Reading Materials for
IC Training Modules
Construction Workshop
IC PROFESSIONAL TRAINING SERIES
Last updated at AUGUST 2009 Copyright reserved by INDUSTRIAL CENTRE, THE HONG KONG POLYTECHNIC UNIVERSITY
Construction Workshop
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Objectives:
A. Builder’s Practices
9 To provide fundamental knowledge of site practices on reinforced concrete, use of different types of formwork, falsework and scaffolding in concrete building construction, 9 To provide practical knowledge on use of different types of finishes, plastering, brickwork and block work in building and civil engineering construction, 9 To develop the ability to appreciate the good practices and quality control in production of concrete on site; the latest construction methods and principles in use of different formwork and associated falsework, 9 To develop the ability to appreciate the good practices and workmanship of brickwork and blockwork, building finishes application including plastering and tiling works, 9 To attain the ability to transform detailed design drawings to real construction including “Setting out” in works of “Structural Concrete Practice”, “Formwork and Falsework” and “Plastering, Brickwork and Blockwork”, 9 To develop a sound knowledge safety practices and proper use of tools and equipment and scaffolding in preparation of formwork and falsework concrete and brickwork construction.
B. Plumbing works
9 To provide fundamental knowledge on water supply and drainage systems used in the local plumbing services works, 9 To develop sound knowledge of practices and safety use of tools, equipment and modern materials used in plumbing services work in buildings, 9 To attain fundamental skills and techniques in plumbing installation and maintenance of water systems and repair of defective plumbing works, 9 To develop the ability to appreciate the good practices, inspection, testing and commissioning of plumbing system.
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Introduction
This practical training is primarily designed for first year students from Department of Civil & Structural Engineering, Department of Building and Real Estate and Department of Building Services Engineering in The Hong Kong Polytechnic University. This chapter covers training programmes of fundamental building practices in construction works namely “Structural Concrete Practice”, “Formwork and Falsework” and “Plastering, Brickwork and Blockwork”.
Throughout the training, considerable emphasis is placed on the types and uses, in Hong Kong, of various materials and in particular modern materials and methods. Also it is expected that the trainees will gain from the training experiences an “appreciation” of good standards of workmanship. The safe use and care of hand and power machine tools forms an integral part of all activities, and the importance of good preparation work, as well as inspection and test methods and statutory requirements are also emphasised.
After the material and process introductory stage the trainees are given “real” work construction projects to do, many of an “on-site” nature. These projects are usually placed in the summer term of first year and will last for about five weeks in which trainees play key roles as in a building contractor. They allow the trainees to get managerial, group and supervisory work experience, and they enable trainees to get a sound appreciation of the techniques and skills necessary to achieve professional construction works. The site work training includes site planning and site office procedures; project design and costing; raw material ordering and control; site organisation; site work and site work supervision; construction; testing; and liaison with concerned parties.
It is considered that the above types of training experiences reinforce the trainees’ academic studies in construction topics and provide a good basis for their later work in the construction industry.
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Contents
Topics Page Construction Workshop Safety Instructions 6 - 9
PART I - Structural Concrete Practice 10 - 25
1.1 Introduction 10 1.2 Materials 10 1.2.1 Cement 1.2.2 Aggregates 1.2.3 Water 1.3 Production of Concrete 11 - 14 1.3.1 Batching 1.3.2 Mixing 1.3.3 Transport 1.3.4 Placing & Compacting 1.3.5 Compaction 1.3.6 Make Good Surface 1.3.7 Curing 1.4 Quality Control 14 - 16 1.4.1 Workability 1.4.2 Concrete Test Cubes 1.4.3 Temperature Control 1.5 Finishes 16 - 17 1.5.1 General Class of Finishes Hong Kong 1.5.2 Finishes Classified by Method of Forming 1.6 Construction Joint 18 1.7 Discussion & Exercises in Concreting 18 - 19 1.8 Type of Reinforcing Steel Bars 19 - 21 1.9 Cutting 21 1.10 Bending 21 1.11 Fixing Reinforcement & Cover to Reinforcements 21 - 22 1.12 Bar Bending Schedules 22 1.13 Discussion & Exercises in Steel Reinforcement 23 - 25
PART II - Formwork & Falsework 26 - 37
2.1 Hand Tools Safety 26 2.2 Woodworking Machines 26 2.3 Safety Rules in Use of Woodworking Machines 27 2.4 Scaffolding and Framework 27 - 30 2.4.1 Putlog Scaffolds 2.4.2 Independent Scaffolds 2.4.3 Framework 2.4.4 Materials 2.4.5 Safety Points for Erection of Scaffolding
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2.5 Falsework 30 2.6 Formwork 30 - 35 2.6.1 Precast Concrete Forms 2.6.2 Formwork for Cast-in-situ 2.6.3 Notes for Design Forms 2.6.4 Materials 2.6.5 Other Formwork Materials 2.6.6 Parts of Forms 2.6.7 Striking of Formwork 2.6.8 Investigative Method for Formwork 2.6.9 Practical Design Notes 2.7 Discussion & Exercises 35 - 37
PART III - Plastering, Brickwork & Blockwork 38 - 56
3.1 Basic Tools of the Trowel Trade 38 - 39 3.2 Materials 39 - 41 3.2.1 Cement Mortar 3.2.2 Cement Lime Mortar 3.2.3 Bricks 3.2.4 Blocks 3.3 Brickwork 41 – 43 3.3.1 Bonds 3.3.2 Procedures of Laying 3.3.3 Failure in Block Walling 3.4 Plastering 43 – 45 3.4.1 Undercoat Plaster 3.4.2 Finish Plaster 3.4.3 Preparation of Background 3.4.4 Applying Procedures 3.4.5 Problems Arising 3.5 Tiling practice 46 – 49 3.5.1 Glazed wall tiles 3.5.2 Mosaic tiles 3.6 Floor finishes 49 - 51 3.6.1 Granolithic Flooring 3.6.2 Cement Screed 3.6.3 Terrazzo 3.6.4 Floor Finishing 3.7 Paving 52 – 54 3.7.1 Interlocking Concrete Blocks 3.7.2 Design Considerations 3.7.3 Plant Requirement 3.7.4 Preparation Work 3.7.5 Laying Procedures
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3.8 Marble & Granite 54 – 55 3.8.1 Dry Mount Fixing 3.8.2 Shaping and Polishing Shaped Profiles 3.8.3 Polishing Procedures 3.9 Discussion & Exercises 55 - 56
PART IV - Plumbing Practices 57 – 71
4.1 Plumbing Systems 57 4.1.1 Cold Water Supply System 4.1.2 Hot Water Supply System 4.1.3 Surface Drainage Above Ground 4.1.4 Foul Drainage Above Ground 4.2 Materials, Valves, Fittings & Tools 58 – 63 4.2.1 Materials for Pipes 4.2.2 Types of Valves 4.2.3 Pipe Fittings 4.2.4 Tools and Machines for Pipework 4.3 Pipework Practices on Bending & Jointing 63 – 67 4.3.1 Student Exercises in Plumbing Practice 4.3.2 Common Symbols Used in Plumbing Works 4.3.3 Calculation of Pipe Length 4.3.4 Bending 4.3.5 Jointing 4.4 Sanitary Appliances Installations 67 – 69 4.4.1 Introduction 4.4.2 Materials Used in Sanitary Appliance 4.4.3 Types of Sanitary Appliances 4.5 Discussion & Exercises 70 - 71
PART V – Construction Project 72 – 74
5.1 Introduction 72 5.2 Learning Outcomes 72 5.3 Brief Syllabus Content 72 – 73 5.4 Learning Approach 73 5.5 Assessment 73 - 74
REFERENCES 75 – 78
BIBLIGRAPHY 79
RECOMMENDED READINGS 80
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CONSTRUCTION WORKSHOP SAFETY INSTRUCTIONS
General Safety Rules 1. When working in the construction workshops, you must wear safety helmet, safety shoes and appropriate personal protective equipment when performing tasks, 2. You should wear long trousers to reduce the risk of contact with sharp object or exposure to chemical or sparks; wearing of loose clothing in the workshops should be avoided, 3. Never attempt to use any tools/machines; unless you are fully trained and instructed in their uses, 4. You must wear appropriate personal protective equipment when working
with power driven or hand tools (e.g. abrasive wheels, cartridge operated fixing tools, drilling tools, screw drivers, hammers and chisels etc.), 5. Always report to your supervisors, if there is any defective tooling, 6. Always keep the workplace clean, dry and tidy, 7. Always bend your knees to a crouch position and keep your back straight when lifting objects, 8. You should be alert of the safety notices and posters in the workshops. Do not rush through an operation; you should not proceed on any task if you are uncertain of the safety procedures, 9. You must know where to assemble in case of fire. Be familiar with the fire escape route.
Precautions to be taken when working in “Formwork Workshop”: 1. Always ask permission from your supervisors before using any machines,
2. You must wear earmuffs and a face shield when using any machines,
3. Before using any machines, make sure all guards are correctly positioned and all hands are away from machines,
4. You must use push-sticks when using the electrical saw machines,
5. Students are not permitted to clean the dangerous parts of the machines unless instructed by the supervisors,
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6. You must wear appropriate personal protective equipment or when using hand tools (e.g. saws, sanding machine, drilling machine, hammer and chisels etc.).
Precautions to be taken when working in “Scaffolding Workshop”: 1. You must wear safety helmet, safety shoes and safety belt if necessary, 2. When erecting metal scaffold, you must follow the supervisor’s instructions, 3. Proper access and egress provided should be used and no climbing along the standards/ledgers of the scaffold should be allowed, 4. Don’t do any unsafe acts in particular when working on the scaffold, 5. No scaffold should be used unless it has been inspected by competent supervisor.
Precautions to be taken when working in “Structural Concrete Workshop”: 1. You must wear protective gloves when bending/fixing steel bars, 2. Always wear suitable goggles when grinding, 3. Always wear protective goggles and gloves, when cutting. Look out for the sharp end of cutting steel bar, 4. Make sure all safety guards are fixed and effective, before using powered tools/machines, 5. Never remove/change any part of any tools/machines, 6. Always knock the protruding nails into the wood immediately after dismantling formwork, 7. When batching concrete, you must wear protective mask, spectacles and gloves, 8. Always turn off the concrete mixer/cement mortar mixer, before loading and
unloading the materials.
Precautions to be taken when working in “Brickwork Workshop”: 1. When grinding and cutting bricks, blocks or tiles, you must wear suitable
safety gloves and spectacles,
2. Always wear safety mask and spectacles when mixing cement mortar, 3. You must wear safety goggles, mask and ear-muffs when polishing bricks/stones with grinders,
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4. Always wear ear-muffs when cutting paving block/tiles.
Precautions to be taken when working in “Structural Steel Workshop”: 1. Wear safety gloves and spectacles when handling and moving steel members. Look out for the sharp ends of the cut steel members, 2. You must wear safety goggles, mask and ear-muffs when performing cutting and grinding on steel members using steel cutting and grinding machines, 3. Welding activities should be kept to minimum and for demonstration only in this workshop, 4. Use fume extractor to extract fumes outside the workshop during welding process. The welding area should be well surrounded, kept dry and free of combustible materials; special precautions should be made to protect trainees around being affected by the intense visible light, 5. Always wear suitable protective clothing, gloves, goggle and face shield, when performing welding and handling the hot steel members.
Precautions to be taken when working in “Plumbing Workshop”: 1. Always be careful about the rotating parts of threading machines which are easy to clamp clothes/hair/fingers, 2. Wear safety gloves when handling sharp edges of the pipe works, 3. When using fire-gun, you must follow manufactures instructions and also ensure liquefied petroleum gas (LPG) is firmly connected to the fire gun and the surrounding area is free of combustible materials, 4. Make sure you have enough working space so that you don’t endanger other person nearby when using hand tools (e.g. stained spanner, wrench, hammer, chisel, screw driver etc. ...),
Precautions to be taken when working in “Anchoring System Workshop”: 1. Always ask permission from your supervisors before using any drilling machines,
2. Students should understand the working principles of different anchor
system before commencement of any installation of anchor system,
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3. You must wear suitable protective gloves, dust mask, goggles and earmuffs when drilling holes for anchor bolts and mixing chemical mixtures for adhesive anchoring system, 4. You must use the proprietary hammering shield for protection of hand during installation of push-in anchoring bolts.
Precautions to be taken when working in “NDT in Construction Workshop”: 1. Always ask permission from your supervisors before using any NDT machines, 2. Students should understand the working principles of different NDT system before carrying any NDT, 3. You must wear suitable protective gloves and goggles when carrying carbonation test using Phenolphthalein solution.
------Note: For safety management purpose, students working in this workshop are required to sign the student record sheet to ensure they have read and understood the above safety instructions. ------
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Part I – Structural Concrete Practice
1.1 Introduction
Concrete is a basic and major material in the local construction industry. When making structural elements of large buildings, the columns, the slabs and the beams, these members are subjected to tensile stresses and concrete is weak in resisting tension, steel is added to the members, hence the term "reinforced concrete" (R.C.).
1.2 Materials
1.2.1 Cement
Ordinary Portland cement (O.P.C.) which is manufactured to comply with BS 12 is most commonly used for making concrete where no special properties are required. It develops strength quickly enough for the general run of concrete works. Other types of cement such as Rapid hardening Portland Cement, white Portland cement, etc. are used for special purposes. Cement must be kept dry in silos, or in 3-ply paper bags, it should be kept under cover and off the ground.
1.2.2 Aggregates
Sands and crushed stone, such as granite are in common use as aggregates. The essential requirements of aggregates are durability and cleanness. In Hong Kong fine crushed stone is generally used rather than sand. Aggregates of size >5mm is classified as coarse aggregates, size ≤5mm is classified as fine aggregates. Aggregates should be stored properly to avoid contamination.
1.2.3 Water
Water has always to be present in fresh concrete, not only to hydrate the
cement but also to convert it into a paste and thus make the concrete
workable. Obviously the mixer must not contain significant quantities of
impurities which might adversely affect the hardening or durability of the concrete.
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1.3 Production of Concrete
1.3.1 Batching
Careful use of accurate measuring equipment is essential if good-quality concrete is to be produced.
Batching of cement should be by weight or by the use of a whole number of 50 kg or 45 kg bags. Batching of aggregates should normally be by weight, but with light-weight aggregates and with small batches, volume batching may be desirable. If sand is batched by volume, allowance must be made for 'bulking', an increase in volume which occurs when the sand is moist.
1.3.2 Mixing
Mixers : a. Tilting drum
b. Non-tilting drum
c. Reversing drum
d. Forced action pan mixer
Tilting mixer
Most mixers are fitted with power-operated loading hoppers and automatic or semi-automatic water-measuring devices. Some mixers also have admixture dispensers fitted. It is normally best to add the water at the same time as the other materials to ensure its even distribution.
When the concrete is mixed the complete contents of the drum should be
discharged in one operation; an intermediate wet hopper may be used if it
is not possible to remove all the contents from the area of the mixer immediately. If this is not done, there is a risk that the larger aggregate
may separate from the mix, so that different container loads will have
different proportions. At the start of the day the batches will be harsh and stonily because some mortar will stick to the inside of the drum and around
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the blades. To counteract this, the proportion of coarse aggregates should be reduced for the first two batches.
After use, the mixer should be thoroughly washed out and the blades cleaned to prevent hardened concrete building up around the drum and blades. The inside of the drum should be inspected regularly and any blades which are worn or broken should be replaced. Inspection and maintenance are necessary to avoid reduction in efficiency and loss of time due to a breakdown.
1.3.3 Transport
A number of methods of transport are available, ranging from hand wheelbarrows to concrete pumps. The chosen method will depend on the size and complexity of the site and such factors as whether or not a crane is available. In all cases the concrete must be transported so that it does not segregate or becomes contaminated. Where concrete is to be placed below the level of the supply, a chute should be considered because gravity is the cheapest means of transport, but it must be borne in mind that there is still a danger of segregation.
1.3.4 Placing & Compacting
Before the concrete is placed in its final position, the formwork has to be checked for its stability, dimension and alignment according to the design requirement. The insides of the forms should be inspected to make sure they are clean and have been treated with release agent. Where the forms
are deep, temporary openings should be provided for this inspection.
Rubbish such as sawdust, timber and cans, should be removed or blown out
by compressed air.
1.3.5 Compaction
If concrete is to achieve its maximum strength, it must be compacted so
Poker vibrator
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that it contains the minimum amount of unwanted air. This is easy with a wet, workable mix, but the excess water will form unabsorbed bubbles in the concrete, reducing its strength. Thus vibrators, which enable a drier mix to be completely compacted to achieve the production of better quality concrete.
The most common type of vibrator is the internal vibrator or poker. This is a vibrating tube at the end of a flexible drive. Pokers vary in size, usually from 25 to 75 mm in diameters. It should be placed vertically in the concrete, held in position until air bubbles cease to come to the surface. This should be repeated at about 0.5 m centres. The concrete should be placed in layers not exceeding 600 mm thick, and the vibrator should be lowered at least 100 mm into the layer beneath.
External vibrators are occasionally used, but they are often used particularly in heavily reinforced walls and the webs of deep beams, where it is difficult or impossible to insert an internal vibrator.
Slabs are best compacted by vibrating tamping beams. These combine the action of a screed and a vibrator, but they are only effective for a limited depth. In general, a slab more than 150 mm thick should be compacted with a poker vibrator and finished with a vibrating beam.
Note: Over-vibration may cause segregation.
1.3.6 Make good surface
Produce a concrete finish as specified. (refer to the notes 1.5.1 to 1.5.2)
1.3.7 Curing
The setting and hardening of cement depend on the presence of water.
Drying out, if allowed to take place too soon, results in low strength and a
porous concrete. To prevent evaporation of moisture and the consequent formation of cracks in the surface, the curing must begin immediately after the concrete has been placed and finished. One method is to cover the concrete surface with impervious plastic sheets or to spray the surface
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with a composition which forms an impervious membrane preventing evaporation. Some of these curing membranes contain a dye which may discolour the finished surface.
1.4. Quality Control
1.4.1 Workability
The measurement of the workability of fresh concrete is of importance in assessing the practicability of compacting the mix and also in maintaining consistency throughout the job. In addition, workability tests are often used as an indirect check on the water content and, therefore, on the water/cement ratio of the concrete. In this instance, the relationships between w/c ratio and workability is established in the laboratory or early in the site works; then, by maintaining the correct proportions of cement and aggregates at a constant workability, the w/c ratio is controlled. Periodic measurements of aggregate moisture content are made to check that the mix proportions are correct.
Workability Cost of concrete Time/cost of manpower
High High Low
Low Low High
Slump Test For most concrete, the slump test is a practical means of measuring the
workability. Changes in the value of slump obtained during a job may
indicate changes in materials, in the water content or in the proportions of the mix, so it is useful in controlling the quality of the concrete produced.
Degree of Slump (mm) Type of construction Workability (20mm max. size aggregate)
Low 10-25 Simply reinforced large sections with vibration
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Medium 25-50 Moderately Reinforced sections vibration, ordinary with beams and slabs
High 50-125 Sections with heavily congested reinforcement where vibration is difficult.
Slump test tool set
1.4.2 Concrete Test Cubes
The most common test for hardened concrete involves taking a sample of fresh concrete and putting it into special cube moulds (150mm cube normally) so that, when hardened, the cubes can be tested to failure in a special machine in order to measure the compressive strength of the concrete.
The results obtained from these compression tests on the hardened concrete cubes are used mainly to check that the strength of the concrete is
above the minimum strength which had been specified; the results can be
used to access to control which has been exercised over the production of concrete.
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On the other hand, cube test can be used to certify the possible formwork striking time.
The correct procedures to be adopted for sampling, making and curing cubes are given in Cube test tool set CS1 1990: Testing Concrete.
1.4.3 Temperature control To produce higher quality concrete, the fresh mix should be kept below 32°C, it can improve the concrete strength developed in suitable speed, reduce evaporation of water and avoid formation of cracks due to too high temperature. The control method is to mix the concrete with ice water or add suitable retarder.
1.5. Finishes
1.5.1 General class of finishes in Hong Kong
Class of finish Characteristics
Unformed finishes ( U1 to U5 ) All refer to the Hong Kong Construction Standard CS1 : 1990 Formed finishes ( F1 to F5 )
Treated finishes ( T1 to T6 )
1.5.2 Finishes classified by method of forming
a. Direct Method Finishes
This method makes use of the plastic character of fresh concrete.
Therefore, by tamping the "plastic" concrete, variety of shapes and
forms can be obtained by direct method. Basically, there are 2 types of direct method:
(1) In-situ forming - by using specially made formwork. i.e. texture performed on the thrilling.
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(2) Precast techniques - by profiling machine. b. Indirect Method
Indirect method is defined that the finishing surface is formed after casting by means of special treatment such as chemically by acid or mechanically by hand or powered tooling at its immature stage.
There are many types of indirect method, e.g.
(1) Brushing and Washing
After normal placing and compacting, the outermost cement skin is brushed and washed away to expose the aggregate before the concrete becomes too hard.
(2) Abrasive/Grit Blasting
Different effects and depth of exposure can be produced, depending on the distance at which the nozzle is held from the concrete and also on the age of the concrete. Care should be exercised in using abrasive blasting because the silicon material used is hazard to health and may cause lung diseases.
(3) Bush Hammering
The action of the bush hammer is to cut and spall away the
shin of hardened cement paste that has formed on the surface of the concrete. c. Indirect Method
Combination of direct and indirect method.
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1.6. Construction Joint The reinforced concrete construction work cannot be completed in one operation, such as a building, construction joint will be provided between each stages of concrete work (floor to floor). A good construction joint is required to expose with sound and rough concrete surface by chisel hacking or retarder and wash-out, and it should have a clean and moist surface to receive the fresh concrete.
1.7. Discussion & Exercises in Concreting In this exercise, trainees are required to work as a team and organise themselves to carry out concreting practices as described below:
Suggested procedures: • Take a formwork prefabricated in the Formwork workshop, estimate total quantity of concrete required • With the mix proportion given, calculate materials required for concreting i.e. weight of aggregates, cement, water etc • Batch different materials for mixing of concrete by weight • Final check on strength of formwork and brush mould oil on the form surface to be in contact with concrete. • Prepare apparatus for slump test and cube test, tools for transportation and equipment for compaction of concrete
o Mix concrete with a drum mixer o Carry out slump test and take record of workability of concrete o Place the mixed concrete to the prepared formwork layer by layer and carry out compaction by poker vibrator
o Finishing up the top finish of the unformed concrete surface and cover with plastic sheets for curing.
o Place concrete to 2 concrete cube steel mould s for cube strength tests
o Strike the formwork of the concrete and carry out cube strength test after 7 days
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o Make report on the whole process
1.8. Type of Reinforcing Steel Bars
Reinforcing bars are available in various sizes and grades. The grade designates the yield strength of the material used in the manufacture of the bars.
Of the several types of steel reinforcement for concrete, the most commonly used are the plain round bars and the high-yield deformed bars
to BS4449. Ordinary round bars have a minimum yield stress of 250 N/mm2 (grade 250) and deformed high tensile bar shall have a minimum tensile stress of 460 N/mm2 (grade 460).
Preferred nominal sizes of reinforcement:
Bars diameter (mm) 6 8 10 12 16 20 25 32 40
The use of Y50 re-bar is not permitted by B.O.O. and because of its weight,
it is not commonly used in HK.
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High yield bar
Mild steel bar
Reinforcement should not be bent or straightened in a way that will injure or fracture the material. All bars should preferably be bent cold. Bending of high yield steel bars to complicated shape should be avoided.
a. Description of Reinforcement in R.C. (Detail) Drawing
Typical example : 7 T 25 - 03 - 200 T for reinforcement in slab means
7 no. of bars in the top layer
Type of bar (high yield steel) 200mm centre to centre
Diameter of rebar, e.g. 25mm bar mark
b. Abbreviations
R or M round mild steel bars
T or Y high yield steel bars
B bars in bottom of slab
B1 the 1st bottom layer of bottom reinforcement
T bars in top of slab
T1 the 1st top layer of top reinforcement
E.F. bars in each face
N.F. bars in near face of wall or column
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F.F. bars in far face of wall or column
A.P. bars alternately placed
A.R. bars alternately reversed
A.S. bars alternately staggered etc
1.9 Cutting
Length of steel reinforcement are normally 12m long, they will be cut into suitable of length according to the working drawing, grouped in different sizes and sent for bending.
1.10 Bending Steel bar bending machine either of annually or power driven can used to bend specified shape and size of steel bars. On site, bars should be stacked off the ground and in such a way that it
is easy for the bar bender to find the Electrical bending machine sizes and lengths required. The steel grade marks or identification tags attached to the bars by the manufacturer should always be clearly visible.
1.11 Fixing Reinforcement & Cover to Reinforcements
Unless the bars are rigidly fixed in the correct position, the reinforcements
may be displaced during concreting, particularly when the concrete is being
vibrated. Top layers of horizontal steel should be well supported on steel chairs so that they are not displaced by operatives walking on them or by other excessive loads.
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At all intersections, the bars or links should be securely tied together with ∅1.6mm soft iron wire. The ends of the wire ties must not point towards the face of the concrete, and all ends should be cut off. As soon as steel fixing has been completed, off cut of binding wire must be removed from the insides of forms using an industrial vacuum machine. Where the reinforcement is congested or complicated, spot welding may be allowed. However, all welding should be carried out with low temperature welding rods. Before concreting, the reinforcement should be free from mud, oil, paint, loose rust and scale. Release agents should not be allowed to come into contact with the bars.
The normal concrete cover - the distance from the outside of the reinforcements to the concrete surface - should be as given on the working drawings. Small, precast concrete blocks or proprietary plastic spacers may be used for maintaining the correct cover. All reinforcement projecting above the formwork should be secured to prevent being displaced while the concrete is being placed.
Spacer blocks
1.12 Bar Bending Schedules
Bar bending schedules are very important parts of detailing. The method of
showing the bar bends in the schedule should be as given in BS8666:2000, Specification for schedule, dimensioning, bending and cutting of steel reinforcement for concrete.
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1.13 Discussion & Exercises in Steel Reinforcement
In this exercise, trainees are required to work as a team and organise themselves to carry out steel reinforcement practices as described below. In the given R.C. drawing of a floor of small building, it shows the steel reinforcement details of slab, beam and column; trainees have to select one of the structural elements for their team to practice.
Suggested procedures: • Read and identify the bars in the R.C. drawing, • Prepare a bending schedule for one structural elements, beam, slab or column, • Pick up adequate amount of steel bars of right type and sizes, • Cut and Bend the required steel bar according to prepared bending schedule, • Prepare the hand tools and spacer blocks for steel bar fixing, • Fix the reinforcements as shown in the R.C. details, • Inspect and comment on the steel bars fixed by other groups with reference to the designed R.C. details, • Discuss the implication of arrangement of bars against the placing of concrete and the structural design, • Make report on the whole process.
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3600
1800
400 1B/A/1-2 (300X400)
A 400
120 120
1S1 1S2 3000 1B/1/A-B (300X300) 1B/1/A-B (300X300) 1B/2/A-B 1B/1-2/A-B (300X300)
B 400
1B/B/1-2 (300X400) 12
GENERAL ARRANGEMENT OF TYPICAL BUILDING FLOOR
10T10-3-250 B1 10T10-2-250 T1
4T10-4-250 T1 10T10-3-250 B1
10T10-1-250 T1 4T10-4-250 T1 10T10-1-250 T1
A 1290 1290 320 320 1290 1290
A A 2340 2340 2340 2340 2340 200 200 200 200 8T10-7-300 T2
1290 1290 10T10-5-300 T2 320 320
12
1 2 1
7 7 6 6
3 3 A-A
Reinforcement Details of Floor Slab
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1 2
850 850 1
2T12-12 2T8-10 2T10-11 2T12-12
250
400 3T10-13 1 1200 1200 5T10-15-300 LINK 5T10-15-300 LINK
2T10-14 2T10-14
1B/A/1-2
12 12
105 10 418.522
13 13 13 1-1
Reinforcement Details of Main Beam
BA 800 800
2T10-19 2T10-16 2 2T10-19 200 2T10-17 2 2350 9T10-18-300 LINK
1B/1-2/A-B (1B/1/A-B,1B/2/A-B SIMILAR)
16 16
18
17 17 2-2
Reinforcement Details of Secondary Beam
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Part II – Formwork & Falsework
2.1 HAND TOOLS SAFETY
Hand tools should ALWAYS be kept in good condition and good working order.
Use them correctly, carry them carefully, and store them safely.
2.2 WOODWORKING MACHINES
Circular Saw
The principal uses of the circular saw are ripping, crosscutting, bevel and compound angle cutting, rebating and grooving.
Disc Sander
It is used for rouge shaping, sanding end grain and making outside curves.
Band Saw
The band saw is used for cut curved and irregularly shaped pieces.
Surfacing Planing Machine
For surfacing materials to a desired thickness and width. It is most often used to smooth as plane the edges and faces of boards.
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2.3 SAFETY RULES IN USE OF THE WOODWORKING MACHINES
i. Always ask permission from the person in charge, before using any machine.
ii. Avoid wearing loose clothing, button or roll up your sleeves. Remove your necktie as well.
iii. Lay out and carefully plan your work before using the machine.
iv. Remove rings and pendants.
v. Maintain a well-balance position on both feet.
vi. Always wear safety goggles or a face shield.
vii. Always use push stick when using circular saw and surface planing machine.
viii. Don't forget to use every safety guard provided by the machine.
ix. When demonstration goes on, don't keep too close to the machine.
x. Try to check everything clear away from the moving parts of the machine before witching on it.
2.4 SCAFFOLDING AND FRAMEWORK
A scaffold is a temporary structure from building operations; it includes any working platforms, ladders and guardrails. Basically there are two forms of scaffolding:
2.4.1 Putlog Scaffolds
This form of scaffolding consists of a single row of uprights or standards set
away from the wall at a distance which will accommodate the required
width of the working platform. The standards are joined together with
horizontal members called ledgers and are tied to the building with cross members called putlogs. The scaffold is erected as the building rises and is mostly used for buildings of traditional brick construction.
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2.4.2 Independent Scaffolds
An independent scaffold has two rows of standards, which are tied by cross members called transoms. This form of scaffold does not rely upon the building for support and is therefore suitable for use in conjunction with framed structure. This can be achieved by using a horizontal tube called a bridle bearing on the inside of the wall and across a window opening with cross members connected to it; alternatively a tube with a reveal pin in the opening can provide a connection point for the cross members. If suitable openings are not available then the scaffold should be strutted from the ground using raking tubes inclined towards the building.
2.4.3 Framework
Framework is used for the support and the protection of workmen engaged in building. It comprises horizontal, vertical, and diagonal members up on which scaffolding planks are laid. Since a man cannot work satisfactorily at a height greater than 2 m above where he stands, scaffolding must be erected as the building increases in height.
2.4.4 MATERIALS
a) Scaffolding can be of:
i) Tubular steel,
ii) Tubular aluminum alloy,
iii) Bamboo.
In H.K. bamboo scaffolds are commonly used for temporary
access and support purposes. There is a Code of Practice for
Bamboo Scaffolding Safety and the Buildings Department has provided guidance in design and construction of bamboo
scaffolds.
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b) Scaffold Fittings
Fittings of either steel or aluminum alloy are covered by the same British Standard as quoted above for the tubes. They can usually be used in conjunction with either tubular metal unless specified differently by the manufacturer. The major fittings used in metal scaffolding are:
Standard - the vertical member of scaffolding that transmits the load to the base; it should rest on a solid foundation.
Sole plate - the horizontal member forming a solid foundation to support the standard.
Base plate - the support for the foot of standard in metal scaffolding.
Ledger - the horizontal member that ties and secures the standard.
Transom - the horizontal member upon which the scaffolding planks rest.
Cross brace - the diagonal member of scaffolding used to base the standard rigidly.
Working platform - the horizontal placed boards that rest on the transoms, or putlogs, to form the working platform.
Toe board - the horizontal board placed against the outer edge of the working platform to prevent articles falling from the platform.
Guard rail - the horizontal member placed about 900mm above the
scaffold planks on a scaffold more than 2 m above the ground.
2.4.5 SAFETY POINTS FOR ERECTION OF SCAFFOLD
i. Must wear safety helmet. ii. Minimum width of working platform should be 400 mm, (650 mm for those used for the movement of materials).
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iii. Ladder should be project 1050mm min above the working platform and well secured by rope before use. iv. Ladder should be inclined at about 1:4 or 75º. v. Guardrail must be fixed at about 900 mm to 1150 mm above the working platform. vi. Inner standards should not fix more than 300 mm away from the wall. vii. Toe board should be 200 mm high or more. viii. Sole plate must be used for soft ground. ix. All fittings and ladder must be well secured.
2.5 Falsework
The falsework is supporting a timber shuttering of typical R.C. beam/slab of a building floor, it is composed of light duty steel tubular framework system; the allowable load per leg is 22.5 kN as recommended by the manufacturer.
Falsework Details
2.6 FORMWORK
2.6.1 Precast concrete forms
Precast concrete usually has to be made within fine limits of accuracy and to a high degree of finish. The mould boxes have therefore to be carefully made to permit these standards in casting. It is necessary to be able to
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strike a mould when the concrete is in a very green state, both to permit early re-use of the forms and to enable the finished article to be cleaned down when in a workable state. A panel or unit should come square away from the concrete face and not side off it.
2.6.2 Formwork for cast-in-situ
Inspection is very important in all stage formwork, and should consist of checking the various forms, to ensure sufficiently strong and rigid enough to support the dead load of the concrete as well as to allow for the temporary live load of workmen wheeling barrows and the tamping vibrating of concrete. The checking should be included all wedges, braces and shores should be periodically inspected, as once a form commences to bulge it is practically impossible to rectify when pouring has commenced.
2.6.3 Notes for design forms
• Forms should be reusable for many times, • Forms should be designed for easily stripping and also can be quickly reassembled, • Forms should be strong enough to withstand the tamping of concrete.
2.6.4 Materials
Timber most commonly used is Douglas fir or British Colombian pine and plywood in Hong Kong now.
When the finished concrete is not covered in any way Fare Face it is
necessary to select timber fairly free from knots and coarse grain. May be
use plywood or metal form.
Green or freshly stuff should not be used for formwork. Timber for
formwork should be particularly seasoned. Fix to bolts can be put inside a plastic tube for easy withdrawn when sticking formwork and formwork should be oiled before using.
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Plywood surfaces may be:
Untreated - 1 to 10 uses
Resin-coated - 5 to 20 uses
Holes can be filled with epoxy fillers or repaired with a simple plug driven into the hole.
Screws, nails, staples etc can usually be used but a minimum edge distance of 9 mm is recommended.
Where possible, standard size sheets (1200 x 2400 mm) should be used. In addition curved formwork with sufficiently rigid framework, can be used.
2.6.5 Other Formwork Material
Steel - The use of steel is largely confined to proprietary formwork systems.
Aluminum - Aluminum has many of the properties of steel with substantial weight savings.
Glass fiber reinforced plastic (GRP) - GRP material is strong lightweight material manufactured from polyester resin, reinforced with glass fiber.
Rubber - Rubber materials are generally used as form liners when complex shapes are required to be cast into the concrete.
Plastic sheet - Plastic sheets are used as form liners to produce an almost endless variety of low relief patterns.
2.6.6 Part of forms
Brace – member, usually diagonal, which acts in tension or compression and
stiffens a frame against distortion.
Falsework – temporary structure, which supports the forms, is provided usually for a large permanent structure construction such as a bridge.
Kicker – a small concrete upstand cast above floor level to position wall or column forms for the next lift and to assist the prevention of grout loss.
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Raking shore – a support to an unsafe building designed to be left in place when the building is struck.
Prop – a strut which is light enough to be man-handled when adjustable it is known as an adjustable prop.
Runner – a longitudinal member spanning across a number of support members and lacing them together (may be used to carry a beam soffit).
Spreader – spreaders are short lengths of wood, concrete, or steel fixed between the faces of wall formworks. They keep the formwork apart to the required thickness of the wall until the concrete is poured. Precast concrete speakers have a hole through the center for bolting.
2.6.7 Striking of Formwork
The period, which should elapse before the formwork is struck, will vary from job to job and will depend on the concrete used. Formwork must not be removed until the concrete is strong enough to be self- supporting and able to carry imposed loads. The time of striking should be related to the strength of the concrete and, obviously, soffit forms to beams and slabs must be left in place longer than is necessary for the side form.
Striking must be carried out with care to avoid damage to arise and projections, and it may be necessary to protect some of the work from damage immediately after removing the forms. Before soffit forms and
props and removed, the concrete surface should be exposed carefully, in order to ascertain that the concrete has hardened sufficiently.
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Table: Minimum periods before striking formwork (General Specification for Building 2007 Edition, ArchSD)
Formwork Striking Time Concrete without PFA Concrete with PFA Vertical formwork to columns, 24 hours 30 hours walls and beams (unloaded) Soffits formwork to slab (props 4 days 4 days left under) Props to slab (unloaded) 10 days 10 days Soffits formwork to beams 7 days 7 days (props left under) Props to beams (unloaded) 16 days 16 days Props to cantilevers 28 days 28 days Inclined formwork to top 12 hours 12 hours surface
2.6.8 Investigative method of Formwork
Formwork for Beam and Column and Staircase
All formwork must be easy to strike after concreting. Care is needed to see that no piece is keyed into the concrete, particularly end grain of timber. As few nails as possible should be used and those that are used should be left with heads standing so that they can be easily removed, unless they are in the form face. Nails must not be driven both ways in an internal angle. Dovetailing helps to give added holding power against direct withdrawal.
Adequate supports should be provided both vertically and laterally by
means of timber or steel props or struts.
2.6.9 Practical Design Notes
Wall sheeting
Concrete paste maybe squeezed out from joints between form panels when the concrete is under tamping or vibrating. In order to minimize these
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defects to line the surfaces with waterproof paper, or use plywood or sheet metal.
Beam and column
Great care must be taken in the method framing and allowance for stripping. For column allow CLEAN-OUT TRAP at the floor level. The amount of rubbish can be collected before pouring concrete. Compressed air or water can be used to clean out the formwork. A most essential item in column and beam work is the corner fillet. Sharp corner in concrete is easily to break, especially when stripping. So a triangular strip is nailed on the insides on the box.
Slabs
The formwork panels are usually placed 600 to 900 mm side by side. Paneling might be used with a great amount of repetitive work.
2.7 Discussion & Exercises
Tubular Scaffolding Fabrication
In this exercise, trainees are required to work as a team and organise themselves to fabricate the scaffolding as described below.
Suggested procedures: i. Position the adjustable base-plates, spaced according to the lengths of the ledger and transom horizontal members. ii. Fit the basic standards or standards into the adjustable base-plates; fit
the horizontal members; check the structure is level.
iii. Fit the first working platform to ease the erection.; fit the complete working platform in the access bay
iv. Build the first lift; fit the ledger and the transom horizontal members.
v. Fit the access working platform in the access bay; lower the ladder;
check continuously that the structure is level. vi. Fit the working platform in each cell of the first stage; stabilize the structure longitudinally by fitting cross braces at the side away from the working area.
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Formwork Design & Fabrication
In this exercise, trainees are required to work as a team and organise themselves to design and fabricate the formwork as the sketch below.
Student Exercise- Erection of Independent Scaffold
1 960 1 830 1280 200 700
50
L ONGI TUD I NA L BR AC E 1 000 150 ARD RD BO BOA TOE TOE
STAND CROSS B RACE 1000 AIL RD R GUA LADDER 975 100
JACKPLATE 350
Suggested procedures:
i. Take measurements of the final concrete column and beam structure
ii. Design the formwork and associated supports; and sketch the
working drawings for the iii. Calculate the quantities of timber plywood for the formwork
iv. Prepare the adequate amount of plywood and cut to the required shapes v. Erect the column forms first and provide adequate lateral supports
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vi. Erect the forms for the simple supported and cantilevered beam and provide adequate vertical supports vii. Check the internal dimensions of the finished form against the designed. viii. Check the tightness of every adjacent plywood boards and check stability of the whole form.
CONCRETE COLUMNS AND BEAMS (CAST IN-SITU)
200 500 2400
600 2400 600 1200
ELEVATION 600 400
PLAN
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Part III – Plastering, Brickwork & Blockwork
3.1 Basic tools of the trowel trade
Brick trowel: used to pick up mortar and to spread it to an even thickness in preparation for the lying of the bricks. It can also be used for the rough cutting and trimming of a brick.
Plastering trowel: used to apply plastering materials onto the surface, with its thickness of the steel plate, the flatness of the surface can be achieved
Finishing trowel: used to get a smooth surface after apply the final coating. (a similar shape to the plastering except thin steel plate used).
Plumb rule: another name of spirit level, used to establish a plumb (vertical) line and the level line.
Plumb bob: used to establish vertical alignment of the surface, and the correct checking of the surface
Brick knife: bricks or blocks are cut with a hammer, but when a clean, sharp edge is required, a brick set or brick knife (for local practice) is used. It can be used as assistance in mortar spreading.
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Jointer: used to finish or strike vertical & horizontal joints
Bucket: used to contain mortar or other masonry materials for the workers.
Steel square: a measuring tool which has at least two straight edges and at right angle.
Chalk box: consists of a metal or plastic case with cotton line inside a pool. It helps the mason to establish straight lines in layout work. Permanent lines can be produced by addition of Chinese ink.
Wood float: a rectangular piece of timber about 250 x 125 x 20 mm thick. It has a handle for handling and is used in circular motion to flatten plaster, also use to hold mortar during transferring of plaster.
3.2 Materials
Mortar is a composition of certain materials mainly used for the bedding
bricks in the building of walls. The types of the materials and the mixing have a considerable effect to the strength, durability, and the appearance of
the effect. Main components are sand, lime and cement.
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3.2.1 Cement mortar
A mix proportion of 1:3 cement and sand, is required to give good workable mortar. It is suitable for high strength engineering brickwork. Leaner mixes will become harsh and unworkable.
3.2.2 Cement lime mortar
The addition of lime to cement mortar will improve the workability considerably and allow a lower cement-sand ratio to be used. A low strength mortar will thus result due to a higher proportion of cement and lime mortar.
Gauge mortar: 1: 1: 6 (cement: lime: sand) or 1: 2: 9 suitable for internal
works.
3.2.3 Bricks
Bricks are usually made from clay (BS 3921) or sand and lime and are available in a wide variety of strength, types, textures, colors and special shaped brick to BS 4729.
There are rectangular blocks of hard, durable insert material, of a size suitable to be handled with one hand, of standard dimensions 215 x 102.5 x 65 mm thick. Clay bricks are fired earth or shale. They are formed by pressing in mould or by extrusion and formed by wire cutting process, and then dried and fired in a kiln.
3.2.4 Blocks
Concrete blocks are walling units, for the heights must not exceed the length or six times the thickness.
There are two main types:
a. Dense aggregate block
It made from dense aggregates (BS 882, 1983), suitable for general use in load bearing external walls including works below ground level.
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b. Light weight aggregate block
It is made either with lightweight aggregates of with aerated concrete. Aerated concrete block is defined in BS 6073 Pt 1 1981 as consisting essentially of an inorganic cement agent with or without the addition of suitable fine inorganic aggregate.
The aerated structure is formed either by generation of a gas by a chemical action within the mix prior to hardening or by mechanical incorporation of air into the mix.
Actual size various e.g. 390mm x 190mm x 100mm and 440mm x 140mm x 90mm.
3.3 Brickwork
3.3.1 Bonds
Bond is set out length of wall working from each end to ensure no vertical
joints are above one another is consecutive courses. Walls, which are not in exact bond length, can be set in Broken Bond or Reversed Bond. A quarter bond is obtained by placing closer next tooth end header or corner header, or a three-quarter brick is used.
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a. English Bond: It formed by lying alternate courses of stretchers and headers, it is one of the strongest bonds (89 facings bricks /m²).
b. Flemish Bond: It formed by lying headers and stretchers alternately in each course. Not as strong as English Bond but is considered to be aesthetically superior uses less facing bricks (79 facing bricks / m²).
c. Stretcher Bond: It consists of only stretchers on elevation except at corners in half or quarter lapping spaces.
English Bond Flemish Bond Stretcher Bond
3.3.2. Procedures of laying i. Setting out the boundary of the structure with the chalk box, ii. Check out the correct datum with a spirit level or water level, iii. Pre wet the bricks into saturated condition. (except concrete blocks), iv. Dry laying the designed pattern to check the correct spacing, v. Prepare mortar into good consistency, vi. Spread mortar bed (approx. 10 mm thick.), vii. Build up the corner bricks as reference with guided thread attached on top of the material,
viii. Place the bricks into correct position with true alignment includes
horizontal and vertical, ix. Strike off excess mortar with the trowel,
x. Strike onto the joints with a jointer to compress the mortar to have a
water-resistant result and nice appearance,
xi. Proceed to other layers until finish this structure, xii. Double check all alignment and level, protect it with a polyurethane sheet without any exposure in weather.
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3.3.3 Failure in block walling
a. Erosion: due to the action of wind laden with dust and driving rain.
b. Cracking: reversible movement caused by moisture changes in the fine particles of the material and the porosity of the blocks.
Irreversible movements in cement products usually start during the setting of cement in the form of shrinkage. Overloading, uneven settlement and impact also cause cracks in wall.
3.4 Plastering
It is usually built up as a two-coat system, consisting of an undercoat and a finish coat, i.e. a wet mixed material applied to internal and external walls as a finish to fill any irregularity in the wall surface and to provide a smooth continuous surface suitable for direct
decoration.
3.4.1 Undercoat plaster
The undercoat is designed to even out any irregularity on the wall surface of
the internal and external wall. The undercoat is a mix based on cement and sand called cement mortar, usually 10-20 mm thick.
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3.4.2 Finish plaster
The finish coat should be applied to a thickness varying from 3 mm to 10 mm depending upon the types of materials and applied to internal and external wall.
The finish coat of external wall is a mixed based on a cement and sand called cement mortar, most are usually 10mm thick, that is to prevent the penetration of water into the wall.
The finish coat of internal wall is a mix based on cement and lime called putty coat or smooth coat, finish coat of plaster applied with trowel to give a smooth finish.
3.4.3 Preparation of background
Most background surfaces in new buildings require no preparation before plastering and these include brickwall and concrete wall. If however, the brickwork is dirty, dry, smooth or composed of dense facing bricks then it may require brushing, raking out of joints or applied with a bonding adhesive as necessary.
In-situ and precast concrete is certain to require cleaning and spatterdash or coating with a bonding adhesive.
3.4.4 Applying procedures
i. Damp / spray the background of the wall surface, ii. Prepare mortar in right consistency,
iii. Transfer mortar on wood float thoroughly,
iv. Provide DOTS AND SCREEDS as reference,
v. Pitch the spaces between the screeds and rule off with a straight edge,
vi. Use the wood float to work the surface to a sandy gritty finish, vii. Roughen the coating with a metal comb to provide good keys for further coating,
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viii. For external corners, metal cramps with straight edge may be used in order to achieve sharp arris. Later release in a diagonal direction.
Apply float on Dot formation Check vertical Apply screeds after pitching alignment
3.4.5 Problems arising
Cracks: Either result from the movement of rendering or the background. This movement may be in the form of shrinkage die to rich mix, quick evaporating of water from mortar by sun radiation.
Bond failure: A wall surface of smooth dense blocks may not offer enough mechanical key. The porosity and suction of the background affect adhesion. Spray the background with water before application is essential.
Crazing: They may be caused by a high suction of the background or undercoat.
Hair cracks: The use of clean cement in powder or slurry form to daub the
surface of a finishing coat. Single coat rendering increase the possibility of crazing.
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3.5 Tiling practice
3.5.1 Glazed wall tiles
Internal glazed wall tiles are usually made to the recommendations of BS 6431.
The material is usually mixed to the desired consistency shaped and then fired in a tunnel over at a high temperature (1150°C) for several days to form the unglazed biscuit tiles. The glazed pattern and color can now be imparted onto the biscuit tile before the final process at a temperature slightly before the final firing (1050°C) for about 2 days.
The unglazed back of the tiles are porous and absorb moisture very fast, therefore advisable to soak tiles in water before fixing.
Sizes: modular 100 x 100 x 5 mm thick.
200 x 100 x 6.5 mm thick.
Bedding of internal wall tiles usually of a cement rendered or plastered surface should be flat, dry, stable firmly attached to the substrate and sufficiently old enough for any initial shrinkage to have taken place.
Wall Finish
Material: glazing/ceramic tiles bonding agent (cement paste), i.e. powder form + water or adhesive.
Tools: brick trowel, container, and straight edge.
Procedures:
i. Immerse the tiles into water for half an hour (approx.),
ii. Hack the wall and clean thoroughly if surface is smooth,
iii. Set out the work, start from a corner and at the base of the wall, iv. Bed a horizontal temporary support against the wall, (not greater than 1 unit size height) and spray water over surface,
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v. Prepare the adhesive add cement to water without stirring until a semi-fluid is formed i.e. paste, vi. Butter cement paste on the back of the tiles in wavy pattern or evenly spread (dotting method should not employed), vii. Start with the layer just above the temporary support, lay the first two tiles beside the center line, then spread out to the left and right (in most cases), viii. Press the tile against the wall with a gentle force and ensure it is vertically attached, tap it slightly into position, ix. Allow a small joint as possible due to the quality control of tiles, ensure plumb and flatness by using a spirit level and a straight edge, x. By moving the trowel or the fingers over the edges of newly fixed tiles, one can easily tell if the edges are flat to each other or not, xi. Proceed on with another tile, leaving a space of 1-2 mm between two tiles for adjustment for irregularity of tiles, xii. After completing one layer of tiles, proceed on other layer upwards. xiii. Carefully cut the tiles with tile cutter, xiv. When finishing lying to desired level, remove the support and complete the lowest layer, xv. Fill the gaps with cement paste by a brush, xvi. Clean the surfaces of tiles with a wet cloth.
Embedding a temporary horizontal Mark vertical alignment support
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Buttering the cement paste on Fixing them in position
Tile cutter
3.5.2 Mosaic tiles
Mosaic tiles are another kind of good protective coating, due to its good durability on appearance and good resistance to weather, usually applied to external or internal surfaces and floors.
Following procedures:
i. Apply the cement paste on the surface and float it evenly with the
help of trowel and straight edge, ii. Apply the cement paste evenly on the mosaic tiles with a flat board
as support on the back,
iii. Attach these tiles to position with correct alignment that correctly set
up before,
iv. Lightly tapping on the backing paper with a plastering trowel to its alignment, v. do another neighbor sheets as before,
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vi. grouting all open joints with cement slurry and wet up all the backing paper, vii. Wait for suitable duration until the backing paper has thoroughly absorbed with the moisture, viii. Detach the paper from the tiles carefully, any damage should make good on the tiles, ix. Final alignment must be checked and clean up the surface thoroughly, x. Apply extra protection such as thin polyurethane sheeting on the surface.
Step 1. Step 2. Step 3. Step 4.
Step 5. Step 6. Step 7. Step 8.
3.6 Floor finishes
3.6.1 Granolithic flooring
a) monolithic method b) separate method
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a) Monolithic method
Laying the topping within 3 hours on the concrete slab. The mix should be composed in proportions of 1:1:2 by weight of cement: fine: aggregate: coarse aggregate. The amount of water should be just sufficient to obtain a workability that allows the topping to be fully compacted. The topping should have a minimum thickness of 18 mm. At about 2 hours after the topping is laid and fully compacted trowel it to a smooth finish.
b) Separate method
Laying the topping in bays not exceeding 15 sq. m² super of about 5 m x 3 m with a thickness of 37 mm.
Preparing the surface of the base concrete thoroughly by removing the laitance so that the aggregate is exposed, and brushing with water over the surface well then, removing any surplus water before grouting. The grout should be composed of cement mode into stiff slurry with water.
This will provide a bond between the topping and the base. The surface is then trowelled and cured.
3.6.2 Cement screed
The concrete floor may be topped with 25-mm thick cement and sand screed trowelled to a smooth finish. The usual mix is 1:3 and a coloring agent may be added.
3.6.3 Terrazzo
Terrazzo consists of a colored cement binder or matrix and marble chips
mixed to specified proportions. The finishing is hardening, attractive and
resistant to chemical attack. Terrazzo, sometimes referred to as 'Granolithic'
finish behaves in the name way as concrete. Ebonite strips are used to divide the terrazzo into bays to resist expansion and shrinkage.
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Clean the sub floor thoroughly and brush the bay to be laid with cement grout. To minimize excessive differential movement of finish and the subfloor it is to lay the terrazzo while concrete subfloor is still’ green'
3.6.4 Floor Finishing
Material: mosaic tiles, cement screeding (1:3) in semi-dry condition,
Tools: trowels, straight edge, spirit level, wood float, cloth and brush.
Procedures:
i. Make cement pegs and fill the cement screed. ii. Compact the cement screed with a steel trowel and float to required level. iii. Flour "fresh" dry cement powder over the screed and spray with water. iv. Fix the sheet of mosaic tiles on the cement paste according to the trademarks if applicable. (or follow the arrowheads) v. Press the tiles downwards evenly and gently. vi. Proceed on the other sheets, leave a uniform space between adjacent tiles. vii. Spray water over the tiles and wait for some time (say 1/2 hour). viii. Also brushing over the back of tiles with water in order to maintain the best absorption. ix. Peel off the paper carefully after the paper absorbed adequate water
and become soft.
x. Fill up the joints by brushing or rubbing against the tiles with cement
mortar in liquid form to grout the joints thoroughly.
xi. Clean the surfaces of tiles with sea sand and then protect the finishing surfaces.
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3.7 Paving
In-situ concrete is indisputably one of the most versatile general footpath surfacing, offering simplicity, economical and basically satisfactory result, particularly for sites, which are congested with many manholes and columns.
Damage and premature deterioration are attributed to:
• Poor standard of construction, primarily due to poor workmanship and lack of adequate supervision, • Numerous trench openings and poor reinstatement. After backfilling, a long period of time is usually required before permanent reinstatement of the trench is carried out. The temporary earth path may settle due to poor compaction or become soft and muddy due to rain, • Vehicles illegally mounting on the footpath, • Uneven settlement in newly reclaimed areas.
3.7.1 Interlocking concrete blocks
• paving blocks -are usually about 225 x 125 and 60 mm thick in size. • sand - BS 882, not more than 10% retained on 5 mm sieve. • kerbs - pre cast products of concrete drainage outlets and channels.
3.7.2 Design considerations
• Allowed free drainage and do not encourage trapping of dirt, • Allowed a high grip texture on the surface, • The joint pattern of any area of precast slabs needs careful consideration and planning to cater for changes in direction, • Joints should be staggered on downhill sections to prevent channeling of water and the "WASHING OUT" of joints, • A sealing dry mix of 1:6 cement: sand should preferably be brushed into joints,
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• Richer mixes should not be used, as this will increase the difficulty in future repair works.
3.7.3 Plant requirement
Plate vibrators for blocks up to 80 mm thick; plate area 0.20 - 0.40 m². Centrifugal force 7-16 kN, frequency 75-100 Hz.
3.7.4 Preparation work
i. If possible delay excavations until the paving operations can commence and the ground are reasonably dry. ii. Strip/excavation to required levels. iii. Grade/level bottom of excavation, remove any obstructions or soft spots and add compact additional material to provide surfaces of uniform bearing capacity. iv. Place sand immediately after compaction of formation. Before lying and bed and blocks, it is necessary to ensure that all kerbs and other edge restraints are erected. Ensure that all are ready for the paving operations. Ensure that there is an adequate supply of sand of uniform optimum moisture content. v. Spread to specified grades and levels and compact to a finished thickness of not less than 50 mm. vi. For pedestrian paving with two passes of minimum 2Tonne roller or other plant attaining equivalent compaction. vii. For vehicular paving with four passes of minimum 4Tonne roller or
other plant attaining equivalent compaction.
3.7.5 Laying procedures:
i. Kerbs and margins must be completed prior to placing of sand layers.
ii. Commence lying as soon as the sand bed is laid and place the blocks butt-jointed in a manner that does not disturb the sand. iii. Lay to the specified interlocking pattern. iv. Use edge blocks at perimeters or cut blocks to provide clean edges.
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v. Compact blocks with sufficient passes of a plate vibrator. vi. Do not compact near the edge of blocks unless they are restrained. vii. After initial compaction, brush sand over the finished paving and vibrate into spaces between the blocks. Sweep surplus sand away, check levels and keep clean. viii. Finished levels should be within ± 10 mm of specified levels. Finish 3 to 5 mm above manhole covers, gully gratings or similar items. ix. A minimum cross-fall of 1:40 is recommended.
3.8 Marble and granite
Marble and granite have long been highly
popular decorative building materials in this part of the world. Quarrying of marble and granite are done in Italy, USA and many countries providing a variety of color and texture for every purpose. If required the outlook of wall or floors are perfectible. As a natural material, the marble or granite shall be sorted out in batch of same color for different area of application.
3.8.1 Dry mount fixing
On the external wall, the general design technique is to contrast with large glazing or curtain wall to create a strong texture different. Granite slabs can also be combined with glass as part of the curtain wall system or
cladding system.
Actual thickness of granite slabs for cladding depends on the type of
stone and the size of panels, generally ranging from 30 mm to 40 mm.
The granite slabs are fixed by stainless steel hanger bolt mounted. Slab joints can be open or sealed with silicone at 5 to 10 mm wide.
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3.8.2 Shaping and polishing have shaped profiles
Shaping and polishing of the marble or granite edges by stone grinder with discs and polishing compound. There is also special machinery to cut, grind or polish different marble and granite stores into various shapes.
3.8.3 Polishing procedures:
• Form various shapes / edges created by grinder with abrasive discs, • Polish edges by grinder with polishing discs (#120 / 220), • Apply top quality wax to the edges.
3.9 Discussion & Exercises
In this exercise, trainees are required to work as a team and organise themselves to carry out real work practices on brickwork, plastering and tiling as described below:
Suggested procedures:
Bricklaying and Plastering
i. Setting out / leveling, dry bond (define proper spacing),
ii. Prepare mortar in good consistency, spread mortar bed,
iii. Build up corner blocks with guided thread ( 10 mm ), iv. Placing bricks, strike off excess mortar, v. Proceed to upper layer, final checking on level / verticality,
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vi. Rendering: to apply coats of cement mortar to external faces of wall. (1:3), vii. Plastering: to apply coats of cement / gauged mortar to internal faces of wall (1:1:6), viii. Damp the background, transfer mortar with trowel / wood float, apply by dots & screeds method, ix. Pitching all other surfaces, floating (rough / textured surfaces), x. Defects / failures checking, using cramps for external corners with straight edge attached, xi. Remove in diagonal way after plastering, wire scrapped on if extra keys required.
Tiling: (ceramic/glazing)
i. Prepare necessary materials, tiles and paste, ii. Mark alignment and provide temporary support, iii. Butter evenly on back of tiles, fix firmly to position, leaving tolerance (irregularity of matl.) from center to edges, cut the edges if required,
iv.. Grouting all joints with paste and clean the tiles surface.
Bonding (English Bond, 1B / 225 mm Building Practice on brickwork)
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Part IV – Plumbing Practices
4.1 Plumbing Systems
The plumbing works in the local building industry can be generally categorised as the followings:
- Cold water supply system
- Hot water supply system
- Surface water drainage above ground
- Foul water drainage above ground
4.1.1 Cold Water Supply System
a. Direct System - in this system all sanitary fittings are supplied with cold water direct from the main, and a stop valve or non-return valve is required to install before water meter.
b. Indirect System - in this system, the drinking water used in the building is supplied from the main and water used for other purposes is supplied indirectly from a cold water storage.
4.1.2 Hot Water System
a. Centralised System - water is heated and stored centrally and distributed throughout the building by means of pipeworks. The heating of water is usually achieved by means of a boiler fired by gas, oil or solid fuel.
b. Localised Water Heating System - supply of hot water by localised systems use electric or gas water heater sited either directly over the fitting being supplied. The length of pipeworks and heat losses from them are therefore reduced considerably and the cost of construction of a boiler room is eliminated.
4.1.3 Surface Drainage Above Ground
It is generally the pipework system for collecting rainwater onto the roof of building and discharging it away to the underground drainage system outside the building.
4.1.4 Foul Drainage above Ground
It includes generally the soil, waste, and ventilation pipework and fittings in the building. It functions to convey discharges from appliance to underground drains and can be arranged in three different ways: two- pipes, one-pipe and single-stack systems.
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4.2 Materials, Valves, Fittings and Tools
4.2.1 Materials for Pipes
In Hong Kong, pipes for plumbing work are generally made of the following materials: Cast iron, Ductile iron, Stainless Steel, Mild Steel (galvanised), Copper, and Plastics. Choice of materials for different piping systems depends on the properties of and the suitability of the materials. The common types of pipes used in local plumbing work are summarised as below:
4.2.2 Valves
The term 'cocks', 'valves' and 'taps' are used to name fittings required to control the flow of fluids in a pipeline. Cocks and valves are usually used to control the flow along a pipeline, whilst taps are usually used at the end of a pipeline for draw-off purposes.
Stop Cock - used on high pressure systems, such as water supply mains. On the other hand, it functions to keep water non-returned.
Gate Valve - used for the control of fluids in low-pressure systems, such as on distribution pipework from storage cisterns.
Ball Valve - are used to supply water to storage and flushing cisterns and to automatically shut off the supply when the correct water level has been reached.
Bib Tap - Screw down type which designed to shut off the supply slowly and thus prevent water hammer.
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4.2.3 Pipe Fittings
The pipe fittings are used to:
i. alter the direction of a pipe alignment
ii. connect a branch with a main
iii. close an end
iv. connect two pipes of different sizes
Systems Foul Water Pipe Hot WAter Surface Water Cold WAter Drainage Drainage Material Supply Supply Above ground Above ground Copper
DI
GI PVC Lining Stainless Steel CI
MS
UPVC
MDPE
PB
a. Types of Fittings
Elbow - A fitting that makes an angle between adjacent pipes. The angle is always 90o unless another angle is stated. For larger radius, it is a bend.
Tee - A fitting that has one side outlet normal to the run.
Return Bend - Return bend is largely used for making up pipe coils for steam heating and for water boilers. They are U-shaped fittings with a female thread at both ends.
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Cross - A pipe fitting with four branches arranged in pairs, each pairs on axis, and the axes are at right angle.
Y Branch - It is similar to a tee, except that the side outlets are set at angle of 45o to
60o instead of 90o.
Bushing - A pipe fitting for the purpose of connecting a pipe with a fitting of a larger size, being a hollow plug with internal and external threads to suit the different diameter.
Plug - It is used for closing the end of a pipe or a fitting having a female threads. Usually a square head countersunk head is used for the small sizes, and a hexagonal head for the larger sizes.
Cap - It is used for closing the end of a pipe or fitting having a male thread.
Flange - It is simply a disk for closing flanged fittings or flanged pipe lines.
Offset - A fitting is used to offset the pipe line by bending the pipe, but ordinarily where the offset between the axes of the two pipes is of standard dimension
Nipple - A tubular pipe fitting usually threaded on both threaded ends and less than 300mm in length.
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Reducer - A fitting having a larger size at one end than at the other.
Tubular Trap - It may be in form of 'P' or 'S' shaped traps.
Bottle P Trap - It is usually a plastic fitting in waste system for easy maintenance work.
b. Fixing and Brackets for Various Types of Pipes
Various methods are used for pipe fixings to walls, brick wall and cement surfaces.
Pipe Types Pipe Brackets CI DI MS CU PVC Cast Iron
Galvanised Malleable Iron
Steel
Plastic Coated
Copper Alloy
Pipe Brackets:
4.2.4 Tools and Machines for Pipework
a. Pipe Wrenches
Straight Pipe Wrench - general uses.
End Pipe Wrench - for pipe working in restricted spaces.
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Strap Wrench - Best for any polish pipe, e.g. plastic pipes.
Hex Wrench - Hex jaw design gives multi- sided, secure grip on the all shaped nuts, unions, and valve packing nuts.
Basin Wrench - Sparing-loaded jaws provide fast, one-hand ratcheting.
b. Pipe Cutters
3 or 4 wheel pipe Cutters - Fast, clean pipe cutting by hand or power, can only be rotated through 120o-130o, suitable where space is limited.
Roller Cutter - can be turned through 360o, it prevents forming of external burr and the spiral-cut.
c. Threading Tools
Manual Pipe Threader - with dies for threading light-duty pipe.
Threading Machine - power driven threading machine for threading/cut- grooving/bevelling/close nipples/chamfering of pipes.
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d. Plumbing Benders
Hand Compression Pipe Bending Machine - this type of machine is used to bend light gauge copper pipes up to 25mm bore and mild steel pipes up to 15mm bore.
Manually operated Hydraulic Bending Machine - this machine uses hydraulic pressure to bend steel pipes of 15mm to 75mm bore.
e. Pressure Test Pump
Tests hydraulically for the leaks in installations which are required to be leak proof.
4.3 Pipework Practices Bending & Jointing
4.3.1 In this section practical training is arranged for students to appreciate the local practices in plumbing trades which include understanding of Vertical Pipe Line Diagrams, preparation of materials and associated installation methods.
4.3.2 Common Symbols Used in Plumbing Works
Stop Cock Gate Valve
Storage Cut Off Float Cistern Valve
Ball Valve Non-return Valve
Meter M Draw Off Points
G Pump Set Heater
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Y-pattern Vent Pipe
Strainer
Twin Sphere Level Control Rubber Expansion
4.3.3 Calculation of Pipe Length
In calculation the length of pipe segments in the plumbing works, allowance for the projection of the fittings and the threaded length of the pipe must also be considered. The actual length of the steel pipe (stainless steel, G.I. pipes) includes the lengths of usable pipe thread.
Approximate Length of Usable Pipe Thread: Pipe size Dimension A Pipe size Dimension A 1/4" 3/8" 1" 9/16" 3/8" 3/8" 1 1/4" 5/8" 1/2" 1/2" 1 1/2" 5/8" 3/4" 1/2" 2" 11/16"
A sectional sketch with dimension "A" for pipe fitting:
A
Thread Joint
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4.3.4 Bending
Metal and plastic pipes can be bent to minimise the need for expensive connectors and so as to reduce the cost of installing pipe systems. Bending of copper and G.I. pipes of diameters up to 75mm may be done by hand compression or hydraulic bending machine. Bending of plastic pipes are generally by heat treatment processes.
lever arm oil pressure former valve
pipe stops manual bender plus pin
hydraulic press-bender
4.3.5 Jointing
There are many types of jointing for water pipe. Steel Threaded Joints, Flange Joints, Compression Joints, Weld Joints, Cold Weld Joints and etc.
However, they can be classified into two nature of jointing: Rigid Joint and Flexible Joint.
4.3.5.1 Steel Threaded Joints (Stainless Steel and G.I. pipe) - for threaded joint, all pipe fitting are tapped with internal pipe thread, the plumber needs only make the external pipe thread. The jointing process is as below:
- Cut the pipe to the required length; - Ream the inside of the pipe; - Thread the pipe with the die or threading machine; - After threading, wipe the thread clean; - Apply pipe joint compound in the male thread; - Tighten the joint with a pipe wrench.
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4.3.5.2 Copper Tubing Joints
a. Capillary solder joint - it depends on capillary action drawing free-flowing molten solder into the gap between the fitting and tube.
- Cut the tube to the required length; - Ream the cut end and remove the burrs of the tubing; - Clean the tubing and the fitting socket with sand cloth; - Apply flux to the tube end and fitting socket; - Assemble the pipe and fitting; - Apply heat to the tubing first, but only momentarily, and then to the fitting until solder melts; - Remove the flame and feed solder to the joint until a ring of solder appears at the end of the fitting; - Remove excess solder with a cloth while the solder is still pasty, leaving a fillet around the end of the fitting as it cools.
b. Compression Joints - Cut the tube to the required length; - Ream the cut end and remove the burrs of the tubing; - A swaged end formed on the tube and the nut is put on the tube before forming a swaged end; - Insert tube end into fitting; - Tighten cap nut with a spanner.
tightening soft copper nut ring
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4.3.5.3 Plastic Pipe Joints a. Rubber Ring Joint - this joint may be either of integral socket design or it may consist of a separate sleeve-type coupling.
- Clean dirt and grit from socket; - Insert the rubber so that it seats evenly in the socket; - Clean the spigot back to reference mark and apply lubricant to chamfer; - Align spigot and socket and push pipe home until reference mark is just visible at socket mouth.
b. Solvent Weld Joint - solvent weld joints are made by solvent bonding, producing a welded system much like a metal welded system.
- Cut the pipe squarely, remove the burrs and slightly chamfer the external pipe edge; - Degrease the spigot and socket; - Apply the solvent cement as pre-marked; - While the surface is still wet, push the spigot home into the socket with a slight twisting motion and remove the excess cement with soft cloth.
4.4 Sanitary Appliances Installations
4.4.1 The use of water in building and other purposes is made possible and
convenient by the provision of sanitary appliances which are of
appropriate form and have water supply either from the main, or from hot or cold water storage vessels. It is essential that the supply water is not contaminated by foul water and for this reason in most cases the taps
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are designed to discharge above the flooding level of the appliance, to prevent the risk of back siphonage of foul water into the supply pipe.
4.4.2 Materials Used in Sanitary Appliance Glazed Earthenware - for sinks and w.c. pans - well to form complicated shapes - relatively cheap - produces products of good colour Glazed Fireclay - produces a tough appliance - resistant to knocks and hard wear - for urinals, sinks and w.c. pans in publics Vitreous China - used for all types of appliances - relatively weak - non-absorbent even when it is unglazed - various colours may be obtained Mild Steel - galvanised or enamelled - used for toughs and sinks - relatively cheap Stainless Steel
- used for sinks, wash basins, w.c. pans etc.
- rather expansive - good appearance may be obtained
- highly resistant to hard wear
Acrylic Plastic
- various colours, and excellent appearance - light in weight - relatively cheap - hot water tends to soften the material
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G.R. Polyester - More expensive and stronger than acrylic plastic - a good coat finish is essential - various colours may be obtained Cast Iron - mainly for large appliance such as baths - strong but heavy in weight - very cheap - finished by firing on vitreous enamel
4.4.3 Types of Sanitary Appliances a. Soil Fittings: - water closet - sinks b. Waste Fittings: - wash basins - sinks - baths c. Flushing Cisterns: - piston flushing cistern - bell-type flushing cistern - automatic flushing cistern
atomspheric overflow pressure
flow s trap sink mixer single trap water closet basin section
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4.5 Discussion & Exercises In this exercise, trainees are required to work as a team and organise themselves to carry out plumbing practices as described below. In the two given pipe line drawings, the general layouts and connection fittings of the pipework are given, trainees
Suggested procedures: Part A - Working procedure of steel pipe installation (20mm, 15mm GI/Stainless Steel)
• Prepare materials required for the exercise, • Set out alignment of steel pipe system on the working bench, • Assemble all pipe fitting on the pipe alignment and get necessary pipe data, • Pipe connection with fittings and close pipe system with connector, • Copper pipe is installed by tilting appropriate fitting, • Water test
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Part B - Working procedure of copper pipe installation (15 mm copper pipe)
• Prepare materials required for the exercise, • Set out alignment of copper pipe system on the working bench, • Assemble all pipe and fitting according to the specified alignment, • For capillary solder joint, spigot of copper pipe and socket of pipe fitting should be cleaned, • Apply flux to the captioned joint. Note that all capillary solder joint should be installed before heat treatment, • Apply heat treatment by fire gun. Take care of the high temperature of the copper pipe, • Close the pipe system by mechanical joint, • Water test.
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Part V – Construction Project
5.1 Introduction
The training programme is intended to enhance development of all-roundness and professional competences of construction students. Students are provided opportunity to learn about the roles and tasks of a contractor to gain some insight into the construction engineering profession, to provide work integrated environment for construction students to apply their professional knowledge / skills in a real-life situation.
5.2 Learning outcomes
On successfully completing this subject, students will be able to:
Category A Professional/academic knowledge and skills
• use technical knowledge in construction practices to plan and design method statements for typical construction process; • apply basic construction and quality control methods in typical building construction work; • apply interpersonal skills to work co-operatively as a member of the construction project team; • use building and construction terminology to communicate and interact effectively with peers and working partners in construction project; • develop basic project management skills in construction site project.
Category B Attributes for all-roundedness
• recognize the roles and contributions of other team members and demonstrate the ability to adapt and change; • manage personal issues, handle interpersonal situations to reduce mis- understanding and conflict among peers and team members; • develop problem solving ability with respect to limitation of resources available.
5.3 Brief Syllabus Content
By participating in this module, students will be introduced with the general practices and the roles of the clients, their representatives and the contractors in running a construction project in different stages. Apart from utilizing the construction technology learnt from lectures and basic construction practices training, this construction project will be introduced to students with emphasis placed on project planning, management and construction safety throughout the project. The indicative work-integrated learning syllabi are summarized below:
Site project management Project progress planning & co-ordination
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Engineering design & drawing Site survey & setting out Site construction according to design Construction methods Good construction practices Construction safety Quality and quantities Control Site records and documentations Communication with client, supervisors and other parties Problem solving, lateral thinking & decision making
5.4 Learning Approach
The work integrated construction project will be a real site project administered and constructed by the students under the supervision of IC staff. The scope of work will in general involve miscellaneous renovation works and minor structures construction in school campus improvement projects. Students are required to formulate themselves their own site organization structure and will team-play different roles as in a contractor, the IC staff as the site supervisors and mentors will co-ordinate the student contractor teams to complete the assigned tasks in the construction project.
5.5 Assessment
The assessment of students is mainly based on their work attitudes and continuous performance throughout the project; peer assessment among trainees will also be a factor contributing the overall results. At the completion of the on-site construction project, each trainee is required to prepare a short written report and give an oral presentation in front of the project team to share experiences and knowledge gained in the project; which forms part of the assessment of trainees in the module.
The assessment rubrics are shown below:
Part 1: Work Attitude 40%
Time-keeping ( including lateness, absence without approval etc) 5%
Safety behavior 10%
Work attitude throughout the project work 15%
Team-working & helping others 10%
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Part 2: On-site Construction Work 25%
Technical skills and leadership capabilities, orally, written 25% communication skills related to the site work
Part 3: Written Report and Oral Presentation 25%
Written Report 15%
Oral presentation 5%
Contribution in preparation of the group project report 5%
Part 4: Peer Review Average 10%
Peel review by the volunteered “Management Team” on individual’s 10% overall performance
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REFERENCES
Part I – Structural Concrete Practice • ASD (1999). “Report on Concrete Admixtures for Waterproofing Construction”. ASD, HKSAR, • ASD (2007). “General Specification for Building (2007) Vol. 1 & 2”. ASD, HKSAR, • Buildings Department, PNAP275 (2003). “Use of Recycled Aggregates in Concrete”. Buildings Department, HKSAR, • BS12:1996. “Specification for Portland Cement”. BSI, • BS882:1983, Specification for aggregates from natural sources for concrete, BSI, • BS5075 Part 1:1982 & Part 3:1985, Concrete admixtures, BSI, • BS8666:2000, Specification for schedule, dimensioning, bending and cutting of steel reinforcement for concrete, BSI, • BS EN 12620:2002, Aggregates for concrete, BSI, • Buildings Department (2004). “Code of Practice for Structural Use of Concrete 2004”. Buildings Department, HKSAR, • CEDD (2009). “General Specification for Civil Engineering Works (2006 Edition) Volume 1, 2 & 3”. CEDD, HKSAR, • Concrete Technology Committee (2006). “Construction Standard, CS1:1990 – Testing Concrete Volume 1 & 2”. Works Branch, Development Bureau, HKSAR, • Concrete Technology Committee (1995). “Construction Standard,
CS2:1995 - Carbon Steel Bars for the Reinforcement of Concrete”. Works
Branch, Development Bureau, HKSAR,
Part II – Formwork, falsework and scaffolding
• AS3610:1995. “Australian Standard on Formwork and Falsework for
concrete”, • BS5975:1996. “Code of Practice for Falsework”. BSI, • BS 8110:1985. “The Structural Use of Concrete”. BSI,
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• Buildings Department. “Guidelines on the design and construction of bamboo scaffolds”. Buildings Department, HKSAR, • C. K. Austin (1978). “Formwork to Concrete”. 3rd edition, G. Godwin, • Concrete Society (1995). “Formwork: a guide to good practice”. 2nd edition, Concrete Society, • Construction industry research and information association (1995). “Formwork striking times – criteria, prediction and methods of assessment”. CIRIA Report 136, • Construction workers registration ordinance (amendment of schedule 1) NOTICE 2007, • Environmental Protection Department (2006). “How to Apply for a Construction Noise Permit” Environmental Protection Department, HKSAR, • Harrison, T.A. and Clear, C. (1985). “Concrete pressure on formwork”. CIRIA Report 108, Construction industry research and information association, • HK-Beam Society (2005). “The HK - BEAM Society Newsletter summer 2005, Enhancing Hong Kong’s Built Environment”. HK-Beam Society, • Irwin AW. Sibbald WI (1983). “Falsework-A handbook of Design and Practice”, • John A Walton (1979). “Woodwork in Theory and Practice”. Hornsby, N.S.W., Australian Publishing, • Joint Committee of the Concrete Society & The Institution of Structural Engineers (1986). “Formwork: a guide to good practice”. Joint Committee, London,
• Labour Department (2001). “Code of Practice for Bamboo Scaffolding
Safety”. Labour Department, HKSAR, • Labour Department (2001). “Code of practice for metal scaffolding safety”.
Labour Department, HKSAR,
• M. M. Waters, Concrete Society & Institute of Structural Engineers (1971).
“Technical Report on Falsework”. Concrete Society, London, • Martyn Bramwell (1976). “The International Book of Wood”. Mitchell Beazley, London,
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• Ronald E. Brand (1975). “Access Scaffolds in Tubular Steel”. McGraw-Hill, London, • William P. Spence & L. Duance Griffiths (1995). “Woodworking Basics – The Essential Benchtop Reference”. Sterling Pub. Co., New York. • Woodworking Tools, Material, Processes Spence, Griffiths,
Part III – Plastering, Brickwork and Blockwork • BS 3056. “Size for refractory of bricks”. BSI, • BS 5628-3:2005.”Code of Practice for the Use of Masonry-Materials and Components, Design and Workmanship”. BSI, • BS EN 771-1. “Specification for masonry units”. BSI, • ASD (2007). “General Specification for Building”. ASD HKSAR,
• Hodge J.C. (2006). “Brickwork for apprentices”. 5th edition, Elsevier Butterworth-Heinemann. • Lilley A.A. & Clark A.J. (1981). “Concrete block paving for lightly trafficked roads & paved areas”. Cement and Concrete Association.
Part IV – Plumbing • Building Development Department, 1984, General Specification for Building Architectural Office, Hong Kong • Charles N. McConnell (1989). “Plumbers and Pipe Fitters Library: Materials, Tools, Roughing-In, Volume 1”. 4th Edition, Wiley, • Charles N. McConnell (1989). “Plumbers and Pipe Fitters Library: Water
Supply, Drainage, Calculations, Volume 3”. 4th Edition, Wiley,
• Engineering Industry Training Board (1979). “EITB training Element, Cold Bending Copper and Carbon Steel Pipes up to 50mm bore”. EITB,
• Ernest Hall (1977). “Home Plumbing”. Newnes Technical, London,
• Hall F. (1985). “Plumbing Technology”. 2nd Edition, Longman Scientific &
Technical, • Miller James (1993). “Basic Plumbing Techniques”. Ortho Books, • Oravetz Jules, Sr. (1967). “Plumbers and Pipe Fitters Library: Materials, Tools, Roughing-in, Volume 1-3”. Indianpolis,
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• RIGID Tool Co (1991), Catalogue No. RT-191 Dec 1991, • Smith, C. J. (1998). “Practical Plumbing”. Macmillan Education Ltd., • The Institute of Plumber, Guide to the Installation of UPVC soil pipe system.
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BIBLIGRAPHY
Part I – Structural Concrete Practice
• Concrete Finishes and Decoration, HL Child, • Concrete Practice, Cement and Concrete Association, • Man On the Job, Cement and Concrete Association, • Reinforcement Detailing Manual - Robin Whittle.
Part II – Formwork, falsework and scaffolding
• Buildings Department (2004). “Code of practice on wind effect in Hong Kong 2004”, Buildings Department, HKSAR • BS 1139-2.2:1991. “Metal scaffolding – Part 2: Couplers – Section 2.2: Specification for steel and aluminum couplers, fittings and accessories for use in tubular scaffolding”. BSI, • Labour Department (2001), Code of Practice for Metal Scaffolding Safety,
1st edition. Labour Department, HKASR • Labour Department (2009), Code of Practice for Bamboo Scaffolding Safety, 2nd edition, Labour Department, HKASR
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RECOMMENDED READINGS
• BS 7973 Part 1 & 2:2001. “Spacers and chairs for steel reinforcement and their specification”. BSI, • BS 8500 Part 1 & 2:2002. “Concrete – Complementary British Standard to BS EN 206-1”. BSI, • BS EN 197 Part 1:2000. “Cement – Composition, specifications and conformity criteria for common cements”. BSI, • BS EN 206 Part 1:2000. “Concrete - Specification, performance, production and conformity”. BSI, • BS EN ISO 17660 (2008). “Permitted welding process for reinforcement”. BSI. • BRAND, R E. (1975). “Falsework and access scaffolds in tubular steel”. McGraw‑Hill, London,
• BS5975:2008. “Code of practice for temporary works procedures and the permissible stress design of falsework”. BSI, • National access and scaffolding confederation (2008). “Guide to good practice for scaffolding with tubes and fittings”. TG20, London, • PERI GmbH Formwork and Shoring. http://www.perime.com/products.cfm, • PNAP 153 (1992). “Tropical Hardwood Timber”. Buildings Department, HKSAR, • L. Fan & Yim (2008). “Construction Management and Civil Engineering Practice in Hong Kong”. Association of Engineering Professional in Society Ltd..
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