-17, CHANDIGARH
Physical condition of exposed concrete surfaces of heritage buildings in
Sector-17, Chandigarh show distinct or marked alteration or damage of
stipulated exposed concrete surfaces.
Conservative assessment of the heritage buildings show that; 11346.59 m2
i.e. 2.45% is altered or damaged due to human intervention i.e. alteration
of the exposed concrete surface with cement plaster / paint / hoardings etc.,
which require repair and restoration.
The total exposed concrete surface of 462536.00 m2
is damaged due to
effects of air pollution / carbonation / algae / microbial action and requires
restoration, sustainable treatment and regular maintenance.
Altered / damaged concrete façade of Bank Square
Heritage Buildings, Sec-17, Chandigarh
Altered / damaged concrete façade of Heritage
Buildings: poor or unhealthy City Landscape

16. CCA HERITAGE BUILDING FACADE
Chandigarh College of Architecture: Heritage
Building façade concrete surface texture damaged
due to effects of weathering, carbonation, algae /
microbial action
Exposed concrete façade sunshade partially
damaged due to weathering / air-pollution /
carbonation action before sand blasting
Heavy duty 10 Kg. psi. sand blasting machine at the
CCA New Library Building Block Façade

17. CCA Conservation Team
interacting / assessing the
effect of sand blasting on
exposed concrete surface
with Er. Ravinder Chadha
of M/S Prime Engineers

18. FINDINGS AND CONCLUSIONS
Dry process cleaning with sand / shot blasting is not desirable as it
damages its sensitive / fragile concrete surface texture. Alternately, wet
process cleaning of the carbonated concrete surface with with water hose
pipe, soft brush or bucket-sponge with potable water before, so as not to
damage the surface texture of the concrete façade. It is also noted that the
entire CCA Library Block exposed concrete surface façade will require
repair / restoration. So as to ensure cost effective restoration of the
exposed concrete façade CCA Heritage Building without damaging the
concrete / brick surfaces, the following alternative is recommended:
• Wet process cleaning with water hose pipe, soft brush or bucket-
sponge with potable water before, so as not to damage the surface texture of
the concrete façade.
• Restoration / treatment of exposed concrete with natural building
material only, i.e. a workable mix of concrete (cement, sand, grit) for repair
of structural damage or cement-putty mix (white cement based filling agent)
for restoration of concrete surface textures.
• Application of protective coating with petroleum based insecticide mix
on interior concrete surfaces or silicon, polymer protective coating on
concrete / putty mix on exterior exposed concrete surfaces.

19. THANK YOU