Safety Precaution In The Workshop

Safety precaution; this can be define as a safety guide that control the behaviours of personnel to prevent them from accident, lost of life, etc.
Accident in the workshop is the occurance of disaster which may lead to injury to personnel, fatality, damage to property; equipment, material amd lost of man-hour due to unsafe act and unsafe condition.

Categories of accident in the Workshop.


accident in the workshop are cause through the following categories:

1. Human fault

2. Machine fault

3. Natural fault

1. Human fault
; this is a cause of accident that occur due to human fault through carelessness, ignorance, or when a person working or visting a workshop failed to obey the safety precaution while working. This cause of accident affect most of the people working in the workshop and causes serrious damages or even makes a particular job done be delayed.
Example of such accident may includes the following reason below;
¡. Falling from the roof or walkin over barriers.
¡¡. Erecting or desination of scalford
¡¡¡. Playing with workshop tool when your are told no to do so and also handling material or tool

2.

Machine fault
; this is another category cause of accident in the workshop that occur by machinery when improper use of the machine or improper fixed of the machine and its parts in accordance with the manual or safety guide.
Example of such accident may includes;
¡. Electricity spark or shocking which may leads to fire outbreak
¡¡. Improper used of the machine
¡¡¡. Improper fixed of machine and chemical combution among others

3.

Natural fault
; natural fault of accident is another categorie of accident that is not cause by either human or machine fault, it occurs naturally on its own such as wind break, flood, thunder storm and some other wheather factor; which can cause collapses and damages to the workshop and building fracstructures.

Safety rules and precaution to be observed in the workshop


:- Always wear safety guard (gears) in the workshop.

:- Do no operate a machine that you are not familier with unless you have been used to it.

:- Isolate machinery that are powered by electricity or air compressed when not in used.

:- Avoid oil spillage in the workshop.

:- Do not used dull tool.

:- Eating, smoking and drinking (alcohol) should be prohibited in the workshop.

:- Avoid carrying tool in your pocket and overloaded material in your hand.

:- Maintain all the service records of machines and equipment. It wil not only save time but also help you to take care of respectative breakdown.

:- All tools and accessories must be kept back at their relevant places. Keeping them any where will lead to chaos and ineffecient working.

:- The gangway through the workshop must be kept clear.

:- Non slips mat should be used in front of machines where necessary, and machines should be sensibly placed to avoid overcrowding and suitably anchored to vibration.

Construction management

Construction management and planning begins with a complete analysis of the job, down to its smallest component part. The production of each is planned in terms of the optimum material and taking account of the resources in labour and plant management. The whole is then fitted into a closely integrated programme, the ideal of which is that each component should be ready on time, in correct balance of quantities, at the right place; that the flow of work should be logical and in single direction. That the distance traveled and the amount of lifting and handling during this flow should be the minimum possible; that machine and men should be employed to capacity without breaks or delays due to shortages or errors in the programme at each point should be adequate and excercise complete control in timing, quality and quantity. The result is a patter of very good great complexity, always in motion, yet never, in the ideal, allowed to fall out of rhythm or balance.

Preliminary Operations In Construction

Preliminary operations refers to all activities involves on a construction site before the actual work commences; some of this operations may includes:

- Site acquisition

- Site investigation

- Grubbing up and levelling

- Escavation of vegetation top soil


- SITE ACQUISATION: The acquisation of any construction site is basic responsibilities of the client, however it is necessary to provide the client with some factors to be consider while making the choice and the selection of the construction site. Therefore site acquisation requires a professional approach while working with land owners and goverment agencies.
Among the major things to be consider while making selection of building or construction site may includes:

¡. Location of the plot or site; the area of any plot will have effect on both the cost of the land itself and the economic of construction vis-a-vis; ligthing, ventilation, orientation of building with respect to sunlight, and the wheather changes of that particular of the construction site and also the evenness of the area and the nature of existing study all have to be considered.

¡¡. Climate Variation of the area; climate variation are more widely pronounced between regions but differences exist even within a given regions- some parts normaly suffered as a result of wind problem while others battle with turential rain and drainage problems. All of this most be considered also when acquiring a piece of land depend on it's uses.

¡¡¡. The elevation of the site; the elevated sites are mostly preffered than the valley area as they provide better horizon and land scapes, never the less building on hill site may required wind breakers or parapette walls, in other to protect those structures against bad wheather.

¡v. Nature of soil; it is important to have an idea, knowledge or information on particular piece of land before it is selected for any kind of buildings, this will intermed effect the type of foundation and materials to be used during construction.

V. Proximity of public utilities; it is necessary that the building plots expecially those that are made resdentials purpose be selected within zone where access to public utilities will not purse a major problem to the inhabitant to those buildings intended such as school, market, hospitals, water supply base, etc.

- SITE INVESTIGATION: Basically envolves a specifically visit to be acquired on construction plot in other to ascertain it major features particularly the nature of the site, the soil composition of the site and the bearing capacity of that soil. It is also important to note the amount and nature of preliminary work to be done.
The site investigation will also help in reveiling the exact nature of the sorrounding plots and possible ornamental tree that may needs to be left during grubbing up and levelling of the site. It is also essential to note other features that may left or avoided during the work.

- GRUBBING UP AND LEVELLING: This is a process of roting of fallen down of unwanted trees on site and shrubs on a virgin site and also the activities of falling up the low land dishes, glowly on the construction site. In either case the area to be levelled up most be well marked out and read to ensure that no decayed organic matter are covered underground within the soil topography of the construction site.

- ESCAVATION OF VEGETATION TOP SOIL: This is considered as the major aspect of site clearance starting with the grubbing up before any building operation on site commences, the vegetation top soil needs to be cleared from the area upon which the structure will stands.

Plastic in relation to building

Plastic is an artificial subtance that can be shaped when soft, into many different forms and has many different uses.
Plastic has become an indispensable part of the building and construction industry. Plastic in relation to building products have several distinct available advantages over traditional exterior building materias.
One advantage to the consumer is that plastic building materials typically require less maintenance than other traditional materials. Unlike wood, plastic do not swell with moisture absorption, do not need to be repainted, and do not succumb to rotting or insect infestation.
Compared to metal, plastic will not dent or rust, scratches can be buffed out and finished parts never have to be repainted.

Classification Of Plastic


plastic is classified into two types; namel:
1. Thermoset plastic;
2. Thermoplastic

-Thermoset is a term used to described plastic that become permanently hardened when heated or cured. The curing process of thermoset causes a chemical reaction that creates permanent connections between the materials molecular chains. Due to their molecular bond, thermoset plastics have superior durability and will not change shape due to estreme thermal and chemical conditions, thus often outperforming other building materials.

-Thermoplastic is a term used to described plastics that becomes soft and pliable, but do nit set when heated. Thermosetplastics have the ability to harden into a particular mould but because there is no chemical change that occurs during the curing process the materials is able to be reprocessed numerous time. The major advantage of thermoplastic materials is their ability to be recycled, though continual recycling may adversely affect the quality of the polymer.

Properties Of Plastic


1. Ductility; is a property of a plastics that that permit it to be permanently drawn, bent or twisted into varrious shape without breaking.

2. Elasticity; is that property that enable a plastic to return to its original shape when the force that causes the change of its shape is been removed.

3. Toughness; is the properties at which plastic will withstand tearing and may be stretched or otherwise deformed without breaking.

4. Hardness; this property refers to the ability of a plastic to resist abration, penetration, cutting action or permanently distortion.

Characteristic Of Plastcs used in building structures


- A plastic can be transparent like the wing screen of a vehicles.

- It can be made into insulator because it was a bad conduct of heat.

- It can be drilled, melted and casting.

- It can be weld and impressed or heated to form another object.

- Plastic material are easy interm of labour.

Uses Of Plastic


* Plastic can be used for floorinr e.g terazo floor.

* It can also be used as roofing material e.g in refugees camp and Fulanis most especially in african continent used sack and nylon for floor carpets and roofing.

* Plastic materials can be used for ceiling materials e.g pvc, nylon.

* Plastic can be used in wiring installation of a building e.g duct wiring and conduit wiring.

* Plastics are good source of materials used in construction of window, door, and furnitures such walldrobe, carbinets, chairs, among others. They can also serves as wall tilling.

* It can be used to joint items on parts of a building. Example plastic cement is used to gloed tile and water closet filling.

Bitumen subtance in relation to building

A bitumen is also known as asphalt; is the stickly, black and highly viscous liquid or semi-solid present in most crude petroleums and in some natural deposits; it is a subtance classed as a pitch. Until the 20th century, the term asphaltum was also used.
The term asphalt and bitumen are often used interchangeably to mean both natural and manufactured forms of the subtance.
The primary use of this subtance it is in road construction, where it is used as the glue or binder mixed with aggregate particles to create asphalt concrete. Its other main uses are for bituminous waterproofing products, including production of roofing felt and for sealing flat roof.

Uses of bitumen.


- A bitumen is used to refers to a mixture of mineral aggregate.

- It is also often used as generic term for road surfaces.

- It is also used for oil refinery product used to pave roads and manufacture roof shingles and varrious water proofing products.

- It is used also to seal the plank on ocean-going canoues.

-it can be used for flooring incase of water lock and can still be used for highly remarkable used in emulsion paint to increase the wheather resistances and permanence of paint to make the structure so furnished and beautiful.

Characteristic of a bitumen subtances.


* A bitumen is a subtance that can be separeted from other components; as the subtance is completely soluble in carbon disulfide, and composed primarily of a mixture of highly condensed hydrocarbons.

* Due to its highly viscous nature, asphalt cement must be heated so it can be mixed with other aggregates at the mixing plant.

Properties of Bitumen.


* The properties of bitumenious subtance being dependent upon the type, size and amount of aggregate used in the mixture all of which are adjusted to provide the required properties for the desirable application.

* It is sticky, black and highly viscous liquid or semi-solid.

Advantages of Bitumen.


1. It is a good subtance used in building flat roofing.

2. It can be separeted from other componet when heated and can also serve as a good waterproofing agent.

3. Bitumen subtance can be added to other aggregates such as stone, gravel, clay, gravel, etc in aggregate mixed; which serves as a source of nutrient to the structure to be stronger and free from craking due to wheather implications.

Disadvantages Of Bitumen.


1. Bitumen can easily crushed down if not supported with good anchor in term of roofing and upstairs flooring, lintel among other.

2. It takes time in its finishing.

References


http://www.lexiscoating.com/modified-bitumen/

http://www.eurobitumen.be/bitumen/types-bitumen

http://en.m.wikipedia.org/wiki/bitumen

Aggregates

Aggregates are materials used as filler with binding material in production of mortar and concrete.

¤ They are derived from rocks.
¤ They form the body of concrete.
¤ They reduce shrinkage.
¤ 70-80% it contained of concrete
¤ They have considerable effect on properties of concrete.

Characteristic of good aggregates.

* Clean
* Hard
* Strong
* Durable
* Graded in size

To increase bulk density, two types of aggregates are used;

Coarse:- grit (main)

Fine:- sand (filler)

Types of Aggregates

Natural Aggregates.
.'. Obtained from quarries of igneous, sedimentary and metamorphic rocks.
.'. They are usually sieved and washed before used in concrete.

Artificial Aggregates.
.'. It obtained from broken bricks, blast furnace slag, synthetic aggregates.
.'. Broken bricks are used for mass concrete and foundation bases.
.'. Blast furnace slag is not suitable for reinforced concrete works. It is used for precast.

Classification of aggregates

Based on size aggregates is classified into:

- Coarse aggregate.
- All-in aggregate.
- Fine aggregate.
- Grounded aggregate.

Coarse aggregate

mix of fine and coarse ; not recommended for quality concrete.

Fine aggregates

.'. Passing through 4.75mm sieve, smallest- 0.06mm.
.'. Could be fine, medium or coarse.

Graded aggregates

Aggregate of a particular size e.g graded aggregate of nominal size of 20mm.

Classification of Aggregates based on shape

* Rounded aggregate; which has poor interlocking.
* Irregular aggregate; which develops good bond.
* Angular aggregate; which has good bond (most suitable)
* Flaky

Fine aggregate

Sand (greater than 0.07mm) is used as fine aggregate in concrete and mortar.

It is a granular form of silica.

Grade of sand is important in its workability; very fine and very coarse sand are unsatisfactory for making concrete or mortar.

Impurities such as clay, dust and organic materials adversely affect mortar and concrete. They can be removed by washing.

Coarse aggregates

crushed, in crushed or partially crushed gravel or stone which is retained on 4.75mm sieve.

Function of aggregates

~ Prevent shrinkage and development of cracks on a building or any related structures.

~ Furnish strength to mortar and concrete.

Cement

Introduction

- cement generally refers to adhesive and cohesive material which are capable of bonding together particles of solid material into a compact durable mass.
- mass of calcalerous cement containing compound of lime as it chief constituent
- primary function of cement is binding fine and coarse aggregate together.

Classification of cement

.'. Hydraulic cement:- which sets and hardens in water such cement consist portland cement among others.

.'. Non-hydraulic cement:- is the one that does set and harden in water example of such cement is Plaster Of Paris (POP) cement among others.

Sources of cement

Cement can be manufactured from either natural cement stone or artificially by using calcareous and argillaceous materials.

¤ Natural cement consist of roman cement, puzzolana cement, medina cement.
¤ Artificial cement consist of portland and special cement.

Uses of cement

1. For its high strength; cement are used in bridge piers, light house lofty towers.

2. For large structures; cement can be used in bridge construction, silos, and chimney among others.

3. For structures exposed to action of water; cement can be used in reservoirs, dams, dock yards among other thing.

Manufacture of Cement

Calcareous and argillaceous raw materials are used in the manufacture of portland cement.

Calcareous; this contains cement rock, marl, chalk, marine shell.

Argillaceous; this contains silicates of alumina-clay, shale, slate, blast furnace slag.

Cement is manufactured by dry or wet process

Dry process

Limestone and clay are ground to a fine powder separately and are mixed. Water is added to make a thick paste (slurry). The cakes of the paste are dried and charged into a rotary kiln. The kiln dries out as it flows, the water being evaporated first and then it reaches its maximum of 1500c thereby fusing the material into clinker. The clinker is cooled and ground to fine powder. A small amount of gypsum is added to retard the setting cement. As been described below
CHALK (CaCo3)+CLAY=>ground with H2O=> SLURRY=>SIEVING=>ROTATING KILN=>GRIND CLINKER+GYPSUM=>Bagged as CEMENT.

Wet process

crushed raw materials are field into a ball mill and a little water is added. When the mills is operated, it pulverizes the materials to form slurry with water.

The slurry is passed to silos where its is adjusted to desirable chemical composition.

The corrected slurry is then fed into a kiln where it loses moisture and forms lumps or noodles.

They are finally burned at1500c into a clinker. The clinker is then ground, and gypsum added.

CHALK(CaCO3)+CLAY=>GROUND WITH H2O=>SLURRY=>SILOS(Where chemical composition is adjusted)=>ROTATING KILN=>CLINKER=>GRIND CLINKER+GYPSUM=>Bagged as CEMENT.

Setting and hardening of cement

Cement set when mixed with water by way of a complex series of chemical reactions. The different constituents slowly crystallize and the interlocking of their crystal give cements its strength. Gypsum is added to retard the setting of cement.

Types of Cement

1. Rapid hardening portland cement.
2. High alumina cement.
3. Super sulphated portland cement.
4. Sulphated resisting portland cement.
5. Portland slag cement.
6. Low heat portland cement.
7. Portland puzzolano cement.
8. Masonry cement.
9. Air entraining cement.
10. Water repellant.

Link to www.wikipedia/cement.com for more info about cement