p14+ +mufid+al+samerai+ +presentation.unlocked

8/22/2019 P14+ +Mufid+Al+Samerai+ +Presentation.unlocked

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Prof. Mufid Samarai

Sharjah Research Academy

Sharjah, UAE

ASSESSMENT AND REPAIR OF BUILDING ANDBRIDGES


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PART ONE

The Concrete Equation

Deterioration of Concrete Structures

Durability Issues Effect of Materials

Deleterious Substances

Corrosion of Reinforcement Exercise


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Materials / Prof.Mufid Samarai

Raw Materials

Cement + Water+Fine Agg. +

Coarse Agg. +AdmixturesMixing + Transportation + Placing +

Finishing + Curing

Manufacture+

Equat ion o f Con crete

Cement+Water+Fine Agg.+Admixture+Mixing+Transportation+Placing+finishing+curing

Strength+Durability+Impermeability+Pleasant Appearance+ Utility+Insulation+Resistance toChemical Attack+ Resistance to Vibration

Product


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IMPORTANCE OF QUALITY CONTROL

It is vital to educate the industry and society to the importance of quality

control and quality assurance and to realize that the additional cost andeffort spent on quality is a greater saving in the long run.

Good construction is always cheaper than poor construction

It is a known fact that you seldom improve quality by

cutting cost, but you can often cut cost by improving

quality.


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Failure of Concrete and Concrete Structures:

There are many causes for the failures of concrete and concrete structures and in most

cases it does not mean complete collapse of the structural element, but that it is no longer

,in a proper way, serving the purpose for which it was designed. It is believed that the

most common causes of failure and the percentage of its occurrence are as follows:

Damages due to Compounds of concrete 40%

Damages due to manufacture of concrete 22%

Damages due to structural design 12%

Damages due to excessive loads 8%

Damages due to foundations 7%

Damages due to fire, etc. 4%

Damages due to collapse of structure 5%


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The problemTypes of Deterioration


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Deterioration & Corrosion

Corrosion is the gradual destruction of material, usually metal,

by chemical reaction with its environment.

Causes:

1. Design Failure

2. Physical Damage

3. Poor Workmanship

4. Structural Movement


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The problem Construction DefectsFeature Cause Effect

Co lour

variations

Variable aggregates Inclusion of

contaminants or deleterious particles

Variable surface texture of theformwork

Staining from formwork

Sugars in some plywood formwork

Uneven curing

Generally only a cosmetic problem

Step in the

surface

Incorrect alignment of formwork

Movement of formwork

Generally a cosmetic problem, but may lead to reduced cover to

reinforcement and long -term durability problems

Blowholes Air trapped against the formwork Slight local reduction in cover to reinforcement, depending on

the blowholes size, but Generally cosmetic problem,only needs to

be filled if filmforming protective coating is to be applied

Honey combing Inadequate aggregate grading and/or

poor compaction

Significant local reduction in the protection to the reinforcement,

could lead to less of effective concrete section

Grout loss Inadequate section of formwork Significant local reduction in the protection to the reinforcement,

Sand runs on

vertical surface

Excessive bleeding Generally a cosmetic problem, but may lead to reduced cover to

reinforcement and long -term durability problems. (May also

indicate plastic settlement cracks on horizontal surface

Scaling Movement of the formwork after

compaction thus removing support

Cosmetic problem only

Staining Rust on formwork before casting:

corrosion pre-duets from elsewhere

(e.g. starter bars that have been

exposed for a period)

Failure of curing membrane to break

down

Cosmetic problem only


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Factors affecting durability

Internal

Causes

Weathering Chemical Action Wear

Freezing

&

Thawing

Moisture

VariationInorganic

SaltsAcids TrafficWindWater

Alkali-

Aggregate

Reaction

Volume

Changes

Permeably

&

Absorption

External

Causes

Temper-

ature

variation


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Effects of Deterioration & Corrosion

1. Frost Attack

2. Chemical Attack

3. Carbonation

4. Alkali-Silica Reaction

5. Chloride Attack

6. Freezing and Thawing

7. Abrasion-Erosion Damage


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Specifying for durable concrete

1. Classification of exposure condition

2. Emphasis on low permeabilty - via

Concrete cover

Mix constituents

Compaction

Curing

3. Specific requirements - eg

Sulphates

Chlorides

ASR

Abrasion

Freeze/thaw


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Adequate cover Adequate cover over the reinforcing steel ensures that

the diffusion of aggressive species to the steel level isdelayed. Rasheeduzzafar et al. (1986), based on their

field and laboratory studies, have recommended a safe

cover for reinforced concrete structures exposed to

various aggressive environments of the Arabian Gulf, as

given below:

Exposure conditions Recommended cover

thickness (mm)

Building components which are permanently exposed to the salt-

laden corrosive atmosphere

50

Building components which are protected against weather and

the aggressive conditions of exposure

25 to 38

Concrete components exposed to seawater and footings as well

as other main structural members cast against the ground

75


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Cube compacted& cured in astandard way

"LABCRETE"

Zone of much poorer

quality concrete

Zone of poorerquality concrete

Zone of poorerquality concrete

Zone of generallyhigher quality

concrete"HEARTCRETE"

"COVERCRETE"

Cross section of a beam

"SITECRETE"

The various "CRETES" according to Dewar


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Durability of RC structures

The durability of a reinforced concretestructure can be related to its permeability

to liquids and gases

an increase indurability can normally be achieved by areduction in the water/cement ratio, which

reduces both the level and size of capillarypores.


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Typical Local Specification for Durability

Parameters.

Test Method Limits

WaterAbsorption-BS 1881 part122

Maximum2% at 28days

WaterPermeability- DIN 1048

Maximum10 mmat 28days

Rapid Chloride

Permeability(RCP),ASTMC1202

Maximum

2000coulombs at 28days


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The problem - Materials

Aggregates ( Coarse & Fine) : contaminated

salty aggregates leads to corrosion of steel,unsound ones leads to deterioration of concrete

and poorly shaped aggregates (Flaky or

elongated) require more water to produce

workable concrete. Other aggregates relateddeterioration:

Aggregates Shrinkage and Swelling

Aggregates Softening

Alkali-Silica Reaction

Contaminated water: used in mixing and

curing causes corrosion of reinforcing steel.


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Admixtures

concrete mixtures incorporating fly ash, silica fume,or fine cements frequently have a low to negligiblebleeding rate, making such mixtures highly sensitiveto surface drying and plastic shrinkage, even under

moderately evaporative conditions (ACI 234R).

Certain admixtures increase the time of initial settingor reduce the amount of water needed for a giveninitial slump or both, but such concretes may stiffen

faster, sometimes too fast even for a cement and anadmixture that separately meet all specifications ,


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pulverized-fuel ash (PFA)

ground granulated blast furnaceslag (GGBS).

condensed silica fume (CSF)

metakaolin (MK)


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Descriptions and Code of practice Advantages Disadvantages

1. The Intrinsic Properties of Concrete1-1. Mix Design PropertiesCement Type(ASTM 150)

Type 1 OPC Isolate steel to avoidattack by chloride

Spoil by sulfateexposure

Type 11 MSRC Isolate steel to avoidattack by chlorideSulfate resistance

5 < C3A< 8

Type III R.H.C For cold weather Not fit in UAEenvironment

Type IV LH.C. For Mass concrete Spoil by sulfateexposure

Type V SRC Sulfate resistance Unable to stopChloride attack

1-2. Cement dosage(variable as to structural design)

300 550 Kg Low permeability Higher heat ofhydration

1-3. Free Water Cement Ratio(DIN 1048 30mm to 60 mm BS5328)

0.36 up to 0.5 Low permeability Low workability

1-4. Use aggregate and dune with lowSO3, Mg2O3 & Acids content, (BS5328)

Not always available

2. Good workmanship

Temperature control, Slump Control,Smooth finish, Preventing watervaporization, (BS 5328)

32o int. 45o ext.

3. Proper vibration(BS 5328)

Avoid honeycombs toreduce air void aspossible stopsegregation

4. Proper curing Prevent sulfate cracksReduce shrinkage

5. Concrete cover Increase as possible Protection for steel

Table : Intrinsic Durability-Enhancing Measures of Concrete in the Region.


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BS8007, CIRIA 91 and

Concrete Society Digest 2 Gross simplification

Not always safe

Crack control not

prevention

(Water retaining

structure designed to

BS 8007)


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Concrete with a waterpermeability coefficient

of not greater than 1x10-

12m/s and with amoderate to high

sulfates resistance

binder (ASTM C1157M)is recommended .

REMARKS


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Durability of ConcreteComponent(s

Descriptio Cause Involve Sympto

Alkali-aggregat Reaction of siliceou Aggregate Coarse "map-crackingaggregates by alkali with viscous flui

ion eruptin

Sulfate attac Reaction of past Paste General cracking an

components wit softenin

sulfate

Acid attack Dissolution by acid Paste (aggregate) General etching o

surfac

Rebar corrosion Rusting of ste Reinforcement Cracks with rust staabove location o

reinforcement

Frost attack Freezing of water i Paste General scaling an

pores spalling at surfac

D-crackin Freezing of water i Aggregate Fine crack patter

pores roughly parallel t

joints in pavemen

Fire damag Decomposition o Paste (aggregate) Cracking and spallin

hydration products an

development of intern

stresses

Thermal cracking Internal stresses fro Paste (aggregate) Localized crackin

Shrinkag restraine

contraction

D R ti RILEM TC 104


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Damage Rating as per RILEM TC 104Damage Damage rating

1( very slight) 2( slight) 3(moderate) 4(severe) 5(very servere)

Cracks in

unreinforcedconcrete

Width 10mm with

spalling

Plastic shrinkage

or settlement, early

thermal

contraction or

drying shrinkage

cracks

Single short

crack

Several

short

cracks

Many short

cracks

Few long cracks Many long cracks

Effects of

reinforcement

corrosion

Individual

narrow cracks

along lines of

bars

Several

narrow

cracks

along lines

of bars

Wide cracks

with edge

spalling or

hollow areas

Many Wide cracks,

some loss of

concrete by

spalling

reinforcement

visible and heavily

corroded

Complete loss of

cover concrete

protruding

Reinforcement,

substantial loss of

reinforcement section

Pop-outs Three-legged

cracks

Pop-outs

barely

noticeable

Pop-outs

noticeable

Holes30mm in

diameter

Surface weathering

or erosion

Barely

noticeable

Clearly

noticeable

in patches

Continuous

weathering

over

area10mm deep


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CHLORIDES Penetration of the chlorides starts at the surface, then

moves inward. The rate of penetration is governed by the

following factors: a) The amount of chlorides coming into contact with the

concrete,

b) The permeability of the concrete, and

c)The amount of moisture present.

Eventually, the concentration of chlorides in contact with

the reinforcing steel will cause corrosion when moistureand oxygen are present.

As the rust layer builds, tensile forces generated byexpansion of the oxide cause the concrete to crack anddelaminate.

Spalling and delamination occur if the natural forces ofravit or traffic wheel loads act on the loose concrete.

cracking overmain steel

tell-tale ruststaining


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Chloride Diffusion shall be Documented- Deterministic Approach

A (10C)

Cs=1.0%

Ccr=0.1%

n=0.30

t0=28 days

D0=1010-13 m2/s

B (30C)

Cs=1.0%

Ccr=0.1%

n=0.30

t0=28 days

D0=4010-13 m2/s

0

0,2

0,4

0,6

0,8

1

1,2

0 20 40 60 80 100 120

Distance from surface [mm]

Northern Europe

Middle East

Critical concentration

34.1 68.20

0,2

0,4

0,6

0,8

1

1,2

0 20 40 60 80 100 120

Distance from surface [mm]

Chloride concentration [%]

Northern Europe

Very hot climate

Critical concentration

34.1 68.2


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Evaluation

Carbonation

tKD CR

Where

D: Depth of carbonation (mm)

KCR: Rate of carbonation mm/yr1/2

t: Service Life in Years

42.0

22.15.2

KR

St

Wheret: Service Life in Years

S: Concrete cover in mm

R= w/c ratio

K: Cl- Content of exposure

solution in PPM

Evaluation

Chloride

Time for carbonation to reach


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Time for carbonation to reach

reinforcement (years)

External concrete sheltered from rain

coverw/c

10 mm 30 mm

0.7

0.5

5 45

15 135


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Enhancements to Chlorides

For structures exposed to chlorides the following enhancementscan be considered (Walker , 1998, 1999 & 2000). Note, that some

of these measures are also useful in offsetting carbonation. 1. Addition of surface treatments or coatings to prevent ingress.

2. Addition of corrosion inhibitors to the concrete mix to reduce theaction of chloride.

3. Addition of coatings to reinforcement to protect its surface.

4. Use non-corroding reinforcement such as stainless steel orpossibly fibre composite materials.

5. Catholic protection

6. Where structurally possible use unreinforced concrete.

note:expansivenature ofcorrosion

Sulfate Attack


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Sulfate Attack

The presence of sulfates in soil and ground waterhas long been a source of attack of concretebelow ground. In hardened cement, calciumaluminates hydrate can react with sulfate salts toproduce a sulphoaluminate some 27% larger in

volume than the solid phase, resulting in gradualdisintegration of the concrete.

Concrete with a water permeability coefficient ofnot greater than 1x10-12 m/s and with a moderateto high sulphate resistance binder (ASTMC1157M) is recommended

.


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sulphates

What is Corrosion of Steel?


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The electrochemical nature of corrosion

anode

+ve

cathode

-vecathode

-ve

What is Corrosion of Steel?

the chemical or electrochemical reaction between a material,usually a metal, and its environment that produces adeterioration of the material and its properties.


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Why is Corrosion of Steel a Concern?

When reinforcement corrodes, the formation ofrust leads to a loss of bond between the steeland the concrete and subsequent delaminationand spalling. If left unchecked, the integrity of

the structure can be affected.

Rust has a substantially higher volume than steel-theoretically

up more than six times greater, depending on oxygen

availability

Stages in Reinforced Concrete Degradation


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Stages in Reinforced Concrete Degradation

Degradation of reinforced concreteoften happens in the following fourstages:

Stage 1: Initially, the concrete appearsto be sound with relatively littlemacroscopic cracking and no reddishdiscoloration from corrosion productformation.

Stage 2: Macroscopic cracks haveappeared and the concrete surface isstained by reddish corrosion products.

Stage 3: Spalling of the concretecover over the reinforcing steel is

clearly visible, due to the formation ofvoluminous corrosion products,

Stage 4: Severe spalling of theconcrete cover over the reinforcingsteel is evident, leaving thereinforcing steel bars directly exposed

to the atmosphere.


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2. Propagation

Corrosion of Reinforcement

1. Initiation

Carbonation Chlorides

Carbonation and chlorides


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Cracking

Why Does Steel in Concrete Corrode?

Rust

Reinforcing Steel

Carbonated zone


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When concrete carbonates to the level of the steel rebar, thenormally alkaline environment, which protects steel fromcorrosion, is replaced by a more neutral environment. Underthese conditions the steel is not passive and rapid corrosionbegins.

Cement Matrix

Carbonated Zone

Steel

Rust


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When chloride moves into the concrete, it disrupts the passive

layer protecting the steel, causing it to rust and pit.


Corrosion Process


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Type of Damage

Transverse cracking

Spalling of concrete

Corrosion inducedlongitudinal cracking

Delamination

Rust and staining Loss of integrity


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Good surface finish Curing

CementAggre-

gateWater

Mixing

Placing Compaction Form_workTempe-

rature

Min.

Moisture

Loss

Quantity

Air entraining

Admixture

Factors that improve

durability

Suitable materialsHomogeneous

Concrete

Workabiliy

Factors that improve

Durability


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Design Strategies for Durability

Avoid or prevent degradation

Reduce environmentalloading

Non reactive aggregate(AAR)

Non-corrodingreinforcement

Cathodic protection

Air entrainment

Service life design

Select the materialcomposition and detailingto resist identifieddegradation risks for aspecific period of time

Multi-Stage ProtectionStrategy


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PART TWO


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PART TWO

Evaluation of Concrete Structures

Types, causes and evaluation of Cracks Non-Destructive tests Maintenance types and Procedures Exercise


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The 3-Stage

Process

Leadingto repair

Investigation

Investigation- Preliminary Survey


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Investigation Preliminary Survey

It is a walk around structure & consists of:

Familiarization with type and extent ofdeterioration

Collecting samples of loose concrete or

lumps that can be easily pulled out

Plan access to hidden areas

Set safety requirements

Equipment required: notebook, camera,measuring tape, hammer, binoculars,

original drawings, papers marked with

grid for sketching

Investigation- Preliminary Inspection


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Investigation Preliminary Inspection

Its objective is to develop an initial of the most

likely causes of deterioration. It mainly consists of

inspecting :

Cracks: location, type, orientation, width and

Length, (To make cracks more visible, spray

concrete with water and avoid noon hours)

Deterioration (spalling, pop-outs, discoloration)

Leaks, damp patches or lime-scale

Reinforcement corrosion

Previous repairs

Location and condition of joints

Condition of any Bearings

Sample of Preliminary inspection Form


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Sample of Preliminary inspection Form

Diagnostic techniques


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Diagnostic techniques visual assessment

Delamination -hammer/chain

covermeter - presence ofreinforcement

chloride analysis

phenolphthalein test for

carbonation half cell measurements to

ASTM C876

resistivity

corrosion rate (linearpolarisation)

permeability

ultrasonics

petrography

radar


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EVALUATION OF RESULTS

Correlation differences between the laboratory conditions and site conditions can vary, and this can affect the

accuracy of our calibration

The variability of the particular test method, the operator skill and the variability of the concrete under

test, control the accuracy with which test results can be calibrated against a particular desired concrete

property

Member

type

Typical 28-day in-situ equivalent

wet cube strength as % of standard

cube strength

Average Likely range

Column 65% 55% - 75%Wall 65% 45% - 95%

Beam 75% 60% - 100%

Slab 50% 40% - 60%

Material Control

and construction

Assumed std.

devn. of control

cube(s)(N/mm2)

Estimated std.

devn. of in-situ

concrete (s )

(N/mm2

)Very good 3.0 3.5

Normal 5.0 6.0

Low 7.0 8.5



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Tests have well-defined procedures and the methods used for the calculation and assessment of different

parameters from directly measured values will depend to a large extent on the test method used

Variation in properties of hardened concrete tend to be random and requires that the results be analyzed usingvarious statistical tools such as graphical and numerical methods

The number of test types, location and points used has a

significant bearing on the ease with which the variability of

concrete within members and between members can be

assessed.

Test method

No. of individual reading

recommended at a location

Standard cores 3

Small cores 9

Schmidt hammer 12

Ultrasonic pulse

velocity

1

Internal fracture 6

Windsor probe 3

Pull-out 4

Pull-off 6

Break-off 5

Test method

Typical COV forindividual member of

good qualityconstruction

Best 95% confidence limitson strength estimates

Cores standardsmall

10%15%

10% (3 specimens ) 15% ( 9 specimens )

Pull-out 8% 20% ( 4 tests )

Internal fracture 16% 28% ( 6 tests )

Pull-off 8% 15% ( 6 tests )

Break-off 9% 20% ( 5 tests )

Windsor probe 4% 20% ( 3 tests )

Ultrasonic pulse velocity 2.5% 20% ( 1 test )

Rebound hammer 4% 25% ( 12 tests )

introduction


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introduction While concrete look nice when they are new, over time the concrete can chip, crack

and crumble.

Cracks and potholes form due to the freezing and thawing of water that has seeped

through smaller cracks, weed or grass growth in small cracks, and general wearand tear.

Regular maintenance will prevent this problem.

This is usually easy to do and requires up to a half day to complete depending onthe condition and size of your repairs.


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Types

ofCrack

s

External

Restraint

TYPES

OF

CRACKS

BEFORE

HARDENING

AFTER

HARDENING

CONSTRUCTIONAL

MOVEMENT

PLASTIC

EARLY FROST DAMAGE

PLASTIC SETTLEMENT

PLASTIC SHRINKAGE

FORMWORK MOVEMENT

SUB-GRADE MOVEMENT

STRUCTURAL CREEP

DESIGN LOADS

ACCIDENTAL OVERLOAD

THERMAL

FREEZE / THAW CYCLES

EXTERNAL SEASONAL TEMPERATURE VARIATIONS

EARLY THERMAL CONTRACTION

Internal

Temperature

Gradiets

CHEMICAL

CORROSION OF REINFORCEMENT

ALKALI-AGGREGATE REACTIONS

CEMENT CARBONATION

DRYING SHRINKAGE

CRAZING

SHRINKABLE AGGREGATES

PHYSICAL


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Plastic

settlement

Plastic

shrinkage

Plastic shrinkage

Corrosion

Early

thermal

contraction

Alkali-silica

reaction

Crazing

Shear

cracks

Long term drying

shrinkage

Tensio

nbendin

g

cracks

Types of Cracking


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Structural cracks

Types of Cracking1. Structural cracks

2. Non structural cracks or Intrinsic cracks

Non Structural Cracks


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Non Structural Cracks Intrinsic or non structural cracks are attributable to chemical

or physical changes taken place within concrete.

The classification of intrinsic cracks might enable designersand contractors to take measures which will either preventor control these cracks.

Reinforcing bars

Intersecting cracks

Coincident cracks

Cl ifi ti f k


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Classification of cracks

Cracks maybe separated into two classes forthe purpose of deciding upon the type ofrepair.

a) dormant cracks .

1) fine cracks:2) wide cracks:

3) fractures :

b) live cracks.


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The problem Cracking occurring during Construction

Plastic Shrinkage Cracks

Plastic Settlement Cracks

Type of defect Typical time of appearance

Plastic settlementcracks Ten minutes to three hours

Plastic shrinkage

cracks

Thirty minutes to six hours

Construction defects On removal of formwork

Crazing One to seven days-sometimes

much later

Early thermal

contraction cracks

One day to two or three

weeks

Longtern drying

shrinkage cracks

Several weeks or months

Chemical attack

(including sulfate

attack)

Few months up to Several

years depending on nature of

the materials

Damage due to

temperature

movement (seasonal)

Probably up to a year ,but

may be longer

Alkali-silica reaction Several years

Reinforcement

corrosion

Several years, but may be

much shorter

Plastic Shrinkage Cracking


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Plastic Shrinkage Cracking

The probability for plastic-shrinkage cracks

to occur may be increased if the setting time

of the concrete is delayed due to the use ofslow-setting cement, an excessive dosage of

retarding admixture, fly ash as a cement

replacement, or cooled concrete

Surface drying is initiated whenever the

evaporation rate is greater than the rate

at which water rises to the surface of

recently placed concrete by bleeding .

concrete mixtures incorporating fly ash, silica

fume, or fine cements frequently have a low to

negligible bleeding rate, making such mixtures

highly sensitive to surface drying and plastic

shrinkage, even under moderately evaporative

conditions (ACI 234R).

231

0.0

0.8

0.2

Crack width and corrosion


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Crack width and corrosion

There is arelationship

between the

crack width and

corrosion of

steel.

Surface

crack

width(mm)

Average

depth of

corrosion(mm)

Average

corroded

length(mm)

0.13 0.16 9.2

0.25 0.16 12.9

0.51 0.18 12.8

1.27 0.21 15.0 >0.05

0.1

0.4

1.0

0.5

1.5

Reducing cracks


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Reducing cracksCracking in con crete can be reduc ed signi f icant ly or el iminated b y obs erv ing the

fol lowing pract ices:

Use prop er subgrade preparat ion, inc luding u ni form s upp ort and propersubb ase mater ia l at adequate moistu re con tent .

2. Minimize the mix water content by maxim iz ing the size and amou nt ofcoarse aggregate and use low -shr ink age aggregate.

3. Use the lowest amou nt of m ix water required for w orkabi l i ty ; do n otpermit over ly wet consis tencies.

4. Avo id calcium chlor ide admixtu res.

5. Prevent rapid loss of su rface moisture w hi le the concrete is st i l l plast icthroug h us e of spray-appl ied f in ishin g aids or plast ic sh eets to avoidplast ic-shr ink age cracks.

6. Provid e contractio n jo ints at reasonable intervals, 30 times the slabth ickness.

7. Provide isolat ion jo ints to prevent restraint from adjo in ing elements ofa structure.

8. Prevent extreme changes in temperature.

9. To m inimize cracking on top of vapo r barr iers, use a 100-mm thick (4-in.) layer of sl ight ly damp , compact ib le, drainable f i l l choked o ff wi th f ine-grade mater ial . If co ncrete mus t be placed direct ly on polyethylene sheetor other vapor barr iers, use a mix with a low water content .

10. Pro er l lace conso lidate fin ish and cure the concrete.

Testing- Scope and Guidance


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Testing- Scope and GuidanceTesting is performed in order to obtain sufficient

information on the condition of the deteriorated

structure so that the appropriate remedial repairmethod is implemented. The sampling rate, type

and location of tests shall include:

Different elements (Columns, beams, Slab)

Typical deteriorated areas

Typical Non-deteriorated areas

Areas with Different exposure conditions

Previously repaired areas

NO TESTS SHALL BE CARRIED OUT UNLESS IT IS

KNOWN WHAT THE RESULTS WILL BE USED FOR

Testing Types of Tests & Location


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Location: Concrete on top layer tends to be weaker than the

bottom one- well distribution shall be maintained

ASSESSMENT OF PROPERTIES


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Property under

investigationTest Equipment type

Corrosion of

embedded steel

Half-cell potential

Resistivity

Linear polarization resistance

Cover depth

Carbonation depth

Chloride concentration

Electrochemical

Electrical

Electrochemical

ElectrochemicalChemical/microscopic

Chemical/electrical

Concrete quality,

durability and

deterioration

Surface hardness

Ultrasonic pulse velocity

Radiography

Permeability

Absorption

Petrographic

Sulphate content

Air content

Abrasion resistance

Mechanical

Electromechanical

Radioactive

Hydraulic

Hydraulic

Microscopic

Chemical

Microscopic

Mechanical

Concrete strength

Cores

Pull-out

Pull-off

Break-off

Penetration resistance

Maturity

Mechanical

Mechanical

Mechanical

Mechanical

Mechanical

Chemical/electrical

Integrity and

performance

Pulse-echo

Acoustic emission

Thermoluminescence

Thermography

Radar

Reinforcement location

Strain or crack measurement

Load test

Mechanical/electronic

Electronic

Chemical

Infra-red

Electromagnetic

Electromagnetic

Optical/mechanical/electrical

Mechanical/electronic/ectrical


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TYPES OF TESTS Destructive tests:

These conventional methods enable thestrength of the concrete to be measured byway of cores or cubes cut from the concrete.However, this is not possible in all cases andespecially not for slender members.

Non-destructive tests:

By definition, the strength properties arenot measured directly so some otherproperties are measured and the strengthestimated by calibration. Naturally, thesemethods have the great advantage thatconcrete is not damaged. For example: Ultra-sound test and Schemed Hummer Test.

Partiall y destructi ve tests:

In these tests, the concrete is tested tofailure but the destructive resulting is verylocalized and member under test is notweakened to any significant extent Forexample Core test. .



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Testing Types of Tests & LocationDirect: equipment gives direct result for property

being tested

Indirect: the required property is determined

indirectly

Qualitative: Test will not yield quantitative results

A Range of Techniques used for the Non-DestructiveTesting of Concrete


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surface

absorption

of water

Indentation Rebound

surface

hardness

surface methods

pulse

velocity

shock waves

pulse

attenuation

ultrasonic

pulse

propagation

damping

capacity

torsional longitudinal

damping

capacity

flexural

Resonance

Vibration methods

Radiography

x-rays rays

Absorption Back -Scater

Radiometry

Neutrons

Radio acive methods

Magnetic

steel

detection

Microwave

absorption

Dielectric

Conductivity

Electrical

methods

Non-destructive testing of concrete

Testing of Concrete

Testing Types of Samples


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Testing Types of Samples

Lump Samples: They are broken small pieces from the

structure good for visual examination and chemical

testing.Cores: are cylindrical shape samples cut by a drill with

hallow barrel tipped with industrial diamond bit. Core

diameter for compressive strength can be either 100, 120,

or 150 mm

Dust Samples: are obtained

directly from structures using

hand held rotary drills and

dust is collected via a shroud

around the bit or by skewedtube connected to a plastic

bag as shown in the adjacent

figure

Testing - Sampling


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Testing SamplingFor elements that contain chloride, it is suggested

that 10 % of each elements (Col, Beams, slabs) to

be tested with a minimum of 3 from each type.

The Building Research Establishment, suggests

the following:

Classification of Various Test Methods


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Destructive tests.

These conventional methods enable the strength of the concrete to be measured by way of cores or cubes cut

from the concrete. However, this is not possible in all cases and especially not for slender members.

Non-destructive tests.

By definition, the strength properties are not measured directly so some other properties are

measured and the strength estimated by calibration.

Naturally, these methods have the great advantage that concrete is not damaged

Partially destructive tests.

In these tests, the concrete is tested to failure but the destructive resulting is very localized

and member under test is not weakened to any significant extent

Ultrasonic Pulse Velocity


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Ultrasonic Pulse Velocity

The ultrasonic pulse velocity technique is based on the ability to measure the propagation velocity of a pulse of

vibrational energy which has passed through a concrete medium.

Knowing the direct path length between the transducers, and the time of travel, the pulse velocity through the

concrete can be obtained.

Property under

investigationTest

Corrosion of

embedded steel

Half-cell potential, Resistivity, Linear

polarization

Cover depth, Carbonation depth

Concrete

quality,

durability anddeterioration

Surface hardness, Ultrasonic pulse velocity

Radiography, Relative humidity,Permeability,

Absorption, Sulphate content.Expansion, Air

content ,Cement type and content,Abrasion

resistance

Concrete

strength

Cores, Pull-out, Pull-off, Break-off

Penetration resistance, Maturity

Integrity and

performance

Pulse-echo, Dynamic response, Radar

Acoustic emission, Thermography

Strain or crack measurement, Load test

V= L / T

Where:

V=Pulse velocity

L= Path length, mm

T= effective time, microsecods

IN-SITU Testing


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IN SITU Testing

Half Cell potential: It measures the electrical

potential on the surface of steel to qualitatively

estimate the its likelihood of corrosion.

Potential P

( mV)

Risk of

corrosion

P > -200 mV 5 %

-350< P< -200 50 %

P< -350 95 %

Half Cell Potential


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Half Cell Potential

BS 1881

PurposeTo determine the risk ofcorrosion in reinforcement.

Results Range

Our results

They range between -200 and -300mV, then we conclude thatthere is 50% risk of corrosion

Concrete Chloride Content


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Concrete Chloride Content

bS 1881

PurposeInspect corrosion of reinforcement

Result Ranges

Not to exceed

Max. Chloride content = 0.4% by weight of cementfor reinforced concrete, InGulf only allow for 0.3%.

= 0.1% by weight of cement

for prestressed concrete Our Results

Ranges between 0.04% and 0.1%

TESTING OF CONCRETE


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METHOD STANDARDS PRINCIPLE

FEATURES

ASTM BS 1881

Rebound

hammer

C805 Existing

concrete,best

used

comparatively

Pull out C900 207 Existing

concrete , high

variability

Pull off 207 Existing

concrete

surface orpartially cored

Break off C1150 207 New

construction or

Exsisting

concrete

IN-SITU Testing


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Surface Hardness: Rebound (schmidt) hammer: used

to indirectly asses the strength of Concrete

Near Surface Strength: used to asses the strength ofconcrete near surface

1) Pull out Test 2) Capo (Cut and Pull-out)

3) Pull off Tests 4) Break off Tests

5) Penetration Resistance

Ultrasonic

Pulse Velocity

Test: used to

assess variationin the strength

and presence of

Void,

Honeycombs Direct IndirectSemi-Direct


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correlation between the pulse velocity & cube compressive

strength

20

22

24

26

28

30

32

34

36

38

40

4.7 4.8 4.9 5 5.1 5.2 5.3 5.4

Pulse KM/s

C

ompressiveStrength(N/mm2)

Maintenance Management System


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Maintenance Management System

Policy & Resources

Committee

Property

Department

Architects Quantity Surveyor

Engineers BuildingMaintenance

Area surveyor

Senior surveyor

Surveyorstechniciansinspectors

Valuers Rural Practice

Maintenance is a combination of any actions carried out to retain an item

in ,or restore it to an acceptable condition


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The maintenance of structures is done to meet thefollowing objectives:

Prevention of damages and decay due to natural

agencies to keep them in good appearance andworking condition.

Repair of the defects occurred in the structure andstrengthen them if necessary.

i f i


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Necessity of MaintenanceThe maintenance of structures is done to meet the

following objectives: Prevention of damages and decay due to natural

agencies to keep them in good appearance andworking condition.

Repair of the defects occurred in the structure and

strengthen them if necessary. MAINTENANCE is a combination of any actions

carried out to retain an item in ,or restore it to anacceptable condition


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Types of Maintenance1. Routine Maintenance (Cyclic Maintenance)

2. Preventive Maintenance (Scheduled maintenance.

3. Corrective Maintenance (Emergency maintenance.)

R ti M i t


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Routine Maintenance

Its the service of maintenance attended to thestructure periodically.

It is done by the fund provided annually for thepurpose which is normally 1 % of the costof construction.

This is rendered to meet day to day problem ofnormal nature and includes the inspection,

planning the program and executing thesame.

It includes white washing, patch repair toplaster, replacement of fittings and fixtures,binding of road surface.

Preventive Maintenance


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Preventive Maintenance

The maintenance work done

before the defects occurred ordamaged developed in the

structure.

It includes through inspection,planning the program if

maintenance and exacting the

same.

It depends upon thespecifications, condition and

use of structure.


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It is the maintenance done after the defects or

damage occurs in the structure.

Corrective Maintenance:

Wh t t k ti


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Corrosion

0

0.5

1

When to take action

Relative

deterioration

Time to onset of corrosion

Time to first cracking

Time to first spalling

Time to failure

Time

A summary of a decision making process for investigating and assessing


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Routine inspection

Required as part of asset management systemAd hoc inspection because:

Evidence of cracking or spalling of concrete

Requirement for durability assessment of structure

Change of use or ownership

Initial assessment of current state of structure

Investigation, testing and durability assessment

(These can be different for individual elements of the structure)

Determine cause of deterioration and whether it is corrosion related

Determine degree of deterioration

Establish:

Intended use of structure

Design life of structure

Residual service lifespan

Required performance characteristics

Consider:

original design approach

Environment and contaminationConditions during construction

Conditions of use

History of structure

Identification of active deterioration mechanisms

Type A Type B Type C Type D

Carbonation Cast-in chlorides Ingressed chlorides Carbonation & Chlorides

Contributory

deterioration

mechanisms

Evaluation of deterioration

Establish cover depth

Establish chloride concentrations

Establish depth of carbonation

Establish condition of steel

Assess structural implications

Monitoring

Periodic Continuous

Modeling and prognosis

Future chloride concentrations

Future depth of carbonation

Future corrosion rate of steel

Detailed assessment of condition of structure or element

Choose repair and protection principle appropriate to type of durability deterioration process


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PART THREE

Purpose and Scope of Concrete Repair


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Purpose and Scope of Concrete Repair

Repairs are performed in various ways on concrete

structures in order to extend its service life

Time

Deterioration

End of Service Life

Initiation Period Propagation Repair Cycles


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Average chloride ion content by weight of cement (%)

4b 40 years-old concrete structures

Negligible

Low Very highHigh

Low Moderate

Moderate

High

Damp

environment

Dry

environment

Dry

environment

Damp

environment

0 0.60.4 0.80.2 1.51.0

Low Moderate

Moderate

High

Very High

Very high

Where the reinforcement is still

within the alkaline zone (pH>10)

Where the reinforcement is in

lower alkaline condition (pH


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Repair techniques


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The scope of repair works is summar ized as fo l low s:

Replacement of spalled areas

Sealing of cracks wider than 0.2mm

Application of Additional Cover

Protective Coating System to Concrete Surfaces

Waterproofing System

Bearings

p q

Materials for repair


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1) Resin mortars:

To resist a wide range of aggressive chemicals. Having the ability to cure under environmental

condition.

2)Epoxy mortars: In a well formulated epoxy mortar the shrinkage

can be as low as 20 micro strains.

3)Bonding coats: bonding coats are used to promote the adhesion of

the repair composition to the concrete substrate.

Details of specimens and test methods utilized to

determine the properties of resin based repair mortars


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Test methodNo. of

specimens

tested per

component

Property

ASTM C 308 [14]3Pot life

ASTM C 884 [15]3Rate of cure

BS 6319 part 4 [12]3Adhesion

ASTM C 579 [16] Method A6Compressive

strength

ASTM C 307 [17]6Tensile strength

ASTM C 580 [18]6Flexural strength

ASTM C 580 [18]6Elastic modulus

ASTM C 531 [11]6Shrinkage

ASTM C 531 [11]6Thermal expansion

ASTM C 1202 [13]3Chloride

permeability

ASTM C 267 [19]3Chemical resistance

determine the properties of resin-based repair mortars

Details of specimens and test methods utilized to determine the properties of bond coat materials.


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Test methodNo. of

specimens

tested per

componen

t

Property

BS 6319 part 4 [12]6Improvement in

bond

ASTM C 1202 [13]3Chloride

permeability

Non-standard3Carbonation

Non-standard3Electrical resistivity

Details of specimens and test methods utilized to determine the properties of steel primers.

Test methodNo. of

specim

ens

tested

percompon

ent

Property

ASTM D 4541 [21]3Adhesion to steel

Non-standard3Sensitivity to steel

cleaning

ASTM D 1654 [22]3Resistance to salt

exposure

ASTM G 78 [23]3Crevice attack

Non-standard3Resistivity

Details of specimens and test methods utilized to determine the properties of surface coatings.


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Specimen sizeTest methodNo. of

speci

mens

tested

percomp

onent

Property

62x 100 x 300 mm (concrete)ASTM D 4541 [21]3Adhesion

25x 25 x 250 mm (mortar)Non-standard3Crack bridging

75mm dia and 50 mm high (concrete)Non-standard3Chloride diffusion

50mm dia and 72 mm high (mortar)Non-standard3Moisture resistance

150x 150 x 150 mm (concrete)DIN 1048 [24]3Water permeability

50mm dia and 72 mm high (mortar)Non-standard3Carbonation

resistance

25x 25 x 25 mm (mortar)ASTM C 267 [19]3Chemical resistance

Sealers and Concrete Surface Coatings


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Environment Preferred concrete surface treatment material

CO2 Silane/siloxane with acrylic topcoat; acrylic coating

Sulfate Silane/siloxane with acrylic topcoat

Chloride Silane/siloxane with acrylic topcoat; silane; acrylic coating

Purpose Suggested coating

Cement-based Resin-based

Moisture barrier Polymer-modified cement Epoxy resin

Chloride barrier Epoxy-modified cement Epoxy resin

Crack bridging Polymer-modified cement Epoxy resin

CO2 barrier Polymer-modified cement Acrylic or epoxy resin

Chemical resistance Polymer-modified cement Epoxy resin

Repair- Reinstatement with Mortar1 Breaking Out


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2- Cleaning The ExposedReinforcement & Substrate

1- Breaking Out

Spalled Concrete

3- Applying protective

Coating to exposed steel

4- Soaking or applyingBonding agent to substrate

6- Reinstatement with mortar

(Patching)

7- Curing

5- Install formworks for

slurry type mortar

Repair- Reinstatement with MortarTypical ShuttersMethods of


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Method

of fixing

anchors

Typical Shutters

For Repair

Methods of

Breaking concrete

Repair- Cathodic ProtectionIt is used to prevent or reduce corrosion rates It works by


99/123

It is used to prevent or reduce corrosion rates . It works by

connecting the metal reinforcement to another material which

is anodic in relation to the metal reinforcements. The metal

becomes a cathode and its corrosion is reduced. Twosystems are used:

Sacrificial anode: It consists of small

zinc, or magnesium blocks tie around

reinforcements at 50 to 75 cm. They aremore reactive than steel and reacts with

chloride faster.

Impressed Current System: Inert

material (mesh) connected to a DC

power supply so that the reinforcement

will stay protected in a cathode state

Re-Alkalization & CL- ExtractionRe-Alkalization is an electrochemical


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Re-Alkalization is an electrochemical

treatment for reinstating the passive

state around reinforcement. This is

achieved by passing an current thruthe concrete to then reinforcement

using an externally applied anode that

is attached to the concrete surface.

Chloride Extraction is anelectrochemical process for removing

corrosive chloride from concrete. It is

achieved by applying an electrical field

between reinforcement and an external

anode mesh. As a result Cl- are

transported towards the anode and outof the concrete. Also a high PH is

formed and protection of steel is re-

established.

Repair Other Techniques


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Coating:

Barrier Coating form a film on the surface Ex :Epoxy coating, Acrylic, Polyurethane and Polymer

cement coating

Pore Blocker: They are solvents that do not form a

film on the surface. Instead they penetrate thecapillary pores and block them via crystallization.

Pore liner: Also do not form a film on the surface.

They react with the silica in concrete to create a water

repelling compound.

Sealer: they form a film on the surface and also

penetrate the pores to block them.

Crack Injection: Resin is injected under

Repair Other Techniques


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Crack Injection: Resin is injected under

pressure through drilled holes that intersecting

the cracks in order to close these cracks and

prevent contamination from reachingreinforcement.

Corrosion Inhibitors:

Calcium Nitrate: they are added to concrete at the time of mixing

and reacts with the ferrous of the steel to make a passive stable

layer up to certain chloride concentration. They are usuallyapplied at a rate of 2 liters of Calcium nitrate / kg of Chloride

concentration per m3 of concrete.

Migrating Corrosion Inhibitors (MCI): Recently developed,

they follow the same principles of calcium nitrate but can be

applied on the surface of the concrete. It is claimed that they

migrate from the surface to the reinforcement to react with it and

form on its surface a monomolecular layer which displace any

chloride and protect the reinforcement from attack. Rate = 1l/m3

Repairing Techniques


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Repairing optionsNo repair Partial Repair full repair

Repairing process:Reinforcement Replacement

Concrete removalConcrete cleaning

Old reinforcement cutting and cleaning

Reinforcement Protection

Coupling systemIt is recommended for the deck slab due to limitation of space

Straight labs system

It is recommended for the wing wall

REPAIR METHOD (Galva shield )


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Can be used in corrosive environments includingchloride contaminated and carbonated concrete

Extends service life of patch repairs User-friendly and easy to install

Galva shield XP anodes provide localized corrosion

protection in reinforced concrete buildings andstructures. The palm-sized anode consists of agalvanic zinc core surrounded by an activecementitious matrix

The Benefits

Repair to spalled concrete


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Install structural supportingsystem as necessary.

Remove spalled concrete instages observing structuralrestrictions to a depth of50mm behind thereinforcement .

Delineate the area to a voidfeathering affects.

Welding new pars.

Apply epoxy coating to

provide adhesion toconcrete.

Apply replacement concreteof cementations mortar.
http://www.vseal.com/surfacedefects/spalling.php


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Repair ing c racks


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Repair ing c racks



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Repair of cracks:

All cracks are treated the same way except thedifference between live cracks and dead cracks

Live cracks are sealed with flexible material tosupport the effect of its movements

Dead Cracks are sealed with a cementitiousmaterial

Repair failure


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Repair failure

debonding

shrinkage

cracking

corrosionagain

evident

Sealing of cracks & joints


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g j Perrier to drilling for injections

points ,reinforcement shouldbe located using a covermeter.

Spaces between the injectionspoints shall be temporarilysurface sealed along thecracks or joints.

All injection joints shall becleaned using oil freecompressed air.

Injections should start at oneend and work progressivelyalong the joints or cracks.

Repairing cracks


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1-Chisel out the crack 2-Clean loose material

3-Apply at thin layer of bonding 4-Mix vinyl reinforced patching

5- Variation when repairing a large crack

Tips


112/123

Tips

Repair concrete cracks when the temperature is above 50 F degreesand overnight temperatures are not expected to drop below freezingthe next few nights.

Don't do repairs when it's too hot or too windy. The material will dryout too fast resulting in a weak repair. If this is unavoidable, then putplastic over it or shade it.

After you repair concrete cracks, it's always a good idea to put a coatof concrete sealer over the area to help prevent water seapage.

If your repairs are a darker color than the surrounding concrete, tryrubbing it with a flat stone. This will turn it white making it less

noticable.

If you plan to acid stain, be sure the caulk or patching used for anyrepairs contains cement or cementations material. If not the acid won'treact and the repairs will be left uncolored.

Protection of Reinforcing Steel


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Use of Inhibitors: Inhibitors are normally added to concrete to protect thereinforcing steel. They are widely used as durability enhancing materials forreinforced concrete structures. An ideal corrosion inhibitor is a chemical

compound that when added in adequate quantity can prevent corrosion ofembedded steel and has no adverse effect on the properties of fresh andhardened concrete. Several inhibitors have been proposed to inhibitreinforcement corrosion in the presence of chloride ions. Lafave (2002)reviewed nearly 50 papers and reports from research on corrosion-inhibitingadmixtures used individually in structural concrete. Based on the literaturereview they arrived at the following recommended optimum admixturedosage for corrosion protection of mineral and chemical admixtures: Silicafume(10 to 15%) cement replacement, Fly ash (25 to 35%) cementreplacement, GGBFS (40 to 55%) cement replacement, Calcium Nitrite (15to 25 L/m3) of concrete.

Mineral Corrosion Inhibitors: Mineral corrosion inhibitors that are mostcommonly used in the UAE are: Silica Fume, Fly ash, and Ground

Granulated Blast Furnace (Sabouni, 1999).

Chemical Corrosion Inhibitors: The most commonly used chemicalcorrosion inhibitors is calcium nitrite. Calcium nitrite is typically mixed intoconcrete as slurry. In concrete, calcium nitrite promotes stabilization ofreinforcing steel's natural passivating layer. Nitrite is an inhibitor thatreduces the transport of ferrous ions to the electrolyte; in other words, nitrite

blocks the current path between adjoining mats of reinforcement. The

Avoid Deterioration by Mixing Stainless Steel with Black Steel


114/123

In humid atmosphere

Different electro-chemical

potentials leads to Galvanic

Corrosion (Bi-metal corrosion)

In alkaline concrete

High pH leads to the sameelectro-chemical potentials,

hence no corrosion !


115/123

Coating and alloying of rebars


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Coating and alloying of rebars

One of the ways of preventing corrosion of thereinforcing steel is by applying a protective coating onthem.

Coating of conventional reinforcement with organic orinorganic coatings may also result in the prevention ofcorrosion by isolating the steel from coming in contactwith oxygen, moisture, and chlorides.

Epoxy coating and zinc coating (i. e., galvanization) are

also utilized. Yet another way of minimizing the steel corrosion is

through micro-alloying the same.

corrosion inhibitors


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Contamination Preferred corrosion

inhibitor

Chloride (0.8% Cl-) 4% calcium nitrite or 4%

calcium nitrate

Chloride and sulfate

(0.8% Cl- + 1.5% SO3)

4% calcium nitrite or 3%

calcium nitrate

Sea water 4% calcium nitriteBrackish water 2% calcium nitrite

Unwashed aggregate 4% calcium nitrate

A recent study, on the effectiveness of four types of corrosion inhibitors,

calcium nitrite, calcium nitrate, and two organic inhibitors in

contaminated concrete, conducted by Al-Amoudi et al. (2003) showed thatalthough all the four corrosion inhibitors investigated were effective in

delaying the initiation of reinforcement corrosion. However, calcium nitrite

was distinctly efficient in the concrete specimens contaminated with

chloride, chloride plus sulfate and sea water

Monitoring


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Monitoring

Monitoring is primarily a diagnostic or controlprocess to help understand the in-service

performance or management of a structure. It is

also a valuable tool in the routine assessment of

a structure. Monitoring may be either a periodicor repeated activity, or a continuous recording of

data.

The major advantages of continuous


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The major advantages of continuous

monitoring are that:

1. Electrochemical probes embedded in a new

structure can give early warning of potential

durability problems, especially in critical areas.2. Once installed, access is not required again

3. Retrofitted probes can be used to access the

effectiveness of remedial techniques.

SILOS


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Recent Improvements


121/123

The increasing availability and use of Mineral Additions (such as

microsilica, pfa and ggbfs) as cement replacements

Advances in local formulation and production of highly efficient SuperPlasticisers which have enabled the Free Water/Cementitious Ratio to bereduced to 0.35, or even less

Recognition of the importance of the thickness and the quality of theconcrete in the cover zone

Improvements in the quality of Epoxy Coated Rebar

Improvements and increased use of surface coating materials

The availability of Corrosion Inhibitors

The increased use of Cathodic protection and prevention systems

REFERENCES ACI Committee 318 (1999), Building Code Requirements for Structural Concrete

(318M-99) and Commentary (318RM-99), American Concrete Institute, Michigan,

USA


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USA.

ACI Committee 440 (2002), Guide for the design and construction of externally

bonded FRP systems for strengthening of concrete structures, American Concrete

Institute, Michigan, USA.

FIB Bulletin 14, Design and use of externally bonded FRP reinforcement for RC

structures. 2001.

Macdonald, M. D. and Calder, A. J. J. (1982), Bonded steel plating for strengthening

concrete structures, International Journal of Adhesion and Adhesives, No. 4, pp. 119-

127.

Meier, U. (1997), Repair using advanced composites. International Conference :

Composite Construction - Conventional and Innovative, Innsbruck, Austria, IABSE,

pp. 113-123.

Neale, K. (2001). Strengthening reinforced concrete structures with externally-bonded

fibre reinforced polymers - design manual no. 4. ISIS Canada, Winnipeg, Manitoba,

Canada.

SAI (2001), Concrete structures, Australian Standard AS3600-2001, Standards

Australia International, Sydney, Australia. Teng, J. G., Chen, J. F., Smith, S. T. and Lam, L. (2002). FRP strengthened rc

structures. Chichester, England, John Wiley & Sons, Ltd.

BRE Information Paper-Testing Anti-Carbonation Coatings for Concrete. . . . . . . . . . . . . . . . . .

AASHTQ-,Guide Specifications for Polymer Concrete Bridge Deck Overlays-Reference on ly. .

Corrosion Management

, ACI 222R-01-Protection of Metals in Concrete Against Corrosion. . . . . . . . . . . . . . . . . .

V BRE Digest 444 Corrosion of Steel in Concrete

Part3:ProtectionandRemediation 1679

BRE D53-Guide to the Maintenance, Repair, and Monitoring of Reinforced

Concrete Structures-Reference only1691

i/'ts TR 36-Cathodic Protection of Reinforced Concrete. . . . . . . . . . . . . .

CS TR 37-Model Specification for Cathodic Protection of Reinforced Concrete. . . . . . .

A Monograph No: 2-An Introduction to Electrochemical Rehabilitation Techniques. . . . . .. . . . . .

CPA Monograph No: 4-Monitoring & Maintenance of Conductive Coating Anode

Cathodic Protection Systems 1819

CPA Monograph No: 6- The Principles and Practice of Galvanic Cathodic Protection for Reinforced Concrete Structures1823

CSA S448. 1-93-Repair of Reinforced Concrete in Bui ldin gs-Reference only . . . . . . . . . , . .. . . . . . . .

FIP-Guide to Good Practice for Repair and Strengthening of Concrete Bridg es-Reference only . . . . .

ACt 345.1 R-92 (Reapproved 1997)-Routine Maintenance of Concrete Bridg es-Reference only . . . . . .

REFERENCES


123/123

ACt 345.1 R 92 (Reapproved 1997) Routine Maintenance of Concrete Bridg es Reference only . . . . . .

CS TR 33-Assessment and Repair of Fire-Damaged ConcreteStructures. . . . . . . . . . . . . . . . . . . . . . . .

CI 546.1 R-80 (Reapproved 1997)-Guide for Repair of Concrete Bridge Superstructures. . . . . : . . . . . .

ACI 546.2R-98-Guide to Underwater Repair of Concrete. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ACI 210R-93 (Reapproved 1998)-Erosion of Concrete in Hydraulic Structures. . . . . . . . . . . . . . . . . . . .

ACI 210. 1 R-94 (Reapproved 1999)-Gompendium of Case Histories on Repair of

Erosion-Damaged Concrete in Hydraulic Structures 1979

USACE EM 1110-2-2002, Chapter 8-Evaluation and Repair of Concrete Structures. . . . . . . . . . . . . . .

CI362.2R-0D-Gu'de for Structural Maintenance of Parking Structures. . . . . . . . . . . . . . . . . . . . . . . . .

ACPA TB-020.02P- The Concrete Pavement Restoration Guide:

Procedures for Preserving Concrete Pavements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

ACPA TB-002.02P-Concrete Paving Technology-Guidelines for Full Depth Repair. ..

ACPA TB-003.02P-Concrete Paving Technology- Guidelines for Partial-Depth SpaIi Repair

ACPA TB-005P- Technical Bulietin-Guidelines for Unbonded Concrete Overlays. . . ..

ACPA TB-008.01 P-Diamond Grinding and Concrete Pavement Restoration. ..

ACPA TB-007P- Technical Bulietin-Guidelines for Bonded Concrete Overlays. . . . . ...

MSHTuide Specifications for Polymer Concrete Bridge Deck Overlays. . . . . . . ..

CRA-Standard Method of Measurement for Concrete Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

CS TR 38-Patch Repair of Reinforced Concrete-Subject to Reinforcement Corrosion. . . . .. . ...

ICRI Guideline No. 03735-Guide for Methods of Measurement and Contract Types for Concrete Repair Work

ACI 22.1 R-93 (Reapproved 1998), Chapter 3-Causes, Evaluation, and Repair

of racks in concrete Structures

ICRI Guideline No. 03734-Guide for Verifying Field Performance of Epoxy Injection of Concrete Cracks..

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