Approved Licensed Structural audit of old and dilapidated buildings in Mumbai Thane Navi Mumbai India

CSR Consultant & Associates Building Audit & Structural Health report system
Project Management Consultant www.buildingrepair.in
“HEALTH CHECK SYSTEM FOR RESIDENTIAL BUILDINGS”
CSR Consultant and Associates undertake Building Surveys, BUILDING AUDITS, prepare Building health
reports, provide Waterproofing treatments, Re-plastering and Painting work estimates, society Civil
maintenance, RCC Structural reinforcement systems, prepare Civil repair budgets, Repair estimate, Project
Management Consultancy, PMC for Civil repair projects to ensure that the project is being carried as per
Client’s requirements within the best value proposition and budget. CSR technical management team
establishes the effective centralized Cost Management and Change Monitoring system for the Society
members during the course of project.
Our Building Audit / Health reporting / Project Management Consultancy services are classified into four
typical stages.
1. Pre contracting- Building surveys /audits
• Identify damages and repair quantum
• Initial budgetory estimate
• Preliminary cash flow
• Preliminary cost plan & cash flows
2. Tendering & Documentation
• Procurement strategy – packages, tendering & contracts
• Preparation of contract documentation
• Preparation of standard &consistent BOQ
• Tender review & analysis
• Preparation of Letter of award & Contracts
3. Post contract Cost Control & Monitoring
• Cost control & administration
• Change management strategies
• Progressive cost plan & monitoring of costs
• Periodic project cost report
• Indent & check measurements / quantities, Material reconciliation

4. Post contract Financial Management
• Standard procedures for progress payments
• Attend update meetings and evaluations
• Periodic checks & progress payments
• Preparation of final accounts
• Financial & contractual close-out
Most of the Societies planning to undertake Civil repairs and Painting work for their respective buildings
have few FAQ’s like.
1. WHY DOES THE SOCIETY NEED CSR? : Every society has got their unique Civil repair problems,
demanding very specific technical feasible solution. Therefore, Societies need to have technical
assistance who has enormous experience in the Civil Engineering field. CSR comes in handy for
drawing technical solutions.
2. CONTRACTORS CAN DIRECTLY GIVE US ESTIMATES & QUOTATIONS? Grabbing estimates and
quotations from various contractors would be time consuming and tedious task while comparing. -
-- To get the competition on single platform, one needs to ink out basic requirements of the
society - Externally and Internally. It may not be feasible to ask all the contractors to visit every
single owners property. CSR can professionally assist you to develop a Technical Tender document
as per your specific needs.
3. OUR SOCIETY MEMBERS CAN SUPERVISE WORK IN PROGRESS ? : Most of the members may be
qualified in their respective fields. But do you have full time experience with the Civil repair
industry? Are you aware of the Industry standards? Are you aware of the Civil Engineering
methods? Can you devote time on daily basis? Are you equipped to face unforeseen
circumstances? --- Because, we at CSR, ensure methodology, quality and measurement. CSR
maintains log reports, material management, time management, complaint registers, billing and
accounting.
4. WHAT IS THE BENEFIT OF APPOINTING CSR? Being a third party, society members can be rest
assured to have impartial decisions. A professional guidance can help avoid conflicts or show
stoppers to get going.
5. BUT, CSR SERVICES WILL JUST ADD TO OUR COST? : CSR supports right from audit, tender
preparation, tender issues, selection of contractor, progress of work, balance sheet of project and
final closure report. Secondly, CSR services shall save ‘n’ times the total CSR’s service cost;
inculcating technical knowledge, time track, minimizing of unnecessary work, justified usage of
society fund and peace of mind. No professional can carry Building Audit / Surveys at free of cost,
without any hidden vested interest. Professional and genuine services never come cheap. Beware
of free malpractices sold in the market.
For more details, please feel free to call / write to the co-ordinates mentioned.
Thanking you…
With regards,

For CSR Consultant & Associates
Authorised Signatory
9323547766 I csrconsultrajesh@gmail.com
Annexure A report
BASIC GUIDELINES FOR HEALTH CHECK REPORT BY CSR CONSULTANT AND ASSOCIATES
1. Cover Page
Report title
Name of building (which has to be audited)
Location / Address of building
Iconic photo of the building (optional)
Date of report
Details of Audit Company
Details of Professional Engineer
Endorsement / Signature of Professional Engineer
Statement by the building owner accepting the report and reviewed the results and
recommendations
Name, designation and signature of building owner’s representative accepting the report.
2. Table of Contents
Executive Summary
Introduction
Methodology and instrumentation
Data analysis and findings including graphs and plots
Summary of recommendations

Conclusion
Appendices
3. Executive Summary
All information in the Executive Summary should be drawn from the detailed information
in the full report. The Executive Summary should contain a brief description of the audit,
including:
Name of building owner and location of building audited
Objectives of audit
Key systems and equipment analysed
Dates of audit
Summary of results and recommendation on overall and major components of the
central plant, including estimated cost, energy savings and payback period.
4. Introduction
Brief description of building audited – number of floors, GFA, air-conditioned areas, type of usage,
occupancy, hours of operation, year built, etc.
Information on tenants in facility or building audited (If applicable)
Scope of audit, elaborating what systems or equipment were studied GMIS-EB ‘HEALTH
5. Declaration of code compliance
The measurement works shall comply with Municipal Corporation codes defined and Health Check
report guideline.
6. Methodology and Instrumentation
Instrumentation specification table.
Proposed instrumentation plan in detail; Schematics or point listings of where instruments are
installed.
Detailed instrument installation and measurement procedure/method statement. Pictures and
maps showing the locations of the installed instruments and sensors. All sensors must be
calibrated before installation.
Manufacturers’ calibration data may be sufficient as long as the installation conditions match the
conditions of calibration. Manufacturers’ calibration data should include documents of traceability
to the calibration facility and, ultimately, traceability to national standards.

STRUCTURAL AUDITS
1. STRUCTURAL AUDIT – PERIODICALLY:
Periodic “Structural Audit”, of the building and compliance thereon, also positively restricts the
BMC (or others /owners), from declaring the building as “dilapidated” and ultimately from
receiving notices of eviction from the building. Such notices would also mean revocation of
buildings “Occupancy Certificate” and increase in Water Charges.
2. STRUCTURAL AUDIT – CHECKING:
“Structural Audit”, of the building means EVERYTHING connected to the conduct of a Building,
which includes strength of the buildings Columns, Beams, Pillars, Iron Bars & Plaster, Sewage
discharge systems, Water pipeline systems, Electrical cabin and wiring system, Lifts, Podiums ….
a) Structural Audit parameters will vary for Residential buildings, Commercial buildings and
Industrial buildings.
b) Some “quack” type Structural Auditors, perform a superficial check and issue a manipulated
Structural Audit Report, to the Society, with the connivance of the apathetic Society office bearers.
3. STRUCTURAL AUDIT – RESTORE TO NORMALCY:
A Structurally unfit building shall be prone to sudden collapse without any warning, at the first
instance of an earthquake, which in turn means risking the Life and Property of the buildings
residents and other people in the vicinity.
a) At present times, there are several technological techniques available, along with
highly experienced technical professionals, where old buildings can be easily refurbished /restored,
to complete normalcy, thus peacefully extending the life of old buildings by further 20-40 years.
b) This helps in gross monetary savings, while still retaining the emotions and sentiments
attached to the building and its co-residents.
4. ILLEGAL ALTERATIONS – BUILDING COLLAPSES:
Around July-2007, a 25 year old building named as “Laxmi Chhaya” (at Borivali West), just simply
collapsed in the early morning hours, just because some greedy shop-owner/s had reduced the
girth of the buildings Column & Pillars. This resulted in loss of Life and Property of the buildings
residents and other people in the vicinity. Today due to courtesy of Human Apathy, everything is
back to normal and the losses of human lives are apathetically and conveniently forgotten by all
concerned. No lessons learned.
5. WHAT SHOULD BE CONDUCTED DURING STRUCTURAL AUDIT?

A “prudent” Structural Engineer would reflect the following in his Structural Audit Report,
highlighting the relevant violations under the Municipal Laws, while keeping upfront the Approved
Plans of the Building:
a) Any changes and contraventions of the Approved Plans /Availability of Sanctioned Plans.
Whether Building has been built in conformity to the Sanctioned Building Plans,
b) Availability of approved & sanctioned building Plans, IOD, CC, OC,
c) Changes made to the buildings Columns, Beams, Pillars,
d) Changes made in place of WC, Bathroom, Kitchen, installation of loft water-tanks,
e) Extension OR Covering of Balcony,
f) Removal of Internal walls between rooms,
g) Internally Amalgamating (joining) of two flats, by removing partition walls /doors,
h) Installing over-protruding Grills, Sheds, Chajjas,
i) Conversions of basements OR Stilt /podium parking for any other usage (e.g. Offices, Shops …. )
j) Existence of unauthorized Lofts & Mezzanine Floors in the building,
k) Any other encroachment of Common areas, Refuge areas and Society premises,
l) Installation of illegal Mobile Towers and Hoardings, and adverse effect of same on the building,
m) Whether the building has appropriate Drainage /Sewage lines connected to the Mains,
n) Existence of Open-Well, Bore-Well and other clandestinely built sub-ground level storage water
tanks,
o) Common Electrical Wiring system,
p) Changes in Internal /External Drainage /Sewage lines,
q) Ground and Overhead Water Tanks, Water Meters and supply pipelines,
r) Water logging around periphery of the Building and reverse incline level of ground,
s) Detailed report on the repairs and restorations, that is required in the Building, in terms of the
Approved Plans of the building.
Note: Structural Engineer /Auditor shall clearly outline each Alterations with graphic images and
photographs and the repairs /rectifications /restorations that needs to be done in the Building.
6. STRUCTURAL AUDIT TECHNIQUES :
The Structural Engineer, mandatorily must be a NEUTRAL authority, more so since any
manipulations or fabricated or untrue Structural Audit Report, would mean, criminal prosecution
against the Structural Engineer. An experienced & competent Structural Engineer would conduct
several tests to determine the extent of corrosion, distress and loss of strength in concrete & steel.
Some of the tests means:
a) Concrete Core Cutting & Compression testing for columns, beams and slabs for Strength
Assessment of concrete.
b) Half Cell Potential test for determining the probability of corrosion in the embedded steel.
c) Carbonation test for carbonation depth measurement for Steel.
d) Ultrasonic Pulse Velocity Test (UPV) for Strength Assessment of concrete.
e) Integrity tests for pile foundations and various testing techniques.
7. FIRE EQUIPMENTS:

The Structural Auditor has to inspect the Fire Fighting Systems (as applicable) with the relevant
approved vendor and prepare recommendatory reports, highlighting the repairs and restorations
required, for due compliance of the building Owner /Society.
Failure to install the mandatory Fire Fighting Systems, and to keep maintaining them in working
condition is mandatory, failing which the Fire Department is within its jurisdiction to disconnect
Electricity and Water connections, besides revoking the FIRE NOC for Occupancy Certificate
granted to the building.
8. EARTHQUAKE RESISTANCE:
Presently Earthquake resistance buildings are built & designed as per Indian Standard Codes,
means “Earthquake Code IS 1893-2002”.
a) Under the parameters of “Indian Standard Codes”, the island city of Mumbai is located in
Earthquake (Seismic) Zone III.
b) Some very old buildings, which are not built for Earthquake resistance, can still be retrofitted
appropriately to make it literally earthquake resistant, subject to the building being structurally fit.
This preemptive /precautionary measure will help in avoiding sudden collapse of buildings, during
Earthquake/s, and giving enough time to clear the building, thus helping in saving Life & Property.
9. FAILURE TO CONDUCT REPAIRS:
IF the building Owners /Society, consistently fails to carry out all the repairs and restorations
highlighted in the Structural Audit Report, THEN the BMC is empowered to conduct the repairs
and restorations, on its own and recover the cost of such “repairs and restorations” from the
building Owner /Society. Failure to carry out relevant repairs by the Society, would also lead to
revoking of “Occupancy Certificate”, of the building, thus leading to double the water charges u/s
92 of the BMC Act. The BMC is empowered to file prosecution u/s 488 of the MMC Act and levy
Penalty, for failure to comply with the repairs, mandated in the Structural Audit Report. Criminal
proceedings under Indian Penal Code can also be filed on the Mg. Committee members, for their
deliberate failures and endangering the Life and Property of the building residents.
10. TABLING OF STRUCTURAL AUDIT REPORT:
After the Structural Audit of the Society building is duly concluded, the Society Mg. Committee has
to distribute a Copy of the same to each member at the cost of the Society and then duly call a
Special General Body meeting, to deliberate on the Structural Audit Report and the costs for
repairs and restoration highlighted by the Structural Engineer. The said Repairs and Restoration
has to be mandatorily complied and the General Body of the Society has NO OPTION to avoid the
same. The General Body CANNOT pass any resolution to avoid the said Repairs and Restoration,
under the Structural Audit Report. The repairs & restorations to the building (as applicable) has
to be started WITH or WITHOUT the approval of the General Body. Hence the “Tabling of the
Structural Audit Report”, before the General Body thou necessary, has no relevance under the
Municipal Corporation Act. It has to be mandatorily complied with (repairs) even if the General
Body does not sanction repairs, due to any reasons, whatsoever.

Note: IF the building owner /society do not complete the repairs /restorations, as per the
directions in the Structural Audit Report within 6 month of submission of Audit Report, THEN they
are also liable to be punished under section 471 & 352(B) of the MMC Act.
11. NON-AVAILABILITY OF BUILDING PLANS & OC :
In the event, IF the building’s Sanctioned /Approved Plans and/or Occupancy Certificate (OC) are
not available, THEN the building owner (Society) has to conduct the necessary documentations
and arrange /make the buildings plans etc….
The buildings Occupancy Certificate can be procured, using various compliance parameters, BUT
ONLY after repairing & restoring all illegal alterations /amalgamations.
12. PREEMPTIVE MEASURES :
Even in newer buildings, the building owners (Society) should themselves consider to conduct
“Structural Audit” of their buildings, every Five years, as precautionary measures against
encroachments of common spaces /balconies /niche areas /flower-bed areas and unauthorized
alterations in WC, Bathrooms & Kitchens or Amalgamating two Flats.
Such preemptive Structural Audit would help in timely repairing or reversing back any such
unauthorized alterations /changes, and avoid hairline fractures in the Columns, Beams, Pillars,
Walls and Floors.
The compliance of above, will mean preserving & increasing the overall life of the buildings. This
also serves to save Life, Property & Money of the building residents.
13. CONSPIRACY :
In Mumbai, a conspiracy is emerging with the connivance of the Society Mg. Committee members
and the local builders lobby, to deliberately avoid repairing and restoration of structurally sound
old buildings and then consequently having the building declared as “dilapidated or risky” at the
hands of the local civic body, for the sole objective of Redevelopment of their buildings, for
clandestinely generated monetary benefits.
a) When such conspiracy is appropriately proved, using various parameters and documentations,
the Structural Auditor along with the Mg. Committee members can be successfully prosecuted
in a Criminal Court, under the Indian Penal Code.
14. INTROSPECTION:
In the larger interest of the public, the State Govt., would do well to consider making mandatory,
the preemptive Structural Audit of every old /new building, every Five years, in order to detect
illegal encroachments of common spaces /balconies /niche areas /flower-bed areas and
unauthorized alterations in WC, Bathrooms & Kitchens or Amalgamating of Flats. This will help in
good governance and drastically reduce legal proceedings by the local civic body (Municipal
Corporations), which in turn means lesser leakages and maintaining harmony between Flat
Owners.
Contents

Structural audit of existing buildings
1. What is Structural Audit?
2. Suggested format for Structural audit reports?
3. Structural Audits – recommended tests?
4. Procedure for repairs
5. Building repair – Structural stability report?
The various issues cover the topic
Structural Audit is an important tool for knowing the real status of the old bldgs. The Audit should
highlight & investigate all the risk areas, critical areas and whether the bldg. needs immediate attention. It
should also cover the structural analysis of the existing frame and pinpoint the weak structural areas for
static, wind & earthquake loads. If the bldg. has changed the user, from residential to commercial or
industrial, this should bring out the impact of such a change.
This CSR document gives step by step guidelines for carrying out Structural Audit of old buildings. We have
also provided a detailed format to collect data from the field. The details regarding the various non-
destructive tests and other tests to be carried out are also given. Includes photographs of structural
defects & rectification procedure.
1) What is Structural Audit? How do we carry it?
The Purpose of Structural Audit is :
● To save LIFE & PROPERTY.
● To know the health of your building. and to project the expected future life.
● Highlight the criQcal areas that need to be aRended with immediate eﬀect.
● To proacQvely assist the residents and the society to understand the seriousness of the problems
and the urgency required to attend the same.
● To comply with Municipal or any other statutory requirements.
If we are serious about the Structural Audit, how do we carry it out? What do we tell to our Structural
Engineers? What are our expectations?
STEP 1 :
It is imperative that we must have Architectural and Structural plans of the bldgs. it will be helpful if
we have detailed structural calculations including assumptions for the structural design. The
assumptions can also include the allowable live loads; Whether the bldg. is designed for residential,
commercial, light industry or heavy industry and whether any future provision for adding new floors is
considered? What type of Earthquake loads are considered? Which I.S. Code requirements have been
met?
STEP 2 :

If the Architectural plans and Structural plans are not available, the same can be prepared by any
Engineer by measuring the size of the bldg. & locating the
position of the columns, beams and size of all such structural elements.
STEP 3 :
Inspection of the Bldg. - A detailed inspection of the bldg. can reveal the following :
1. Any settlements in the foundations.
2. Visual cracks in columns, beams and slabs
3. Concrete disintegration and exposed steel reinforcements – photographs can
be helpful.
4. Slight tapping with hammer can reveal deterioration in concrete.
5. Extent of corrosion in reinforcement.
6. Status of Balconies – sagging, deflection, cracks?
7. Status of Architectural features viz. chhajjas, fins, canopies etc.
8. Cracks in walls indicating swelling in R.C.C. members or distress or
deflection or corrosion.
9. Leakages from terrace & Toilet blocks.
10. Leakages & dampness in walls resulting into cracks and corrosion.
11. Changes carried out affecting structure.
Toilet blocks - Added or changes made?
Change of user – from Residential to Commercial to Industrial?
Change of Partition Walls?
12. Status of lift and lift machine room – Type of Maintenance Contract, renewal
of license.
13. Status of electrical wiring from meter room to all the flats. Substation status.
Any explosion in the meter room, substation?
14. Status of overhead & underground water tanks - capacity. Leakages, cracks
& frequency of cleaning, status of pumps.
15. Plinth protection in the compound including status of drainage, water pipes
& pumps. How much the Ground was flooded during recent monsoons?
16. External paint – When last painted and type of paint.

17. Status of repairs & last repaired.
What was repaired?
Who was the Agency?
How much was spent for repairs?
18. Bldg. plans available? When approved?
Occupation Certificate available?
Structural Plans available? Structural Stability Certificate available?
Structural Calculations available?
19. Last Structural Audit prepared?
STEP 4 :
Tests Recommended :
It is important that various tests are carried out in the old bldgs. This will give an idea about the extent of
corrosion, distress and loss of strength in concrete & steel.
Tests may include:
1. Concrete Core Cutting & Compression testing for columns, beams and slabs for Strength Assessment of
concrete.
2. Half Cell Potential test for determining the probability of corrosion in the embedded steel.
3. Carbonation test for carbonation depth measurement for Steel.
4. Ultrasonic Pulse Velocity Test (UPV) for Strength Assessment of concrete.
This can be useful for simple foundations.
5. Integrity tests for pile foundations.
STEP 5 :
Highlight the critical areas and how to go for repairs. For e.g.
1. No. of columns requiring immediate attention including treating rusted steel,
adding new steel, jacketing of columns etc. – Repairing foundations, repairing
balconies, chhajjas.
2. Attending of beams and slabs wherever required.
3. Attending water proofing of terrace, toilet blocks.
4. Attending cracks in external walls and providing good quality of paint.
The critical areas highlighted need to be attended immediately.

STEP 6 :
Earthquake Criteria :
Mumbai is located in Earthquake Zone III as per Indian Standard Codes. The
Earthquake Code IS 1893-2002 provides rigorous analysis and designs of Bldg.
structures so that it can withstand the Earthquake forces. It may be possible to
retrofit the old buildings, so that they do not collapse during Earthquake; but may
develop some cracks and allow enough time for people to escape. Thus saving
precious lives.
STEP 7 :
Compliance of Audit requirements.
Audit is a good thing, but in itself Audit is not sufficient. It is important that the findings and/or
recommendations of audits are implemented satisfactorily, within a stipulated time limit and are certified
by Structural Engineers; Otherwise the Audit findings will remain on paper. Is it a costly process? Of course,
this is going to be costly; but human lives are important and they need to be saved at any cost.
Conclusion:
If your bldg. is more than 15 years old, it is important that rigorous audit is carried out every five years.
After 30 years, every 3 years structural audit should take place. This will be a continuous process as it is
difficult to guarantee future life of old bldgs. However, regular Audits and implementing audit findings will
avoid sudden collapse of bldgs. and save thousands of life. This process will also increase the future life of
bldgs.
Non Destructive Tests: Structural Audit – Recommended Tests
The following NDT tests are required to be carried out on structural elements. However,
it is important that the testing scheme is prepared based on preliminary survey of the
building/structure :

a. Core tests to determine the estimated equivalent in situ compressive strength & to establish
correlation between Rebound hammer test & in situ strength of concrete.
b. Rebound Hammer test to estimate the in situ compressive strength of cover concrete.
c. USPV test to assess the integrity of concrete.
d. Carbonation test to assess the depth of carbonated concrete.
e. Half cell potentiometer test to determine the probability of active corrosion.
f. Cover test to assess the cover provided to RCC structural members.
a. Core Test:
Steps to the Core Tests :
 The reinforcement is detected at planned location with the help of Rebar Locator called Profometer
to avoid cutting of reinforcement.
 The Core cutting equipment is fixed at the planned location & core is extracted.
 The Cores are transported to the laboratory & visual observations of cores are recorded for
interpretation purpose. Reinforcement bars, if encountered, are cut off.
 The Cores are removed from water cut to the required L/D ratio of 2, wherever possible, exactly
perpendicular to the longitudinal axis.
 Both the ends are prepared by grinding up to the tolerance limit as specified by Clause 4:8 of BS
1881:Part 120: 1983 for flatness & parallelism.
 A thin layer of plaster of Paris is applied to ends to ensure proper contact.
 Now the cores are ready for compression testing.
b. Rebound Hammer Test:
Steps to carry out Rebound Hammer Test :
The test is performed as per guidelines given by IS : 1331 (Part 2): 1992 & BS 1881: Part 202: 1986 to
estimate the in situ strength of concrete based on the correlation established between in-situ strength at
the particular location & rebound numbers.
1. The plaster is removed at test locations.
2. For testing, smooth, clean, dry surface without any defect like Honeycombing cracks and hollow sound
is selected.
3. The area of approx. 300 mm x 300 mm is rubbed with carborandum stone to remove loosely adhering
scales, or remains of plaster mortar, if any.
4. In this area 12 points at approximate 30 mm apart are selected in grids.
5. By holding the rebound hammer at right angles to surface of the concrete member, 12 readings are
taken at selected points.

6. Of these readings, abnormally high & abnormally low results are eliminated & average of the balance
readings is worked out.
7. Taking into consideration the factors influencing hardness of the concrete surface like moisture
condition of the surface, carbonation, test location within the member, direction of test etc. corrected
rebound number is worked out.
8. The compressive strength of concrete against each rebound number is obtained from graph prepared
on correlation established between rebound numbers at core test locations & equivalent cube strength
values.
9. The statistical analysis is carried out for this set of values of compressive strengths obtained by above
method.
c. Steps to carry out the USPV test :
1. The plaster is removed at test locations wherever required.
2. For testing, smooth, clean, dry surface without any defect like honey combing, cracks, and hollow sound
is selected.
3. The area of approx. 300 mm x 300 mm is rubbed with carbonation stone to remove loosely adhering
scales, or remains of plaster mortar, if any.
4. Two points are marked on opposite faces of the concrete members. (At exactly opposite locations for
direct transmission of ultrasonic pulses).
5. Grease is applied as a coupling medium to ensure proper contact of the transducers with concrete
surface so that ultrasonic pulse is transmitted through the medium without much disturbance.
6. Now both the transducers are held at correct test locations by applying constant pressure & ultrasonic
pulses are transmitted through the concrete.
7. The machine displays the time taken to travel the known path in microseconds.
8. The velocity is calculated from the reading obtained against each known path.
9. Following velocity criterion for concrete quality grading is given by IS 13311 (PartI) : 1992.
Criterias for grading of Concrete Quality
Ultrasonic Pulse Velocity by Cross probing (Km/Sec.) Concrete Quality Grading
1. Above 4.5 Excellent
2. 3.5 to 4.5 Good
3. 3.0 to 3.5 Medium
4. Below 3.0 Doubtful
d. CARBONATION TEST PROCEDURE :
The powder of concrete is obtained by drilling inside into concrete at selected location. Then the collected
powder is made moist & then phenolphthalein indicator is dropped on it to check any colour change. If the

colour changes to pink, indicates that concrete is not affected by carbonation & if no colour change is
observed, indicates concrete is affected by carbonation.
e. Half-cell Potentiometer Test Procedure:
The half-cell potentiometer consists of a rigid tube, which contains a copper rod immersed in a copper
sulphate solution. This is connected to a voltmeter and another live wire connection comes through
voltmeter to connect it to rebar. To start the experiment firstly the live wire is connected to a rebar of the
test specimen and the rigid tube is put on the surface of concrete and the reading of voltmeter is taken.
Reading gives the potential difference between the electrodes. From the value of the potential difference,
corrosion status inside the concrete can be predicted. The possibility of active corrosion is found out
according to guideline below :
Half cell potential (mV) reading Percentage chance of active corrosion
< -350 90%
-200 to –350 50%
> -200 10%
f. COVER METER TEST PROCEDURE:
The instrument used is PROFOMETER - 4, Rebar Locator Model S, manufactured by M/s. PROCEQ SA,
Switzerland, which is able to perform following functions :
 To locate the bar accurately.
 To assess the clear cover to the bar.
 To calculate bar diameter of the selected bar.
The instrument works on magnetic principle & has limitations of spacing between bars to identify the bars
individually.The limitation of rebar locator instrument to identify bars, its diameter is that depth of rebar’s
from concrete surface should be less than to 70 mm depth & spacing of bars should be more than 150 mm.
Sample Visual Observations
• Chajjas are severely affected by corrosion.
• Severe corrosion cracks are developed in columns.
• Top level slab is severely affected by corrosion, cover of concrete has spalled down and steel is
exposed.
• Front side Chajja throughout the length of structure is severely affected by corrosion.
• Top level beams are affected by corrosion.
• Almost 100% columns in the top floor have corrosion related distress.

Inferences & Remedial measures
1. Polymer Modified Mortar Treatment
2. Jacketing to columns – Micro-concrete.
3. Recasting of Slabs/ Chajjas
4. Water proofing Treatment
Procedures for Repairs
Typical Procedure for Attending Structural Cracks & Damaged R.C.C. Members :
1. Erecting temporary Steel props in required position, prior to R.C.C. restoration, to relieve partial loading
on the structure.
2. Carefully exposing the damaged plaster by plaster breaker or hammer & chisel.
3. Exposing the damaged RCC members namely columns, chajjas beams wherever found loose including
cleaning the rusted reinforcement with light tapping, wire brushing.
4. Passivating the cleaned reinforcement with rust passivator.
5. Applying protective coating to the rust passivated reinforcement from approved suppliers.
6. Applying bonding coat to the entire surface (after watering the surface) to a creamy consistency or from
approved suppliers.
7. Applying polymer modified cementious mortar to the damaged R.C.C. members (with 10mm cover to
the reinforcement) in the proportion suggested by approved suppliers.
OR
8. Strengthening and repairing of damaged R.C.C. members namely columns, beams & slabs by “Building
up” “with Form work” by using MICRO CONCRETE.
OR
9. Jacketing
The Existing columns of any size to be Strengthened by means of jacketing up to the Top of footing, top &
bottom of beam/slab or up to the level as per site conditions only required parts of the walls near columns
shall be broken carefully for shuttering purpose. The damaged concrete & reinforcement shall be treated.
Note : This is only a guideline. The strengthening should be carried out in consultation with suppliers’
requirements and specifications and involving an experienced PMC Engineer.
Typical Procedure for Attending Plaster Cracks :
Waterproofing Treatment for External Surface – Treating Plaster Cracks :

1. Clean the cracks so as to be free from dust.
2. Moisten the surface with water.
3. Filling the cracks with special crack fill approved supplier material.
4. Applying 2 coats of Polymer Coating mixed with water or as per approved supplier instructions
a) Apply first coats of Polymer.
b) After one day interval apply second coat.
c) Sprinkle curing 2 to 3 days.
Note: This is only a guideline. You may use materials from any of the approved suppliers’. The Procedure
should be carried out in consultation with suppliers’ requirements.
Typical Procedure for Replaster of damage portion / Loose Plaster :
1. To identify the loose plaster pockets.
2. Breaking / dismantling the loose plaster pockets.
3. To apply jet of water and clean the opened loose plaster surfaces.
4. Hacking the joints and filling with cement mortar and curing for brick masonry.
5. Apply one coat of cement slurry for old brick masonry.
6. For R.C.C. Members – column, beam, slab, chhajas, pardi etc. apply bonding coat from approved
suppliers.
7. Apply two coats (12mm + 8mm) water proof plastering in CM 1:4 for external surfaces of walls.
a. Apply first coat of plaster 12mm thick
b. Curing 3 days after first coat.
c. Apply second coat of plaster 8 mm thick or match the existing plaster.
d. After second coat of plaster curing is required minimum 7 days.
Note: This is only a guideline

Approved Licensed Structural audit of old and dilapidated buildings in Mumbai Thane Navi Mumbai India

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Approved Licensed Structural audit of old and dilapidated buildings in Mumbai Thane Navi Mumbai India

Similar to Approved Licensed Structural audit of old and dilapidated buildings in Mumbai Thane Navi Mumbai India (20)

Recently uploaded

Recently uploaded (20)

Approved Licensed Structural audit of old and dilapidated buildings in Mumbai Thane Navi Mumbai India