CONSTRUCTION TECHNOLOGY & maintenance

CONSTRUCTION TECHNOLOGY &maintenance

CEM 417SOURCES FROM slide:

MOHD AMIZAN MOHAMDMOHD FADZIL ARSHADSITI RASHIDAH MOHD NASIRFKA, UiTM Shah Alam.

Construction Plants

WEEK 6

WEEK 6CONSTRUCTION

PLANTS- Principles and factors of plant selections- Types, functions and capabilities of moving machines

At the end of week 3 lectures, student will be able to :

-Describe the principles and factors of plant selections. (CO1; CO2; CO3)

- Identify various types of construction equipments, i.e., moving, stationary, compaction and lifting machines. (CO1; CO2)

- Identify the types, functions, capabilities and selections of moving machines. (CO2; CO3)

LEARNING OUTCOME

THREE PINCIPLE CONSIDERATIONS:- Technical efficiency

Ability Requirement Correct specification timeframe

Commercial and financial ability Cost

Availability Supplier (location and numbers of supplier) within the timeframe

CONSTRUCTION PLANT

FACTORS SELECTING EQUIPMENT1. The function to be carried out2. Standard or special types of equipment3. Capacity of the equipment4. Method of operation5. Replacement of parts6. Maintenance and repairs7. Investment costs8. Operating cost

TYPES OF CONSTRUCTION EQUIPMENTS Used to ground leveling and bulk

earthmoving. Divided into two :-Moving Machines-

Bulldozers, loaders, scrapers, graders and trenching machines

The excavated material is removed, transported and deposited

For removal of large of earth Stationary machines

Face shovels, backhoes, draglines and grabs The excavator loosens the soil and loads without changing

position Loss of mobility compared to scrapers and bucket loaders More force may be applied

COMPONENTS OF

WORK

APPLICABLE TYPES OF PLANT

Clearing and grubbing Bulldozer, rake- dozer

Excavation Shovels (power shove ,back hoe, dragline, clamshell), tractor –

shovel, bulldozer, ripper, breaker

Loading Shovels (power shovel, backhoe, dragline, clamshell), tractor-

shovel, bucket wheel excavator

Excavation and loading Shovels (power shovel, backhoe, dragline, clamshell), tractor-

shovel, bucket wheel excavator

Excavation and hauling Bulldozer, scrape-dozer ,scraper

Hauling Bulldozer , dump truck, belt conveyer

Spreading and grading Bulldozer, motor grader

Compaction Pneumatic-tired roller, tamping roller, vibrating roller, road roller,

vibrating compacter, rammer, tamper, bulldozer

Blasting Drilling (crawler, pneumatic,hydraulic), air compressor, lorry

Equipment of Earthwork Plant

MOVING POSITION MACHINES Bulldozers and angledozers

High powered tractors with caterpillar or crawler tracksFitted with a mould board or blade at the front for

stripping top soil, clearing vegetation and oversite excavations up to depth of 400 mm

Work by pushing the material ahead of the machine Also for opening up pilot roads, spreading and grading

MOVING MACHINE -BULLDOZERS AND ANGLEDOZERS For back filling operations the angledozer

with its mould board set at an angle (in plan) to the machine center line can be used

Assembled in two separate sections base frame

Attached with dozer blade, drive sprockets (a projecting tooth on a wheel or cylinder that engages with the links of a chain or with perforations in film to make the chain or film move forward) and

rollers for the track and support for the upper body Superstructure

Engine, transmission, hydraulics, cab and controls (mounted on the base frame)

MOVING MACHINE - CRAWLER TRACKS

Advantages Ability to deliver greater effort

especially in operating on soft footing such as

loose soil or muddy soil Ability to travel over muddy surface Ability to operate in rocky formations

where rubber tires might be seriously damaged

Greater floatation because of the lower pressure under the tracks

Greater versatility on jobs

MOVING MACHINE –WHEEL MOUNTED

Advantages:- Higher travel speeds on the job or from one job

to another Elimination of hauling equipment to transport

the bulldozer to a job Greater output especially when considerable

travelling is necessary Less operator fatigue Ability to travel on paved highways without

damaging the surface

MOVING MACHINE - CABLE CONTROL Advantages :-

Simplicity of installation and operation Simplicity of repairing the controls Reduction in the danger of damaging a machine , as

the blade can be move up and ride over a rigid obstruction such as heavy boulder

MOVING MACHINE -HYDRAULIC CONTROL Advantages: -

Ability to produce a high down pressure on the blade in addition to its weight to force the blade into the ground

Ability to maintain a more precise setting of the position of the blade

BLADES USED Types of blades : -

Straight ‘S’ blade Universal ‘U’ blade Angle ‘A’ blade Cushion ‘C’ blade Rake

STRAIGHT ‘S’ BLADE

Used for heavy work Most versatile bulldozer Equipped with a push plate

effectively used for loading scraper

Most blade are curved, but the section perpendicular to the line of push is straight

The maximum of push should not exceed 100m as the machine is uneconomical for earth moving over a greater distance

‘S’ Straight Blade

UNIVERSAL ‘U’ BLADE

The blade in cross-section has a much deeper curvature, almost a ‘u’ shape

Efficient for moving big loads over long distance as in land clearing, stockpile work and pushing up for loading

Shall combined with a tilt cylinder to improves its ability to ditch, pry out and level

Effecting to light flowing type of soil

ANGLE ‘A’ BLADE The blade in plan view is angled Can also be positioned straight or angled 25

degrees to either side Designed for side casting, backfilling and

other similar tasks Can reduce the amount of manoeuvring

required to do this job

CUSHION ‘C’ BLADE

Used on a large tractors for on-the-go push loading

Rubber cushion allow the dozer to absorb the impact of contacting a scraper push block and effective travelling speed is up to 5 km/h

When not push loading, the dozer can be used for general dozing jobs

A blade consisting a heavy duty ribs which retained coarse rock, roots etc, but allow finer material to pass through

Used in digging and pushing stumps and rock and also in spreading of rock rip-rap

RAKE

Rib

FACTORS INFLUENCING SELECTION OF BLADES

Type of material to be moved1. Particles size and the shape of materials to be moved

Rounded particles tend to roll and required a tractor of lesser power than for angular particles

2. Voids ratios of the soil in the bank or undisturbed condition

A soil with small voids will be well bonded and difficult to move until the material is loosened

3. Moisture content of the soil greatly affects the pushing forces required

Soils with high moisture content levels such as clay tend to be heavy and required large pushing effort

4. Size of machine and the traction capabilities

MOVING MACHINE - SCRAPERS The piece of plants consist of a power unit and a

scraper bowl used to excavate and transport soil where surface

stripping, site levelling, light clearing, rough and fine grading, bank sloping, ditching/channel and cut and fill activities

Particularly for large volumes Produce a very smooth and accurate formation

level

Three basic types:- Crawler-drawn scraper Two-axle scraper Three-axle scraper

MOVING MACHINE - SCRAPERS

CRAWLER-DRAWN SCRAPER

Has truck and gooseneck arrangement Consist of four-wheeled scraper bowl towed

behind a crawler power unit Hauling speed - less than 8 km/h Scraping speed – less than 3 km/h

Is an integrated self-propelled unit Two-axle

have two wheeled power unit has advantages over its four wheeled power unit or three axle due to its manoeuvrable

Offers less rolling resistance and has better traction since the engine is mounted closer to the driving wheels

Three-axle Advantages of being able to use its top speed more

frequently, generally easier to control and power unit can be used for other activities which is not possible with most two-axle

WHEEL SCRAPER

LOADING OF SCRAPERS Scrapers are loaded by the following methods:-

Self loading in loose soils Push loaded by crawler tractor Elevating self loading Push pull Top loaded by hydraulic excavator or front end loader

SCRAPER CUTTING BLADECutting Blade for Scrapera. Standard Blade – used for fine

grading and finishing and for general earthmoving operations where the soils are not too stiff or hard

b. Drop Centre Blade – Operates in broad range of soil and for stripping grass and root bound soils. The centre section is dropped so as to prevents the dam up of the materials inside the bowl when loading and unloading.

c. Double Drop Centre Blade – Used in heavy clay or where the material has a tendency to loosed in sheets.

d. Drop Centre Tooth Mounted Blade – operates efficiently on material which are hard or crusty.

MOVING MACHINE - GRADERS Similar to bulldozers – have an adjustable

mould blade fitted either at the front of the machine or slung under the centre of the machine’s body

Use for finishing fine limits large areas of ground which has been scraped or bulldozed to the required formation level

Can only be used to grade the surface since their low motive power is insufficient to enable them to be used for oversite excavation work

Classified by number of driving wheels

TYPES OF GRADERS - SIX WHEELED DRIVE GRADERS

Extremely good manoeuvrability and best for heavy work

Poor underfoot conditions

Leaning wheelBlade (Mouldboard)Drawbar

Mouldboard lifting

High traction for their weightRequire a wider working path and operators

need to learn unusual operating techniques to make use of their superior potential

TYPES OF GRADERS - FOUR WHEELED DRIVE GRADERS

Able to pivot in the middle Smaller turning radius- so can turn in much

quicker time Three modes of operations

Straight mode Articulated mode - allows turning Crab mode – rear driving wheels to remain firm

ground while the machine cuts banks, side slopes or ditches

TYPES OF GRADERS - ARTICULATED GRADERS

ARTICULATED GRADER POSITION

BLADES FOR GRADERS Consists of a curved mould board ranging

between 3 to 5 m long with replaceable ages on sides and bottom

Used for: Levelling and trimming on the horizontal Levelling and trimming to the slope and vertical face Forming ditches Backfilling along trenches

MOVING MACHINE - TRACTOR SHOVELS/LOADERS Sometimes called a loading shovel or front-end loader Basically in the form of wheeled or crawler tracked

tractor with a hydraulically controlled general purpose bucket mounted in front of the vehicle

Primary function to scope and loose material in the bucket, raise the loaded spoil and manoeuvre into a position to discharge its load into an attendant lorry or dumper

Can also transport, spread and compact fill material depending upon the mounted attachments

The tractor shovel is driven towards the spoil heap with its bucket lowered almost to ground level and uses its own momentum to force the bucket to bite into the spoil heap thus filling the scoop or bucket

MOVING MACHINE - BUCKETS FOR LOADER

Design with long, flat floors to enables them to penetrate the most tightly packed stockpiles

Built for optimum payload and road retention

Faster cycle times lower operating costs

Flexibility to match with the job Increased production and

optimum performance Two types:-

General purpose buckets Penetration bucket

MOVING MACHINE - BUCKETS FOR LOADER

Buckets for loader

GENERAL PURPOSE BUCKETS Use in most application Equipped with bolt-on teeth, bolt with reversible cutting

edge or bolt on tooth and segments Use spade-edge bucket for rock digging to improves

ability

PENETRATION BUCKET• Use for material requiring

moderate breakout and impact forces

• E.g grading or stripping top soil

• Cutting edge is equipped with weld-on, flush-mounted teeth adapters and integral corner teeth adopters

Curved, sharp side bar

Flush mounted weld-on teeth

Flat floor

Tip Options Tooth Options

COMBINATION FOUR-IN ONE BUCKET Is the most favourable Can be set in the scrapper position, bulldozing

position, spreading and levelling and back dragging

Consist of two major segments:- The rear segments is a dozer blade with a straight

cutting edge The front segment is hydraulically operated calm with a

straight cutting edge at the front, equipped with digging teeth

COMBINATION FOUR-IN ONE BUCKET

Rear

segment

Front

segment