staj raporu pursaklar water treatment plant building ingilizce

8/6/2019 Staj Raporu Pursaklar Water Treatment Plant Building Ingilizce

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Middle East Technical University

Department of Civil Engineering

Summer Practice Report on the Construction of the

Pursaklar Water Treatment Plant Building

Subject:

Geotechnics

Structure

Water Resources

Hydraulics

Coastal & Harbour

Transportation

Materials of Construction

Construction Management

Geodesy

Date of Completion: 25 /10 / 1999


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1. T A B L E O F C O N T E N T S

TITLE PAGE 1

1. TABLE OF CONTENTS 2

2. PREFACE 3

2.1. Name of the Company 3

2.2. Contact Address 3

2.3. History 3

2.4. Missions of DS in TURKEY 3

2.5. Organization 5

2.6. Organizational Scheme 7

3. INTRODUCTION 8

4. MAIN TEXT 12

4.1. Quantity Measurement and Cost Estimating 12

4.1.1. Concrete Quantity Measurement 12

4.1.2. Formwork Quantity Measurement 13

4.1.3. Reinforcement Quantity Measurement 14

4.2. Formwork 15

4.2.1. Minimum Period for Removal Of Formwork 19

4.2.2. Sequence for Removal of Formwork 20

4.3. Concrete 21

4.4. Reinforcements 24

5. CONCLUSION 27

6. APPENDIX 28

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7. NOTATION 41

8. REFERENCES 41

2. PREFACE2.1. Name of the Company

The General Directorate of State Hydraulic Works (DS)

2.2. Contact Address

DS 5

th

Blge MdrlEskiehir Yolu 8. Km. / ANKARA

2.3. History

DS was established byLaw 6200 inDecember 18, 1953 as legal entity and brought

under the aegis of the Ministry of Energy and Natural Resources. It is charged with "single

and multiple utilization of surface and ground waters and prevention of soil erosion and flood

damages". For that reason, DS is empowered to plan, design, construct and operate dams,

hydroelectric power plants, domestic water and irrigation schemes. The total number of stuff

of the DS is about 25.330 in the end of year 1994.

2.4 Missions of DS in TURKEY

The General Directorate of State Hydraulic Works (DS in Turkish acronym) with a

legal entity and supplementary budget is the primary executive state agency of Turkey for

Nations overall water resources planning, managing, execution and operation.

The main objective of DS is to develop all water and land resources in Turkey. It

aims at all the wisest use of the principal natural resources.

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The DS's purpose "to develop water and land resources in Turkey" covers a wide

range of interrelated functions. These include irrigation, hydroelectric power generation;

domestic and industrial water supplies for large cities; recreation and research on water-

related planning, design and construction materials.

Projects, master plan and feasibility reports are prepared for the development of water

resources. In this respect, required main data are collected by DS from the river basin surveys

which are related with flow and meteorological, soil classification, agricultural economy,

erosion, maps, geological conditions etc issues.

The specific responsibilities of DS can be listed as below:

To make basic investigations such as;

-Stream flow gauging,

-Soil classification,

-Agricultural economics,

-Geological surveys,

-Water quality analysis,

-Modelling for water structures,

To carry out the survey and planning for river basin development

To prepare master plan and feasibility report to determine technically and

economically optimal solutions of water resources project in the river basins.

To construct dams and hydroelectric power plants;

To build irrigation and drainage systems;

To operate all structures against floods;

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To perform all studies for surveys, investigation, conservation and utilization of

ground water.

To develop all stages of water supply and water treatment plants for settlements over

100 000 population.

The responsibility of supplying domestic water of the villages was given to DS by

the law number 7478 which was titled "The Law relating water supply of the villages",

thereafter in 1964, this responsibility was transferred to former General Directorate of

Rural Roads, Water and Electricity Supply (now to General Directorate of RuralServices - GDRS) by the date of July 16, 1964 upon its establishment;

To build or have built auxiliary buildings and installations for operation and

administration;

To temporarily occupy and/or to expropriate lands and real estates for the execution of

above works;

To procure, rent and operate materials, tools, spare parts, machinery and permanent

equipment;

To reclaim swamps;

To improve navigable rivers.

2.5. Organization

DS has a three-tiered organization. Its top management level is the General

Directorate office in Ankara. The secondary management level is also the department office

of General Directorate in Ankara. The tertiary management level consists of the Field or

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Regional Directorate offices. At present, there are 26 Regional Directorates dispersed

throughout Turkey.

The 26 Regional Directorates are comprised of Central Regional Offices, Field

Division Offices and Field Section Offices. Major functions of these offices are firstly collect

data in the field of mapping, hydrometric measurements, agricultural economy, land

classification, drainage, groundwater and geology, and secondly to evaluate them for the

planning, construction and operation of water structure

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2.6. Organizational Scheme

Table 1: Organizational Scheme of the Company

O R G A N I Z A T I O N C HD S

B O A R D O F I N S P L E G A L A D V I S O

D E P T . O F W A T E R S F O R E I G N R E L A T

D E P T . O F R E A L E S D E P T . O F I N V E S T I

D E P T . O F T E C H . R E S D E P T . O F D E S I G N

D E P T . O F D A M S A N D D E P T . O F G E O T E C H N

D E P T . O F O P E R A T D E P T . O F M A C H I N E

D E P T . O F T E C H D E P T . O F P E R S O N

D E P T . O F P L A N N I N D E P T . O F A D M I N I S T

D S I S C Y P R U S P R O O P E R A T I O N A L D I R E C T

B U R E A U M A N A C I V I L D E F E N S E

P U B L I C R E L A T 2 6 R E A G O I N A L D

D E P T . O A C C O U N

H E A D O F F I N A N

D E P U T I E S O F D I R

D I R E C T O R G E N E R A

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3. I N T R O D U C T I O N

The main purpose of summer practice is sparingly a step of transition from theory to

practice. It is aimed, in summer practice, to make the student have some idea about his field

of study in actual life and learn how things are carried on in the market.

The summer practice gives the student necessary information about how the

construction works is done in civil engineer point of view. This includes:

- Quantity Measurement & Cost Estimating

- Formwork

- Reinforcement Work

- Concrete Work

The project engaged on is the Pursaklar Water Treatment Building. The work

comprises the design, construction, supply and erection of equipment and start up processes of

Kaya Bayndr Dam water treatment plant having 30 000 m3 / day capacity and Pursaklar

Drinking Water Treatment Plant having 75 000 m3 / day capacity within the border of Ankara

and 5th Regional Directorate of DS according to the form and nature expressed in the contract

and addenda. In this project, what aimed is to benefit from the water, reserved in the ubuk II

Dam. This dam has a distance of 38 km from the location of the project (Pursaklar). The

reserved water will reach this location with the help of head (level) difference.

Some important information about ubuk II Dam, obtained during summer practice

may be gven as below:

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Table 2: Properties of ubuk II Dam.

Location Ankara

Purpose Domestic and industrial water supply

Construction (starting and completion) year 1961 1964

Embankment type Earth fill

Dam volume 1 100 000 m3

Height (from river bed) 61.00 m

Reservoir volume at normal water surface elevation 24.60 hm3

Reservoir area at normal water surface elevation 1.20 km2

Annual domestic water 38 hm

3

And at the end of the project, this building will provide about 1 m3/sec drinking water.

The rated output capacity of the water Treatment Works at Pursaklar will be 75 000 m3 / d.

This will be provided in one stage.

The input capacity will be rated output capacity plus water discharged from wash

water settlement thanks plus minor losses.

The rated output shall be the Works output at a continuous rate over 24 hours. The

design of the Works shall allow for changes in raw water inflow according to changes in

demand for treated water.

Under normal conditions the minimum output will be 40 800 m3 / d.

The plant shall operate satisfactorily at all of the output rates and the elements of the

Works shall be hydraulically designed for the capacities given below:

- Inlet flow control 75 000 m3 / d

- Rapid mixing chambers,flocculators and clarifiers 75 000 m3 / d

- Pipe works, channels

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upstream and downstreamof clarifiers 75 000 m3 / d

- Filters, pipe work and channels 75 000 m3 / d

- Channels and pipe work

downstream of filters 75 000 m3 / d

- Chlorine contact tank 1 700 m3

- Treated water tank 3 500 m3

Table 3: Parties of the Contract.

This agreement is executed by the General Directorate of State Hydraulic Works (DS)

of the one part and OTV S.A. (Omnium de Traitements et de Valorisation), HIDRO OTV

The employer:

DS Genel Mdrl (State Hydraulic Works)

mesuyu ve Kanalizasyon Dairesi Bakanl

06100 Ycetepe Ankara /TRKYE

The engineer:

DS V. Regional Directorate

Eskiehir Yolu 8. Km.Ankara / TRKYE

Tel: 287 93 20Fax: 287 93 40

The Contractor:

OTV S.A. (Omnium de Traitements et de Valorisation)

Le Doublon 11, Avenue Dubonnet92.407 Courbevoie Cedex / FRANCE

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ehir ve Endstri Sularn Artma Ltd. ti. And ATA Hikmet ATAMAN ve Ort. n. Tic. Ve

San. A.. joint venture group of the other part.

The contract price:

The Contract price as bid by the Contractor and accepted by the Employer is

composed of 85.454.478 FRF. using the foreign exchange buying rate of the Turkish Central

Bank on (1 FRF = 747,19 TL) (05/08/1991).

The summer practice is the first step and one of the most important steps to civil

engineering profession since it enables the apprentice to train himself on his subject of study.

Therefore, if the one tries to adapt himself on the subject and feels as a civil engineer, the

summer in his engineering practice can be very useful life.

4. M A I N T E X T

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The summer practice enables the student to learn about the civil engineering

principles in the real life as mentioned in the introduction above. Therefore, the summer

practice is of great importance in a civil engineer's life, especially for the engineers who start

the work first time.

The duties that are related to civil engineering are important since they are

interrelated. That is to mean, if one of these duties does have a hitch, everything is affected

because of that problem. In order to avoid this, one (the civil engineer) should coordinate

these very well with the other employees in the field.

The duties mentioned above can be listed as quantity measurement &(and) cost

estimating, formwork, concrete work and reinforcement work.

4.1. Quantity Measurement & Cost Estimating

Quantity measurement & cost estimating seem to be easy, but it is vital since it

determines the amount of the materials used and thus the total cost (Cost of the materials, the

occupation, the energy etc.) (Etc.: and so on). In addition, if an error in the calculation of the

amount of the materials is not realized in the field (although it is a small probability), it may

conduce to hazardous results since the project is disturbed.

In the summer practice three types of quantity measurement have been done.

These can be classified as follows:

4.1.1. Concrete Quantity Measurement

In the calculation of the amount of the concrete, there are some principles to be taken

into consideration. If the amount of the concrete to be found is just for the columns, the walls,

or the curtain wall, it is enough to calculate the areas of the cross-sections (top view) and

multiply them with the height of the objects. Then, the voids caused by the windows, lintels,

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doors etc. are subtracted from the first result. On the contrary, for the places where the height

changes due to the alternating slab thickness or the width of the beams or because of the

beam-column junction, the above procedure is not applicable. In these situations, the lateral

cross-section (side view) and the slab thickness should be observed from the project and the

cross-sections and the heights should be used in the calculation accordingly. Then the voids

are subtracted as above. After the result is obtained, it is multiplied by the unit price in order

to calculate the estimated cost.

After the calculation, the outcome should be in m unit. In the calculations

done in the summer practice the outcomes have been with many decimals due to the

geometry. In this situation, the amount has been rounded off to the upper integer number.

This is due to the fact that, to adjust the amount of concrete without rounding off is time

consuming.

4.1.2. Formwork Quantity Measurement

The amount of the formwork used in the construction is calculated before the

implementation since the formworks should be oriented in a suitable position with the right

dimensions and amount. Otherwise, as in all quantity measurements it affects the economy

and disorders the coordination between the works.

In order to calculate the amount of the formwork for a region, the lateral cross-

sectional areas (in m) of the region have been calculated. In the calculation, the total length of

the formworks has been found by simply adding the lengths observed from the top view of the

project. Then, the total length has been multiplied by the height of the region. As in the

calculation of the amount of the concrete, the change in the height should be taken into

consideration. The outcome has been multiplied by the unit price in order to obtain the

estimated cost.

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4.1.3. Reinforcement Quantity Measurement

Reinforcements are one of the main materials in the construction work, especially for

reinforced concrete buildings. They are indispensable for reinforced concrete buildings since

they are very important to resist the action of static and dynamic loads.

The amount of the ironwork has been calculated by adding the lengths of the iron bars.

These operations have been done by using the Turkish Standards about the reinforcements.

The number of the iron bars to be used for one room has been calculated by dividing

the length of the room to the clear interval between the iron bars. However, for the rooms that

are not perfect rectangles, another way has been developed. The length of the one bar has

been found by taking the mean value of the longest side and the smallest side (parallel to the

bars).

In the regions such as rooms, which are connected to each other statically, some multi-

layers have been formed. The length of the multi-layer has been determined according to the

Turkish Standards. Turkish Standards states that the length of a multi-layer is 50 times of the

diameter of the bar. For example, for a bar with 20 mm diameter the length of the multi-layer

equals to 50*=50*20=1000 mm which is equal to 1 m. (: diameter of the iron bar)

Therefore, the lengths of the bars have been calculated by considering the above

principles. Then they have been grouped according to their diameters and added to each other

within themselves. The results obtained have been multiplied by the appropriate densities of

the bars, which are determined according to the diameters. Then the weights of the bars have

been obtained.

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The lengths of the bars used in the calculations are in meters unit where the densities

are in kg/m unit. Although the dimension of the outcome is kgs, the outcome has been

converted into tons, which is the expression in the construction work.

As a conclusion, it can be said that one of the main aspects of civil engineering is the

economy. Therefore, the amount of the materials used in the construction should be

determined accurately.

4.2. Formwork

Formworks are used in the construction work in order to give the desired shape to the

freshly placed concrete. Therefore, it is of great importance to use the formworks efficiently

in the site. If it is thought deeply, it can easily be recognized that the orientation, shape, and

size of the formworks affect the strength of the concrete. Besides, any trouble in even only

one member may cause the structure to be unsafe. In order to encounter this problem, the

civil engineer and the labourers should be careful when establishing the formworks.

The formwork, together with its attendant scaffolding, timbering, shoring, strutting

etc., is supplied and fixed for placing of concrete. The formwork shall be adapted for all cases

in every respect to the shape of the concrete structure to be built.

Plywood, suitable wood panels, or steel plates and steel profile were used for supportand binding as formwork materials.

Some important points that were taken in consideration during formwork may be listed

as below:

Formwork shall be firmly supported, adequately strutted, braced, and tied to withstand

the placing and vibrating of concrete and the effects of weather. The tolerance on line and

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level shall not exceed 3 mm and the soffits of beams other than prestressed beams shall in the

absence of any specified arc be erected with an upward camber of 2 mm for each 1 m of span.

Ground supports shall be properly founded on footings designed to prevent settlement.

All joints in formwork including formwork for construction joints shall be tight

against the escape of cement and fines. Where reinforcement projects through formwork, the

form shall fit closely round the bars (See Picture: 4, and Picture: 5)

Formworks shall be so designed that it may be easily removed from the work without

damage to the faces of the concrete (See Picture: 6, and Picture: 7). It shall also incorporate

provisions for making minor adjustments in position, if required, to ensure the correct location

of concrete faces. Due allowance shall be made in the position of all formwork for movement

and settlement under the weight of fresh concrete.

Where overhangs in formwork occur, means shall be provided to permit the escape of

air and to ensure that the space is filled completely with fully compacted concrete.

Formwork shall be provided for the top surfaces of sloping work where the slope

exceeds 20 degrees from the horizontal and shall be anchored to enable the concrete properly

compacted and to prevent flotation, care being taken to prevent air being trapped.

Openings for examination of the inside of the formwork and for the removal of water

used for washing down shall be provided and so formed as to be easily closed before placing

concrete. Before placing concrete all bolts pipes or conduits or any other fixture which are to

be built in shall be fixed in their correct positions, and cores and other devices for forming

holes shall be held fast by fixing to the formwork or otherwise.

Formwork in contact with the concrete shall be treated with a suitable non staining

mould oil to prevent adherence of the concrete except where the surface is subsequently to be

rendered. Care shall be taken to prevent the oil from coming in contact with reinforcement or

with concrete at construction joints.

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All formwork and scaffolding shall be of rigid and safe construction. These should be

constructed in accordance with the requirements of TS 647 and they must be arranged such

that no excess deformation or sagging should occur.

Wooden formwork shall be constructed such that no leakage of grout should take

place when compacting the concrete and it shall not be affected by the use of vibrators.

The formwork should transmit safely to the ground all forces, which are effective

during its use. Special attention should be paid to the formwork and scaffolding which is

supported on intermediate flooring or other structural members, as in the construction of

additional floors or restoration works.

The scaffolding should be suitable to distribute the loads from its vertical posts to the

ground and special measures should be taken in loose and frozen grounds. To enable

transmission and distribution of loads, sound and immovable regular cornered wooden blocks

should be placed under the posts (no stones or bricks should be used for this purpose) In cases

when these supports cannot be made in one piece and they are arranged in two or more stacks,

safety against tilting should be achieved. The inclined columns should also be safe against

slipping.

The formwork and scaffolding should be arranged so that they can be dismantled

easily, safely and without vibration or impact. For this purpose wedges, sand boxes, screws,

jacks and similar formwork dismantling apparatus should be used.

To enable structural parts with large spans to take their originally designed form after

dismantling the formwork and scaffolding, the formwork and scaffolding should be deflected

in the reverse direction.

Before pouring of the concrete, the inside of the formwork should be thoroughly

cleaned and wetted if necessary. Cleaning holes should be left for this purpose at the bottom

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of columns, at the exit of cantilevers and under deep beams. The formwork and scaffolding

should be thoroughly checked before and during pouring of concrete.

Faces of formwork in contact with concrete shall be free from adhering foreign matter,

projecting nails and the like, splits or other defects, and all formwork shall be clean and free

from standing water, dirt, shavings, chippings or other deleterious matter. Joints shall be

watertight to prevent the escape of mortar or the formation of fines or other blemishes on the

face on the concrete.

The formworks are established in the groups of slab & beam formworks and the

column & curtain wall formworks.

In the summer practice in order to establish the slab & beam formworks, firstly

scaffoldings have been assembled addition to the columns and the curtain walls present. They

have been located so that the joints meet with each other with true orientation and true height.

Then the standard ridges of cross-section A=5*10 cm have been put on the top portions of

the scaffoldings, which are 10 cm wide and therefore two ridges may be placed on. After this

process, battens have been attached perpendicular to the ridges with the nails. Then the

formworks have been attached on the battens, again with the help of nails. When doing this

operation, the formworks have been given a proper shape by the help of the saws and the

bench saws in order to connect them to each other. After all, before the reinforcements have

been attached, the surfaces of the formworks have been greased by the formwork release

agent.

For the lay out of the column & curtain wall formworks, the operation is somehow

different. When establishing the formworks for these elements formworks have been greased

before they are laid out. This is because that, opposite to the formworks for the slab & the

beams, reinforcements is attached before the formworks are established in these kinds of

structures. (See Picture: 9, and Picture: 10)

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The process of establishing these formworks is also different. Firstly, for the

formworks to stand on the ground some supports have been pounded on the ground. Then the

formworks have been pinned on these supports and some posts have been used to hold the

formworks. In addition, in order to withstand the pressure of the concrete during the

placement, hardening and setting processes of the concrete, some bells have been used for

these kinds of formworks.

Formworks are the materials to give the concrete the desired shape. One can easily

say that the properties of the concrete depend on the dimensions. Therefore, efficient use of

the formworks has to be done when establishing them.

4.2.1. Minimum Period for Removal Of Formwork

The period between completion of a concrete pour and dismantling of formwork will

depend on the type of cement used, quality of concrete, water / cement ratio, type of load on

the reinforced concrete structure, the magnitude of loads and weather conditions.

Just after removal of formwork, special attention should be paid to parts of the

structure which are to carry the same loads as those foreseen in the calculations (such as the

condition of the base beneath the concrete poured before it takes set, and the condition of the

under roof slabs of the structure on which a roof is being constructed)

Table 3: Periods for removal formwork

Type of Cementused

Beams SideFormwork, Wall,

Column, Bridge PierFormwork

Slab FormworkUpright Beams, In large -

span slabs

Portland Cement PC325 or KPC 325 3 days 8 days 21 days

Portland Cement PC

400 or PC 500 2 days 4 days 8 days

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In special cases, for large spans and large dimensions the periods for removal of

formwork shown above can be increased up to twice. When sliding or movable formwork or

similar methods are used, if the weather conditions are very favorable and special curing

methods are applied, then the values given in Table - 3 can be decreased by suitable amounts.

In unfavorable weather conditions and especially in frosty weather, the decision for

the period of removal of formwork may be based on results of compression tests to be carried

out on samples hardened under the same conditions as the concrete of the structure.

The spare struts should be left in their places for 14 days where PC 325 or KPC 325

Portland cements are used, and for at least 8 days where PC 400 or PC 500 are used. The

days when the temperature falls below + 5 C should not be taken into account in these

periods.

4.2.2 Sequence for Removal of Formwork

Removal of formwork should start from the pedestals and columns and later the slab

and beam formwork should be removed. When special formwork techniques are applied, the

requirements for such techniques should be followed.

The parts, in formwork or scaffoldings, which are used as supporting members, should

first be taken down by loosening the formwork removal and scaffold lowering arrangements.

During this operation forcing, hitting, tilting, and shaking should be avoided.

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4.3. Concrete

Concrete is an artificial material, which consists of a binding medium (cement paste)

within which are embedded particles or fragments of a relatively inert filler material

(aggregate) (Turanl et al., 1998).

The components declared above may be listed as Portland cement, aggregate and

water.

Portland cement is a finely powdered substance usually grey or brownish grey,

composed largely of artificial crystalline materials, the most important of which are calcium

and aluminium silicates.

The Portland cement is a material obtained from mixing the clinker obtained from the

calcining operation of clayey and calcerous raw materials with the relatively in less amount of

gypsum (3%-6%) and powdering this mix (Erdoan et al., 1995). The Portland cement gains

binding properties when mixed with water. That is to mean, the duty of the cement in the

concrete is to bind the particles with the help of the water.

Aggregates have the most strength giving properties in a concrete. Therefore, it is of

great importance to use the aggregates as efficiently as possible with the other materials.

The last but not the least member of the concrete is water. Water is used to sustain the

cement to gain binding properties. Therefore, the amount of water used in the concrete should

be determined very accurately in order to eliminate the problems that can be faced resulting

from the water amount.

The proportions of the materials described above are determined by the concrete mix

design. The type of the Portland cement used in the construction site was P 42.5 (425

kgf/cm at the end of 28 days) and the concrete used was BS25 (250 kg/ cm at the end of 28

days). The concrete mix design is as follows:

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Table 4: Concrete Mix Design

WATER (lt./m3) CEMENT (kg/m3)AGGREGATE

(Kg/m3)TOTAL (kg)

205 350

0-5mm

5-15mm

15-25mm

2329839 629 306

The materials that make the concrete should be loaded into the mixer in the following

order.

Firstly, the mixer should be loaded with the coarse aggregate. Next, a small amount of

the water prepared for mixing the concrete should be added to the mixer, which should then

be turned 1 or 2 revolutions. Then the other materials, sand (together with pozzolan if used)

and cement should be added and the mixer should be started. Lastly, the remaining mixing

water should be added to the mixer (if chemical admixtures are used these should be run for a

minute after loading all the individual elements forming the concrete. If the aggregate is not in

the forms of saturated dry surface, the duration of mixing may be arranged as; mixing for

three minutes, waiting for 2 minutes and again mixing for two further minutes and again

mixing for two further minutes.

In order to succeed the replacement of the concrete without any harmful effect such as

segregation, the excess amount of entrapped air etc., the machines used in the concrete work

are designed to be developed. These machines may be listed as internal vibrators, external

vibrators, and converters, mobile and stationary concrete pumps and mixer trucks.

Here, it should be mentioned that when pouring the concrete some protections have to

be taken. For example, when pouring the concrete, concrete should not strike the

reinforcements which results in segregation (See Picture: 19, and Picture: 20). Also for the

members with large volume, the concrete should not be poured continuously, on the contrary

it should be poured step by step. That is to mean, a reasonable amount of concrete should be

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poured and then it should be waited for the concrete to settle in the formworks (but not to

harden or set). This is due to the fact that, large volume of concrete exerts a high amount of

pressure on the surface of the formworks resulting in deformation or even disintegration of the

formworks. After the concrete has been poured, the internal vibrators and the converters have

been used in order to compact the concrete, therefore, disabling segregation. If this operation

has not been done, the concrete would expose to harmful segregation and all of the strength

properties would be affected.

Concrete is the most used construction material in the structures all over the world.

This property of the concrete results from the facts, economy and applicability. It is easy to

use the concrete in the site and also it is economical since it does not need many operations.

This does not mean that it is easy to produce the concrete. On the opposite, concrete needs

serious care during the production, placing and finishing operation.

The production of the concrete has been done in the concrete station. The concrete

have been prepared in this concrete station according to the values in table 1. Then the

concrete have been placed in the mixer trucks and carried to the site (See Picture: 18). For

the places where the mobile concrete pump can reach, it has been preferred. Following this

operation, the finishing operation has been done. In this stage, the concrete has been let to

harden and set.

After setting the concrete has been cured by freshening up with water. The cause of

this operation is to prevent the cracks on the surface and in the concrete to occur. The reason

of the cracks is that the hardening and setting processes of concrete is exothermic and during

these chemical reactions large amount of energy dissipates.

After a couple of days (when the concrete takes enough strength), the process for to

build another floor has been started.

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Table 5: Classes and Design Strengths of Concrete

NOTE:BS-14, BS-16, BS-20 andBS-25 are Normal Strength Concrete,BS-30, BS-35,

BS-40, BS-45, andBS-50 are defined as High Strength Concrete.

4.4. Reinforcements

Reinforcements are indispensable structural materials for the reinforced concrete

buildings. They almost give all of the tension resisting properties of the concrete. Therefore,

they are of great importance for the strength of the reinforced concrete.

The maximum length of the bars used in the construction work is determined by the

Turkish Standards. However, before using the iron bars in the construction, they have given

proper lengths and shapes in order to use them for different purposes. These shapes may be

listed as stirrup iron, fret, multi-layer, and pilye (See figure 1).

Class(BS)

Cylindrical CompressiveStrength ((kgf / cm2)

Equivalent CubeStrength (kgf / cm2)

BS 14 140160200250300350400450500

160200250300350400450500550

BS 16BS 20BS 25BS 30BS 35BS 40BS 45BS 50

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BENT UP REINFORCING BRIDGE STIRRUP

FRET MULTI-LAYER

Figure 1: Some iron shapes and their names used in the construction

These elements have important properties in a reinforced concrete. Bentups are used in

order to resist tensional forces. The bentups have been established in right locations, right

dimensions and in right numbers according to the project. The reinforcing bridges are used in

order to take the action of applied loads between two layers of reinforcements (See Picture:

14 and Picture: 16). Stirrups undertake the duty of preventing the concrete and the iron bars

to disintegrate in the presence of an earthquake. They have also been established by giving a

proper shape and adjusting the distance between them according to the project. Frets are used

in the cylindrical columns and they have a spiral shape. The duty of the frets is similar to the

duty of the stirrups. Multi-layers are used when it is needed to connect two bars.

The diameters of the iron bars are various. These various diameter-having bars have

been used in different locations. For example, for the locations such as the garage, auditorium

etc. that would resist high loads the bars that have thick diameters have been used. In addition,

in the lower floors, more reinforcement has been used relative to the upper floors (See

Picture: 15 and Picture: 17). This introduces some advantages such as a lighter and an

economical structure.

When establishing the iron bars, firstly the iron bars have been arranged according to

the geometry of the location (See Picture: 14). Then they have been put top on top and

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connected by thin wires. Before the concrete has been poured, in order to adjust the clear

cover some concrete made rectangular prisms have been put between the reinforcements and

the formworks. These help the concrete to spread between the reinforcements and the

formworks. Otherwise, the reinforcements may face to an exposure danger.

In the upper floors, the number of solders has been decreased since the upper floors

resist a lower amount of load. ).

Advantages and Disadvantages of Reinforced Concrete:

The advantages are:

- The materials are easily obtained.

- It is easy to make.

- It is very durable.

- The cost of maintenance is practically low.

- No painting is required.

-

It is impermeable to moisture.- Great rigidity.

- Its fire resisting properties are good and it is a poor conductor of heat.

Some disadvantages are:

- Its own weight is a considerable percentage of the load

to be carried and must always be taken into account in design (but lighter than

mass construction in stone or plain concrete).

- A considerable quantity of timber is required for the

forms and the false work necessary during erection.

Reinforcements in a construction should be arranged so that they can resist the

application of tensional forces. Due to this reason, when orienting the iron bars the geometry

should be compatible with the project.

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5. C O N C L U S I O N

The summer practice gives skills that are directly applicable to the career of the

apprentice. During the summer practice, one learns about the real engineering life. In point of

civil engineers, one may gain knowledge about almost all of the aspects of civil engineering.

These may be listed as quantity measurement and cost estimating, formwork, concrete work

and reinforcement work. All of these members belong to the civil engineering life should be

known definitely. In order to succeed this, one should be inside these events.

During the summer practice, the apprentice is given some duties such as quantity

measurement, reinforcement, and concrete control. This inoculates the feeling of the

responsibility and enables to feel the taste of the job. As a result, the summer practice

improves the person both characteristically and in point of real engineering life. Only in this

way, the summer practice may reach its real purpose.

The aim of the summer practice is to enable the apprentice to learn about the

construction work and the real engineering life. Therefore, it is very important to make use of

it since in the university the student is given just the theory of the profession. Otherwise, after

graduation the engineer may face some difficulties because of the differences between the

university and the real life.

Lastly, it can be recommended that the apprentice should make use of the summer

practice as efficiently as possible in order to overcome the problems in an easier way in the

future. That is to mean, the summer practice is not a waste of time but on the contrary it is a

first step to the engineering life, which affects the career of the person directly!

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staj raporu pursaklar water treatment plant building ingilizce

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