REPORT OF THE INDUSTRIAL TRAINING

(INTERNSHIP)

Student: DUSENAYO Theoneste

Company: GLISCO

Date of starting the internship: September 12, 2011

Date of completion: October 28, 2011

Submitted at nur on 21st November 2011

NATIONAL UNIVERSITY OF RWANDA

FACULTY OF APPLIED SCIENCES

DEPARTMENT OF CIVIL ENGINEERING

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DEDICATION

To the Almighty God, His Son Jesus Christ our Savior and the Holly Spirit

To my family

To my classmates

To the National University of Rwanda

To the Faculty of Applied Science Staff

To the Department of Civil Engineering Staff

To GLISCO Staff

I dedicate this work.

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ACKNOWLEDGEMENT

My sincere thanks are first to my Dear Mother NYIRASAFARI Marie Chantal together with my

family who encourage me along all my studies especially my little brother SIBOMANA Noel

Odenwald for his assistance to his home to KIGALI and our elder brother ITANGIMBABAZI

Jean d‟Amour for he visited us.

Special thanks are to the National University of Rwanda through the Dean of the Faculty of

Applied Sciences Dr. Adronis NIYONKURU and the Head of Department of Civil Engineering

Dr. Umaru Garba Wali for they intervened in financing this internship.

Great thanks are to the lecturers of our department, our Chief of Promotion (C.P) TUYISHIME

Jerome who did everything possible to help his class in everything we faced and all my

classmates as we shared any information about our concerns.

From the deepest of my heart, I acknowledge also the assistance of the Great Lakes

Infrastructures & Services Consultants (GLISO) staff through its Managing Director

HABIMANA Joseph and all his staff and the friends we worked together at GATENGA site

namely Eng. HABIYAKARE Eric, UWIZEYIMANA Théogène, NSABIMANA Callixte and

Maman Kate.

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ABSTRACT

The students ending the third year in the Faculty of Applied sciences, department of Civil

Engineering at the National University of Rwanda, are supposed to carry out internship in the

companies exerting works relative to their fields in order to have hands-on experience and apply

the theory they have studied for the three years in participating in output production.

The hereafter reported internship has been carried out in GLISCO company (Great Lakes

Infrastructure & Services Consultants) located in the Capital City of Rwanda-Kigali; the Head

Office is in KICUKIRO District, GASHUGI building near ex. MINICOM House: 1st floor. The

company provides both services and works.

I have spent much of my time in the unity of supervision of works of building a two-storey

Health Center in GATENGA Cell. Those works are in hands of the Strong Construction

Company whose Head Office is located in Nyarugenge District-RUBANGURA House. The

client is KICUKIRO District. The rest of my time has been spent in office where we were

dealing with the tender process.

The internship spanned along one month and half from 12th

September to 28th

October 2011. At

the site I worked together with Eng. HABIYAKARE Eric, Mr. UWIZEYIMANA Théogène

(GLISCO) and Mr. NSABIMANA Callixte from the executing company (STRONG

CONSTRUCTION COMPANY). In the office I worked together with Eng. HABIYAKARE

Eric.

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FOREWORD

Civil engineers are responsible for working as communicator between engineers, clients,

contractors and senior management with help of excellent knowledge of related subject and

communication skills to present the ideas and points effectively. They carry out complex projects

using latest engineering techniques and tools. However, candidate working as a civil engineer

must be having excellent design skills to complete the project with good result and within time.

Civil engineers works in the areas such as roads, railroads, buildings, airports, bridges, harbors,

dams, channels, pipelines, water system, sewage systems etc. except these duties they prepare

public reports such as deeds, bid proposals, statement of environmental impact and many more.

Civil engineers are also responsible for other duties as needed.

The subject of this internship is turning around anything that can lead the student to reflect and

develop any possible field of those cited above. In GLISCO Company, we had chance to explore

some building implantation techniques and bid proposals preparation.

Though the preliminary works like site installation and preparation were accomplished before

my arrival, I had by the builder, a certain review about them. I prefer to write this report in three

chapters, the first about building implantation, and the second about tender process in which the

bid proposals preparation is found and the last, the shortest, covering conclusion and

recommendations.

The copies of the recommendation letter, the insurance certificate and the admission letter

constitute the last pages of this report.

In spite of little time available for the internship as not a small number of building operations and

techniques have not been observed this report includes many and basic but also interesting points

for civil engineers ready to start their career after ending their undergraduate studies.

DUSENAYO Theoneste

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Table of contents

DEDICATION................................................................................................................................ i

ACKNOWLEDGEMENT ............................................................................................................ ii

ABSTRACT .................................................................................................................................. iii

FOREWORD................................................................................................................................ iv

CHAPTER I: BUILDING IMPLANTATION ........................................................................... 3

1.1. Site installation ..................................................................................................................3

1.2. Site preparation .................................................................................................................3

1.3. Site management ................................................................................................................4

1.4. Supervision ........................................................................................................................4

1.5. Workers .............................................................................................................................5

1.6. Works ................................................................................................................................5

1.6.1. Skeleton frames ..........................................................................................................5

1.6.1.1. Foundations .........................................................................................................6

1.6.1.2. Beams ..................................................................................................................8

1.6.1.3. Columns ..............................................................................................................9

1.6.1.4. Walls (building walls and partition walls).......................................................... 11

1.6.2. Concrete ................................................................................................................... 13

1.6.2.1. Concrete mix design .......................................................................................... 14

1.6.2.2. Water/cement ratio ............................................................................................ 14

1.6.2.3. Reinforcement ................................................................................................... 15

1.6.3. Mortar ...................................................................................................................... 16

1.6.4. Quantity surveying ................................................................................................... 17

1.6.4.1. Fill ..................................................................................................................... 17

1.6.4.2. Concrete and rubble-stones ............................................................................... 17

1.6.4.3. Beams, columns, wall masonry, doors, windows, slabs, roof, finishes … ............ 18

1.6.5. Leveling using the dumpy level ................................................................................. 18

1.6.5.1. Leveling ............................................................................................................. 18

1.6.5.2. Basic dumpy level .............................................................................................. 18

1.6.5.3. Using the dumpy level ....................................................................................... 20

1.6.5.4. Stadia wires ....................................................................................................... 22

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1.6.5.5. Setting to a level ................................................................................................ 22

CHAPTER II: TENDER (OR BID) PROCESS ....................................................................... 23

2.1. Some definitions ............................................................................................................... 23

2.2. Public procurement .......................................................................................................... 25

2.3. Some important documents .............................................................................................. 28

CHAPTER III: CONCLUSION AND RECOMMENDATIONS .......................................... 29

Copy of the recommendation letter ........................................................................................... 31

Copy of the insurance certificate ............................................................................................... 32

Copy of the admission letter....................................................................................................... 33

References .................................................................................................................................... 34

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CHAPTER I: BUILDING IMPLANTATION

To implant a building a thorough preparation is necessary. Assuming that everything concerning

bids is handled and all necessary contractors have already signed, the party in charge of

implantation installs and prepares first the site (preliminary works), gather all necessary

materials to start the task and recruit workers for this purpose. In the same time, the party in

charge of supervision gets ready for his attribution. The client also will have to verify whether

his works are being done well. These three parties work together since the beginning of the

project until the final structure is submitted. Note that what concerns bids (Tender Process) is

developed in chapter two.

1.1. Site installation

The builder, after enclosing the site, he needs where to store his materials and equipments to start

the work. He needs also the office where the site management and other operations relative to the

work are carried out. That way he chooses a place on the site where to build that facility. If

necessary the supervisor office is also built but both the builder and the supervisor can work in

the same office but with different working tables. He won‟t forget the important thing

concerning self-relief that he will build latrines for both the staff and workers. If the site is not

accessible the builder will also think of the access road.

1.2. Site preparation

Site preparation involves all necessary works for the first works or materials needed for the

building itself can be started or set up. The earlier works are the topographical survey of the site

and the soil investigation to determine its profiles and soil bearing capacity in order to decide

about cuts and fills – site excavation and grading. Those are results from soil investigation that

will also determine which kind of foundation needed for a given building. This topographical

survey and soil investigation are carried out by the building client‟s surveyors. It is them also

who will plot plans which the builder will execute.

Mechanical shovels or excavator and bulldozers are appropriate tools in this construction step.

After the ground is graded, the actual construction works can be undertaken.

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1.3. Site management

The builder and the site manager are the main staff at the site and they are recruited by the

Managing Director of the company in charge of the execution of the project. That builder will

thereafter recruit workers like masons, carpenters, and those workers in charge of iron

frameworks together with their helpers. After recruitment he will send their list to the Managing

Director who will later provide their wages. Wages are different according to the experience and

function of a given worker. The build whose everyday‟s job is at the site is responsible of the site

organization in order to reach the following objectives:

1. Quality: set works to time series to insure that any work is well done on defined

standards;

2. Rapidity: time management;

3. Economy: not abuse materials and workers.

Anything from the store either tools or materials for a given work is noted by the site manager in

an appropriate account book. This manager has also to know which number of workers are

present everyday as he/she makes a call before and after everyday‟s work. Each worker has his

own time card where his attendance is signed and it is that card which will determine the number

of days he was present in order to sum his wage after a given period. According to the company

wages are paid weekly, per two weeks or monthly. The builder, the site manager and workers

have to agree with about when the work starts, when they have break and when they have pause

for resuming the next day.

1.4. Supervision

The supervisor is recruited by the Managing Director of the company in charge of the

supervision. He is responsible to check whether the standards defined in the bidding document

are respected and he will work as the quantity surveyor. The surveyed quantities are written in a

report and submitted to his Managing Director. I don‟t want to go deeper in the process those

quantities are handled along the project up to its termination; it is defined in the contract between

the parties. The supervisor will work together with the builder to agree on standards compliance

and discuss possible modifications of implementation plans that they will report to both the

Managing Directors of the companies in charge of the supervision and the execution. These latter

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will in turn give the report to the contracting authority (or the client). A meeting at the site is

often held between the three parties to confirm such modifications if necessary. In his office, the

supervisor has a diary in which he writes everyday‟s activities about how the site is progressing.

He has to report a delay or advancement of works at the site.

1.5. Workers

Workers as introduced in 1.3 are masons, carpenters, iron frameworks workers and their helpers.

The builder is he who will interpret the drawings on the implantation plans and show workers

what to do. These workers are recruited according to their prior skills and experience. Ones of

most skilled workers can be selected as foremen or supervisors of their coworkers as they are

divided into groups to perform appropriate tasks to accelerate the project. Any worker is

assumed to do his job properly. If not so, the foreman will correct him or report him to the

builder once he declares himself unfit to that work. The builder will change him the work or

make him lose his job.

1.6. Works

During my period of one month and half I had for the internship, except less of that time I spent

in studying the tender process, I attended works of setting up substructures up to the installation

of the columns and some walls filling. The following paragraphs are detailing those works.

1.6.1. Skeleton frames

Basically, these are a series of rectangular frames placed at right angles to one another so that the

loads are transmitted from member to member until they are transferred through the foundations

to the subsoil. Skeleton frames can be economically constructed of concrete or steel or a

combination of the two. At GATENGA site this latter is the case. The members of the skeleton

frame are beams, columns, foundations, floors, roof and walls.

Each member has appropriate function as stated below:

Beams span between columns and transfer the live and imposed loads placed upon them

to the columns.

Columns are vertical members that carry the loads transferred by the beams to the

foundations.

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Foundations are the bases to which the columns are connected and which serve to

transfer the loadings to a suitable load bearing subsoil.

Floors may or may not be an integral part of the frame; they provide the platform on

which equipment can be placed and on which people can circulate.

Besides transmitting these live loads to the supporting beams they may also be required

to provide a specific fire resistance, together with a degree of sound and thermal

insulation.

Roof similar to floors but its main function is to provide a weather- resistant covering to

the uppermost floor.

Walls are the envelope of the structure, which provides the resistance to the elements,

entry of daylight, natural ventilation, fire resistance, thermal insulation and sound

insulation.

Recall that at GATENGA site, on October 28, 2011, the closure date of the internship, only

foundations, ground floor beams, columns and some walls were already built. The work of

building those members is well attended and the procedure is still in mind.

1.6.1.1. Foundations

Excavation of trenches for pad footings

Trenches are of different dimensions as pad footings are. The depth of each varies according to

the result of the static penetration test carried out before. These footings will constitute the

substructure of the future building. So, the substructure of the building can be defined as the part

of the building located below the ground floor and which extends down into the ground. The

other part of the building above the ground floor is called the superstructure.

Topsoil and subsoil – general excavation

Recall that before these trenches are excavated, the general excavation had to be carried out first.

This consists in removing the topsoil containing a very high proportion of organic matter as well

as bacteria, insects and other creatures such as worms. Below the layer of topsoil there is a thin

layer of material which is neither topsoil nor subsoil but is considered to be topsoil for our

purposes in building construction. It is a transitional layer where the two forms of soil meet.

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The subsoil layer lies below and has no organic constituents in its make-up. The topsoil is

removed because (1) Topsoil has no load-bearing capacity and therefore cannot hold a building

up, nor has it sufficient cohesion, depth or mass to allow the anchoring of a building in it. (2)

Topsoil contains organic matter which if left under the building would rot and cause a health

hazard and/or give off methane gas which could cause an explosion, or hydrogen sulphide which

has an unpleasant odor as well as being a health hazard. Rotting vegetation also attracts vermin,

particularly insects, and this could be a source of disease etc. (3) Vegetable roots, bulbs, corms,

seeds or tubers left behind could sprout under the building and cause damage to any treatment

applied over the area of the building, particularly damp proof layers. Roots can penetrate

drainage and ducting systems, blocking or disrupting supplies or discharges.

Subsoil is the one with a safe load-bearing capacity. Some subsoil can be able to carry the load

of simple low-rise buildings without the need for special techniques or precautions and the other

are capable of carrying the loads imposed by much larger buildings with appropriate foundation

techniques or requiring special techniques or precautions for even the most simple of structures.

After trenches are excavated in the subsoil, the wet concrete is poured in those holes in the

ground to make foundations.

Foundation work

Foundations are generally made by pouring wet concrete into holes in the ground. The shape

involved can be simple or complicated and everything in between. Our case in GATENGA, we

were only concerned with simple shapes – boxes of rectilinear dimensions of concrete cast in the

ground and presenting a horizontal surface on which walls can be built. Before pouring the

reinforced concrete, we first poured a layer of plain concrete technically termed the blinding

concrete of 50 mm thick. This layer is horizontally laid and is considered as the cleanser of the

hole where the footing has to be settled.

The foundation of GATENGA Health Center consists of pad footings of reinforced concrete

connected by trenches filled with stones masonry. This type of foundation is used to support and

transmit the loads from piers and columns. The most economic plan shape is a square, but if the

columns are close to the site boundary it may be necessary to use a rectangular plan shape of

equivalent area. Above each pad, a sub-column is erected to meet the level of the ground floor

where the superstructure will start; starter bars are incorporated to meet piers and columns. At

8

the same time the said masonry of stones is built to reach the same level. The instrument called

dumpy level or only level is used for this purpose. The foundation is reinforced by reinforcement

steel bars in order to avoid failure which can be bending or punching shear.

Foundation quantity surveying

The engineer working as the quantity surveyor has to measure the depth of both pad footings and

foundation trenches so that he can report easily the amount of the excavated soil and calculate

the amount of soil to refill the hole when compacted after necessary concrete is cast and stones

are built. This will allow the engineer also to report the amount of materials (stones or concrete)

used in foundation. This latter point about quantity surveying is developed in what is going to

follow later.

1.6.1.2. Beams

Beams at GATENGA site are of reinforced concrete.

Reinforcement preparation

The reinforcement frame is made according to the formula provided by the designer. The correct

design of a reinforced concrete beam will ensure that it has sufficient strength to resist both the

compression and tensile forces encountered in the outer fibers, but it can still fail in the „web‟

connecting the compression and tension areas. This form of failure is called shear failure and is

in fact diagonal tension.

Concrete has a limited amount of resistance to shear failure, and if this is exceeded reinforcement

must be added to provide extra resistance. Shear occurs at or near the supports as a diagonal

failure line at an angle of approximately 45° to the horizontal and sloping downwards towards

the support. A useful fact to remember is that zero shear occurs at the point of maximum

bending.

Reinforcement to resist shearing force may be either stirrups or inclined bars, or both. Stirrups

are the case at GATENGA site and are all spaced of 20 cm for the ground floor beams deposited

on rubble-stones foundation.

The cross section of the beam is anticipated to be a square of 25 cm side. So the reinforcement

frame is of 20 cm side and the other 5 cm are for coating 2.5 cm each side. Reinforcement

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frames are made to be transported to the final location in the building and they are often

connected at intersections and quoins.

Casing preparation (mould)

The casing is of wood. Wood planks are arranged linearly and in parallel to leave inside the

space corresponding to the dimensions of the beam stated above and set to the level using the

dumpy level. This casing is made at the final position of the beam in the building as these beams

are in-situ-cast and it has to be fixed firmly in order to keep the building axes.

Concrete cast

This is the operation of filling wood casing to make beams and provide with them the pre-

designed shape (our case is rectangular). Before casting, the workers in charge will have to

verify whether all the casings are set to the same level and that there are no holes in planks where

fine aggregates from the concrete might escape what could damage the beam. The concrete and

the way it is worked are detailed in the next point.

1.6.1.3. Columns

A column is a vertical member carrying the beam and floor loadings to the foundation, and is a

compression member. As concrete is strong in compression it may be concluded that, provided

the compressive strength of the concrete is not exceeded, no reinforcement will be required. For

this condition to be true the following conditions must exist:

Loading must be axial.

Column must be short, which can be defined as a column where the ratio of its effective

height to its thickness does not exceed 12 (effective height may be calculated by formula

and tables in Section 3.8.1.6 of BS 8110-1). After this third point, see the Section 3.8.1.6

of BS 8110-1).

Cross-section of the column must be large.

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These conditions rarely occur in framed buildings: consequently bending is induced and the need

for reinforcement to provide tensile strength is apparent. Bending in columns may be induced by

one or more of the following conditions:

Load coupled with the slenderness of the column – a column is considered to be slender

if the ratio of effective height to thickness exceeds 12;

Reaction to beams upon the columns – as the beam deflects it tends to pull the column

towards itself, thus inducing tension in the far face;

The reaction of the frame to wind loadings, both positive and negative.

The minimum number of main bars in a column should not be less than four for rectangular

columns and six for circular columns (eight bars for both square and circular columns at

GATENGA site), with a total cross-sectional area of not less than 0.8% (4.02% at GATENGA

site) of the cross-sectional area of the column and a minimum diameter of 12 mm (20mm at

GATENGA site). To prevent the slender main bars from buckling, and hence causing spalling

(Spalling is a result of water entering brick, concrete or natural stone and forcing the surface to

peel, pop out or flake off. This is because there is moisture in the concrete. In basements,

especially, moisture and often salt, too, pushes outward from the inside. Eventually, spalling can

cause crumbling and destruction of a structure) of the concrete, links or binders are used as a

restraint. These should be at least 6 mm diameter (8 mm at GATENGA site) and not less than

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one quarter of the largest main bar diameter (1 of 2.5 or 40% at GATENGA site). Isn‟t the

building overdesigned? This is the question we often ask ourselves to the site unfortunately we

could not review the project!

All bars in compression should be tied by a link passing around the bar in such a way that it

tends to move the bar towards the centre of the column; typical arrangements are shown in Fig.1.

The reinforcement frames for the columns are joined to the starter bars and the mould in wood is

made not necessary at the column‟s position, to be brought with three sides joined. The fourth

side is for sealing the mould. The verticality of the column, firstly well centered, will be insured

by plumb lines. The concrete will be poured from above but at not very high distance to avoid

segregation.

Fig.1.1. Typical arrangements of reinforcements (ROY CHUDLEY AND ROGER

GRRENO)

1.6.1.4. Walls (building walls and partition walls)

Walls usually are solid structure that defines and sometimes protects an area. Building walls

have one main purpose: to support roofs and ceilings while partition walls are for the purpose of

separating rooms, or dividing a room. Partition walls are usually not load-bearing. Walls (both

building and partition) at GATENGA site are constructed with bricks from clay.

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Masonry construction

Walls of 20 cm think are constructed with mortar (Mortar is a workable paste used to bind

construction blocks together and fill the gaps between them. The blocks may be stone, brick,

cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure.

Modern mortars are typically made from a mixture of sand, a binder such as cement or lime, and

water. Mortar can also be used to fix, or point, masonry when the original mortar has washed

away). Mortar placed horizontally below or on top of a brick is called a “bed” and mortar placed

vertically between bricks is called a “perpend”.

Coordinating sizes

The coordinating sizes allow the bricks to be built together in a number of different ways,

illustrated in Fig.1.2. It is important to build brickwork to the correct coordinating size for the

particular working size of brick specified.

The bonding of bricks to form walls

Bonding of bricks refers to the practice of laying the bricks in layers or courses and in any of a

number of patterns or bonds to form a wall of a homogeneous construction, i.e. the individual

bricks overlap each other in adjacent layers, the pattern alternating in adjacent layers or after a

number of similar layers. The patterns in these layers are formed with whole and cut bricks as

well as with bricks manufactured to a „special shape‟ other than the standard rectilinear one. At

GATENGA site, the used cut bricks are three-quarters called three-quarter batts.

Fig.1.2. Coordinating sizes of bricks (ROY CHUDLEY AND ROGER GREENO)

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1.6.2. Concrete

Concrete is a plastic mixture of aggregates, Ordinary Portland cement and water. Occasionally

additives are included which have much the same effect as those put into mortar. The plastic

mixture is poured into moulds or directly into the ground and allowed to set. Reinforcement of

steel rod or bar can be fixed in place before pouring in the plastic mixture.

Such concrete would be termed reinforced as opposed to plain concrete. The concrete can be

placed in its plastic condition in the position it is meant to occupy in the building – in-situ

concrete. If cast in moulds away from its final position it is precast concrete. Let‟s see in

details the concrete constituents in the following:

a) Aggregates

Aggregates can be:

Coarse – gravel or crushed rock retained on a 6 mm sieve

Fine – sand passing through a 6 mm sieve

Coarse aggregates used at GATENGA site are crushed rock from GASABO District of Kigali

City more exactly at RUSINE while fine aggregates are from MUKUNGURI, RUHANGO

district in the southern province. The quarries fulfill gradation properties. Grading of aggregates

means that when mixed, it is insured that all voids between the particles are filled and all

particles are evenly coated with cement.

Aggregate size is given as the largest mesh size used for grading, e.g. 25 mm aggregate would

have all particles passing a 25 mm sieve.

The grading affects the workability; a lower water-to-cement ratio can be used if the grading of

the aggregate is good and therefore strength is also increased. Good grading saves cement

content. It helps prevent segregation during placing and ensures good finish.

b) Water

As with mortars, water is required to react with the Ordinary Portland Cement to obtain a set.

Water is also important in two important properties of concrete:

In wet concrete, a high proportion of water allows easy placing of concrete in confined

areas and round heavy reinforcement, but too much water weakens concrete and may also

lead to water voids being formed where compaction of the concrete is inadequate.

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A low proportion of water is desirable where higher strengths are required.

c) Cement

Ordinary Portland cement is the commonest type in use and it is the one recommended in the

biding document for the GATENGA Health Center. The main chemical compounds in cement

are calcium silicates and aluminates.

When water is added to cement and constituents are mixed to form cement paste, chemical

reactions occur and the mix becomes stiffer with time and sets.

Many other types of cement are available; Hima cement is one of these types and it was

available at GATENGA site.

The constituents above are mixed in the drum concrete mixer to form the plastic concrete before

it is cast.

1.6.2.1. Concrete mix design

Concrete mix design consists in selecting and proportioning the constituents to give the required

strength, workability and durability. The prescribed mix is the one applied at GATENGA site.

This consists in applying specified proportions of constituents to give required strength and

workability. Another type of mix we can say is the design mix, where strength testing forms an

essential part of the requirements for compliance.

1.6.2.2. Water/cement ratio

Unlike mortars, the proportion of water used in concrete mixes is carefully controlled:

Enough to allow easy placement

Enough to give a „set‟

Just enough to avoid water pockets in the concrete.

It is given in litres per 50 kg of Ordinary Portland cement. When using low water/cement ratios a

number of techniques can be adopted to ease placement:

Use of vibrators (the case at GATENGA site)

Addition of air entraining chemicals to the mix – for every 1% by volume of air a 6% loss

in strength is incurred

Addition of water retaining or wetting agents

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Use of a smaller coarse aggregate

Traditionally, concrete mixes for general building work were specified by volume. A 1:2:4 mix

contained one part by volume of Ordinary Portland cement, two parts fine aggregate and four

parts coarse aggregate. A 1:2:4 mix was generally conceded to be a strong concrete, a 1:3:6 mix

a medium strength mix. At GATENGA site a mixture of 350kg of Ordinary Portland cement are

used to mix one meter cube of wet reinforced concrete. Calculations (See table 1.1.) taking into

account the expansion coefficient of 1.2 provide the formula of one sac (50kg) of ordinary

Portland cement mixed with 1:2 volumes of fine aggregate and coarse aggregate respectively.

This volume equals to 0.05714 meter cube. The volume of cement is neglected in any case.

Table 1.1.Concrete and mortar constituents to make one wet meter cube (Théogène Uw.)

Constituents and dosage boxes Mortar Blinding concrete Reinforced concrete

Cement Dose (kg/m3) 250 150 350

Sacs (number) 5 3 7

Gravel + Sand/1cement sac (dm3) 240 400 171.43

Quantity per box (dm3) 80 66.67 57.14

Box dimensions (dm) 4.3 4.1 3.85

Sand proportion (boxes) 3 2 1

Gravel proportion (boxes) 0 4 2

Boxes are made by carpenters at the site under the order of the engineer who determines their

dimensions and their number depends on concrete mixer users for they can be able to manipulate

them.

1.6.2.3. Reinforcement

High yield steel reinforcement round bars are in use at GATENGA site. High yield steel means

that the tensile strength of the bars is 450-425 N/mm2. In foundations reinforcements are united

to form a kind of mesh in which the wet concrete is going to be poured. The mesh can be square

(the case of GATENGA site) or rectangular. See Fig.1.3.

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Fig.1.3. Reinforcement meshes

Reinforcement must be firmly „fixed‟ in the concrete. It must not move. Concrete, when setting,

shrinks and so grips the bar. Grip of reinforcement can be increased by 1) bending or hooking the

ends of the reinforcement bar (the case at GATENGA site), 2) using deformed or square twisted

bar and 3) using both the above. See Fig.1.4.

Fig.1.4. Bent and hooked ends of bar (Construction Technology, ROY CHUDLEY AND

ROGER GREENO)

To prevent reinforcement steel from rusting, it has to be well embedded in the dense concrete as

it is the alkaline environment. For this purpose, workers will have to be careful about the outer

covering when casting reinforced concrete.

1.6.3. Mortar

The mortar is used for stones or bricks masonry. It consists in mixture of cement and sand. At

GATENGA site, 0.08000 meter cube of sand are mixed with one sack of cement or 50kg (see

Table 1.1. above).

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1.6.4. Quantity surveying

This the important work in building construction as it is one of the factors to determinate the cost

of the building. In the course of construction quantity surveyors should be able to advice on the

current cost conditions for any configuration. A quantity surveyor (QS) is a professional

working within the construction industry concerned with building costs. As example, at

GATENGA site, it was discussed about a retaining wall which would be built either in rubble-

stones or in concrete. After quantity surveying, it has been concluded that the retaining wall has

to be of rubble-stones. Another case displayed when it has been revealed, by surveying, that to

set the foundation of the front of the building to the datum, a huge quantity of fill would be

required. So, it has been decided to split the building into two parts and lowering one of 30 cm

from the central corridor. The communication between the two blocks will be enabled by stair

facility. To meet the maximum economic requirement of a client, any quantities must therefore

be kept to the statutory minimum. The builder and quantity surveyor, here the engineer in charge

of supervision, must be careful not to cause any amendment as it is unpleasant to the client.

1.6.4.1. Fill

Each meter cube of the fill has the fixed cost according to the project. For this purpose, the

quantity surveyor will have to determine the total quantity of the fill executed at the site and to

do so, he must measure the volume of holes to be filled. The dumpy level is one of the tools he

can use to accomplish that task and the way it works is going to be developed later in the work of

leveling using the dumpy level. The only dimension it will measure is the depth of the footing or

foundation trench from the datum.

1.6.4.2. Concrete and rubble-stones

The dimensions of both footings and foundation trenches to be filled with rubble-stones (except

depth as each pad footing or trench may have its proper depth according to the subsoil condition)

are well defined in the bidding document. Once respective depths are available, the simple

calculations will provide either the volume of concrete or that of rubble-stones. Each constructed

meter cube of rubble-stone has a well defined proportion of mortar; hence, the volume of cement

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and sand used are also easily determined. The formula of reinforcement is undoubted as the total

length of used reinforcement bars can easily be determined.

1.6.4.3. Beams, columns, wall masonry, doors, windows, slabs, roof, finishes …

Except where modifications have been made, the determination of their quantities is a simple

counting or simple arithmetic calculations. If eventual modifications occur, the quantity surveyor

has to be much careful to avoid unnecessary amendments.

1.6.5. Leveling using the dumpy level

A variety of surveying instruments can be used on a building site to assist in the accurate setting

out of a building on the ground and in setting the levels at which various parts of the building are

to be built. The most basic of these instruments is a level or dumpy as this type of instrument is

often called. The same instrument is used at GATENGA site. This instrument, like other

surveying instruments, uses the principle of setting a telescope so that the line of sight is truly

horizontal no matter which way the level is facing. The whole instrument is contained in a small

box which mounts on a tripod.

1.6.5.1. Leveling

Leveling is a technique used by surveyors and others in the construction industry to determine

the height of land surface or objects in a landscape relative to a known fixed height. The known

fixed height may be a permanent mark or a temporary mark. Such marks are known as

benchmarks (BMs) and can be incisions on the masonry face of a building or pillar for

permanent benchmarks, or simply a block of concrete, the corner of a manhole cover or even a

peg driven into the ground. The whole point about a benchmark is that it has a known fixed

height.

At GATENGA site, one permanent benchmark has been fixed after the grading of the terrain. It

is the reference to start the building but in the course of work temporary benchmarks are used

bearing in mind that they have main reference to the permanent one.

1.6.5.2. Basic dumpy level

The basic dumpy level comprises:

A telescope with a sighting device or stadia wires

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A bubble level on the telescope

A horizontal mounting which will allow the telescope to rotate through 3600

A tripod on which to mount the instrument in a stable state.

The typical dumpy level is shown on the figure below and the following sketch in Fig.1.5. shows

the basic operational parts of only one variety of dumpy level but will serve to illustrate what

they are about. Starting at the centre top and working down the sketch from left to right: the

accurate bubble level is used to finally set the telescope truly horizontal just prior to each reading

taken on the staff; sometimes there is a mirror fitted over it or there is a small eyepiece which

through complex optical system allows the surveyor to view both ends of the bubble, and when

these are in alignment, the instrument is truly horizontal.

Fig.1.5. Typical dumpy level and staff (Construction Technology, Eric Fleming)

The object lens is the large light-gathering lens facing the staff; the larger it is the more light

there will be and the further out the surveyor will be able to use the instrument. The trunnions

either side of the telescope allow it to pivot up and down on its optical axis in bearings set in the

mounting for the instrument. The focusing eyepiece allows the surveyor to focus on the sighting

and reading marks inside the telescope – see stadia wires below. The leveling screw is used to

bring the telescope from nearly level to truly level as indicated by the large bubble level. The

bearing shown is the pivot on which the whole of the telescope and its mounting revolves in a

horizontal plane.

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Fig.1.6. Schematic view of a dumpy level (Construction Technology, Eric Fleming)

The index mark allows the scale below to be read. The transverse locking screw clamps the

bearing so that the telescope is pointing in a „fixed‟ direction. The scale of degrees on the lower

fixed part of the instrument mounting is not much used in general leveling but can be useful in

fixing the horizontal angle of various sights or readings relative to a fixed point in the survey.

The coarse leveling screws are used to set the mounting to an approximate level as indicated by

the bubble level between them – what is not shown is that there are three coarse leveling screws.

Finally, the bottom plate of the mounting has a large threaded hole for securing the instrument to

the top of the tripod.

The instrument works on the principle that if the telescope is set so that the line of sight is

horizontal, then measurements can be taken below (and above) that line of sight or collimation.

These measurements can be used to determine relative height. If a known fixed height is

included as one of the measurements then all others can be calculated relative to it, i.e. a

benchmark.

1.6.5.3. Using the dumpy level

The figure below illustrates the dumpy level in use.

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Fig.1.7. Schematic dumpy level in use (Construction Technology Eric Fleming)

To begin, the dumpy level has to be set up on its tripod so that the telescope‟s line of sight is

truly horizontal. The tripod has to be set on firm ground and the spikes on each leg pushed firmly

into the ground or otherwise stabilized so that they don‟t slip. The table on which the dumpy

level is mounted must be set fairly level – within the limits of the small bubble level(s) mounted

on the table. Finally, the telescope itself is either leveled for any angle of viewing (360◦ in a

horizontal plane) or brought level as each reading is taken; it all depends on the type of dumpy

level being used.

Measurements with the instrument are taken by placing the staff on the selected point and

sighting on it with the telescope. The telescope is focused on the staff and measurements on the

benchmark and points A and B are taken in turn. The first reading on the BM is termed a back

sight (BS). All others except the last are intermediate sights (IS). The last is a fore sight (FS).

A is therefore an intermediate sight and B a foresight.

The surveyor goes with his level book and the table below shows how readings are written down

in that book and how they are worked out.

Table 1.2.How to note readings in a level book (Construction Technology, Eric Fleming)

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1.6.5.4. Stadia wires

A stadia wire is a device placed inside telescopes used for aiming, such as telescopic gun sights,

here in a dumpy level etc. They are also used in other surveying instruments such as theodolites.

When first looking through the telescope to take readings, the surveyor focuses the eyepiece of

the telescope on the stadia wires. Once this is done it generally needs no further attention, the

stadia wires remaining in focus no matter how the focus on the staff is changed. Various styles of

stadia wires are made but the one in Fig.1.8.a) is a fairly common pattern.

The complete telescope is in turn focused on to the staff and the reading taken as shown in

Fig.1.8.b). Note that the staff appears upside down. This is the most common scenario, the

reason being that the additional lenses required to turn the image right way up would reduce the

amount of light reaching the surveyor‟s eye. This is not a problem for work on a building site

where distances would be relatively short, but in the wider surveying field could be quite critical.

Patterns of markings on staffs vary.

Fig.1.8.a) Common form of stadia wire, b) How staff appears to the surveyor when viewed

through the telescope

1.6.5.5. Setting to a level

On building and construction sites, levels of foundation floors, beams, column bases etc… need

to be set. The dumpy level is therefore involved in that work as we did at GATENGA site.

We often fixed a temporary benchmark to a level we wished to set and define the collimation.

All the sights should be at the same line and pegs fixed.

a) b)

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CHAPTER II: TENDER (OR BID) PROCESS

Any person wishing to start a business as bidder is required to know the tender process. As Civil

Engineers are among people that often found companies and participate in public procurements,

GLISCO Company considered important to provide a session of training about bid process.

2.1. Some definitions

According to the Law No 12/2007 of 27/03/2007 on Public Procurement published in the Official

Gazette no 8 on 15

th April 2007, in its first chapter, article one of definitions, the second

definition is that of the bid or tender as an offer from a bidder. The third definition continues

with the bidder as any potential participant or participant in public procurement proceedings.

Hence all the definitions in the article one of the chapter one of the law introduced above are of

great essence for anybody anticipating participating in public procurement. Here they are, copied

from the Official gazette:

1° “Accounting Officer” means any official empowered to approve reports of the Tender

Committee and sign the contract on behalf of the procuring entity. This official must be

empowered by Law to act as a Chief Budget Manager within the public entity in which he is

employed;

2° “Bid or tender” refers to an offer from a bidder;

3° “Bidder” means any potential participant or participant in public procurement proceedings;

4° “Bidding Document” means the document containing information required for the

preparation of bids, the award process and the tender execution;

5° “Bid Security” means any guarantee by a bank or other relevant institution to allow the

prospective bidder to participate in tendering;

6° “Contract” means the agreement between the procuring entity and the successful bidder;

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7° “Consultant Services” refers to activities of an intellectual or of immaterial nature.

8° “Constructor”, “Consultant” or “Supplier”, means any physical or legal person under

procurement contract with a procuring entity;

9° “Corrupt practice” means offering, giving, receiving, or soliciting money or anything of

value to make a public official partial in the tender award or contract execution process;

10° “Day” refers to every weekday including holidays unless stated otherwise;

11° “Fraudulent Practices” refer to any act of lying, providing misinformation, including

collusive practices among bidders aiming at influencing the procuring entity to making wrong

decisions or to giving room for poor execution of the contract;

12° “Goods” or “supplies” means objects of every kind and description including raw

materials, products, equipment be it in solid, liquid or gaseous form, electricity, as well as

services that are linked to the supply of the goods if the value of those services does not exceed

that of the goods themselves.

13° “Performance security” means any guarantee by a bank or any other relevant institution

established to guarantee the procuring entity that in case the contract is not performed, be it

technically or at the level of deadlines, the procuring entity would receive the amount provided

for such a guarantee;

14° “Procuring entity” means Central Government authority, Local Government authority,

public institution, commission, Government project, parastatal, agency, or any specialized

institution engaged in procurement process and entering in contract with the successful bidder.

15° “Public Procurement” refers to the supplies or goods, works, consultant services and other

services as they may be needed by a procuring entity;

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16° “Tender Committee" means a committee established by the procuring entity to assist the

Procurement Unit, in the bid opening, evaluation and recommend for award of procurement

contracts;

17° “Services” refers to any services other than consultant services.

18° “Successful bidder” means a bidder whose offer has been accepted after being considered

the most competitive both technically and financially. It also refers to one who has concluded a

procurement contract with a procuring entity without having been subject to tendering

proceedings;

19° “Terms of reference” means the document prepared by the procuring entity defining the

requirements for an assignment and means to be made available, concerns to be taken into

account as well as the expected results;

20° “Works” mean all activities related to the realization of building or engineering works upon

the request by the client.

Not only these definitions are important but the entire law has to gone through in order to work

as a good bidder what leads to success.

The ultimate goal of the bid process is to ensure open and free competition. In the following,

some points highlighted from the law are going to be discussed.

These key definitions are accompanied by other articles about the public procurement as it is

well explained in the full law. We are now concerned with some of the articles we had chance to

explore during the internship but we don‟t copy them as they are instead we try to write a kind of

summary.

2.2. Public procurement

This summary is started by the public procurement. As it is defined in article one, definition 15,

it refers to the supplies or goods, works, consultant services and other services as they may be

needed by a procuring entity; the procuring entity is also defined in definition 14 of article one

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chapter one. In article 25 of chapter three, it is explained the rules concerning description of

goods, works and consultant services.

The figure below shows the handwriting of Eng. HABIYAKARE Eric explaining the public

procurement and evaluation of bids.

Fig.2.1. Evaluation of bids by Eng. HABIYAKARE Eric

The article 64 of chapter three and section three states that The Tender Committee shall evaluate

each technical proposal on the basis of criteria disclosed in the request for proposals. This

request for proposals includes:

1° the consultant‟s relevant experience for the assignment;

2° the quality of the methodology presented;

3° qualifications of key personnel proposed for the assignment;

4° transfer of knowledge, if required in the terms of reference;

5° the extent of participation by nationals among key staff in case of international tendering;

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The article 65 in the same section is about evaluation of financial proposals. The article starts

stating that the financial proposals shall be opened and evaluated only after completion of the

technical proposal. It continues with other requirements to open them and explains the way to

success. The regulations of procurements play a big role in that matter.

Sometimes all bids can be rejected according to the reasons provided in article 40 of chapter

three.

Below there is an example we had, of three bidders submitting their proposals to the client. It is

assumed that the technical proposal (T) will cover 80% of the score and the financial proposal

(F) 20%. The formula for the final score can so be written

Sfinal = 0.8T + 0.2F (2.1)

The financial score F is computed according to the formula:

(2.2)

where Fm is the cheapest financial proposal and F‟ is the considered financial proposal (that of

the current bidder).

The following table shows the bidders with their respective technical scores acquired before and

their financial proposals in the third column. The fourth column is filled with the financial score

after applying the formula (2.2). Which bidder is going to be successful? Of course the one who

will have much score after applying the formula (2.1). Before one can do any calculation to fill

the table below, he has to notice that the cheapest financial proposal Fm is 7,000,000 RWF.

Table 2.1.Evaluation of bids (Eng. Eric HABIYAKARE)

Bidders Technical score (%) Financial proposal (RWF) Financial score (%)

Bidder 1 75 10, 000,000 70

GLISCO 70 7, 000,000 100

Bidder 3 82 12, 000,000 58.33

For Bidder 1,

For GLISCO,

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For Bidder 3,

Let‟s then apply the formula (2.1):

For Bidder 1,

For GLISCO,

For Bidder 3,

Observations: Bidders cannot have trust in only one proposal. Technically, GLISCO would seem

to fail immediately and the third bidder successes. On contrary, after financial proposals

evaluation and the combination of the two a change displays; GLISCO becomes the successful

bidder and the others fail. It is then GLISCO who is going to sign the contract.

Article about the contract and other relevant rules are not gone through due to little time, but the

law on public procurement introduced above clarifies everything.

2.3. Some important documents

Any bidder is urged to have administrative documents, technical documents and financial ones.

Among those documents we can say the trade register from Rwanda Development Board RDB;

the certificate of no claim to the RRA (Rwanda Revenue Authority); the bidder has also to be

registered in the Social Security Fund of Rwanda SSFR (CSR) and register for VAT (Value

Added Tax) in RRA. He will have to buy the bidding document, to possess the inspection

certificate and the bid bond…

After checking all these documents and the bid evaluation terminated, the successful bidder gets

ready to sign the contract with the client; both the parties ought to respect everything written

inside.

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CHAPTER III: CONCLUSION AND RECOMMENDATIONS

According to the works and observations done at the site, the points developed in the following

paragraphs are highlighted.

The implantation of a building is a large task so that the building team has to be careful in order

to achieve the strength and the quality of the building. This care is needed from preliminary

studies and design of the building, through terrain excavation and building construction up to the

latest work on the building when it is then available for service.

The dumpy level is a very necessary instrument at the construction sites as it easies the work of

leveling and a part of quantity surveying where depths are to be determined.

Lack of attention in some works can cause losses in workers and materials and slow down the

project. We can say for instance when the builder might be careless about where footings have to

be set; once one or more footings are built where they could not be, they will be rearranged and

any work done before together with used materials and the time included are a loss.

The skeleton frame is the main support of the whole building and is largely made of concrete.

The builder should remember that the preparation of the reinforced concrete and casting it is one

of the most important factors to strengthen the building.

The segregation of the concrete is one of the factors to fear while constructing any concrete

structure and this has to be avoided as it causes losses of money once structures facing such a

case are destroyed and rebuilt. The concrete has to be workable with enough viscosity and the

control of the vibration is of great importance to avoid segregation.

In chapter two dealing with the tender process, we can recall that to be a successful bidder, one

has to know well all regulations and requirements to write and submit proposals either technical

or financial or both of them for a given tender. The law on Public Procurement referred to in this

report details everything about the tender process.

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This internship, even though it spanned not for a long time, it is the good key for any civil

engineer preparing to begin his carrier. It develops theoretical acquisitions and translates them

into reality.

The National University of Rwanda should keep on strengthening its excellence in education and

service to the people as the engineering skills it provides are found practicable and reveal

incomparable. It should also make multilateral relations with companies executing engineering

works and services in order to help students to get carrying out their internship easily and

advantageously for both the students and the company.

The students should feel confident of what they study and make deep research to meet the civil

engineering market where they are needed for the country development. “The theory we had is

not like dreams my dear students; courage!”

GLISCO and other companies as well, could have no fear to recruit the National University of

Rwanda graduates as they have excellent background in matter of civil engineering carrier.

Ideas of readers of this report about any subject are of great essence. Thanks.

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Copy of the recommendation letter

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Copy of the insurance certificate

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Copy of the admission letter

34

References

I. GLISCO by

1. Eng. HABIYAKARE Eric and

2. UWIZEYIMANA Théogène

II. STRONG CONSTRUCTION COMPANY by

1. NSABIMANA Callixte

III. Textbooks

1. Construction Technology, An illustrated introduction, Eric Fleming;

2. CONSTRUCTION THECHNOLOGY FOURTH EDITION, ROY CHUDLEY

AND ROGER GRRENO;

3. Reinforced Concrete, Design Theory and Examples Second Edition. T.J MAC

GINLEY and B.S. CHOO BS8110 / NUR Main Library;

IV. Electronic sources

1. Official Gazette of the Republic of Rwanda Year 46 n° 8, 15 April 2007/ LAW N° 12/2007

OF 27/03/2007 ON PUBLIC PROCUREMENT

[http://mininfra.gov.rw/index.php?option=com_content&task=view&id=62&Itemid=93]

2. http://www.bestsampleresume.com/sample-engineering-resume/civil-engineering-

resume.html