CONSTRUCTION PLANT AND EQUIPMENT

Topic 1: Introduction
Good project management in construction must vigorously pursue the efficient utilization of labor, material
land and equipment. The use of new equipment and innovative methods has made possible wholesale changes
in construction technologies in recent decades. The selection of the appropriate type and size of construction
equipment often affects the required amount of time and effort thus the job-site productivity of a project. It is
therefore important for site managers and construction planners to be familiar with the characteristics of the
major types of equipment most commonly used in construction.

Construction Plant and Equipment is a subject that deals with operating, using and maintaining
building and civil construction machinery and plant. It also addresses health and safety regulations
related to the use of various machines.

Selection of appropriate type and size of equipment affects the amount of time and effort thus job
site productivity of project.

Reasons or benefits for using construction plant

 better quality work
 Increase the rate of output through work progress with the best effective and efficient methods. High
work output.
 Reduced overall construction costs especially for large contracts
 Carry out activities which cannot be done manually. to do them more economically and much faster
 Eliminate the heavy manual work by human thus reducing fatigue and eliminating various other
hazards and health issues.
 Maintain the planned rate of production where there is a shortage of skilled or unskilled labor
 Maintain the high quality standards often required by present-day design and specifications
(technical, Economic Considerations, Company-Specific, Site-Specific, Equipment Specific, Client
and Project-Specific, Manufacturer-Specific, Labour Consideration)
Factors affecting selection of construction equipment’s and plants
 Economic considerations such as owning costs, operating labour costs and operating fuel costs of
equipment are most important in selection of equipment. Besides, the resale value, the replacement
costs of existing equipment and the salvage value associated with the equipment are also important.

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 Company policy on owning or renting’. While emphasis on owning may result in purchase of equipment
keeping in mind the future requirement of projects, the emphasis on renting may lead to putting too much
focus on short-term benefits.
 Site conditions-both ground conditions as well as climatic conditions. For example, the soil and profile of
a site may dictate whether to go for a crawler-mounted equipment or a wheel-mounted equipment. If there
is a power line in the vicinity of the site one may go for a fixed-base kind of equipment rather than a
mobile kind of equipment.
 Construction equipments come with high price tags. While it may be tempting to go for the equipment
with low initial price, it is preferable to opt for standard equipments. Such equipments are manufactured
in large numbers by the manufacturers, and their spare parts are easily available, which would ensure
minimum downtime. Besides, they can also fetch good salvage money at the time of their disposal.
 The owner/client preferences. This may not be in line with the construction companys preferred policies
as far as equipment procurement is concerned. The schedule, quality and safety requirements demanded of
a particular project may in some cases force the company to yield to the demands of the client.
 A construction company may prefer to buy equipment from the same manufacturer again and again, and
that too from a specific dealer. This may be to bring in uniformity in the equipment fleet possessed by the
company or because the company is familiar with the working style of the manufacturer and the dealer.
 Shortage of manpower. In some situations this may lead to a decision in favour of procuring equipment
that is highly automated. Further, the selection of equipment may be governed by the availability or non-
availability of trained manpower.

Performance/work evaluation

Performance evaluation helps in the communication between the contractor and the customer/client
of the construction project, so that the latter can monitor the status of construction. It also serve as a
basis for implementing the changes required in each procedure, allowing optimisation efficiency and
enhanced performance.

Performance can be evaluated by

Monitoring the processes;- this provides information that enable checking the status of processes and seek to
control the activities. The information provided by can be used in the correction of activities to enhance
perfomance;
Assessing the performance of a project – it is based on the final results of the procedures and can be used as
a benchmark for future similar activities or for comparison with pre-established values. Its value is intended to
help undertake the general assessment of the procedures.

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Topic 2: Types of construction equipment’s

Typically, construction equipment is used to perform essentially repetitive operations, and can be broadly
classified according to two basic functions:

Construction plant and equipment may also be categorised as follows

1) Excavation, loading equipment’s and grading equipments

2) Compaction
3) Concreting equipment’s
4) Bitumen laying equipment’s
5) Transporting equipment’s
6) Lifting and erecting equipment’s
7) Piling plant
8) Drilling and blasting equipment
9) Equipment for dewatering and grouting
10) Auxiliary equipment’s

Topic 3: Excavation, loading and grading equipments

Earthmoving may include site preparation; excavation; embankment construction; backfilling;

dredging; preparing base course, sub-base, and sub-grade; compaction and road surfacing. For
earthmoving operations, material is placed in three categories - rock, soil (common earth), and
unclassified. Soil weight affects the performance of the equipment as how dozers push, graders cast,
and scrapers load the material.

Equipments under this category include;-

a) Excavators
b) Front shovel
c) Front end loaders
d) Backhoe/ backactor
e) Dozers
f) clamshell
g) Trenchers
h) Motor graders
i) Scrappers

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a) Excavators

They consist of
 Boom
 stick (dipper arm)
 bucket and
 cab on a rotating platform known as the house that sits atop an undercarriage with tracks or
wheels..

Excavators are extensively used in many roles such as;-

 digging of trenches and foundations

 demolition
 general grading/landscaping
 heavy lifting (e.g. lifting and placing of large concrete pipes)
 river dredging
 Driving piles in conjunction with a pile driver.

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b) Front shovel

The front shovel consists of crawler tracks, house, cab, boom, stick and a shovel. It is known for
large shovel capacity used to load heavy-duty hauling trucks. The shovels are available in either front
or bottom dumping models. In bottom dumping shovels, the shovel separates in the middle so the
material can drop through the bottom instead of tilting the bucket forward and dumping out the front.

The main application of shovels is to move earth. It digs above track level in an upward motion
crowding material away from itself. It has high breaking force capable of excavating heavily
compacted dirt and rocks, but because of its short boom and stick, it must be close to the material it
is digging.

c) Front end loaders

Loader is a machine that uses a wide tilting bucket on the end of movable arms to lift and move
materials such as sand, debris, dirt and mud into other vehicles, thereby clearing rubble and digging
materials in the construction sites.

Wheeled loaders are more popular since they provide better mobility and speed. The flexibility of
usage is low as compared to a backhoe. Loaders are largely used as complimentary products for
material re-handling in construction applications.

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d) Backator/ backhoe

Comprises of a small backhoe in the rear end, a tractor, front shovel and replaceable bucket.

It can duplicate the work of a bulldozer, front end loader and excavator. The backhoe loader also has
the advantage of being driven directly to the different job areas. These can also be associated with
variety of other instruments like augers, hydraulic hammers, asphalt grinders and grapples.

The attachment of different tools allows backhoe loaders to do multiple jobs like;-

 Light demolition
 Transportation of light building material;
 Digging holes;

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  Paving roads;
 Breaking asphalt;
 Small urban engineering projects.

e) Clamshell

The clamshell bucket is a sophisticated articulating two-piece bucket mechanically hinged at the
middle to form a claw-like appendage with an internal volume. It is attached by a hangar or
bracket and uses ground engaging tool on its cutting edge to dig in a vertical direction.
Clamshell buckets are commonly used in dredging, excavation or material handling, however,
each application has its unique requirements and has to be designed optimally for maximum
efficiency. Clamshell may be operated by hydraulic, mechanical (cable) or by both hydraulic
and mechanical means.
Hydraulic clamshell bucket is designed to be attached onto an excavator. The dual or quad
hydraulic cylinders/rams mounted on the outer rim of the bucket provide excellent digging
force. The inner side of the bucket has a smooth surface for easy unloading of high viscosity
material such as mud and clay, while the outer layer is reinforced with additional layer of wear
strips.

The fully mechanical clamshell is designed specifically to be used on a crane for large capacity
dredging and digging applications. The opening and closing action is operated via cable. The
inner side of the bucket has a smooth surface for easy unloading of high viscosity material such
as mud and clay, while the outer layer is reinforced with additional layer of wear strips. The
hanger is constructed with high tensile steel.
Telescopic dipper arms are used where dip excavation work needs to be carried out in tightly
spaced environment. The single centred mount hydraulic cylinder/ram clamshell bucket is
specifically designed to be used on a telescopic dipper arm. The unique and powerful
customized hydraulic cylinder/ram delivers smooth opening and closing actions with strong
penetration force which is a pre-requisite for an effective telescopic clamshell bucket.

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 Applications:
 Digging pits for ground construction work.
 Ideal for digging and loading material in tight and limited spaces.
 Material handling, loading and unloading industrial wastes, grains, sands, etc.
 Heavy duty mechanical clamshell is ideal for dredging application by crane.
f) Dozers

Dozers equipped are heavy machines used for clearing and grading land, usually having continuous
treads and a broad hydraulic blade in front.
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Parts of a grader include;-

 Tractor,
 blade and
 rippers.

The blade may be lifted and forced down by hydraulic rams.

 For digging, the blade is held below surface level;
 For transporting, it is held at the surface level
 For spreading, it is held above the surface level, as the tractor moves forward.

Depending on the nature of the work, dozer blades come in three varieties that are

 Straight Blade, which is short having no lateral curve and no side wings and used only for fine
grading;
 Universal Blade, which is very tall and curved and has large side wings capable to carry more
material
 Combination Blade, which is short in length, less curved and has smaller side wings.

A ripper – mounted on the end opposite the shovel. The ripper is used to break up compacted ground or
paved areas.

Uses of dozers include-

 In Earthmoving;
 Road construction;
 Lifting various materials;
 Breaking pavements and compacted grounds;
 Digging of canals;
 Land clearing and land levelling;
 Preparation of construction sites;
 Removal of civil engineering projects.

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g) Trenchers

Trenchers perform functions like

 Landscaping;
 Irrigation;
 Plumbing;
 Underground utility construction for water and sewer services;
Special trenching components available to cut through rocky soils, paving and frozen ground etc.
Based on the size and usage these can be categorized as chain trenchers, wheel or disc trenchers and
bucket trenchers. With attachments like backhoes, saws and reel carriers, trenchers become more
versatile and efficient.
Trenchers must be handled with extreme care because they are very dangerous equipment’s.

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h) Motor graders

A motor grader is an earth-moving apparatus equipped with a long blade used to level a surface of
roads and construction sites. Graders can produce inclined surfaces, to give cant (camber) to roads.
At the end it has a plow which stays close to the ground. A blade is situated under the cab to spread
and push gravel.

Motor graders operated from the centre of the machine are used for

 levelling the surface during earthwork in embankments and providing blanket surface before
spreading ballast and laying track.
 to set native soil foundation pads to finish grade prior to the construction of large buildings and
for underground mining.

i) Scrappers

The scraper cuts soil with a sharp blade at the front bottom of the bucket. The soil is stored in the
bucket and can be released at the required location. The construction scrapers have hydraulically
operated bails and push blocks with hooks.

They are one of the most versatile equipment that performs different functions is used for excavating,
digging and hauling of materials.

Uses of scrapers include

 Preparing the ground for the new loads of solid waste; in preparing work at landfills
 in preparing the sites for construction (road, etc.) through digging, loading, hauling and
dumping the wastes materials etc.

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Topic 4: Compaction Equipments
The function of compaction equipment is to produce higher density in soil mechanically.

The basic forces used in compaction are static weight, kneading, impact and vibration.

Kneading- it is the process of pressing and stretching of soil particles at the same time applying pressure

Ramming- is the process of forcing soil particles close together by pounding action

Compacting technique involve energy application to loose material or other material which increases
density and consequently its load-bearing capacity.

Compaction- is the process by which solid soil particles are packed more closely together by
mechanical means and it is achieved through reduction of air voids. It is a rapid process and it is an
artificial process

Consolidation- is the process by which soil particles are packed more closely together under the
application of static loading. It is achieved through gradual drainage of water from soil pores. It is a
natural process and is strictly applicable for saturated or nearly saturated clays or soils with low
permeability

Advantages of soil compacting include:-

 Water seepage is minimized
 Damage from frosts is prevented.
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  Load bearing capacity of soil is increased.
 Contraction and swelling of soil is reduced to a certain extent.
Different types of compactors are used for different types of soils, e.g.
 static steel wheel and pneumatic rollers for thin layer of soils
 Impact machines like jumping jack rammers for cohesive type of soils;
 Plate compactors for granular soils and asphalt. For soils with greater cohesive content,
machines like
 Vibratory rollers available in single and dual drum models with either smooth or pad-foot drums
are used. Soil compactor plays an important role in many infrastructure projects.
Equipment’s under this category include
a) Rollers
b) Jumping jack rammers
Rollers:

They are important engineering vehicle for the roads and highway constructions and used for the
compaction of dirt, gravel, concrete, and asphalt. In landfill compaction too, road roller has great
utility. Its size varies from simple drum with a handle, to a size of many tonnes. Based on their sizes
rollers are of following types:
 Sheep-foot Roller: A sheep-foot roller has almost hoof like structures protruding from a
roller to provide pinpoint pressure all across the soil. Protruding studs on the drum is similar
to a sheep-foot, which provides a kneading action. For compaction of plastic soils like clay or
silt it is very effective. On granular materials, sheep-foot rollers tend to shove rather than
compact such soils. The sheep-foot roller works very well on cohesive soils and as well in
wet conditions

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  Combination Rollers: Combination rollers are used for better efficiency and for the
compaction of asphalt base and sub-base courses for road construction and road maintenance.
Some of the compact rollers also use vibratory system on the front drum for density
requirements and four pneumatic tires in the rear to provide impermeability and smoothness
of the material. Compacted material manipulated by the four pneumatic

 Tandem Rollers: Tandem rollers have their utility in soil and asphalt compaction,
construction and repair on small to medium jobs on highways.

Dynamic compaction

This is a method that is used to increase the density of the soil when certain subsurface constraints
make other methods inappropriate. It is is used to increase the density of soil deposits. The process
involves of dropping a heavy weight repeatedly on the ground at regularly spaced intervals. The
weight and the height determine the amount of compaction that would occur. The weight that is used,
depends on the degree of compaction desired and is between 8 tonne to 36 tonne. The height varies
from 1m to 30m.

The impact of the free fall creates stress waves that help in the densification of the soil. These stress
waves can penetrate up to 10m. In cohesion less soils, these waves create liquefaction that is
followed by the compaction of the soil, and in cohesive soils, they create an increased amount of
pore water pressure that is followed by the compaction of the soil. Pore water pressure is the pressure
of water that is trapped within the particles of rocks and soils.

The degree of compaction depends on the weight of the hammer, the height from which the hammer
is dropped, and the spacing of the locations at which the hammer is dropped. The initial weight
dropping has the most impact, and penetrates up to a greater depth. The following drops, if spaced

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closer to one another, compact the shallower layers and the process is completed by compacting the
soil at the surface.

Most soil types can be improved with dynamic compaction. Old fills and granular soils are most
often treated. The soils that are below the water table have to be treated carefully to permit emission
of the excess pore water pressure that is created when the weight is dropped onto the surface.

Topic 5: Concreting equipment’s

These include

a) Crushing plants
b) Sand making machines
c) Sand washing machines
d) Concrete mixers
e) Concrete vibrators
f) Concrete block machine
g) Concrete placers and pumps
h) Slip form

a) Crushing plant

Crushing plants are the huge assembly of machines designed to recycle and reprocess the rubbles of
buildings, roads, or other materials into commercially sized aggregate for use as base materials or
other value-added applications such as ballast for various applications.

Crushing plants are either static assemblies or mobile assemblies and consist of different arrays of
equipment’s like screens, pre-screener, intake hopper, magnetic separator, conveyor both undersized and
oversized, loading conveyor and crushing units like jaw crusher, cone crusher etc. They find their
applications in Road Construction; Building Construction; Construction of over bridges; Construction of
pavements and paths etc.

b) Sand making machines

The machine consists of feeding hopper, rotopactor, sand screen, conveyors, elevators, electrical prime
movers and controls, etc. Rotopactors of varying sizes are used to crush stone from which sand is
obtained. The sand so produced is utilized in the construction of buildings, pavements, streets, roads etc.

c) Sand washing machine

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Sand washer is used to remove the dust in sand. It aims at improving the quality of sand. Sand
washing machinery drives the impeller in the water groove to move like a circle transmitted by
electric motor and decelerator and then mixes, overturns, cleans and discharges the sand or slag
pellets in the water groove.

d) Concrete Batching and Mixing Plant:

A concrete batching and mixing plant is a huge set up of machines meant to combine cement,
aggregates such as sand or gravel, and water to form concrete (ready-mixed). These plants are either
mobile or stationary and their sizes range from portable mixer to heavy industrial mixing plant.

Stationary plant mixer, mixes the concrete before it is discharged into a truck mixer. Revolving
drums, conveyor and diesel or electric powered engines are used in this plant. The truck mixer is
used primarily as an agitating haul unit at a central mix operation. Dump trucks or other non-
agitating units are sometimes used for low slump and mass concrete pours supplied by central mix
plants.

Mobile concrete mixing plant is also very popular and widely used. Mobile concrete mixer plant is a unit
mounted on a trailer, which carries sufficient unmixed materials, such as cement, sand, coarse aggregates,
water, and any chemicals required, for special mix specifications to the job site. In this type of plant
cement, sand and aggregates are carried in separate bins. The materials mixed proportionately are mixed
with water and then discharged through the conveyor system.

e) Concrete mixers

There are essentially three classifications of mixers: the drum mixer, pan mixer, and continuous
mixer. Each of these mixers can be further classified as batched or continuous, free-falling or forced
movement, and stationary or portable.

The main types of mixers include

i) The drum mixer

ii) The pan mixer

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Tilting drum mixer: A tilting drum mixer is one whose drum in which mixing take place is tilted for
discharging. The drum is conical or bowl shaped with internal vanes, and the discharge is rapid and
unsegregated so that these mixers are suitable for mixes of low workability and for those containing
large size aggregate.

iii) Pan type mixer:

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A pan type mixer is a forced–action mixer, as distinct from drum mixer which relies on the free fall
of the concrete inside the drum. The pan mixer consist of a circular pan rotating about its axis with
one or two stars paddles rotating about vertical axis of pan.

Concrete Mixer Truck: The hydrostatic truck mixer transports concrete/mortar directly from plant to
the place where it is to be poured. It has a wide range of applications specially for mass concreting works
like Multi-storeyed buildings, Bridge works etc. The basic function of transit mixer is to maintain the
concrete's liquid state, through the turning of the drum till the point of delivering at construction site.

iv) Concrete vibrators

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Since concrete contains particles of varying sizes, the most satisfactory compaction would perhaps
be obtained by using vibrators with different speeds of vibration. Concrete vibrators used include

 Immersion or Needle Vibrators: This is perhaps the most commonly used vibrator It
essentially consists of a steel tube (with one end closed and rounded) having an eccentric
vibrating element inside it. This steel tube called poker is connected to an electric motor or a
diesel engine through a flexible tube. The diameter of the poker is decided from the
consideration of the spacing between the reinforcing bars in the form-work.

 External or Shutter Vibrators: These vibrators are clamped rigidly to the form work at the
pre-determined points so that the formwork and concrete are vibrated. They consume more
power for a given compaction effect than internal vibrators. The external vibrators are more
often used for pre-casting of thin in- situ sections of such shape and thickness that cannot be
compacted by internal vibrators.

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  Surface Vibrators: These are placed directly on the concrete mass and best suited for
compaction of shallow elements and compaction of very dry mixes. The main application of
this type of vibrator is in the compaction of small slabs, not exceeding 150 mm in thickness,
and patching and repair work of pavement

v) Block making machine and equipment’s

Example is a hydraulically operated concrete block machine that produces blocks of different types
like solid, hollow, paving, tree guard blocks of different shapes and sizes. The table-top vibrator in
machine provides optimum vibration in the mix so that the ratio of cement used can be reduced
substantially without affecting the strength of the blocks. The other important equipment’s used in
stand type hydraulically operated concrete block machines are vibratory motor, pump motor,
hydraulic levers, hopper and hydraulic filler

vi) Concrete placer and pumps

Concrete Pumps: They are used to supply concrete to places, which are difficult to reach by other heavy
machines. Concrete Pumping Equipment’s are concrete pump, heavy-duty pipe, hose and other
accessories. When pressure is applied to a column of fresh concrete by the concrete pump, it forces the
concrete through a lubricated pipe. Concrete pumping is useful in the areas where space available for
construction equipment is limited. It is faster and saves enough man power and energy. It is all weather
operation and does not require heavy equipment’s like cranes and hoists for other construction
operations.

Concrete Placer: This Machine can be used for Bridges, Culverts, mass Concreting Purpose and Canal
Works. It can pour concrete at the height of 27 feet and has ability to fold for Towing without removing
discharge hopper. Mechanical power for the conveyor is provided by an engine, which drives a Hydraulic
Double Pump.

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vii) Slip-form

This may be defined as a method of continuously moulding or forming concrete, with the use of a
moving formwork. The rate of movement or slipping is controlled by the setting or curing rate of the
concrete, which must be capable of supporting at least its own weight when exposed by the moving
formwork. This is undoubtedly the most unique aspect of slip forming, the ability of concrete to
stand safely and unsupported within 2 to 4 hours after being placed into the formwork in a plastic
state.

Used in construction of reinforced concrete wall structures such as silo complexes, chimneys, reservoirs,
bridge piers, in ground shafts, dam structures etc. The major components of slip form System are
Shuttering/form panels, Walers, Yokes, Working decks, Hanging scaffolds, Truss system, Hydraulic
jacks, Jack rods, Pumping units for jacks, Bracings, Operation screws, Extraction jacks, and
Miscellaneous equipment.

Topic 6 : Bitumen laying equipment’s

a) Asphalt Pavers:

They are used for distribution, shaping and compaction of asphalt layer. Material is discharged from
the lorry in a tipping action.

viii) Asphalt Road Cutter

It is a machine that removes the existing asphalt surface of roadways, runways, or other asphalt
surface. It can be operated both manually and mechanically and can be attached with any tractor or
backhoe that gives it maximum downward pressure. It is suitable where precise cutting is required.

b) Bituminous distributor

This is a truck-mounted plant for generating liquid bituminous materials and applying them to road
surfaces through a spray bar connected to the end of the truck. Bituminous materials include both asphalt
and tar which have similar properties except that tar is not soluble in petroleum products. While asphalt is
most frequently used for road surfacing, tar is used when the pavement is likely to be heavily exposed to
petroleum spills.
ix) Road Cleaning Machine:

They use high pressure air blower within a short time thereby saving labour, time and also bitumen.
This machine is provided with a rotary brush which mechanically operates and cleans the dust
particles settled on the road.

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 x) Chip Spreader

Used for maintaining the quality and giving the roads a long-lasting effect, stone chipping is one of the
most effective methods and this is done by a chip spreader, which is a unique self-propelled machine for
laying of pre-coated chipping. A chip spreader through chip sealing gives special protective wearing
surface to an existing pavement.

xi) Ballast Spreader

The road pavers can be used for laying initial layer of ballast. The paver can be loaded with ballast
using track dumper/tipper and spread by the road paver on the finished formation to maintain
uniform thickness and width. The light road roller can be used for compaction of the initial layer.

Topic 7: Transporting equipment’s

They adopt two modes of transportation

 Horizontal movement- examples tippers dumpers conveyor belts

 Vertical movement- examples mobile hoists, cranes pumps and chutes

a) Dumper:

This is usually an open four wheeled vehicle with the load skip in front of the driver. The skip can tip to
dump the load; this is where the name "dumper" comes from. They are used to carry loads and materials
to the construction sites. A towing eye is fitted for secondary use as a site tractor to tow such things as an
air compressor to run pneumatic drills. The main applications of dumpers are in transporting materials to
construction sites, in manufacturing and production line.

xii)

Dumper Trucks/ Tipper

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Dumper trucks (also called as Tipper) are those trucks whose contents can be emptied by raising the front
end of the platform pneumatically so that the load is discharged by gravity. They are available in various
sizes and mainly used in activities such as to clear material wastes from the building construction sites to
supply materials to the construction sites etc. Another form of truck is the standard truck, which does not
have a tipping bucket

The can be classified based on

 Weight or load carried in tones eg 5,6, 20,25 tonnes lorry

 Based on number of wheels or number of driving wheels eg 4×4 or 4×2 etc

Lifting erecting and equipment

Commonly used equipment’s include folk lift truck, cranes and derricks. Most derricks are stationary
while most cranes can move from place to place under their own power. The terms derricks and
cranes are sometimes used interchangeably

Types of lifting equipments

 overhead cranes and their supporting runways.

 patient hoists.
 motor vehicle lifts.
 vehicle tail lifts and cranes fitted to vehicles.
 a building cleaning cradle and its suspension equipment.
 telehandlers and fork lifts.
.

a) Lift Truck/.folk lift

A lift truck is a machine, which lifts and transports materials by using forks under the load. They are
available in different models and capacities for different working environment and requirement. Load is
lowered, raised and tilted by the mast, which is operated hydraulically and consists of a cylinder and
interlocking rails. The applications of lift trucks are lifting and removing of materials to the job sites and
in various construction projects

xiii) Hoists

They include chain, boom and electric hoists.

Boom hoists-They are used to lift weights on the hooks that are
attached to the special metal ropes. They are mostly used as
industrial machine to load containers

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Chain Hoist- they consist of chain rope and pulley and is
used to move the load up and down

Electric hoist-Is a modernized form of chain and boom hoist it

is used for handling materials in industries

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xiv) Cranes and derricks

 Cranes:- These are the huge tower like machineries having ropes meant to lift or to lower
any heavy devices. Cranes are not permanent structure and either fixed in the ground or
mounted on certain vehicles. Cranes are operated either through cab operator or through
infrared or radio signals. Cranes are used for the loading and unloading of goods in the
transport industry, for the movement of debris, sand, mud and other materials in the
construction industry and for the assembling of heavy equipment in the manufacturing
industry

 Derricks:- They are commonly used to lift equipment of materials in industrial or building
construction. A derrick consists of a vertical mast and an inclined boom sprouting from the
foot of the mast. The mast is held in position by guys or stifflegs connected to a base while a
topping lift links the top of the mast and the top of the inclined boom. A hook in the road line
hanging from the top of the inclined boom is used to lift loads. Guy derricks may easily be
moved from one floor to the next in a building under construction while stiffleg derricks may
be mounted on tracks for movement within a work area.

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  Dragline Draglines are amongst the largest mobile equipment ever built on land, and weigh
in the vicinity of 2000 metric tonnes, though specimens weighing up to 13,000 metric tonnes
have also been constructed. They can be used to lift heavy materials and equipment used for
land levelling.

Piling plant
A pile driver is a mechanical device used to drive piles (poles) into soil to provide foundation support for
buildings or other structures. The term is also used in reference to members of the construction crew that work
with pile-driving rigs.

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Types of piles include Timber (treated or untreated), Concrete (precast, reinforced and pre-stressed
concrete and steel composite.

Pile driving equipment include diesel hammers, vibratory hammers, and impact hammers.
Regardless of the application, our experienced team can help select the right pile driving equipment
for your particular job. The pile driving equipment is used for driving on different types of pile
including steel sheet piles and H-Piles.

Types of pile hammers include

 Drop
 Single acting steam or compressed air
 Double acting steam or compressed arif
 Differential acting steam or compressed air
 Diesel
 Hydraulic
 Vibratory drivers

Drilling and blasting

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These equipment’s are used for rock excavation The task of rock excavation includes loosening,
loading, hauling and compacting. The loosening operation is specialized for rock excavation and is
performed by drilling, blasting or ripping.

Equipments under this category include;-

a) Drilling equipment’s
b) Rippers
c) Rock tunnelling equipment
a) Drilling equipment’s

Types of drilling equipment’s include:

 Percussion drills- penetrates and cuts rock by impact while it rotates without cutting on the
upstroke. Common types of percussion drills include a jackhammer which is hand-held and
others which are mounted on a fixed frame or on a wagon or crawl for mobility.
 Rotary drills- cuts by turning a bit against the rock surface
 Rotary-percussion drills - combines the two cutting movements to provide a faster penetration
in rock.
Drilling Rig: A drilling rig is a machine, which creates holes in the ground. The term "rig" therefore
generally refers to the complex of equipment that is used to penetrate the surface of the Earth's crust.

xv) Rippers

Tractor mounted are capable of penetrating and prying loose most rock types. The blade or ripper is
connected to an adjustable shank which controls the angle at the tip of the blade as it is raised or
lowered. Automated ripper control may be installed to control ripping depth and tip angle. Hydraulic
Breakers: Hydraulic breakers can be mounted on some equipment (called as carriers) such as backhoes,

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excavators etc. The application of hydraulic breakers mainly lies in breaking concrete roads; breaking
rocks and asphalt surfaces; trimming of RCC pile heads; concrete demolition projects involving bridge
decks, foundations and pavement

xvi)

Rock tunnelling equipment’s

They include special tunnel machines equipped with multiple cutter heads and capable of excavating full
diameter of the tunnel. Their use has increasingly replaced the traditional methods of drilling and
blasting.

Grouting and dewatering equipments

Grouting
Grouting is often use to stop the penetration of water in sub-soil with high permeability, such as in
fissured and jointed rock strata. Row/s of holes are bored on the soil and, usually cement grout, are
injected under high pressure. The cement grout will penetrate into the voids of the sub-soil and form
somewhat an impermeable curtain vertically separating the ground water.

Cement grout is usually a mixture of cement and water, or cement and sand under ratio maximum
1:4. Sometimes chemical grout can be used to form a gel which can increase strength and reduce
permeability of soil. (eg. Sodium silicate + calcium chloride = calcium silicate, which is a silica gel)

The following provisions can contribute certain degree of water-tightness to the basement during the
construction:

 Sheet piling
 Diaphragm walls
 Suitable grouting to the sub-soil

In addition, ground water can be further control by the use of the following arrangement:

 Sump pumping

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  Well point systems
 Shallow or deep-bored wells
 Horizontal ground water control
 electro-osmosis method

Auxiliary equipment’s
Air compressors and pumps are widely used as the power sources for construction tools and equipment.

Air compressors used pneumatic construction tools which include drills, hammers, grinders, saws,
wrenches, staple guns, sandblasting guns, and concrete vibrators.

Pumps are used to supply water or to dewater at construction sites and to provide water jets for some
types of construction

Matching of Construction Equipment and Plant

On any construction job a number of equipment and plant are employed for execution. They often
work in combination to produce the end-product.
Examples
Construction of concrete dam.
The construction involves the production of aggregates, handling of ingredients such as cement,
aggregates, water and admixtures, batching and mixing the concrete, handling of the mixed concrete
which involves transportation and placement and compaction. Each of the items are performed by
different equipment and plant. All the activities have to be performed at the same rate so that there is
no stoppage of work for want of equipment or product of the previous operation. Thus matching of
construction plant is essential.
i) The crushed aggregates produced by the aggregate processing has to be handled by the belt
conveyor system at the same rate.
ii) The batching and mixing plant which produces the mixed concrete should balance the
aggregate processing and conveying plant.
iii) The transportation equipment be it flat body truck with concrete buckets, or agitator cars,
bucket on cable way or dump trucks should match the mixers. The concrete vibrators should
be adequate to compact the concrete as it is unloaded by the transportation equipment.
iv) Where cranes are needed to unload the buckets they should balance the transportation and
compacting equipment.

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Another case is excavation and transportation of earth by a combination of power shovels or
draglines and carriage by dump trucks.
v) The product of excavation of the shovel has to handled efficiently by the carrier units.
In either case, the matching between equipment and plant is very essential. Even if any plant or
equipment is inefficient or unable to handle the product which it has to handle at the same rate as the
previous operation the production of the entire process is sure to fall. This will lead to increase in the
cost of unit of production and in the project cost.

Safety precautions
Some causes of hazards
Many of the hazards which do arise have the following causes:
Poor mechanical design (breaks in use, not powerful enough, components fracture or malfunction)
Poor functional design (not properly designed for the stated purpose)
Misuse (not used as designed)
Used in the wrong circumstances (e.g. ground collapses under a crane)
Poor maintenance (breaks or emits noxious gases)

These cause the following hazards

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  Falling machinery or parts of machinery
 Crushing due to impact of moving or toppling plant and equipment
 Falling from plant and equipment
 Limbs or bodies caught in machinery
 Physiological damage through vibration
 Poor ergonomics-design of equipment to reduce operator fatigue discomfort and injury
 Physiological and psychological damage through repetitive work
 Stress caused by poor environment (noise, heat, poor ventilation, chemicals, noxious gases)
General safety strategies
 Plan each stage of the project with safe working as one of the primary objectives.
 Ensure the appropriate equipment is used for each operation including the provision of protective
clothing.
 Encourage everyone to work together in developing and maintaining safety.
 Provide adequate training and instruction.
 Ensure adequate supervision.
 Maintain adequate records and undertake full accident investigations.
 Provide full feedback information to all participants.
Safety precautions on moving vehicles, earth-moving and materials-handling equipment
They must have:
An electrically operated acoustic signalling device
Searchlights for forward and backward movement
Power and hand brakes
Tail lights
Silencers
Reversing alarm

Protection of operators
Operators of vehicles and earth-moving or materials-handling equipment should be adequately be protected
against the weather or accidents due to impact, crushing or contact with a moving load by a cab which:
 Is designed and constructed in accordance with ergonomic principles and provides full protection
from adverse weather conditions;
 Is fully enclosed where dusty conditions are likely to be encountered;
 Provides the driver with a clear and unrestricted view of the area of operation;
 Is equipped with a direction indicator and a rear-view mirror on both sides.
on operator protection and efficiency: some considerations
Ergonomic design; especially seat, controls and information displays

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 Protection against crushing, and overturning, must have seat belts
Protection from weather
Protection from dust, fumes, etc
Mirrors and direction indicators
Signaling for changes of direction and reversing
Warning alarms (reversing etc)
Noise control
Brakes with secondary safety mechanisms
Ideally, devices to help with repetitive work

CONSTRUCTION EQUIPMENT MANAGEMENT

Equipment related costs vary between 27 – 40% of the total project costs. Therefore, the standard of
equipment management has an extremely large effect on the execution of the project.

The objective of equipment management is

 to try to improve the safety and quality of the project by mechanized execution
 to reduce the duration and costs of the project.

This could be achieved by

 carrying the necessary equipment to site

 maintaining equipment in good working condition
 Training and keeping competent operators.

HOW TO IMPROVE PLANT MANAGEMENT

Maintenance management of equipment

Involves Planning and implementation of maintenance tasks which includes

 the method and timing of maintenance,

 storage of equipment,
 repair measures,
 Parts stocking.

Aims at keeping the equipment in reliable and maintainable condition. The program targets to lessen
equipment failures shorten downtime due to equipment failure and to repair the equipment at less
cost.

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Basically, there are two types of maintenance programs. These are

 Corrective Maintenance involves emergency, remedial and unscheduled repairs. It is a

reactive as opposed to proactive mode of maintenance. It is based on the policy of ‘operate
the equipment until it breaks down and then repair
 Preventive Maintenance programs. Preventive Maintenance aims at preventing failure,
detecting onset failure and discovering a hidden failure. This is a program, which endeavours
to anticipate failure and the adoption of necessary preventive action before they occur.

Objectives of preventive maintenance

i) To obtain maximum availability of the equipment by avoiding breakdown and reducing

shutdown periods to maximum
ii) To keep the machine in proper condition so as to maintain the equality of the product
iii) To minimize the wear and tear
iv) To preserve the value of the equipment
v) To ensure the safety of workers
vi) To keep the plant at maximum production efficiency
vii) To achieve the above objectives with most economical combination

functional elements of preventive maintained

i) Inspections and checkups

ii) Servicing including cleaning cooling and lubrication
iii) Planning and scheduling
iv) Record and analysis
v) Training of maintance staff
vi) Strorage of spare parts

1) Having a maintenance culture

Maintenance culture is an attitude whereby facilities, systems and structures are kept in functional
and safe conditions at minimum costs.

Lack of maintenance culture on maintenance management of construction equipment by contractors

results in wasted revenues, poor performance, late delivery of projects, premature breakdown of
equipment, high cost of repair, equipment related accidents

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Problems of maintenance culture could be due to a number of reasons including ignorance, poor

state of the economy and lack of technology transfer, poverty etc.

Training

Proper training should be arranged for owners of construction equipment, operators and maintenance
staff. This is on how to cost a piece of equipment, selection and planning of construction equipment,
maintenance planning among other issues.

There should be regular training of plant operators and mechanics. This could save contractors from
lost revenue due to frequent equipment breakdown, lost time due to high equipment downtime and
high cost of maintenance and repair.

b) Operator management

In the case of storage of equipment, which is not under use, the following measures must be taken
care of:

• Clean all parts of the equipment.

• Take action to prevent rusting of parts.
• Drain out the cooling water.
• Cover all openings.
• Use wooden blocks to keep tires off the ground, for wheeled equipment

c) Improving maintenance management

Economic life of construction equipment could be extended if they got proper maintenance.

This would involve having effective

 equipment inspection
 maintenance schedules
 qualified and skilled maintenance personnel
 lubrication management
 proper maintenance records
 equipment performance analysis
 Maintenance standard setting, etc.

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 In order to carry out effective maintenance management reduce the fleet sizes to economical and
manageable levels.

Improving workshops and workshop facilities

Owners of construction equipment should establish workshops facilities for servicing and repairing
their own equipment. Before deciding to set up a workshop, however, the following important
questions should be addressed:

 The type and number of equipment you need to maintain

 The kind of facilities, mechanics, tools and equipment needed to carry out services and
repairs
 The cost involved to carry out the services and repairs in your own workshop compared to
that done by an agent or garage

It should be noted that, the bigger the fleet sizes, the more economical it is to set your own
workshop. But with little construction equipment it is worth to contract out repairs and maintenance
services to reputable workshops.

Having an equipment overhaul policy

Instead of replacing old equipment with new ones, major overhaul could be carried to old machines.
This implies that the overhauled machine should meet the performance of a new machine in all
respects including running costs and reliability.

Each contractor could come up with own overhaul policies for each type of equipment. For example
you could set different overhaul policies to graders, loaders, haul trucks,

Fleet rationalization/standardization

Construction plant and equipment should be of the same type, makes, models and age for easy
maintenance. This reduces multiple number of spare parts and skilled mechanics and operators.

d) Equipment planning and selection

Many construction operations have two or more types of equipment working together. Therefore, in
order for them to work together effectively and economically, their rates of production must be
balanced in size and productivity. For example, if the Loader has a bucket of 3 – 4 m 3 capacity, then
the hauling units should have capacities of say 3, 4 or 6 m3

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In equipment planning, the following should be considered:

 Equipment should be selected to enhance the operating efficiency of each equipment used in
combination.
 The working capacities of every equipment used in combination should be matched.
Examples of this equipment matching include
i) Excavator vs the haul equipment ( transporting equipment). Excavator bucket of 2m 3
should be used with a 2m3 or 4m3 etc
ii) A batching plant should be used with a truck mixer of bigger volume.

Maintenance records

Important to implementing effective management of maintenance of construction equipment, is the

proper recording and documentation of equipment maintenance records and reports.

Such records indicates maintenance manpower man hours available, hours planned for maintenance
work, actual hours worked for maintenance, overtime hours, preventive and corrective maintenance
hours, maintenance costs, causes of equipment breakdown, maintenance skills required, detailed
description of equipment, equipment operating hours, total labour and material costs etc. These data
or reports will assist the organization in: -

a) Tracking down equipment maintenance cost trends.

b) Assessing the effectiveness of maintenance programs.
c) Equipment replacements analysis.
d) Planning and control of maintenance spares and materials.
e) Establishment of maintenance organization

Maintenance Costs

Each type of cost incurred to every construction equipment in its lifetime is supposed to be properly
recorded and taken account of. This is vital information when the management has to make decisions
concerning choice of equipment, equipment life and replacement.

There are two types of Equipment costs they include

i) Equipment operating costs. it includes charges for the operator, fuel and lubricant costs of
repairs and tire replacement.
ii) Equipment ownership costs are those expenses that the owner of equipment must take
account to evaluate and project investment. These would include costs on interest for
borrowed money, taxes, insurance, depreciation costs etc.
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It is very crucial for the revenue accrued from use of each equipment to be recorded so that it could
be established whether the item is earning an adequate return on the invested capital and determined
profitability.

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