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SCHOOL OF ENGINEERING AND TECHNOLOGY

Conventional

Design of a mortar handling machine for high rise buildings

Student Name & Registration Number:

Tanaka Mugabe H121010!

Su"er#ised b$:

%ngineer ' MutenhabundoMr' M' agoneka

( H)T *00 "ro+ect submitted as a "artial fulfillment of the re,uirements of a -achelor of

Technolog$ Honors Degree in )ndustrial and Manufacturing %ngineering

(ugust 201

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.ha"ter one

1'0 )ntroduction

This project intends to come up with mortar elevating machine that will help in the reduction of the usage of

highly strenuous and costly methods such as wheelbarrows to transfer mortar from a lower level to a higher

level in the construction of high rise buildings.Local contractors are facing stiff competition from well-

funded foreign firms, mainly Chinese companies.The !tandard, "#$%&. 'evertheless, most of these

construction companies have resorted to hiring a large number of uns(illed wor(ers so as to help with the

movement of mortar and associated building materials using menial methods such as wheelbarrows and

ropes, this may prove too costly as there may be high spillages of mortar and a ris( of falling on the part of

wor(ers pushing wheelbarrows on unsecured plan(s.

1'1-ackground

)ith the increase in the cost of land and a high rural to urban migration the demand for housing

has increased hence an increase in demand for high rise building to compensate the scarcity of

land *windi, "#$"&. +ccording to utasa $& the demand for high rise buildings has also

been on the increase due to the desire for aesthetics in urban settings, prestige and innovation in

structural systems.

Figure 1.1 Builders using a ramp at a government complex construction site inLupane(Source:Newsday;Pic y ! "u#wa$o%

owever it is one of the most dangerous ris(y economic sectors with /01 accidents being recorded in

!outh +frica in year "#$$of which /#2 of these were fatal fall from heights The !outhern Times, "#$"&.

The picture in figure $.$ shows construction wor(ers using a ramp to transfer mortar from ground to the first

floor of a government comple3 building under construction in Lupane atebeleland 'orth&. The transfer

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of mortar and other building materials from the ground to high floors has seen the use of very

strenuous methods pushing wheelbarrows, pulling ropes and shoveling& and sometimes costly

methods such as cranes. ore than "## ### construction wor(ers in the 4!+ complain of bac(

strains after being employed in the industry for not more than "years55, unt, "#$2&.

+ccording to the 6imbabwean ministry of small to medium enterprise "#$%&, the indigeni7ation policy has

seen a growing number of small to medium construction companies venturing into the construction of high

rise buildings. Though the major concern is that they are failing to brea( even due to high costs of labor

hence they have struggled to out compete large organi7ation that can afford mechani7ation and sustain a

high wage bill while still remaining afloat pofu, "#$%&. ost companies have resorted to the usage of

larders though they have limitations when heights e3ceed seven meters. Lengthy ladders are a ris( on their

own. This project is in line with the government of 6imbabwe5s economic blue print launched in 8ctober

"#$% the 6im+!!9T with one of its four pillars focusing on infrastructure and utilities

development. +mong a coc(tail of problems facing the construction industry are low project

turnover: an increase in non-professional and unregistered contractors: obsolete e;uipment,

unfair competition from international companies and a biting li;uidity crunch which has brought

projects to a standstill. pofu, "#$%&

1'2 /roblem statement

+vailable methods of mortar transfer are labor intensive and costly for small construction

companies.

1'* (im

To design and fabricate an affordable mortar handling system for the growing construction

industry.

1' b+ecti#es

To

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1' Sco"e

This project is focused on design of a mortar elevating machine for the growing construction

industry. The main focus of this machine will mainly be on elevating mortar and other building

materials such as concrete to higher levels using less strenuous methods.

1' 3ustification

+vailable methods of mortar elevation have proved to be costly and highly strenuous hence the

intended design will help alleviate small construction companies from high operational cost and

labor intensive activities.

1'4 Research ,uestions

)hat type of material will be needed for buc(ets to minimi7e wear>

)hat ways of protecting moving parts from clogging due to mortar spillage>

)hat is the average weight of mortar per (ilogram used in the construction industry> )hat is average height of buildings constructed by small construction companies>

)hat problems are associated with current methods of lifting mortar>

)hat mechanisms can be used to ma(e the machine easy to retract and e3tend>

1'5 6imitations

Limited resources in the library for researching

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1'7 8antt chart

1'10 .onclusion

The intended design see( to cut the operational costs incurred by small to medium construction

companies in employing a large labor force. This machine will be a once off investment that will

cut the costs incurred in employing and retrenching at every end of a contract. ?t also see(s to

limit the number of fatalities in the construction industry that have lost lives and parts of their

bodies due to strenuous and ris( methods used in the industry.

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.H(/T%R T: 6)T%R(T9R% R%)%

2'1 )ntroduction

?n this chapter focus will be on the review of literature, a general overview of information

accessed on internet journals and a range of te3t boo(s. +n analysis of the methods being used

currently in mortar hoisting, their wor(ing principle the advantages and limitations they bring

about to help bring up a new design that will build on the limitations of the traditional methods.

2'2 Mortar handling machines

+ccording to Lut7"##%& in the early centuries construction within major cities in the world was

completed using bric(s and mortar only, as there were no lift elevators and cranes it was not

possible to build higher than scaffolding could reach. ?n the late $0##@s, new civil engineering

methods and technology redefined limits for high rise construction. ?t became possible to build

ama7ingly high towers, Alan(, $2&. The advancement came with the advent of lift elevators

and new steel manufacturing processes which produced long beams. 9ssentially, architects had a

whole new set of building bloc(s to wor( with, as relatively narrow, lightweight steel beams

could support much more weight than older solid bric( constructed buildings limited to height of

about ten stories Lut7, "##%&.

Alan($2& reveals that from the late $##@s till this date, high rise buildings have been built

using a standard concept of lifting individual steel beam girders by tower cranes. ?t is delivered

to wor(ers assembling them together at each floor level in a vertical and hori7ontal arrangement.

This process is very labor intensive and is very slow. + major challenge that construction

contractors have to contend with is the factor of @time@. ?f a project is not completed by scheduled

dates, then huge fines can be imposed and the cost of construction can soar, pofu, "#$2&.

?n the construction industry many methods are currently being used to lift mortar from the

ground to varying heights above the ground. Aelow is a discussion of the methods being used in

6imbabwe by small construction companies.

2'2'1 Dro" shi""ing crane

T9B9"##& in their user manual handboo( describe a drop shipping crane as a type of

machine which is e;uipped with a hoist, wire ropesor chains, and cranes, that can be used both

to lift and lower mortar and to move it hori7ontally in case of crawler cranes. ?t uses one or more

simple to createmechanical advantageand thus move loads beyond the normal capability of a

6

http://en.wikipedia.org/wiki/Hoist_(device)http://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Chainhttp://en.wikipedia.org/wiki/Mechanical_advantagehttp://en.wikipedia.org/wiki/Mechanical_advantagehttp://en.wikipedia.org/wiki/Mechanical_advantagehttp://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Chainhttp://en.wikipedia.org/wiki/Mechanical_advantagehttp://en.wikipedia.org/wiki/Hoist_(device)

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humans. Cranes are commonly used in the construction industry for movement of mortar and

other heavy e;uipment. The first drop shipping cranes were invented by the+ncient *ree(sto

load and unload ships. They were powered by men or beasts of burden, such as don(eys. These

cranes were used for the construction of tall buildings Alan(, $2&. Larger cranes were later

developed, employing the use of human tread wheels, permitting the lifting of heavier weights.

?n the middle agescranes were built into stone towers for e3tra strength and stability. The earliest

cranes were constructed from wood, butcast ironand steeltoo( over with the coming of

the ?ndustrial Bevolution, T9B9, "##&.

+ccording to Alan( $2& the first @mechanical@ power on a drop shipping crane was provided

by steam engines. The earliest steam cranebeing introduced in the $0th or $th century, with

many remaining in use well into the late "#th century. T9B9 "##& in their user handboo(

e3plains that modern drop shipping cranes useinternal combustion enginesor electric

motorsand hydraulicsystems to provide a much greater lifting capability than was previously

possible. anual cranes are though still being utili7ed where the provision of power would be

uneconomic or unaffordable pofu, "#$2& .Cranes e3ist in an enormous variety of forms D each

tailored to a specific use. !ometimes si7es range from the smallest jib drop shipping cranes, to

the tallest tower cranes, used for constructing high buildings

Figure &.1: 'rop sipping crawler crane (source: !)*)+ ,andoo#%

The drop shipping mortar crane uses a winch mechanism to drop the mortar container which is

then manually loaded using shovels. The winch then pulls bac( the rope bac( and the mortar

container is lifted above the ground to the floors above where it then manually offloaded again

using shovels to empty the mortar container. T9B9, "##&

7

http://en.wikipedia.org/wiki/Ancient_Greecehttp://en.wikipedia.org/wiki/Ancient_Greecehttp://en.wikipedia.org/wiki/Treadwheelhttp://en.wikipedia.org/wiki/High_Middle_Ageshttp://en.wikipedia.org/wiki/Cast_ironhttp://en.wikipedia.org/wiki/Cast_ironhttp://en.wikipedia.org/wiki/Cast_ironhttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Industrial_Revolutionhttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Steam_cranehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Hydraulichttp://en.wikipedia.org/wiki/Ancient_Greecehttp://en.wikipedia.org/wiki/Treadwheelhttp://en.wikipedia.org/wiki/High_Middle_Ageshttp://en.wikipedia.org/wiki/Cast_ironhttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Industrial_Revolutionhttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Steam_cranehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Hydraulic

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+ccording to 6imbabwe Eouth +genda, "#$%&, most small companies have failed to remain

competitive due to high operational cost. This has also affected small construction companies

that has seen most of them shutting down. The drop shipping crawler crane in Fig ".$ is one of

the methods being used by small construction companies in 6imbabwe on high rise building. ?t

will cost an average of G$##per hour to hire and G"# a (ilometer for transportation asimba,

"#$2&.

(d#antages

+ retractable and e3tendable jib allows it to reach higher floors

!ingle operator cuts cost of labor

!hort counter jib and a variable wor(ing radius permits high productivity in e3tremely

narrow spaces.

obility allows mortar to be hoisted over a hori7ontal distance

Disad#antages

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cross-lin(ed polyethylene. Ilastic trays do not rust, and concrete does not stic( to them, shovels

do not cut them, and a sledgehammer will not dent them.

?n a one or two wheeled models, the wheels may be similar to bicycle tires, complete with inner

tubes. !ome handles are metal withfoamor hard plastic grips, while some wheelbarrows

intended for the home gardener have solid wooden handles with no grips onarch "#$2&.

4niversity of !al ford $"& traced the origins of the wheelbarrow bac( to ancient *reece

between 2#H and 2#0 AC during building of the 9leusis temple. The two wheel wheelbarrow

originates from China during the an

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?t is easy to use with no ;ualification needed to operate it

Disad#antage

Be;uires a lot of human effort to move material laborious&

?t has a lower carrying capacity

?t is more ris( when using it above ground with poor loading leading to a tip over

!egregation of concrete may occur if the route is too bumpy

2'2'* -ucket and Ro"e s$stem

?t is one of the most traditional methods whose origins can date bac( to as far as construction can

be traced, having originated from the ancient way of fetching li;uids from a depth, Camillo,

$"&. ?t has moved from manual pulling of ropes to the electrically powered winch system

shown in Fig ".%. The buc(et is hoisted in a bight in the hoisting rope. ?n the customary hoist one

end of the holding rope is made fast aloft to the trolley or frame wor( of the hoisting tower

depending on the design and after passing around sheaves in the buc(et the other end of each

rope is ta(en to the closing and holding drums respectively of the hoisting machine. The hoisting

winch is fi3ed levels above the ground with a motor which helps pull up the mortar buc(et using

a rope which is made of a fle3ible steel wire, T9B9 "##&.

Fig &.0 winc system used to oist a mortar uc#et (source: !)*)+ ,andoo#%

Camillo $"& describes a winch as a mechanical devices used to pull a heavy loads upwards.

They are used to pull in, let out, or otherwise adjust the tension of a rope or cable. !imple

designs consist of a rope or cable wound around a drum or barrel. The drum rotates in a

hori7ontal a3is and may be powered by steam, a hydraulic motor, or an electric motor. ?ndustrial

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winches are designed to move heavy loads and come in a variety of configurations. ost winch

drums are made of fabricated steel and designed for a specific loading capacity. *reat

communication is needed between the operator and the people offloading and loading the mortar

buc(et. *reat s(ill is needed especially on securing a heavy load. ore than %#= of first time

users of a winch in the !outh +frican construction industry get injured, with H#= losing their

middle fingers due to poor rigging s(ills unt: "#$2&

(d#antages

!mooth in operation minimi7ing segregation of mortar

Few people can operate it thereby cutting cost of labor

Large ;uantities of mortar can be hoisted with minimum human effort

?t has fail-safe feature such that in the event that power is interrupted a fail-safe bra(e is

automatically engaged

Disad#antages

?t is costly to install

?t poses danger to ine3perienced users

any other methods can also be used besides the ones discussed above though these methodssuch as mortar buggies mortar tubs with wheels and handles& which are usually loaded at

ground level then hoisted or for( lifted to the scaffold then rolled onto an inside support floor,

wheeled to wor(ers for offloading. This method is usually used big organi7ation who can afford

for( lifts. !ome buggies are engine powered.

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Fig &.2 n engine powered mortar uggy (source: !e -rigins o/ te eelarrow%

2'* Mortar .haracteristics

The word mortar comes from a Latin word mortarium which means crushed. +spdin $0"2&

defined it as wor(able paste used to bind building bloc(s such asbric(sand concrete masonryunitstogether, fill and seal the irregular gaps between them, and sometimes add decorative colors

or patterns inmasonrywalls. Iretoria Iortland cement $& defines mortar in its broadest

sense as an inclusion of pitch, asphalt, and soft mud or clay, such as used between mud bric(s.

ortar bonds individual bric( together to function as a single element. ortar is composed of a

thic( mi3ture of water, sand, and cement. )ater is used to hydrate the cement and hold the mi3

together.

Fig &.3 uc#et o/ cement mortar (source: Bed roc# industries; pic y: P "c'onald%

The first mortars were made of mud and clay. ?n the early centuries because of lac( of stone and

an abundance of clay, Aabylonian constructions of around 1/##AC9 were made with lime or

pitch being used as mortar. The earliest evidence of mortar usage were in the arrapa city in

Ia(istan around "1##AC9 where they used (iln fired bric(s and gypsum as mortar +spdin,

$0"2&. *ypsum mortar also called plaster of Iaris re;uires a lower firing temperatures so it is

easier to ma(e than lime mortar and sets up much faster Iortland Cement :"#$"&. *ypsum

mortar is not as durable as other mortars in damp conditions. ud and clay with either lime or

gypsum were used in the construction of 9gyptian pyramids around "/##AC9.

ortar is mainly is described as a glue that holds bric(s together made from cement, lime, water

and sand. ?ts main job is to provide stability for the bric(s or stones on a wall Iortland cement:

"#$"&.

12

http://en.wikipedia.org/wiki/Brickhttp://en.wikipedia.org/wiki/Brickhttp://en.wikipedia.org/wiki/Concrete_masonry_unithttp://en.wikipedia.org/wiki/Concrete_masonry_unithttp://en.wikipedia.org/wiki/Masonryhttp://en.wikipedia.org/wiki/Masonryhttp://en.wikipedia.org/wiki/Mudbrickhttp://en.wikipedia.org/wiki/Mudbrickhttp://en.wikipedia.org/wiki/Clayhttp://en.wikipedia.org/wiki/Brickhttp://en.wikipedia.org/wiki/Concrete_masonry_unithttp://en.wikipedia.org/wiki/Concrete_masonry_unithttp://en.wikipedia.org/wiki/Masonryhttp://en.wikipedia.org/wiki/Mudbrickhttp://en.wikipedia.org/wiki/Clay

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2'*'1 T$"es of mortar

ortars are classified based on compressive strength and their bonding properties and fle3ibility,

+spidini:$0"2&. These two properties are very important because they will help in handling and

provide the strength on masonry. 9ach mortar mi3 has cement, hydrated lime and sand

proportions. Choosing a mortar mi3 is based on its viscosity, strength, adhesion and sealing

re;uirements. Aelow is a discussion of the three types of mortar available and their

characteristics according to Construction 9ssential $2&

&.0.1a "ortar mix type N

4sually recommended on e3terior and above grade walls that are e3posed to severe weather and

high heat. ?t has a medium compressive strength and it is usually described as a general purpose

mortar used in above grade, e3terior and interior load bearing installations. These is the mortar

used by most home owners.

&.0.1 "ortar mix type -

+ mi3 with low compressive strength of %/#psi used for interior or non-load bearing walls. ?ts

e3terior use is limited because of its law structural capacity. ?t can be used as an alternative to

type ' for areas with severe cold weather. ?t is easy to apply and is ideal when repointing due to

its consistency. 4sed in above grade and non-loading bearing situations both interior and e3terior

environments.

&.0.1c "ortar mix type S

as a very high compressive strength of a bove$0##psi and a high tensile bond strength ideal

product for masonry at or below grade ?t performs well to fight soil pressure and wind. This

mortar mi3 type can be used for below grade areas e.g. foundations and bric( pavements.

&.0.1d "ortar mix type "

4sually recommended for walls with heavy loads, masonry below grade, foundations, retaining

walls and drive ways. as about "/##psi in compressive strength yet it has poor adhesion.

The rheology of the different mi3es of mortar discussed above have to use a cement with specific

specification for them to be easy to transport for e3ample adhesion, flow and frictional resistance

against container surface, resistance to settlement and resistance to segregation.

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2' Details to consider in design of a mortar handling machine

The intended design will be used in handling different mortar mi3es and concrete which may

need to be cast well above ground level. ortar mi3es and concrete though used interchangeably

they do differ, mortar mi3es are the ingredients that glue other components such as stones

together to form concrete. Though they are different (inds of concrete normal concrete has a

density around "2## (gJm%with cement mortar having an average density %$"#(gJm% Aill

'ye,$1&. anna and illier $2& describes density a physical characteristic, and as a

measure of mass per unit of volume of a material or substance.

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(N Batio of inner to outer diameters of the shaft ( O # for a solid shaft because inner diameter is

7ero &

( This arises due the phenomenon of buc(ling of long slender members

which are acted upon by a3ial compressive loads.

ere, P is defined as,

MMMMMM..M %& hurmi and *upta, "##/&

for LJ Q$$

2'b Stiffness of rollers

Aasic idea of design in such case depends on the allowable deflection and twist of the roller.The

stress at any point on the shaft depends on the nature of load acting on it. The stresses which may

be present are as follows.

Stress due to torsion

MMMMMMMM. 2& hurmi and *upta, "##/=

)here,

TN Tor;ue on the roller

N !hear stress due to torsion

Ma

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2'e Design of chain dri#e

Chain drives are an effective power transmission system. )ith its main advantages being that the

shaft center distances are relatively unrestricted. The center distance between two chainedsproc(ets vary from /#= to %##= or more of the pitch diameters annover, "##"&. Chains also

perform better than gears under shoc( loading conditions

Boller chains are constructed using lin( plates, pins and rollers and connecting them in an

endless chain using a connecting lin(.

Fig &.4 dismantled roller cain (source: www.gearseds.com; picture y: un#nown%

Boller diameter hurmi and *upta,

"##/&

4sing sproc(ets the simple rule is that the of the diameter ratios

BatioO MMMMMMMMMMMMMMMMMM. & >hurmi and

*upta, "##/&

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Iitch

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ma(e the design safe that will cut labor intensiveness in this industry while leaving the

organi7ation with a competitive edge.

ethods discussed below helped to bring up information in chapter four results and findings&

about all permutations considered in coming up with the final design.

*'1 Data collection

Xualitative and ;uantitative data were used though more bias was on using the ;ualitative

approach. Besearch instruments such as informal interviews, ;uestionnaires and site surveys

were construction was ongoing were used to collect relevant data. 4sage of internet and visits to

the library helped on the des( research in a bid to fine tune survey and interview findings.

ethods used e3plained below

*'1'1 bser#ations

+ visit to a construction site in Lupane atabeleland north region where asimba construction

is raising a three story government comple3. These was in a bid to observe the efficiency the

wheelbarrow and ramp method that were being used at the site.

*'1'2 )nformal inter#ie;s

?nformal interviews were conducted at sites that were undergoing construction before the

finali7ation of this document. ?nterviews were done with people of different levels from the

general wor(er to the site managers on how the current methods of hoisting mortar fell short on

end user5s e3pectations. ?nformal interviews were carried in conjunction with observations in a

bid to understand the complaints raised by users of current mortar handling machines and any

improvements they wish to see on the ne3t machines.

*'1'* ?uestionnaires

+ ;uestionnaires is a formali7ed set of ;uestions for obtaining information from respondents.

The main objective being to translate the researcher5s information needs into a set of specific

;uestions that the targeted respondents carry vital information and are willing and able to answer

correctly and elo;uently. Xuestionnaires were prepared and shared among the illiterate in

different level thus from the general hand to the site boss at every visited site so as to get their

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views on this project being done by the researcher. Xuestions were structured to give the

researcher relevant information which can be considered in the intended design.

*'1' 6ibrar$ research

any te3ts boo(s and newspapers were used in the library for the purpose of calculations of the

various components of the intended design. ore so it gave the researcher access to the

engineering handboo(s and journals for some design aspects and calculations they may need

consideration. ?nformation collected from newspaper helped in accommodating the safety issues

that need to be loo(ed at in the intended design

*'1' )nternet

The internet which has made the world a global village help bring information on problems

being faced in the construction industry in some parts of the world. ?nformation from the internet

helped the researcher gather information of past designs their wor(ing principles, their

shortcomings and strengths which the researcher wish to build upon. ?t provided a wide range of

information from which e3periments were conducted to help to bring up the final design. The

internet proved a good research instrument with vast information though some information could

have been tempered with hence its reliability was ;uestionable.

*'2 %ngineering tools and courses used +utoC+

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*'* .onclusion

?nformation gathered through methods mentioned in this chapter and tools stated came in handy

to the researcher in compiling this document. The results of e3periments and researches done can

be fully revealed in the findings chapter. aving used all the above methods discussed above the

ne3t chapter will discuss the results and findings brought about. +ll the discussed methods were

used to try and build up towards a design that will ma(e a niche in the range of methods that are

currently available in the construction industry.

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