sample: PRACTICAL TRAINING 2 REPORT.....

PRERACE

Practical Training (PT) is the one part of the four year B.Sc. (Eng.) degree course offered by the college of Engineering and Technology (CoET) at the University of Dar se Salaam. The Practical Training program takes duration of eight (8) weeks and it is conducted after the second semester of each academic year. The PT implements the theory taught at the college and the practices performed during workshop sessions. The PT has the following main goals;

· To provide knowledge of materials, processes and human relations

· To train the students skills in using equipment’s and tools

· To develop abilities of planning, organizing and communicating

· To foster attitudes of awareness and respect for work and of thinking in terms of cost and efficiency.

· Also provide the reality to those structure leant by students in the class to that on the site.

· Interaction with other construction members at the site whom will work with after completion of the university.

Generally; The Practical Training program provides an opportunity for the students to relate theory and practice. It offers training in a real life that can’t be simulated in lecture rooms or departmental workshops. Thus, besides being productive, the students can learn about the problems they encounter in their future focus enabling them conduct objective assessments of the courses being offered in their undergraduate studies and therefore choosing their options sensibly. None can thus have Engineering professional without Practical Training. PT is therefore a bridge (connection) of one’s professional between the Engineering Training Institutes (colleges) and the construction firms (companies).

ACKNOWLEDGEMENT.

With genuine humility and much respect I thank the almighty God for his endless love and mercy that he provides to me always in my life and for the strength that he gave me during the period of practical training.

It is with profound enchantment that I extend my heartfelt gratitude to the following people

My train officer Eng. SANCHO RWANDALLA

Site foreman Mr. IPALALA

Academic supervisor

Their contribution in my practical training is invaluable, reminiscent and hence unforgettable

I would also like to thank all staffs of WESTERN ENGINEERING LIMITED for the cooperation they have given me during my practical training in their company

May God Bless You All

INTRODUCTION

GENERAL INFORMATION OF THE COMPANY

WESTERN ENGINEERS LIMITED (W.E.L) is a multidisciplinary Local Construction company, founded and registered in Tanzania with Engineer’s Registration Board (ERB) in 1998 as Local Engineering Consulting Firm. NCL is also a member of the Association of Consulting Engineers (Tanzania) (ACET); the association is affiliated to FIDIC.
The firm is wholly owned by ENG SAMWEL RWANDALLA and is also legally registered under the Companies Ordinance (Cap. 212) and currently operating through its office located in Arusha city center, located at OTTU offices complex.

Vision
WEL has the vision of being the Best Engineering Company to all of its Clients. To attain its vision and maintain it, the company has a set of nine core values which are:-

Client's Satisfaction
Flexibility
Openness and Transparency
Team work
Ethics Integrity and Professional conduct
Best quality in construction
Affordability
External region branches expansion
Employment opportunity availability

Missions

· To exceed Client's expectations by providing quality services within the given time frame work.

· Also high efficiency in construction and reaching the contemporary world standards.

· The company also aims at conserving the environment and creating the harmless atmosphere for the beneficiaries of the projects conducted.

These missions have always been possible due to the pre mentioned core values the company has. It is these missions that are taking the company to the fore front of multi-disciplinary engineering projects and management practices.

PROJECT SUMMARY

I conducted my practical training at WESTERN ENGINEERING LTD in Arusha and completed it successfully in all eight weeks. My practical training started on 2th July 2015 and end up on 17th august 2015. The tasks which I mainly performed during my practical training were:

· Slab work

· Column works

· Concreting

· Formwork

· Steel works

· Operation of tools, machinery and equipments

PROJECT LOCATION

The project was located at Arusha district along corner Nairobi road.it is 4km from Arusha bus station, it is at place called Osterbay

PROJECT PURPOSE

The main purpose of the project was to construct 6 storey’s Commercial building

COMPANY SOURCE OF FUNDS AND MANAGEMENT.

Western Engineers Limited’s main source of funds is the on-going projects performed by the company regional wise. The company performs many big projects in Arusha at a rate of 3 projects per year.

Other sources of funds to the company are bank loans and small businesses. Loan from banks has not been an effective source since the interest rates were raised and hence minimized the profits from the project. This is the main setback to the progressively growing construction companies.

WEEKLY REPORTS

1^ST WEEK SUMMARY

BEAM CONSTRUCTION

The beams are the horizontal load bearing structures; they are used to transmit load to the column the slab would be supported by those beams.

SKILLS AND MANPOWER

· Structural engineer

· Site engineer

· Technicians

· 4 unskilled labours

MATERIALS

· Ply wood shutters

· Nails

· Grade 25 concrete

· High tensile steel of diameter 25mm, 20mm, 12mm,10mm and 8mm,(Y25, Y20, Y12,Y10 andY8) complying BS 4661 grade 460.

· Binding wires

· .Spacer block

TOOLS/MACHINE/EQUIPMENTS USED

· Plywood cutting machine

· Hammer

· Tape measure

· Grander machine for cutting steel bars

· Pair of pincers ( for tightening and cutting wires)

· Claw bar (for bending the steel bars) were made by Y32

PROCEDURES

· The steel bars were cut in their lengths and bent to as illustrated in the bending shadle and transported just near by the slab

· The steel bars were lifted using ropes from the ground to the 1^stfloor level

· Spacer blocks were positioned in the bottom of beams to ensure that bottom bars acquire enough concrete cover and prevent their oxidation and rust

· The steel bars were fixed starting from the beam bottom top bars and attached by rings via wire binders followed by slab bottoms and tops separated by chairs

· Spacer blocks were inserted throughout the whole portion with steel bars ready for concreting

INFLUENCE OF THE ENVIRONMENTAL CONDITION

Weather: had no any adverse effects in steel fixing activities

LIMITATION

· receiving of some low quality reinforcement i.e. brittle steel from the suppliers

· problem of corrosion influenced by the climate of the site

SAFETY PRECAUTIONS:

· Helmets

· Boots

· Overalls for the concrete team

CONCLUSION:

Beam construction procedures and techniques are well understood.

2^ND WEEK SUMMARY

STEEL WORKS FOR SLAB CONSTRUCTION

Slab is the horizontal structure in the building where the load is exerted and then transferred to the beams where its again transferred to the columns then down to the foundation and being distributed to the soil (hard stratum).the slabs is used in making the balcony and floors in the building as well as is used in carrying the loads.

SKILLS AND MANPOWER

Ø Students.

Ø Unskilled labours.

Ø Site foreman.

Ø Consulting engineer.

Ø Site engineer.

MATERIALS

· Ply wood shutters

· Nails

· Grade 25 concrete

· High tensile steel of diameter 25mm, 20mm, 12mm,10mm and 8mm,(Y25, Y20, Y12,Y10 andY8) complying BS 4661 grade 460.

· Binding wires

· .Spacer block

TOOLS/MACHINE/EQUIPMENTS USED

· Plywood cutting machine

· Hammer

· Tape measure

· Grander machine for cutting steel bars

· Pair of pincers ( for tightening and cutting wires)

· Claw bar (for bending the steel bars) were made by Y32

PROCEDURES

ü The working drawings were used to establish the level of underside of the floor slab. this became the level of the top of the formwork deck.

ü Put up the supporting framework of props, ledgers, and joists and nails the formwork deck to the joists. When the formwork had been fabricated and assembled the interior of the forms should be cleared of all rubbish, dirty and grease before the application of any mould oil or releasing agent. All the joints and holes should be checked to ensure that they are grout tight.

ü The entire structures were leveled by adjusting the wedges and the diagonal bras were nailed across the props to stiffen them.

ü Inspection was done to the deck for open joints and the gaps were filled with building papers and usable materials.

ü The deck was treated with the oil, which would make it easier to remove the formwork when finished.

ü The electrical conduits for first floor wiring and ceiling lights for the floor below were attached to the formwork.

ü All others pipes for other services were attached.

ü The reinforcement bars as shown on the drawings were cut and bent. They were laid out on the formwork and separated at the intervals by concrete spacer blocks and spacer bars then the bars were tied in position with the soft steel wire.

INFLUENCE OF THE ENVIRONMENTAL CONDITION

Weather: had no any adverse effects in steel fixing activities

LIMITATION

Receiving of some low quality reinforcement i.e. brittle steel from the suppliers problem of corrosion influenced by the climate of

SAFETY:

To ensure safety at the site, the trainees we were given:

· Helmets to protect their heads against falling debris and other

· The use of boots

· The use of safety belt

· Overalls for some worker

RECOMMENDATION.

For the safety of labours and quality of the work all probs must be painted to make them free from rust which may bring the disaster during the the construction.

3^RD WEEK SUMMARY

CONCRETE CASTING FOR BOTH SLAB AND BEAM

Concrete is used to make foundations, floors, stairs and roofs. The general principals of making a concrete are that you mix cement, fine aggregates (sand) and course aggregates with water

Cement: powder produced from clay and chalk or limestone. In general most concrete is made up with ordinary or rapid hardening cement and it is act as a binder.

Aggregate: shape, surface texture and grading (distribution of particle size) which are factors which influence the workability and strength of a concrete mix.25 mm course aggregate was used.

Water must be clean and free from impurities which are likely to affect the quality or strength of the resultant concrete

SKILLS AND MANPOWER

Skilled labourers involved: 1 civil engineer,

1Civil technician.

Unskilled labourers involved: 10 labourers.

TIME REQUIRED

The work took total of 48 hours with approximately 8 hours per day.

MATERIALS USED

· Sand

· Manila strings

· Cement

· Aggregates

· Water

TOOLS AND EQUIPMENT

ü Concrete mixer:.

ü Pumping machine

ü Poker vibrator

ü Hose pipe

ü Basket.

ü Spades

ü Steel trowel.

ü Concrete lift.

PROCEDURES

v Mixing or Preparation of concrete whereby cement, sand and coarse aggregate in ratio (1:2:4) were poured into the concrete mixer.

v Ready mixed concrete were moved to the slab using wheelbarrow and buckets

v Concrete were then poured to the slab.

v Then the poured concrete was compacted using vibrator to remove air inside

v Finally the concrete were left cured for seven days

SAFETY PRECAUTIONS;

To ensure safety at the site everybody were given:

· Helmets to protect their heads against falling debris

· The use of boots

· Overalls or overcoats

RECOMANDATION.

ü The cement had been checked whether it was manufactured recently.

ü The ratio should be controlled while mixing

ü The workers should have safety gears for their health and safety.

ü The pegs and marks exposed should be followed while leveling the concrete.

ü The selection of the equipment should match the work to be done

ü Concrete should be well compacted.

CONCLUSION:

The week ended safely. Also, the activities I learned were well and successfully understood and I appreciate such kind of work.

4^TH WEEK SUMMARY

STEEL FIXING FOR PROJECTING COLUMN AND SHUTTERING OF THE 1^ST STOREY

Formworks for in situ concrete work may be described as a mould or box into which wet concrete can be poured and compacted so that it will flow and finally set to the inner profile of the box or mould.

Formwork is the temporary support structure to hold the wet/green concrete till it hardens

In order to construct formwork, there are requirements followed to be successful in its function:

Safety: it should be strong enough to support the load of wet concrete which is generally considered to be approximately 2400 kg/m³.

It must not be able to deflect under load which would include the loading of wet concrete, self weight and any superimposed loads such as operatives and any barrow runs over the formwork.

Quality: it must be accurately set out, concrete being a fluid when placed; it will take up the shape of the formwork which must therefore be of the correct shape, size and in the right position.

Economy: it should be designed and constructed so that it can be easily erected and struck, so saving both time and money.

It must have grout-tight joints. Grout leakage can cause honey combing of the surface or produce fins which have to be removed. The making good of defective concrete surfaces is both time consuming and costly. Grout leakage can be prevented by using sheet materials and sealing the joints with flexible foamed polyurethane strip or by using a special self adhesive tape.

Form sizes should be designed so that they are the maximum size which can easily be handled by hand or by mechanical lifting device.

Material must be chosen so that it can be easily fixed using either double headed nails, round wire nails or wood screws. The common method is to use nails and these should be at least two and half times the thickness of the timber being nailed, in length.

The design of the formwork units should be such that they can easily be assembled and dismantled without any members being trapped.

01. TYPES OF THE FORMWORKS FOR DIFFERENT PURPOSES.

· Foundation formwork

· Column formwork

· Beam formwork

· Slab formwork

· Stair-case formwork

SKILLS AND MANPOWER

· Site engineer

· Students

· Site foreman

· Unskilled labourers

MATERIAL USED

ü Marine board for making column.

ü Timber (1”*6”, 1”*8”, 1”*10” and 2”*4”).

ü Nail (3”, 4” and 2.5”).

ü Props.

TOOLS/ MACHINES

· Plywood cutting machine

· Hammer

· Tape measure

· Grander machine for cutting steel bars

· Pair of pincers ( for tightening and cutting wires)

· Claw bar (for bending the steel bars) were made by Y32

· Binding wires

PROCEDURES

· The steel bars were cut in their lengths and bent to as illustrated in the bending shadle

· The steel bars were lifted using ropes from the ground to the 1^stfloor level

INFLUENCE OF THE ENVIRONMENTAL CONDITION

Weather: had no any adverse effects in steel fixing activities

LIMITATION

Receiving of some low quality reinforcement i.e. brittle steel from the suppliers problem of corrosion influenced by the climate of

SAFETY:

To ensure safety at the site, the trainees we were given:

· Helmets to protect their heads against falling debris and other

· The use of boots

· The use of safety belt

· Overalls for some worker

5^TH WEEK SUMMARY

CONCRETE CASTING FOR COLUMN

Concrete is used to make foundations, floors, stairs,columns and roofs. The general principals of making a concrete are that you mix cement, fine aggregates (sand) and course aggregates with water

Cement: powder produced from clay and chalk or limestone. In general most concrete is made up with ordinary or rapid hardening cement and it is act as a binder.

Aggregate: shape, surface texture and grading (distribution of particle size) which are factors which influence the workability and strength of a concrete mix.25 mm course aggregate was used.

Water must be clean and free from impurities which are likely to affect the quality or strength of the resultant concrete

The following figure shows the column that is casted with concrete

SKILLS AND MANPOWER

Skilled labourers involved: 1 civil engineer,

1Civil technician.

Unskilled labourers involved: 10 labourers.

TIME REQUIRED

The work took total of 48 hours with approximately 8 hours per day.

MATERIALS USED

· Sand

· Manila strings

· Cement

· Aggregates

· Water

TOOLS AND EQUIPMENT

ü Concrete mixer:.

ü Pumping machine

ü Poker vibrator

ü Hose pipe

ü Basket.

ü Spades

ü Steel trowel.

ü Concrete lift.

PROCEDURES

v Mixing or Preparation of concrete whereby cement, sand and coarse aggregate in ratio (1:2:4) were poured into the concrete mixer.

v Ready mixed concrete were moved to the slab using wheelbarrow and buckets

v Concrete were then poured to the columns.

v Then the poured concrete was compacted using vibrator to remove air inside

v Finally the concrete were left cured for seven days

SAFETY PRECAUTIONS;

To ensure safety at the site everybody were given:

· Helmets to protect their heads against falling debris

· The use of boots

· Overalls or overcoats

RECOMANDATION.

ü The cement had been checked whether it was manufactured recently.

ü The ratio should be controlled while mixing

ü The workers should have safety gears for their health and safety.

ü The pegs and marks exposed should be followed while leveling the concrete.

ü The selection of the equipment should match the work to be done

ü Concrete should be well compacted.

CONSTRUCTION OF STAIRS CASE OF FIRST FLOOR

INTRODUCTION

A stair is a number of at least 3 steps leading from one level to another in order to provide means of movement between different levels of floors of a building

The stairs were located such that they save the purpose for they are provided, all planning needs and consideration of all possible factors were cared, and the stairs were placed near the main entrance since the building is for public uses

ü The type of stairs we constructed was concrete stairs which are widely used in all types of buildings

The waist thickness was 195mm

Number of steps constructed= 7 steps

Height of flight of rise= 200mm

Going of flight =3600mm

Skills and Manpower

Skilled labourers: 3civil technician, 3engineer,8 unskilled: 25labourers

Time required

The work took 8 hours

Material used, their sources and origin

· Course aggregates

· fine aggregates

· Portland cement

· timber and marine boards for formworks

· nails

· Reinforcement bars (steel bars of diameter of 12mm).

· Spacers

· Binding wire

· Marker(chalk)

Tools and machinery used

Concrete mixer, hammer, hand saw, buckets, tape measure, spirit level etc

PROCEDURES FOR THE CONSTRUCTION OF STAIRS

· preparation of material for formwork and timber supports

· measurements to know dimensions and space to locate formwork, to set out -the height from one floor to another was first checked, that total rise was divided into a suitable numbers of risers and then the proportionate size to the go was calculated

· formwork was fixed according to the required dimensions

Steel fixing on the formworks of stairs

Ø main steel bars were placed on the formwork at an appropriate distance apart according to the specific engineering drawings

Ø marking off the dimensions using a chalk for placing distribution bars i.e. 200mm

Ø The main bars were crossed at 90 degrees with steel bars at an approximately 200 apart and firmly tied using binding wire with the help of a pincer.

Ø The fixed reinforcements were overlapped with the previously steel used to reinforce the foundation projecting upwards of floor concrete with dimensions of approximately 400mm found at the start and at the end of the stair case.

Bending of protruding steel was simply done using special mould.

Ø Additional crossing bars were fixed with ready placed steel together with foundation reinforcements projecting.

Ø Block spacers of 1 inch were properly placed beneath the steel reinforcements for the aim of providing an adequate concrete cover to avoid the corrosion of steel.

· Formworking for the steps was accurately done, verticality and horizontality of formwork was ensured using the spirit level, the riser was 150mm and the going was 300mm.

FORMWORKING AND STEEL FIXING FOR STAIRS

· Watering of formwork was done prior to the casting of concrete

· Concreting was done on the constructed structure of formwork by starting on the lowest to the highest point

CONCRETING

· Compaction was properly done using the poker vibrator

· Curing of stairs continued and stripping of formwork was later done

Influence of environmental conditions

Weather: dry/sunny

Work of concreting for stairs was affected by dry condition where by much water evaporates and leading to poor hydration process of the concrete consequently result to frequent curing to control excessive loss of water by evaporation

Limitations

Difficulty in attaining levels of the forms with the use spirit level and uniform dimensions of goings.

Safety precautions

Safety tools: gumboots, safety goggles, hard helmet, etc.

Safety precautions taken:

(i) Wearing safety gears like hard helmet to ensure maximum protection of workers from site risks.

(ii) Wearing of open shoes like slippers is strictly prohibited for the workers; they should put in closed shoes to protect them from injury.

(iii) Long sleeves and pants to reduce skin exposure to concrete or cement dust.

(iv) Remember to wash your hands and before eating, drinking .

Conclusion and recommendation

Advantages of concrete stairs include;

· Higher fire resistance

· Can be casted in any desired geometrical pattern and desired color finish

· Lower maintenance cost compared to other types of stairs

As recommended they must be proportionally right, aesthetically pleasing, and uniform and dimensionally correct.

6^THWEEK SUMMARY

SHUTTERING OF BEAMS OF 2^ND STOREY

Formwork is the term given to either temporary or permanent mould into which the concrete or similar materials are poured

A beam formwork consists of a three sided box which is supported by cross members called head trees or props which were propped to the underside of the soffit board. The floor or roof slab formwork is sometimes called shuttering and consists of panels of size that can be easily handled. The beam form was also used to support the slab formwork and the two structural members were cast together

The slab beams formwork consist of support (props) arranged in rows spaced in 150mm to 200mm apart depending on the thickness of slabs. At our site the beam formwork were immediately supported by the columns.

In order to construct formwork, there are requirements followed to be successful in its function:

Safety: it should be strong enough to support the load of wet concrete which is generally considered to be approximately 2400 kg/m³.

It must not be able to deflect under load which would include the loading of wet concrete, self weight and any superimposed loads such as operatives and any barrow runs over the formwork.

Quality: it must be accurately set out, concrete being a fluid when placed; it will take up the shape of the formwork which must therefore be of the correct shape, size and in the right position.

Economy: it should be designed and constructed so that it can be easily erected and struck, so saving both time and money.

Form sizes should be designed so that they are the maximum size which can easily be handled by hand or by mechanical lifting device.

The design of the formwork units should be such that they can easily be assembled and dismantled without any members being trapped.

TYPES OF THE FORMWORKS FOR DIFFERENT PURPOSES.

· Foundation formwork

· Column formwork

· Beam formwork

· Slab formwork

· Stair-case formwork

SKILLS AND MANPOWER

· Site foreman

· Students

· Unskilled labourers

MATERIAL USED

ü Marine board as the side of beam slabs form work.

ü Timber (1”*6”, 1”*8”, 1”*10” and 2”*4”).

ü Nail (3”, 4” and 2.5”).

ü Props.

1.2 TOOLS USED

ü Hand saw.

ü Tape measure.

ü Rope for lining.

ü Spirit level for lining.

ü Claw hammer and ladders

PROCEDURES

v The all materials were prepared, as the timbers were planed to the required size (1”*6”, 1”*8”, 1”*10” and 2”*4”) and the props were cuts to the required size.

v The soffits of the beams were constructed first followed by the side of the beams internally and the slabs soffits were constructed per the drawing.

v The props were placed 150mm to 200mm apart so as to sustain the loads of and beams.

v Lastly the external side were placed per the drawing and supported per specification as shown to the drawings.

INFLUENCE OF THE ENVIRONMENTAL CONDITION

Weather: had no any adverse effects in steel fixing activities

LIMITATION

Receiving of some low quality reinforcement i.e. brittle steel from the suppliers problem of corrosion influenced by the climate of

SAFETY:

To ensure safety at the site, the trainees we were given:

· Helmets to protect their heads against falling debris and other

· The use of boots

· The use of safety belt

· Overalls for some worker

7^TH WEEK SUMMARY

SHUTTERING OF SLAB OF 2^ND STOREY

Formwork is the term given to either temporary or permanent mould into which the concrete or similar materials are poured

SKILLS AND MANPOWER

· Site foreman

· Students

· Unskilled labourers

MATERIAL USED

ü Marine board as the side of beam slabs form work.

ü Timber (1”*6”, 1”*8”, 1”*10” and 2”*4”).

ü Nail (3”, 4” and 2.5”).

ü Props.

TOOLS USED

ü Hand saw.

ü Tape measure.

ü Rope for lining.

ü Spirit level for lining.

ü Claw hammer and ladders

PROCEDURES

v The all materials were prepared, as the timbers were planed to the required size (1and the props were cuts to the required size.

v the slabs soffits were constructed per the drawing.

v The props were placed 150mm to 200mm apart so as to sustain the loads of and beams.

v Lastly the external side were placed per the drawing and supported per specification as shown to the drawings.

INFLUENCE OF THE ENVIRONMENTAL CONDITION

Weather: had no any adverse effects in steel fixing activities

LIMITATION

Receiving of some low quality reinforcement i.e. brittle steel from the suppliers problem of corrosion influenced by the climate of

SAFETY:

To ensure safety at the site, the trainees we were given:

· Helmets to protect their heads against falling debris and other

· The use of boots

· The use of safety belt

· Overalls for some worker

8^TH WEEK SUMMARY

BLOCKWORKING

A wall is a vertical solid structure, made of stone, bricks, blocks or reinforced concrete, which surrounds, divides or protects an area of land. For our site, we had the walls of blocks except on the lift where we used reinforced concrete and we had stretcher bond.

The strength and durability of wall is primary depend on the following factors:

i. The quality and strength of the blocks

ii. The type of the mortar used

iii. The method of bonding used in the construction

Mortar is usually a mixture of cement and sand or lime and sand or mixture of the three i.e. cement, sand and lime. For our site, we had mortar of cement and sand with the ratio of 1:5 (cement: sand)

On site, we have two types of walls:

1. Load-bearing walls (230mm): Transfer load to the foundation/support and are usually external walls and those supporting roofs, upper floors and other components in a building.

2. Non-load bearing walls (Partition walls: 150mm): Dividing rooms

SKILLED AND MAN POWER USED

· Foreman

· 3 craftsmen

· 3 Uskilled labours

· 2 trainees students

MATERIALS

· Sand

· Cement

· Blocks

· Water

TOOLS/MACHINE/EQUIPMENTS USED

· Trowel

· Spade

· Hammer

· Spirit level

· Plumb bob

PROCEDURE

· Mortar mixing

· Placing the guiding blocks at the ends of the wall location

· Placing the rope to guide block aligning

· Water pouring to the zone to be built in order to remove the dust

o Spreading the mortar using the trowel and maintain the level using the spirit level

· Arranging of the blocks and binding them with the sand-cement mortar using English type of bonding

PROBLEMS

During this week the main problem encountered was the shortage of cement

SAFETY:

To ensure safety at the site, the workers were given:

· Helmets to protect their heads against falling debris and other objects.

· Few workers had their own boots to cover their legs when working and thus protecting them against injuries

CONCLUSION:

The week ended safely since there wasn’t any problem happened or reported. Also, the activities I learned during the six week were well and successfully understood.

SPECIFIC REPORT

STEEL FIXING FOR SLAB (REINFORCEMENT OF SLAB)

Slab is the major part on the building in which the partition of rooms are made after casting with concrete. The reinforcement on slab that comprise of:-

· bottom (bottom one and bottom two) and

· top bars (top one and top two).

These bottom and top bars are separated by the use of spacer chairs which is placed between them, normally the bars are placed on the top of slab formwork which is constructed by the use of marine board or plywood

Reinforcing steel in slab acts not only to resist tensile forces, but also compression. Reinforced concrete gets its strength from the two materials, steel and concrete, working together. To get them working together, it is critical that the steel be adequately bonded to the concrete.

Since in any building that involve the use of concrete that is mixture of cement, sand, aggregates and water there must be involvement of steel due to the fact that concrete is rich in compression and the compensation of this is steel which is rich in tension,

Reinforcement includes deformed bars, plain bars, wire, fabric and steel products, all of which increase the tensile and compressive stress carrying properties of concrete. Steel reinforcement is also the essential contributor towards crack control of concrete structures.

ADVANTAGE OF STEELS WHEN USED AS REINFORCEMENT

Steel is used as reinforcement in concrete owing to its following qualities

· High tensile strength

· Good bond with concrete

· Nearly same coefficient of expansion as that of concrete

· Adequate quality control possible during the manufacture of steel

BASIC REQUIREMENTS TO BE SATISFIED BY REINFORCING BARS

Ø Bond strength

Ø Ductility

Ø Bend ability

Ø Weldability

Ø Fatigue strength

Ø Corrosion resistance

Ø Fire resistance

PRECAUTION FOR STEEL BARS IN REINFORCEMENT

· Should be stored in such a way to avoid distortion and corrosion

· Should not be clean by oily substance to remove rust

· Bars are bent correctly and accurately to the size and shape shown to their required drawings

· If possible bar of full length is used

· No overlap is given in the bar having a diameter more than 36mm

MATERIALS USED

v High tensile steel:, Y16, Y12, Y8.

v Binding wire

v Spacer block

v Pincers

TOOLS/EQUIPMENTS/MACHINE USED

· Pair of pincer

· Crow bar(Y20, Y16)

· Bender (Y20)

· Tape measure

· Bending pipe

· Grander machine

THE LOCAL BENDING MACHINE:

The machine was made out of woods, nails and an iron wage. For ring making machine, the nails were set to give the dimensions of the rings. The distance of the nails from the wages depended on the required length to bend (whether width or height of the ring). When bending, the bar to bend was inserted into a pipe to increase the bending moment and thus simplifying the task.

The diagram below shows how other machine can be prepared and placed for steel bending process.

CUTTING AND BENDING PROCESS

Using a cutting machine (grander), the bars were cut into different sizes including anchorage bends

Using bending machines, the bars were bent into the required shapes depending on their use. The bending machines the local (manually operated) machine.

CUTTING PROCESS BENDING PROCESS

ARRANGEMENT OF STEEL BARS IN THE SLAB

PROCEDURE/PROCESSES USED

· Obtaining the dimension on building that is space enclosed by slab and the whole parts of building

· Cutting the steel bar on required dimension by using grander and bending them on appropriate shape

· Fixing them on the required position into the slab as stated or shown on drawing with binding wire.

· Steel bars are arranged in the slab into tops and bottoms whereby there are top one and two and bottom one and two in which they are given spaces by considering the diameters used

· Normally bottoms one and two are full placed to the slab

· the top one and two are not necessarily fully placed(the top one and two are placed 1/3 of each end of the slab leaving the middle part empty of steel bars)

CONSTRUCTION OF SLABS

DIAMETERS OF THE BARS USED IN THE SLAB AND THEIR SPACING

When reinforcing slab we arrange bottom (bottom one and bottom two) and top bars (top one and top two) in different spaces by considering their diameter

DIAMETER	SPACING
8mm	50mm
10mm	100mm
12mm	150mm
16mm	200mm

TOLERANCES IN PLACING BARS

The strength of any concrete structure can be affected by improper positioning of the reinforcing bars. For example, the lowering of the top bars or raising of the bottom bars by 10mm more than specified in a 15cm slab could reduce its load-carrying capacity by 20%

PROBLEMS AND RECOMMENDATIONS

Problems encountered during construction include;

· Low technology; the technology used in most site activities was very poor. For example lifting up steel bars from the ground to the second floor was done by using a rope. This made the work very difficult and time consuming. Above all it was very dangerous for the ones performing it because the steel bars might have pulled them down the ground if they weren’t strong enough.

· Lack of sufficient safety gears; safety gears especially those to be used during concrete casting were very few. These included gloves and gumboots. Also in days where many workers were needed the helmets become insufficient.

· Lack of first aid kit; there was no safety aid in the site for emergency purposes just in case an accident occurred in the course of working.

· Changes in the working drawings which occurred in course of construction is another challenge for the project.

Relating office design works to real site conditions.
Untimely ordering of new safety gears to replace the worn out ones.
Insufficient provision of safety education among laborers.
Untimely payment of laborers.

RECOMMENDATIONS ON SOLVING THE PROBLEMS:

The client should make all the necessary changes at the early stages of the project to avoid inconveniences which may occur when changes are done in the course of construction.
Drawings should be available at the working places to provide a direct link between the drawings and the actual work.
There should be sufficient provision of education on the importance of safety to the laborers.
Sufficient provision of safety gears like boots, helmets, gloves and masks to fulfill the demand.
Workers should be properly paid to avoid inconveniences
The community should be educated about the HIV/AIDS awareness.
There should be regular replacement of the worn out safety gears.