construction quality control on site

7/30/2019 Construction Quality Control on Site

1/57

CONSTRUCTION

QUALITY CONTROL

ON SITE


2/57

HistoryThe first buildings were huts and shelters, constructedby hand or with simple tools.

As cities grew during the bronze age, a class ofprofessional craftsmen like bricklayers and carpentersappeared.

Occasionally, slaves were used for construction work.

In the middle ages, these were organized into guilds.In the 19th century, steam-powered machineryappeared, and later diesel- and electric poweredvehicles such as cranes, excavators and bulldozers

1- Introduction


3/57

There are different types of buildingslike :

Skeleton reinforced concrete buildings.

Bearing wall buildings.

Steel structures buildings.

Wood buildings.

Environmental buildings (clay and others)

1- Introduction


4/57

1- Introduction

Bearing walls

typeSkeleton type

Steel structure

type
http://upload.wikimedia.org/wikipedia/commons/b/b7/Munich_Frauenkirche.jpg


5/57

1- Introduction

For common use Residential, Administrative, Educational , Governate, .. etc -in our

countries- the most systems used those which

are mentioned before.

We will explain with details the first three types :

RC SRUCTURES.

STEEL STRUCTURES

BEARING WALLS STRUCTURES.


6/57

2- Skeleton Reinforced Concrete Building

A- Structural Elements:

Foundations:i- Plain concrete base (PC BASE) .

ii- Reinforced concrete foundation (RC

BASE).

iii- Reinforced concrete ground beams

which joint the reinforced concrete

bases.


7/57


i- Plain concrete PC base resting on thesoil layers.

Design ofPC base (dimension and

depth ) depends on : Bearing capacity (BC) of soil ( natural soil or

replacement layers ).

Dimension of the column.


8/57


ii- Reinforced concrete foundation.1- Shallow foundation

1-1 Footings:

1-1-1 Isolated footing

1-1-2 Combined footing

1-1-3 Strap footing or balanced footing

1-1-4 Eccentrically loaded footing


9/57


footings


10/57


footing


11/57


1-2 Rafts

1-2-1 Rigid Method

Flat slab analogy

Beam and slab analogy1-2-2 Flexible Method:

Flexible Beam Method

Flexible Plate Analogy

2- Deep foundation

2-2 PILES


12/57


iii- Reinforced concrete ground beamswhich joint the reinforced concrete

bases and other purposes : Type 1 :Base level of beam is the same level of

RC footing base (-)

Type 2 : High level of beam is the same of toplevel RC footing ()


13/57


Columns: Made of reinforced concrete and rest on the RC base

and extend vertically to the level of the ground floorceiling.

Types: Rectangular

Circular

Beams: Made of reinforced concrete and rest on the columns

or girders ( beam) at each floor level. It is divided into two types : main beam or girder &

secondary beams


14/57


RECTANGULAR COLUMN CARPENTAR CHECK THE VERTICALITY


15/57

Skeleton Reinforced Concrete Building

SlabsThere are several types of slabs: Solid slab

Hollow blocks slab

Flat slab.

StairsThere are several types of slabs:

Cantilever type Slab type

Slab beam type


16/57


B- Non-Structural Elements: The Walls:

Made of masonry or brick and are used to fill theopenings between columns and to form the interiordesign.

Doors & Windows :

Doors & windows ; are made of different materialssuch as wood, steel, aluminum, .. etc.

Floor finishing:

Tiles of ground as ceramics or cement tiles , marbles, hard marbles ,wood covering , .. etc.

Wall finishing:

Painting, plastering, wall paper ,..etc


17/57


Advantages:1. It can be constructed with large number of

floors according to a lot of factors :

Bearing capacity of soil.

Design. Economic factors

2. Flexibility in selecting opening dimensions

( doors & windows ) .

3. Flexibility in preparing the interior design.

4. Small dimensions of wall thickness whichaffect in maximizing the interior area .


18/57


Advantages:

5. High resistance to various factors like : Winds

, Earthquakes , Settlement, . etc

6. Easily in construct due to modern techniques,7. Easily in design due to use of PC software.

8. It can easily repaired and maintained due to

use of modern chemicals and tools.9. It does not need continual maintenance like

other types .


19/57


Disadvantages:

Can not resist the temperature andmoisture effect due to the small

thickness of walls. High expenses of components specially

steel.

May affect on neighbor building stabilityin case of deep excavation for foundation(some precautions may be taken in thiscase)


20/57

3- Bearing Wall Type

In this type of buildings we depend on the walls(either brick or masonary ) to transfer the loadson ceilings

( dead load and live load ) to the foundation and

then to soil .Then reach the underneath continuous base( wall foundation ) which distributes the weightto the available layer of soil .

On the other hand we can conclude that thethickness of walls increases as we come near tothe base.


21/57


Building Components:A- Structural Elements:

Flooring slab, Beams, Brick walls, Stairs,

and Foundations.B- Non Structural Elements:

Doors, Windows, and finishing materials.


22/57


A- Structural Elements:

Flooring Slab and Beams :

The design of slab should be ordinary slab

( solid slab with beams ) with suitabledesigned dimension.

We can not use the other typed of slabs( hollow block slab H.B.S or flat slab)

Brick walls:It may be masonary or brick walls , withsuitable thickness specially in the lowerstairs.


23/57

Bearing Wall Type

Stairs :

About stairs it is the same as shown in

skeleton specially slab types and slab

beam type.

Foundations :

The type used is wall orstrip foundation

which is long strip of RC under the wall


24/57


B- Non Structural Elements:

Doors, Windows, and finishing materials.about the material no difference compared

with skeleton type but the pivot point herewhich is important to be taken intoconsideration is : Dimensions

It is recommended to have another beamin mid height properly at bottom ofwindows.


25/57


Remarks : The wall thickness depends on the number of

floors and also span of walls.

Maximum number of floors can be built is notexceed 5-6 floors and reviewed by structuraldesign.

minimum thickness of walls to be used is notless than and reviewed by structural design. 25

cm Last floor may be taken as 12 cm if loads and

spans allow .


26/57


Advantages :

1. Good insulator of sound and temperature

due to its big thickness.

2. It is low in cost compared to the skeleton

concrete buildings.

3. The building works as one unit so it

reduces the effect oflateral forces.

4. Easily in design and construct.


27/57


Disadvantages1. It is difficult to make any changes in the building

specially the walls .

2.The maximum number of floors not exceed sixfloors (economically effect)

3.The thickness of the wall is relatively big so, itreduces the inner dimensions.

4.Wide openings can weak the building .5.We can not use another type of foundation so

we may loose area in case of neighbor .


28/57

4- Steel Structure Buildings


29/57


A Steel building is ametal structure with

steel for the exterior

cladding and internal

support. Such buildings are used

for a variety of purposes

including storage, office

space and living space. They have evolved into

specific type depending

on how they are used.


30/57


Advantages Strong, durable and stable

Enables good design and safety

Rigid and dimensionally stableConstruction is fast compared to other materials

Cheaper than any other construction methods in

case of high buildings like sky scrappers

Offers fast construction

High qualityproduction


31/57


AdvantagesLow maintenance costs

Non combustible

Environmentally friendly

Components can be re-used

Sustainable to temperature effects

Resistant to termites and other destructiveinsects


32/57


DisadvantagesHeat conductivity.

Corrosion.

Faulty design leads to the corrosion of steel inbuildings.

Very expensive specially in countries which isnot steel producers .

Not suitable for small buildings

Needs very skilled labours.

Needs high & expensive techniques inconstruction process

Needs high investments


33/57


Structural steel : is steelconstruction material, a profile,formed with a specific shape orcross section and certainstandards of chemical

composition and strength. Structural steel shape, size,

composition, strength, storage,etc, is regulated in mostindustrialised countries.

Structural steel, such as I-beams, have a large polarmoment of inertia, whichallows the beam to be very stiffin respect to its cross-sectionalarea.

A steel I-beam, in this case used tosupport wooden beams in a house.


34/57


Common structural shapes:

In most developed countries, the shapes available areset out in published standards, although a number of

specialist and proprietary cross sections are also

available .

I-beam (I-shaped cross-section -Standard& BroadFlange I-Beam).

Z-Shape (half a flange in opposite directions).

Angle (L-shaped cross-section equal and not equal )

Channel (C-shaped cross-section) .


35/57

4-Steel Structure Buildings

Tension Members They may have any cross section so long as the net

area is sufficient to carry the design load with areasonable factor of safety and the shape is one whichmay be conveniently connected to continuous members.

The only other structural requirement is that they shouldbe sufficiently stiff to prevent harmful vibration, unsightlysagging, or, when the member must resist a changereversal of stress to compression of small magnitude.

Empirical rules are used to ensure requisite stiffness.

The cross-sectional arrangement of material in axiallystressed tension members (called ties or hangers) isstructurally unimportant.


36/57


Compression Members

The requirements for compression member ( also calledcolumns, struts, posts) are more demanding than thosefor tension member for here the carrying capacity is afunction of shape as well as of area and materialproperties.

The material must be disposed so as to resist effectivelyany tendency toward general or local instability.

This means that the member must be sufficiently rigid toprevent general buckling in any possible direction, andeach plate element of the member must be thick enoughto prevent local buckling.

Some local buckling may be permissible if it is taken intoaccount in evaluating the capacity of the member and if itdoes not result in unsightly waviness or bulges in themember. If no phenomena of instability occur the loadelongation curve will be the same as that of the tension

member.


37/57


Beams The optimum section for flexural resistance is one in

which the material is located as far as possible from the

natural axis.

Naturally there are limitations:1.Abnormally deep beams increase the height and cost of

a structure and they tend to be unstable

2. Web material is required for resisting shear and for

making connections to other members3. The increased cost of deep webs may offset the saving

in flange material.


38/57


Beam-columns

A beam-column is a combination of acompression member and a beam .

its upper limit represents a suitablemaximum to which a factor of safety maybe applied for design.

In this case the limit is defined by stability.A similar situation would exist in columnssubjected to transverse loading


39/57


Connections

Of critical importance in structures are the

regions making up the connections between

beams and columns. The behavior of a connection fabricated by

welding.

Bolts and high strength bolts and rivets are other

methods of connection

It is an effect customarily ignored in design.


40/57


Steel frameSteel frame usually refers to abuilding technique with a"skeleton frame" of verticalsteel columns and horizontal I-beams, constructed in arectangular grid to support thefloors, roof and walls of abuilding which are all attachedto the frame.

The development of thistechnique made theconstruction of the skyscraperpossible.

Rectangular steel frame, or "perimeter frame"


41/57


TrussIn architecture and structuralengineering, a truss is astructure comprising one ormore triangular unitsconstructed with straightslender members whose endsare connected at joints.

A plane truss is one where allthe members and joints lie

within a 2-dimensional plane,while a space truss hasmembers and joints extendinginto 3 dimensions.

Truss bridge for a single track railway,converted to pedestrian use and pipeline

support
http://en.wikipedia.org/wiki/Image:RRTrussBridgeSideView.jpg


42/57


The Vierendeel truss is a trusswhere the members are nottriangulated but form rectangularopenings, and is a frame withfixed joints that are capable oftransferring and resisting bending

moments. Regular trusses comprise

members that are commonlyassumed to have pinned jointswith the implication that no

moments exist at the jointed ends. This style of truss was named

after the Belgian engineer ArthurVierendeel, who developed thedesign in 1896

A Vierendeel bridge
http://en.wikipedia.org/wiki/Image:Grammene-vierendeelbridge_20030618.jpg


43/57

4-Steel Structure Buildings Vierendeel truss

The beauty of this type of trussis that there is no diagonalbracing, the creation ofrectangular openings forwindows and doors is simplifiedand in cases the need for

compensating shear walls isreduced or eliminated.

After being damaged by theimpact of plane hitting thebuilding parts of the framed

curtain walls of the TwinTowers of the World TradeCenter resisted collapse byVierendeel action displayed bythe remaining portions of theframe.

A Vierendeel bridge
http://en.wikipedia.org/wiki/Image:Grammene-vierendeelbridge_20030618.jpg


44/57


The Stress-Strain Curve The relationship between the stress and strain that a

material displays is known as a Stress-Strain curve.

This curve characterizes the behavior of the materialtested.

It is most often plotted using engineering stress and strainmeasures, because the reference length and cross-sectional area are easily measured.

It is unique for each material and is found by recording theamount of deformation (strain) at distinct intervals oftensile or compressive loading.

These curves reveal many of the properties of a material(including data to establish the Modulus of Elasticity, E).


45/57


The Stress-Strain Curve In addition to providing quantitative information

that is useful for the constitutive relationship, thestress-strain curve can also be used to

qualitatively describe and classify the material.Typical regions that can be observed in a stress-strain curve are :

Elastic region

Yielding

Strain Hardening

Necking and Failure


46/57



47/57


Various regions and points on the stress-strain curve.
http://www.shodor.org/~jingersoll/weave/tutorial/img21.png


48/57


A stress-strain curve with each region identified is shownin Figure.

The curve has been sketched using the assumption thatthe strain in the specimen is monotonically increasing -

no unloading occurs. It should also be emphasized that a lot of variation from

what's shown is possible with real materials, and each ofthe above regions will not always be so clearlydelineated. It should be emphasized that the extent of

each region in stress-strain space is material dependent,and that not all materials exhibit all of the above regions.We describe each of the regions in more detail in thefollowing sections


49/57


50/57

Introduction

ConcreteThe word "concrete comes from the Latin word"concretus", which means "hardened" or "hard".More concrete is used than any other man-made materialin the world.

As of 2006, about seven billion cubic meters of concreteare made each year, more than one cubic meter for everyperson on Earth.

Concrete powers a US$35-billion industry which employsmore than two million workers in the United Statesalone. More than 55,000 miles of highways in America arepaved with this material.The People's Republic of China currently consumes 40%of the world's cement [concrete] production.


51/57

Introduction

Concrete is a construction material composed of :

cement (commonly Portland cement) as well as

other cementitious materials such as fly ash and

slag cement .

aggregate (generally a coarse aggregate suchas gravel limestone or granite.

fine aggregate such as sand ) .

Mixing water.

Chemical admixtures if needed.


52/57

Introduction

Concrete solidifies and hardens after mixing with waterand placement due to a chemical process known ashydration.

The water reacts with the cement, which bonds the othercomponents together, eventually creating a stone-like

material. The reactions are highly exothermic and care must be

taken that the build-up in heat does not affect the integrityof the structure.

Concrete is used to make pavements, architectural

structures, foundations, motorways/roads,bridges/overpasses, parking structures, brick/blockwalls and footings for gates, fences and poles.


53/57

Introduction

advantages Sustainable to temperature effects. Low maintenance costs.

Easily repair works due to advanced chemicals used in

repair process. Long life.

Availability to forming in any shape.

Offers fast construction

Availability of raw material used in concreteproduction.


54/57

Introductionadvantages

Availabity of concrete production with special propertiesto be compatible with varies uses.

High resistance in compression reaching 10 20 timesits resistance in tensile stress.

High resistance to the majority of stress likeearthquakes , winds , vibration, sellelments . . etc.

Modern techniques which facilitate the process like :central patch plant , cranes , concrete mixers, ..etc.

Availabity of skilled labors.

Enables good design and safety


55/57

Introduction

10-20.....

.

.

CHEMICAL ADDEDTIVESSET POINT

PERMIABILITY.

.

REPAIR.


56/57

Introduction to RC

Disadvantages:

.

Brittle material so , it can not formed after setting Sensitive to thermal and environmental effects likehumidity and

Creep

Heavy in weight ( unit weight 2200 kgm/m3 for PC &

unit weight 2500 kgm/m3 for RC ) Heterogeneous material , not resisting the permeability

Volume change due to change in temperature.


57/57

Introduction to RC

:-

.

.

.

.

.

2200-2500/3 700/3

construction quality control on site

Documents