Construction & supervision skills.pptx

Construction & supervision skills

Course Outline
Day 1
Introduction to construction management.
What is Construction Project Management?
Characteristics of oil and gas project
Interface with engineering phase
Characteristics of project objectives.
Factors affecting project success.
Project Management process.
Advanced Project life cycle
appraise, select define and execute whole building commissioning system

Day 2
How to achieve Concrete quality control onsite
How to achieve QA on site
what is the benefit for Quality management
Methods for selecting the sample
Methods of testing concrete materials
Aggregates and cement test for quality control
Test for steel reinforcement
Performance test for additives.
Concrete quality control
Concrete mix based on BS
Slump test
Cube and cylinder test

Time Events
Prior to 20th
century
• Quality is an art
• Demand overcome potential production
• An era of workmanship
F. Taylor, 1900s Scientific approach to management resulting in the greater need for standardization, inspection and supervision.
Shewart, 1930s Statistical beginning and study of quality control
Late 1930s Quality standard and approaches are introduced in France and Japan. Beginning of SQC, reliability etc
1942 Seminal work by Deming at the ministry of war in USA, concept of acceptance sampling,
1944 Dodge and Deming carried out seminal work on acceptance sampling
1945 Founding of Japan Standards Association
1946 Founding of the ASQC (American Society for Quality Control)
1950 Visit of Deming in Japan at the invitation of K. Ishikawa
1951 Quality assurance increasingly acceptable
1954 TQC in Japan (Feigenbaum and Juran), book published in 1956
1957 Founding of European Organization for the control of quality (France, Germany, Italy, Holland, England)
1961 The Martin Co. in USA introduced the zero-defect approach. Quality motivation started in USA
1962 Quality Circles are started in Japan
1964 Ishikawa publishes a book on Quality Management
1970 Ishikawa publishes on basics of Quality circle, concepts of Total quality is affirmed and devised in Japanese industries.
1970 to 1980 JIT and quality become crucial for competitiveness. A large number of US and European corporations are beginning to appreciate
the advance of Japan’s industries.
1980+ • Facing the challenges of quality management
• Growth of economic based quality control
1990+ • The management of quality has become a necessity that is recognized at all levels of management.
• Increasing importance is given to off-line quality management for the design of robust manufacturing processes and products,
services.

Evolution of Quality Management Concept
Management of Quality by
Inspection only
Segregate
Good and bad
Good Despatch
Bad Rework Good
Management of Quality
during manufacturing
Process under
control
Final quality
is not ok
Poor
Product
design
Management of
Quality during design
Design &
Manufacturing: ok
Quality
Still not ok
Poor evaluation
of customer
needs
Bad scrap
Management of Quality during design, manufacturing, & deployment
Management of quality thru company-wide quality mgmt system

Quality Assurance is defined as any method or procedure for collecting, processing or
analyzing survey data that is aimed at maintaining or enhancing their reliability or validity.

Quality Standards and Assurance procedures refer to all
the steps including:
1- Translation 2- Training
3- Survey
implementation
4- Data
entry/Data
capturing
5- Data analysis
6- Interaction,
team work and
support
Quality Assurance guidelines also serve to organize survey work and anticipate and plan for
implementation.
These guidelines will also serve as an evaluation template for the study coordinators and other staff for making a
structured and detailed assessment of the process. This will support sites in assessing quality in a systematic manner,
and to identify areas in survey activity that could be improved.

QUALITY ASSURANCE STANDARDS
Quality Assurance Standard for ISO 9001
Quality assurance standard is a written set of instructions and guidelines followed by various industries in order to maintain the
quality of their products or services. Big as well as small businesses adopt these quality standards worldwide and get certification
after audit from the authorized body that ensures the company and its manufacturing or service delivery steps and procedures are in
compliance with the laid down standards and polices. This certification enhances the brand value of the organization, its products or
services and it also instills confidence in the customers. Some QA standard documents are industry specific while some apply to all
organizations. One such universal standard that applies to all types of organizations is ISO 9001.
What Is ISO 9001
ISO stands for International Organization for Standardization. ISO standards for quality are recognized worldwide and hence ISO
certified organizations have far better opportunities to trade in the international market. ISO 9001, quality assurance standard can be
followed by any kind of industry, whether it is service or manufacturing industry. Each organization should develop its own quality
management system in order to adhere to ISO 9001 guidelines. To get ISO 9001 certification, the organization has to undergo three
audits. The first audit is conducted by the quality monitoring and inspection professional from within the organization i.e. internal
auditor. The second such audit is conducted by the customers using the product or service in question, and the third audit is
conducted by the organization that is authorized to grant ISO certifications for quality maintenance.

Benefits Of ISO 9001 2008
The ISO 9001 standard was first published in 1987. The latest edition of the standard is ISO 90012008, which was released in December 2008.
This edition has minor changes as compared to the earlier one i.e., ISO 90012000.
Adhering to this standard benefits the organizations in the following way:
1. Systematic Approach
The standard helps the organizations to function in a more systematic manner. There are defined systems, processes, and procedures in
the organizations to do each and every task. Teams are designated to perform these tasks. Hence, it results in more organized and
systematic approach to work which improves employee satisfaction and retention.
2. Improved Quality
The systems are integrated in the whole organization to deliver good quality products or services. This leads to improved quality and less
rework. All this helps the organization to reduce wastage and increase margins.
3. Customer Satisfaction
The customers trust the organizations that are ISO 9001 certified because this QA standard certification offers a sort or a assurance of the
good practices and systems in organizations. When customers get good products or services in accordance to their requirements, their
loyalty towards the organization increases. This results in more business for the organization. The profits of the organization also
increase.
4. Increased Margins
Margins of the organization improve due to multiple effects. Some of the reasons for increase in margins are
• When good quality products or services are manufactured or delivered, there is very little rework and fewer customer
complaints. This results in lesser wastage and hence increased margins.
• Since according to the requirement of QA standard , there are set procedures, it results in greater employee satisfaction,
which in turn results in greater productivity and improved margins. It also reduces the cost of training the employees.
• Since organization gets more business, their margins improve.

Many people including some quality
professionals do not know what
quality control v/s quality assurance is.
Both these terms are often used
interchangeably. However, both terms are
different in meaning as well as purpose.
Given here are main points of quality control v/s
quality assurance
Inspection

Quality control

Quality assurance

Total quality management (TQM)

Conventional Concrete Materials Limitations
and Problems
Concrete as Building Material
What is concrete?
Sand + Aggregate + Cement + Water + (Additives) + (Steel) => Hydration => Concrete

Constituent materials and Admixtures
Concrete is a composite material consisting of a binder, which is typically cement, rough and fine
aggregates, which are usually stone and sand, and water. These comprise the constituent materials
of concrete. But because of the many variables of the raw materials and how they are processed
and combined, there are many opportunities for problems to appear in concrete. Having a
fundamental understanding of the different materials and manufacturing processes may help those
who inspect concrete to know what problems to look for, where to look for them, and how to
recognize them.
In simple terms:
• cement + water = cement paste;
• cement paste + sand = mortar; and
• mortar + stone = concrete.
Admixtures may be included in the mix to control setting properties.
The chemical reactions that take place when different constituent materials are combined can vary
depending on the properties of the individual materials. The materials can vary in their chemical
makeup and performance characteristics, depending on where they were mined or quarried, and
according to the manufacturing methods used and conditions in the manufacturing plant.

A. Load increases.
B. Damage to structural parts.
C. Improvements in suitability for use.
D. Modification of structural system.
E. Errors in planning or construction
The following figure summarizes
major types of concrete deteriorations
and cracks:
1) reinforcement corrosion,
2) plastic shrinkage,
3) sulphate attack,
4) alkali/aggregate reaction
Types of major RC crack patterns: a) reinforcement corrosion,
b) plastic shrinkage, c) sulphate attack, d) alkali/aggregate
reaction

Binders:
Binders are fine, granular materials that form a paste when water is added to them. This paste hardens and
encapsulates aggregates and reinforcement steel. Immediately after water is added, cement paste begins to
harden through a chemical process called hydration. Hydration takes place at different rates according to the
different properties of the binders and admixtures used, the water-to-cement ratio, and the environmental
conditions under which the concrete is placed. The ways in which binders affect concrete, mortar and similar
products can vary with the chemical and physical properties of the source materials, the constituent
materials, the mix design, and, to a lesser extent, the variations in the cement manufacturing process.
Portland Cement:
There are different types of cement, but Portland cement is the binder used most widely. Although Portland
cement is named after an area in England where its use was originated, today it is manufactured all over the
world.
ASTM International defines Portland cement as “hydraulic cement (cement that forms a water-resistant
product) produced by pulverizing clinkers consisting essentially of hydraulic calcium silicates, usually
containing one or more of the forms of calcium sulfate as an inter-ground addition.”
Portland cement is made by fusing calcium-bearing materials with aluminum-bearing materials. The calcium
may come from limestone, shells, chalk, or marl, which is a soft stone, or hard mud, sometimes called
mudstone, that is rich in lime.
Portland cement

The Cement Manufacturing Process
The entire operation is monitored and controlled
from a central control console that contains
numerous monitors with real-time digital readouts.
Variations: Although there are ASTM standards with which Portland cement may comply, there are a number of factors that
can cause its performance characteristics to vary.
Particle Size: The size of the particles is important because particles that are ground more finely offer more surface area
against which the chemical reactions take place, and these strongly influence the properties of the cement. Cement with
small particles will be more reactive and will gain strength sooner after the hydration process has begun. The total surface
area of the particles in a given volume of material is called its specific surface.
Portland cements have a specific surface of 1,500 to 2,000 square feet per pound of material (ft2/lb), equal to around 300 to
400 square meters per kilogram (m2/kg), depending on type.
Gypsum and Sulfates: Gypsum, also in the form of ground particles, is mixed with the ground clinker to slow the hydration
process enough so that there will be time to place the concrete, screed it, and finish it before it sets. If gypsum or sulfate
materials are added to and ground with the clinker material, they may be reduced in size more quickly than the clinker. This
preferential grinding can result in smaller particles, which increases their ratio of reactivity compared to that of the clinker
material.
For any particular cement, there is an optimum content for both gypsum and sulfate. The details of exactly how sulfates
affect the strength development of concrete are not well understood.

The optimum content of both gypsum and sulfates depends not only on the type of cement design mix, but
also on the:
 chemical properties of both the calcium and aluminum source materials used for the clinker;
 physical properties of the aluminates, such as crystal size;
 varying solubility of the different sources of the sulfates;
 particle size;
 milling temperature; and
 use of admixtures.
As if this weren’t complicated enough, the optimum sulfate content for one cement property, such as
strength, may be different from the optimum content for another property, such as drying shrinkage.
Concrete and mortar can have different optimum contents, which is why different types of cements are
manufactured.
Materials are tested four times during the manufacturing process in an effort to prevent such problems.
The raw materials are tested before they enter the manufacturing process, before entering the kiln, after
leaving the kiln, and before final storage in the main storage silos.
The Cement Manufacturing Process
Cement wafers
used in a portion
of the testing
process
Equipment used to test compressive strength

ASTM Specification C-150 provides standards for eight different types
of Portland cement:
1. Type I is a general-purpose cement used in a wide variety of project types, including
buildings, bridges, floors, pavements, and precast concrete projects.
2. Type IA is similar to type I but is used for projects requiring air-entrainment.
3. Type II generates less heat, generates heat at a slower rate, and has moderate resistance to
sulfate attack.
4. Type IIA is identical to Type II but is used for projects requiring air-entrainment.
5. Type III is a high early-strength cement that causes concrete to set and gain strength
quickly. Type III cement is chemically and physically similar to Type I except that the
particles are more finely ground.
6. Type IIIA is a high early-strength cement used for projects requiring air-entrainment.
7. Type IV develops strength at a slower rate than other cement types and produces lower
levels of heat during hydration. It’s used for large-mass concrete structures from which
there is little chance for heat to escape, such as dams.
8. Type V is used only in concrete structures that will be exposed to severe attack by sulfates,
typically in places where concrete is exposed to soil and groundwater with a high sulfate
content.

ASTM C-1157 includes the following:
1) Type GU hydraulic cement is used for general construction.
2) Type HE is high early-strength cement.
3) Type MS is moderately resistant to attack from sulfates.
4) Type HS is highly resistant to attack from sulfates.
5) Type MH produces moderate levels of heat during hydration.
6) Type LH produces low levels of heat during hydration. This cement type can also be
designed for low reactivity (Option R) with alkali-reactive aggregates.

Aggregates are granular materials that include sand, gravel, crushed stone, river stone, and
lightweight manufactured aggregates, and may occupy up to 75% of the concrete’s total
volume. Since aggregates are less expensive than cement paste, they are added to concrete to
help reduce costs. The properties of aggregates can have a significant effect on the workability
of concrete in its plastic state, as well as the durability, strength, density, and thermal
properties of the hardened concrete.
Where do aggregates come from?
Aggregates are heavy. Quarrying them in a central region and trucking them long
distances is cost-prohibitive, so aggregates are generally quarried locally. This means
that the mineral, chemical and physical properties are likely to be different in different
areas, depending on the local geology. Minerals with different properties can react
differently to chemical processes or conditions in concrete, so aggregates are one
more constituent material of concrete that can have properties that vary.

The maximum size of aggregate should be less than:
1. one-fifth of the narrowest dimension between the sides of forms,
2. one-third the depth of slabs,
3. or three-fourths of the minimum clear spacing between reinforcing bars.
1- Fine
• Natural sand
• Crushed stone
2- Coarse
• Natural gravel
• Crushed stone
• Smooth river rock is also used
with most particles passing through a 3/8-
inch (9.5-mm) sieve
Coarse aggregates generally range
between 3/8- to 1-1/2 inches (9.5
mm to 37.5 mm) in diameter

1½-inch gravel ¾-inch gravel
Squeegee
Lightweight
Common sand Double-washed sand

 Using the largest possible aggregate size is sometimes recommended to minimize the
amount of cement required, as well as to minimize drying shrinkage of the concrete.
 The disadvantage of using large, coarse aggregate is that it increases the chances of bond
failure between the aggregate surface and the surrounding cement paste, since the stresses
at the interface between the two materials are higher than with smaller aggregate.
 It also reduces the total available surface-bonding area.
 The rigidity/deformation characteristics of the aggregate are also important. Extreme
differences in the properties of aggregate and cement paste result in high stresses that
create micro-cracks that can weaken concrete.
 Inadequate amounts of fine aggregates can cause excessive bleeding, difficulties in pumping concrete,
and difficulties in achieving smooth troweled surfaces.
 The bond strength of fine aggregates is not affected much by the shape or texture of the aggregate,
since smaller particles offer a large amount of surface area at which bonding to the cement paste can
take place.
 The surface properties of fine aggregate can affect the amount of water required to keep concrete
workable.
 Bear in mind that excessive amounts of water can weaken concrete by increasing the percentage of
capillary structure left behind as excess water finds its way to the surface as bleed water and then
evaporates.

1. Well-graded aggregate is the result of using many sizes of aggregate in the mix.
2. This helps reduce the amount of cement paste required to fill the spaces or voids
between the individual aggregate pieces.
3. Reducing the percentage of cement paste in the mix helps reduce shrinkage and
lowers the heat of hydration, both of which can crack concrete.
4. It also improves its durability.
5. The amount of aggregate used in a mix is called its packing density.
6. Well-graded aggregate has better packing density than gap-graded aggregate.
7. Gap-graded aggregate has no intermediate-sized pieces, which makes the
concrete more difficult to place and increases its cost, and both of these factors
can affect the final product.

Lightweight Aggregates:
Lightweight aggregates are typically man-
made and are highly porous. Clay, shale and
slate will expand when they are heated, a
little like popcorn. Since most are porous,
they are also moisture-absorbent, which can
affect the amount of water used in the mix.
A few types develop a coating during the
fusion process that reduces their absorptive
properties; however, if this coating is
damaged during handling, the aggregate as
a whole will regain some of its ability to
absorb water. Depending on the percentage
of aggregate that has damaged coating, this
condition can affect the quality of the
concrete if such a variation is not allowed for
in designing the mix.
A facility for manufacturing lightweight
aggregate
Heavyweight Aggregates:
Heavyweight aggregates are usually used
in buildings requiring radiation shielding
and are not of concern to most
inspectors.
Waste Materials as Aggregate:
Many ideas for re-purposing waste
materials have been considered and some
have been tried.
Inspectors may encounter concrete with
problems caused by materials
inappropriately substituted for aggregate.
Some of those waste materials include:
1. building rubble;
2. industrial waste; and
3. mine tailings.

1) Different types of aggregate have different levels of porosity; that is, they can absorb
different amounts of water.
2) Highly porous stone affects concrete differently, depending on whether it is water-
saturated or dry before being added to the mix.
3) Dry stone will absorb more water from the mix, and this can make concrete stiffer and
more difficult to work, which may appear as visible problems in the finished concrete.
4) Water in saturated stone has to be considered when calculating the amount of water to be
added to the mix or the water ratio may be too high, resulting in weakened concrete.
There are four moisture levels:
1. Oven-dry (OD) means that all moisture has been removed.
2. Air-dry (AD) means that surface moisture has been removed and internal pores are
partially full.
3. Saturated surface-dry (SSD) means that the surface moisture has been removed, and all
internal pores are full.
4. Wet means that pores are full, and there is a surface film.
Of these four states, saturated surface-dry is considered the best moisture state. With SSD, the
aggregate is in a state of equilibrium, so the aggregate will not absorb or give water to the
cement paste. However, this moisture state can be difficult to obtain.

Some types of aggregate materials react badly with alkalis from sources in the
concrete or from other sources, such as de-icing salts, groundwater, or sea water. If
the aggregates contain a large percentage of silica, the reaction is called alkali-
silica reaction (ASR). If the aggregate consists of dolomitic carbonate rocks, it is
called alkali-carbonate reaction (ACR).
ASR-damaged concrete
During ASR, which is the more common of the two problems, soluble silica in the aggregate reacts with
soluble alkali to produce an alkali-silica gel. When this gel absorbs moisture, it expands, causing concrete
to crack. It may take a while after the concrete is placed for ASR to appear. Cracks in control joints,
shrinkage cracks, or micro-cracks in the surface that are enlarged by freezing may allow moisture to
enter the concrete and be absorbed by the gel. Some aggregates are non-reactive and others are
reactive to varying degrees.
There is no cost-effective method for mitigation of concrete damaged by AAR. Correction requires
removal and replacement.

 Some types of stone used for aggregates may cause problems by expanding and contracting
during freeze-thaw cycles due to moisture content.
 Aggregates can vary in their resistance to wear.
 Aggregate impurities consisting of fine, solid particles can interfere with the surface
bonding between cement and coarse aggregate.
 Aggregate impurities that are soluble may interfere chemically with alkaline cement pastes
and affect setting times.
 Aggregate from quarries in coastal locations should be cleaned to avoid salt contamination
that may affect the concrete chemically or attack embedded steel.
Inspectors will not always be able to attribute problems they see to particular constituent
materials. Taking the time to learn about the types of raw materials used in their area and the
typical problems that arise related to those materials may help inspectors to better
understand the seriousness of various defects they discover so that they can make the
appropriate recommendations.

Testing To Determine Aggregate
Reactivity

Main building material –concrete- is strong in compression, but weak in tension. The tensile
strength of concrete is only about 10 % (for conventional concretes) of its compressive
strength.
To compensate concrete’s low tensile strength, concrete members are reinforced to carry
tensile loads.
Mechanically two different reinforcement acting mechanisms can be recognized :
1. long fiber or bars reinforcement;
2. short fibers reinforcement.
Long fibers (bars, nets, cage parts) are bearing tensile stress in reinforced concrete till fibers
rupture in one of the beam’s cross section. Tensile beam’s strength is fibers (bars) strength (in
tensioned beams part).
Short fibers are working according to pull-out mechanism bridging cracks. Tensile beam’s
strength is mixed mechanism of fibers strength and fiber-concrete matrix adhesion strength.
There are many types of reinforcement used in concrete structures, metals and non-metals
Long and short fibers reinforcement
under tensile load in concrete (two
different load bearing mechanisms)

Traditional material for concrete
reinforcement is steel.
However, at last times, non-
metallic fibers (steel, glass,
aramid, carbon, polyethylene
and polypropylene) as dispersed
short fibers (as well as different
structures, yarn, chopped yarn,
strings, nets, fabrics and
polymer composite material
reinforcement (bars and cages))
have been intensively
investigated and some of them
used for construction structures.
The following figure summarizes
all types of RC reinforcement.

Non-metallic fibers:
Commercially available non-metallic fibers are characterized by a tensile strength competitive
with steel. In the same time such fibers have a lower density. Main physical and geometrical
fiber characteristics are shown in Table 1.

TESTING WELDED WIRE FABRIC
TESTING DEFORMED BARS
Tensile and Bend Testing of High Strength Rebar (Reinforcement Bar)
1. Mechanical Tests
2. Chemical Tests

Quality means excellence. It is thus a philosophy rather than a mere attribute. The difference between two
objects is judged by their qualities. We set some standards which determine the level of acceptability.
In most industries especially in manufacturing and process industry, the concept of quality management is old
and used extensively.
Nowadays, application of quality management is not only becoming popular but also mandatory in construction
industry.
Just knowing some quality control methods or procedures will not do any good. We must have to adopt and
implement the quality control methods and tools that are available to us. The concept and its practice must be
tuned in harmoniously.
Quality assurance in construction activities guides the use of correct structural design, specifications and proper
materials ensuring that the quality of workmanship by the contractor /sub-contractor is achieved and finally
maintaining the structure after construction is complete through periodic assessments for maintenance and
repairs. Quality control has to be imposed by the contractor whereas quality assurance is carried out by a
separate third party agency engaged by the owner.

Ignorance,
poor detailing,
improper concrete
mix,
substandard forms,
poor construction
practices,
poor materials,
poor workmanship,
excess water,
inadequate curing,
poor supervision,
poor design,
improper quantity
of cement,
inadequate
compaction,
inadequate cover,
lack of technical
knowledge.

Requirements for Good Quality Concrete
 Dense, not too many pores (total pore volume < 16 Vol.-%)
 Water/cement ratio W/C < 0.5 Cement content > 300 kg/m3 Alkalinity pH > 12
 Water dispersible chlorides < 0.35 % related to cement in compacted fresh concrete
 Concrete cover > 2 cm (3 cm)
 Proper grading of aggregate
 Proper aggregate quality Use good quality cement
 Correct cement type (GP, HE, LH, SR, SL); where: (GP = general purpose, HE = high early strength,
LH = low heat, SR = sulfate resistant, SL = shrinkage limited)
 Limit fly ash content
Measures to achieve good Quality Concrete
 Carry out proper compacting procedure
 Carry out the necessary quality checks
 Check the batching plant
 Control the mix at site (Slump Test)
 Do not trust documents without checking
Damage Analysis
 Formation and types of cracks
 Inspection techniques
 Visual inspection
 Cover meter
– Cylinder compressive strength test
– Phenolphthalein indicator
– Half-cell potential mapping

Law of Fives
1 $ spent in Phase A ► = saving 5 $ repair expenditure in Phase B
= saving 25 $ repair expenditure in Phase C
= saving 125 $ repair expenditure in Phase D
The life of a concrete structure
Design, construction and concrete curing
Deterioration initiation processes are underway but damage is not yet
obvious
Deterioration is underway and starts becoming visible
Deterioration process is advanced, extensive damage is
visible
Phase
A
Phase
B
Phase
C
Phase
D

Preparation of quality concrete
Quality control means rational use of
resources.
Quality control procedures implement
appropriate mixing, proper compaction, correct
placement and adequate curing.
Quality control prevents temptation
of over design.
Quality control ensures strict monitoring
of every stage of concrete production and
rectification of faults.
Quality control reduces maintenance
costs.

A typical flow chart showing various steps of concrete mixing is shown in Figure shown. This chart is
adapted from the Quality Assurance Unit of New York City, Department of Transportation, Bureau of
Bridges.

Forms
 All forms shall be well constructed.
 All forms shall be carefully aligned.
 All forms shall be subtle and firm.
 All forms shall be securely braced and fastened together in their final position.
 Forms shall be strong enough to prevent the fresh concrete from bulging and withstand the action of
mechanical vibrators.
 No placement shall be done without the approval of the site engineer.
 Forms shall be designed to resist the pressure resulting from plastic concrete (wt. 24 kn/m3) and a live
load allowance of 2.5 kn/m2 on horizontal surfaces.
 If wooden forms are used, care must be taken to eliminate the formation of joints due to shrinkage of
lumber.
 Forms shall be sufficiently tight to prevent leakage of mortar.
 Inadequate forms often cause bulges or deformations.
 The forms for slabs, beams and girders shall be cambered as indicated on the drawings.
 Forms shall be filleted for about 25 mm at all exposed corners.
 Forms may be constructed of wood, metal or any other approved material. If any metal ties or anchorages
are provided, it shall be so constructed that the embedded portion can be removed at least 50 mm from
the surface of the concrete without injury to such surface.
 Upon removal of the forms, wire ties shall be cut back at least 6 mm from the face of the concrete with
sharp chisels.
 All cavities produced by the removal of metal ties shall be filled with mortar. The surface film shall be
repaired before setting occurs.
 Forms to be reused shall be maintained in good condition as to retain its accuracy of shape, strength,
rigidity water tightness and smoothness of surface.
 Unsatisfactory forms shall not be used.
 All form surfaces that will be in contact with the concrete should be coated with a release agent supplied
by approved manufacturer or an approved material to prevent adhesion of concrete to the formwork.

Vibrating
1. The vibrators should be capable of transmitting vibration in frequencies of not less than
3,500 impulses per minute. Vibrators shall be such that they will not separate the
ingredients of the concrete.
2. The concrete must be vibrated sufficiently to accomplish thorough consolidation,
complete embedment of the reinforcement, produce smooth surfaces free from
honeycombing and air bubbles.
3. Vibration should be able to and to work the concrete into all angles and corners
4. of the forms.
5. The vibrator shall not be used to push or distribute the concrete laterally. The vibrating
element shall be inserted in the concrete mass at a depth sufficient to vibrate the
bottom of each layer effectively, in as nearly a vertical position as practicable.
6. It shall be withdrawn completely from the concrete before being advanced to the next
point of application.
7. A sufficient number of vibrators shall be employed so that thorough consolidation is
secured throughout the entire volume of each layer of concrete at the required rate of
placement. Extra vibrators shall be on hand for emergency use.

Curing of concrete
 The silicates and aluminates of cement react with water to form a binding medium
which solidifies into a hardened mass. This reaction is termed hydration and is
exothermic in nature. The object of curing is to keep concrete saturated until the
originally water-filled space
 in the fresh cement paste has been filled to the desired extent by the products of
hydration of cement.
 For hydration to continue, the relative humidity inside the concrete has to be aintained
at a minimum of 80%. If the relative humidity of the ambient air is that high, there will
be little movement of water between the concrete and the ambient air and no active
curing is needed to ensure continuation of hydration.
 Prevention of the loss of water from the concrete is of importance not only because the
loss adversely affects the development of strength, but also because it leads to plastic
shrinkage, increased permeability and reduced resistance to abrasion.
 Curing is of little importance with respect to structural strength except in the case of
very thin members. On the other hand, the properties of concrete in the outer zone are
greatly influenced by curing as it is the concrete in this zone that is subject to
weathering, carbonation and abrasion.
 The permeability of the outer zone of concrete has a paramount influence on the
protection of steel reinforcement from corrosion. It has been established that the loss of
strength at 28 days seems to be directly related to the loss of water, which occurs during
the first 3 days.

Curing
 The surface of the overlay shall be promptly covered
with a single layer of clean wet burlap as soon as the
surface will support it without deformation usually
within 15-20 minutes after placement.
 Cover the wet burlap with a layer of white
polyethylene film of 4 mil thickness for the entire
duration of wet cure.
 Keep burlap continuously wet during the length of
the wet cure. In hot temperatures soaker hoses shall
be used to cool the overlay under the white plastic
and an extended wet cure of 24 hours is suggested.
Methods of curing
1. Continuous curing for a specified time, starting as soon as the surface of the concrete is no longer
liable to damage is desirable. Such conditions can be achieved by continuous spraying or ponding or
by covering the concrete with wet burlap. On inclined or vertical surfaces, soaking hoses can be used.
If w/c is low, continuous wet curing is highly desirable.
2. The second method of curing is called water barrier method. The techniques used include covering
the surface of the concrete with overlapping polyethylene sheeting. White sheeting is preferable
because it has the advantage of reflecting of solar radiation in hot weather.
3. The third method is spraying curing compounds which form a membrane. It is obvious that the
membrane must be continuous and undamaged. The timing of curing is also critical. The curing spray
should be applied after bleeding has stopped. The optimum time is the instant when the free water
on the surface of the concrete has disappeared so that water shine is no longer visible.

• During placement and finishing operations are
completed, procedures must continue to
protect the concrete from high temperatures,
direct sun, low humidity, and winds.

Alternative Curing And Protection
In very hot weather, it's safer to place
concrete in the dark.
Redding Concrete in Winnsboro, TX.
On plain gray concrete, a white pigmented
curing compound can help reflect some heat
from the sun.
Federal Highway Administration
White curing blankets will help keep the
concrete cooler by reflecting the sun.
PNA Construction Technologies.

TESTING STANDARDS
Some Standards regarding tests for RC structures

 Specific guidance on damage classification is proposed by RILEM
 ACI committee 364 have produced a guide for evaluation of concrete
structures prior to rehabilitation
 Guidance relating to assessment approaches to specialized situations such as
high alumina cement concrete
 Fire and bomb-damaged structures
 BS 1881: Part 201, Guide to the use of non-destructive methods of test for
hardened concrete provides outline descriptions of 23 wide-ranging methods,
together with guidance on test selection and planning
 BS 6089 relates specifically to in-situ strength assessment
 CIRIA Technical Note 143 reviewed those existing in the UK in 1992
 Schickert has outlined the situation in Germany in 1994
 Carino - the worldwide historical development of non-destructive testing of
concrete from the North American perspective .
 ACI Committee 228 - a substantial report reviewing non-destructive methods
 RILEM Committee 126 - in-place strength testing
 UK Concrete Society - technical reports on reinforcement corrosion
assessment and subsurface radar methods.
 FIP
 The Institution of Structural Engineers

Concrete Tests Classifications
A- For Hardened Concrete
1- Non
Destructive Tests
2- Partially
Destructive Tests
- Slump Test
- Temperature
Test
B- For Fresh
Concrete
3- Fully
Destructive tests
Site Tests
Lab Tests

The following steps must be followed for standard sequential test procedure:
1. Visual inspection:
Check the deteriorations, cracks and other imperfection in RC structure or element
using necked eye.
This inspection can help engineers to recognize surface cracks, spalling and faults
related to: -
• reinforcement corrosion,
• sulphate attack,
• plastic shrinkage, &
• alkali/aggregate reaction.
Other deterioration causes can be noticed by eye either in fresh concrete or in short
term / long term hardened concrete like:
 Segregation,
 excessive bleeding,
 honeycombing,
 Long-term creep deflections,
 thermal movements, and
 structural movements.
The following figure illustrates how to schedule test program in field and how to
make decisions. The followed table shows how to figure the faults and deterioration
in RC element.
Visual inspection not only useful for surface inspection, rather it is important in
inspection for: bearings, expansion joints, post-tensioning ducts, etc..

In spite of visual inspection can not lead to final decision for repairing, but it can lead us
what to do in the next step. After visual inspection we may choose the following tests
depend on the specific case:
2. Testing for durability: to find causes and extent of deterioration (see table ))

3. Testing for concrete strength: to find ability of RC element to bear stresses (see table).

4. Testing for comparative concrete quality, and localized integrity: surface hardness,
ultrasonic pulse velocity, chain dragging or surface tapping for delamination and detecting fault
exact location, complex impact-echo techniques, Surface-scanning radar, infrared thermography,
radiography and radiometry for Wear tests, surface hardness measurements, surface absorption
methods, & thermoluminescence for fire damages.
5. Testing for structural performance: Large-scale dynamic response testing, echo techniques,
and static loading test.
No. of individual reading or test recommended per each location are summarized in table :

Non-Destructive Testing of Reinforced Concrete
Reinforced concrete has been used for structures of every type and
size for over a century. Concrete structures built in the beginning of
the twentieth century are still in service, but these are generally
massive works of unreinforced concrete.
The Achilles heel of concrete is the steel reinforcement that is
embedded in it. Although there are deterioration mechanisms that
attack the concrete matrix directly, it is most often the corrosion of
the embedded reinforcing steel that leads to its visible deterioration
(see Figure)
Deterioration of Concrete
Due to Rebar Corrosion.

Investigation:
Reinforced concrete has been used in construction for over a century. Tension
reinforcement helps control cracking and provides ductility. Codes have specified
minimum concrete clear covers for years, depending on exposure. In the last 30 or so
years, however, more attention has been given to chemical exposure, both internally
and externally. Common internal sources of contaminants include the use of beach
sand or chloride-containing admixtures that speed set time. Common external
contaminants generally come in the form of chlorides, either naturally occurring
from seawater exposure or man-made from deicing salts, atmospheric carbon
dioxide or chemical processes.
The high pH of the interior of a reinforced concrete element protects uncoated steel
from corrosion. A protective layer forms on the surface of the steel. Contaminants
such as chlorides and carbonation break down this protection and create conditions
conducive to corrosion. Corrosion of the steel will occur if water and free oxygen are
present. The corrosion by-products, which form rust, expand the size of the steel,
creating large internal bursting stresses, which then cracks the concrete.

Investigation:
Spalled concrete with visibly corroding reinforcement is the end result of this
process.
Non-destructive testing is generally described as testing that imparts little or
no damage to the concrete, although it usually requires sampling or
removing a small amount. Such testing indicates whether any chemical
contamination has occurred and reveals the concrete’s electro-chemical
state. With this information, the engineer can design a remedial repair
program.
Non-destructive testing of concrete structures yields valuable information for
the engineer when investigating problems and can reveal unanticipated or
hidden deterioration. The repair of the structure is guided by the results of
the testing. The types of repair will vary by method and cost. In general,
repairs need to protect both the undamaged and contaminated concrete
elements from future deterioration. However, the structure will still
experience some future corrosion, since any repair generally slows down the
deterioration process but does not totally eliminate it.

Testing Methods:
There are many non-destructive tests that can be performed. The most common test methods
are listed below, with a short description of the test method and an explanation of the results.
The list is not exhaustive. These tests are for uncoated carbon steel reinforcement, either
reinforcing steel or prestressing strands.
Epoxy coated steel or plastic-sheathed post-tensioning strands have protective coatings that
electrically isolate them, and thus these tests will not give meaningful results. These tests are
typically used in the initial evaluation of a structure.
The results may require more sophisticated methods of investigation, such as x-ray, linear
polarization or petrographic analysis.
Some non-destructive test methods listed are totally non-destructive, while other methods
require only drilled holes. Test areas in a structure should incorporate as many of the listed
tests as possible to give a complete picture of the internal properties of the concrete.

Hi-tech devices for Non-
Destructive Testing:
1. Ultrasonic Thickness Gauges,
2. Ultrasonic Flaw Detectors,
3. Ultrasonic Tomographs,
4. EMA Thickness Gauges
5. Acoustic Control Systems

Carbonation:
This test measures the pH of the concrete. Freshly placed concrete normally has a pH between
12 and 13, which provides protection of the embedded steel and prevents corrosion even in
the presence of water and oxygen.
Concrete is considered carbonated when the pH falls below 11.5. At this pH level, only
moisture is needed to initiate corrosion. Phenolthalein solution is a typical color changing
indicator that is used to perform the carbonation tests. The test solution is colorless at and
below a pH of 8.2 and is pink/purple at a pH greater than 10.0. Other indicators are available
that measure different pH intervals. One commercially available indicator measures pH from 1
to 14 with a rainbow spectrum.
Testing is performed by exposing a freshly broken face of a concrete surface. This is
accomplished either by chipping off a small piece of concrete with a rock hammer and chisel, if
the carbonation is shallow, or by drilling a hole with an electric hammer drill. The broken
surface is washed with distilled water to remove dust that may contaminate the surface.
The indicator solution is then sprayed on and the results recorded (see Figure ). The depth of
the probe will need to be increased if only carbonated concrete is found.
Carbonation Testing of Concrete.

Chloride Ion Content:
Deicing salts, on or carried into structures, penetrate the concrete, eventually initiating the
corrosion of any uncoated embedded reinforcement. The accepted threshold value for
chloride content in concrete is 300 parts per million (ppm), above which active corrosion in the
embedded steel will occur.
This threshold becomes lower if the concrete is carbonated. See Figure below for a chart of pH
level vs. chloride threshold level.
Testing is performed by taking powder samples from the concrete with a small electric impact
hammer to create a profile of chloride content versus depth. The sampling should be taken at
approximately 1-inch intervals to a depth below the nearest level of reinforcement.
The chloride environment where the rebar is located is important to determine the durability
of the structure. Samples should be taken from visibly deteriorated areas, from visibly "clean"
areas, and from areas where exposure to contaminants is unlikely, such as the uncracked soffit
of a parking structure.
This last sampling area is necessary to establish background levels of chloride. There is always
some level of chloride present in concrete that comes from the individual components. This is
allowed, but limited, by codes.
Graph of Chloride Ion/pH for
Corrosion Threshold.

Radar Testing and Output
Ground Penetrating Radar (GPR):
Based on reading echoes of pulsed electromagnetic waves, radar measures the difference in materials
by acoustic density. Internal flaws can be measured, as well as the reinforcement and thickness of the
member. The cost of this testing has decreased in recent years, and new software has reduced the
amount of interpretation required by the operator. GPR is expensive, but is cost-effective for testing
large areas. Limitations include "shadowing" of lower layers of re-inforcement and the inability to
determine bar size. See Figure below for a sample of GPR output on a concrete structure.

Half-Cell Potential Testing:
The internal environment of concrete needs free moisture and ions to create the conditions necessary to
allow corrosion. Half-cell potentials estimate the susceptibility of the reinforcing steel to corrosion
activity. A copper-copper sulfate electrode is used as the reference cell.
Testing can be performed on the top or on the underside of a concrete structure. The test area must
contain reinforcement that is electrically continuous throughout. At the limits of the test area, electrical
continuity is confirmed by drilling two holes to the reinforcing mat and then testing the mat for zero
resistance. Test readings are generally taken on a grid spacing of 3 to 4 feet, with a total test area of at
least 300 square feet. Prior to testing, the concrete surface is locally wetted down on the test grid in order
to have moisture available in the concrete matrix. Readings are made by connecting one multitester lead
to the reinforcing mat and the other to the reference half-cell electrode, which generally has a sponge
attached to it in order to give it a good electrical contact with the concrete and also to maintain the
required moisture. Testing equipment that stores the data and creates potential maps is commercially
available.
Half Cell Potential Plot.
Grid Indicates Sample
Locations. Red Areas are
Above the Threshold,
Blue is Below and Green
is Unknown

Half-cell potential readings that are more negative than -350 millivolts
(mV) indicate a 90% probability of corrosion activity, while readings
that are more positive than -250mV have a 90% probability of no
corrosion activity.
Readings between -250mV and -350 mV have an unknown probability
of corrosion activity.
Half-cell testing is performed in temperatures above 40 degrees F in
order to obtain meaningful results. Reference standard ASTM C876 has
a correction factor for temperatures between 40 and 72 degrees F.
The surface of the concrete needs good electrical contact for this
testing to be meaningful. This requires that coatings, such as
waterproofing membranes or sealers, must be removed.
Readings will vary with the internal humidity of the concrete matrix
and are sometimes erratic for very dry concrete. See Figure below for a
typical half-cell potential plot.

Impact-Echo:
Impact-echo is a method that non-destructively finds internal flaws (such as cracks, honeycombing, and others) in
concrete structures using transient stress waves. Software can be used to speed up the interpretation of data. Limitations
are a relatively smooth surface for testing, a maximum effective testing depth of 3 feet, and a poor resolution of small
flaws and objects at this depth.
The impact echo method can also determine the concrete thickness. This requires testing at a known thickness to
calibrate the concrete wave speed. Figure below shows output from impact-echo testing.
Reinforcement Location: The concrete cover over the reinforcing steel is typically the best way to extend the service life of
the structure. "More is better" because it takes longer for contaminants to reach the level of the reinforcing steel.
Sample Output from Impact Echo.

Reinforcing steel is generally located by electro-magnetic means. These devices are
specialized metal detectors that have been calibrated for concrete reinforcement.
However, there are limitations for these devices. Sometimes non-structural steel,
embedded or externally mounted, interferes and/or prevents locating the reinforcement.
To locate isolated reinforcing bars, most available electromagnetic devices are limited to
a concrete thickness of about 12 inches. These devices can only find the nearest layer of
reinforcement and cannot resolve closely spaced bars as individual bars.
GPR can be used in this instance to save time for determining reinforcement over large
areas, or determining reinforcement in areas of externally mounted steel that would
otherwise interfere with electromagnetic devices.
Sounding: The corrosion of embedded reinforcement results in bursting stresses that
create delaminations, which in turn create thin hollow planes parallel to the surface.
These hollow areas can be found by using other tests listed here, but the simplest of the
tests requires only a rock hammer, a length of chain or a piece of rebar. The concrete is
impacted and the resulting sound is sampled for "hollowness". The difference in tone
between solid and delaminated concrete is generally easy to detect.
There is, however, some difficulty in hearing deeper delaminations due to the mass and
stiffness of the overlying concrete. The use of a small sledge hammer can sometimes help
here.

The following figures illustrate some devices and equipments used in different non -
distructive tests techniques
Left: Crack microscope --- Right:
Crack width measurement scale
Left: Typical simple
covermeter Right:
Profometer 3 for
cover thickness

Microcovermeter Single half-cell instrumentation
Wheel’
half-cell
equipment
Four-probe resistivity test
Perturbative measurement of corrosion rate or typical corrosion rates for steel in concrete we have 4
techniques:
1. Linear polarization resistance measuremen.
2. Galvanostatic pulse transient response measurement
3. AC impedance analysis
4. AC harmonic analysis
For Abrasion resistance testing we can use accelerated-wear equipmen to Classify concrete floor slabs in
medium industrial environment

For other partially distructive tests :
(Note: all types of testing RC structures can be detailed in a separate course).
1. Surface hardness methods: Indentation testing, Pin penetration tests, Swiss engineer Ernst
Schmidt (adopted by: ASTM C805 & BS 1881: Part 202), pendulum type rebound hammer,
enlarged hammer head (Type P), etc.
Left: Typical Schmidt Hammer test-- --Right: Digital Schmidt Hammer test
Left: pendulum type rebound hammer-- - Right: minor holes due to hammer on fresh concrete

2. Ultrasonic pulse velocity methods (adopted by BS 1881: Part 203 & ASTM C597):
repetitive mechanical pulse equipments - Pulse velocity equipments, electro-acoustic
transducers, ther American V-meter, the British Portable Ultrasonic Nondestructive
Digital Indicating Tester (PUNDIT), the exponential probe transducer, etc.
Left: PUNDIT Device--------- ---Right: the exponential probe transducer

3. Partially destructive strength tests (report by American standards (e.g. ACI Committee 228,
ASTM C803, ASTM C900 (93), ASTM C42 and ACI 318), British standards (e.g. BS 1881: Part
207 & BS 1881: Part 120) & other international standards like Concrete Society Technical
Report 11:
a) Penetration resistance test: the Windsor probe test & Pin penetration test -Nasser
and Al-Manaseer test,
b) Pullout test: Cast-in methods (The Lok-test & North American pull-out methods), &
drilledhole methods (Internal fracture tests, Torquemeter loading method, Ring
loading method, ESCOT, The Capo test, & Wood-screw method).
c) Pull-off test: bonding of surface repairs, Limpet device, Hydrajaws’ tripod
equipment, etc.
d) Break-off test.
e) Core test.
Penetration resistance testing: the Windsor probe test Some minor defects due to probe test

Pullout test -Cast-in methods: The
Lok-test Pullout test -Drilled-hole method
Torquemeter loading method
Pullout test -Drilled-hole method
Ring loading method
Pullout test -Drilled-hole methods
-The Capo test

Left: Limpet device---- ----Right: Hydrajaws’ tripod equipment
Core test &
specimen

Day 3
Concrete and steel test
Steel bar bending specifications
Allowable tolerance in BS ACI318
Wooden and steel form
Steel detailing
Problem from corrosion
Concrete cover in BS and ACI
NDT for concrete structures
NDT for steel structures
Project Time Management.
Activity Definition.
Tools and Techniques for activity sequencing.
Rules for estimating activity duration.
Schedule development.
CPM method
Outputs from Schedule development.
How to develop a complete plan.
PERT Duration Calculation.
‫موجودة‬
‫ملفي‬ ‫في‬
:
Pmbok
PMBOK3rdEnglish

Day 4
Time Cost and human resource management
Types of resources
Select team member in the project
Project management skills
Resources Planning
Prepare cash flow
Cost Control
Cost and schedule controllable
Use cost to follow up the project.
‫ملفي‬ ‫في‬ ‫موجودة‬
:
Pmbok
PMBOK3rdEnglish

Day 5
Risk assessment for civil engineering projects
Types of risk assessment tools
Types of contracts
Contracts in ISO 9000
Risk analysis and assessment
Evaluate tenders
Bid price component
Risk Assessment workshop for oil and gas projects
‫ملفي‬ ‫في‬ ‫موجودة‬
:
Pmbok
PMBOK3rdEnglish

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