Penauk Assigment - About Block

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UITM KAMPUS SAMARAHAN FACULTY OF ARCHITECTURE,PLANNING, AND

SURVEYING

DIPLOMA OF QUANTITY SURVEYING

(AP114)

CONSTRUCTION TECHNOLOGY

(QSD 182)BLOCKS

PREPARED BY: AHMAD MUSTANIR BIN HADADAK (2009270736)

MOHD. AKRAM BIN ABDUL RAUF (2009474746)

MUHAMMAD FARIQ BIN (2009)

PREPARED FOR: MADAM ASMAH ALIAH BIN BOHARI



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DATE OF SUBMISSION: 24 FEBUARY 2010

INTRODUCTION

Concrete block is usually considered a modular product. The Government's construction

agencies, however, are aware of the costliness to the concrete masonry industry of buying the

molds needed to produce concrete block in hard metric sizes and are attempting to minimize

this expense. Inch-pound (soft-converted) block substitutions are recommended in all cases in

which concrete block is used as a backup or infill material and in which architectural

considerations otherwise permit.

Concrete block in a hard metric size will only be specified in a federal construction project in

cases in which the block will be located in an architecturally exposed area or will be required to

fit together with other modular metric components. The concrete block must also be found to be

available at a reasonable cost.

The Corps of Engineers has stated that approximately 60 percent of the cost of a

concrete block wall is labor, 25 percent is the concrete block, and 15 percent is for other

materials such as mortar and reinforcement. In projects for which concrete block in a hard

metric size is needed, allowing inch-pound (soft-converted) block may save on the cost of the

block, but would substantially increase the amount of cutting and trimming and would

unreasonably increase labor costs. Therefore, in certain circumstances, it is logical and cost

effective for the Government to specify concrete block in a hard metric size.

Total installed cost should be the determining factor in the selection of concrete block.

Most often, concrete block is used as a back-up or infill material; when this is the case, inch-

pound block substitutions are recommended. Where concrete block in a hard metric size is

considered for use as an architectural material or as a primary structural system, cost and

availability should be determined in advance to judge the appropriateness of such use.



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PROPERTIES OF BLOCK

` A concrete block is primarily used as a building material in the construction of walls.

Concrete masonry unit (CMU).

` A concrete block is one of several precast concrete products used in construction.

` Most concrete blocks have one or more hollow cavities, and their sides may be cast

smooth or with a design.

` In use, concrete blocks are stacked one at a time and held together with fresh concrete

mortar to form the desired length and height of the wall.

` These early blocks were usually cast by hand, and the average output was about 10

blocks per person per hour.



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` Today, concrete block manufacturing is a highly automated process that can produce up

to 2,000 blocks per hour.

` The shapes and sizes of most common concrete blocks have been standardized to

ensure uniform building construction.

` The most common block size in the United States is referred to as an 8-by-8-by-16

block, with the nominal measurements of 8 in (20.3 cm) high by 8 in (20.3 cm) deep by

16 in (40.6 cm) wide.

` This nominal measurement includes room for a bead of mortar, and the block itself

actually measures 7.63 in (19.4 cm) high by 7.63 in (19.4 cm) deep by 15.63 in (38.8

cm) wide.

` Many progressive block manufacturers offer variations on the basic block to achieve

unique visual effects or to provide desirable structural features for specialized

applications.

` Another block design, called a split-faced block, includes a rough, stone-like texture on

one face of the block instead of a smooth face. This gives the block the architectural

appearance of a cut and dressed stone.

` Concrete blocks were first used in the United States as a substitute for stone or wood in

the building of homes.

` The homes built of concrete blocks showed a creative use of common inexpensive

materials made to look like the more expensive and traditional wood-framed stone

masonry building.

` This new type of construction became a popular form of house building in the early

1900s through the 1920s.

` While many houses used the concrete blocks as the structure as well as the outer wall

surface, other houses used stucco or other coatings over the block structure.

` The concrete blocks were made with face designs to simulate stone textures:

y rock-faced

y granite-faced



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y rusticated

CONSTITUENTS OF BLOCKS

The concrete commonly used to make concrete blocks is a mixture of powdered portland

cement, water, sand, and gravel.

This produces a light gray block with a fine surface texture and a high compressive

strength. A typical concrete block weighs 38-43 lb (17.2-19.5 kg).

In general, the concrete mixture used for blocks has a higher percentage of sand and a

lower percentage of gravel and water than the concrete mixtures used for general

construction purposes. This produces a very dry, stiff mixture that holds its shape when

it is removed from the block mold.

If granulated coal or volcanic cinders are used instead of sand and gravel, the resulting

block is commonly called a cinder block.

This produces a dark gray block with a medium-to-coarse surface texture, good

strength, good sound-deadening properties, and a higher thermal insulating value than a

concrete block. A typical cinder block weighs 26-33 lb (11.8-15.0 kg).

Lightweight concrete blocks are made by replacing the sand and gravel with expanded

clay, shale, or slate. Expanded clay, shale, and slate are produced by crushing the raw

materials and heating them to about 2000°F (1093°C). At this temperature the material

bloats, or puffs up, because of the rapid generation of gases caused by the combustion

of small quantities of organic material trapped inside.

A typical light-weight block weighs 22-28 lb (10.0-12.7 kg) and is used to build non-load-

bearing walls and partitions. Expanded blast furnace slag, as well as natural volcanic

materials such as pumice and scoria, are also used to make lightweight blocks.

In addition to the basic components, the concrete mixture used to make blocks may also

contain various chemicals, called admixtures, to alter curing time, increase compressive

strength, or improve workability.

The mixture may have pigments added to give the blocks a uniform color throughout, or the

surface of the blocks may be coated with a baked-on glaze to give a decorative effect or to

provide protection against chemical attack. The glazes are usually made with a thermosetting

resinous binder, silica sand, and color pigments.



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We can summarize that the constituent of blocks consists of material :-

(A)Cement

.

Cements used in construction are characterized as hydraulic or non-hydraulic.

CEMENTSWATER

SANDS

GRAVEL

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POWDERED

PORTLAND



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The most important use of cement is the production of mortar and concrete²the

bonding of natural or artificial aggregates to form a strong building material which is

durable in the face of normal environmental effects.

Concrete should not be confused with cement because the term cement refers only to

the dry powder substance used to bind the agregate materials of concrete. Upon the

addition of water and/or additives the cement mixture is referred to as concrete,

especially if aggregates have been added.

Types of modern cement

Portland cement

y Cement is made by heating limestone with small quantities of other materials (such

as clay) to 1450°C in a kiln, in a process known as calcination. The resulting hard

substance, called 'clinker', is then ground with a small amount of gypsum into a

powder to make 'Ordinary Portland Cement', the most commonly used type of

cement (often referred to as OPC).

y Portland cement is a basic ingredient of concrete, mortar and most non-speciality

grout. The most common use for Portland cement is in the production of concrete.

Concrete is a composite material consisting of aggregate (gravel and sand), cement,

and water. As a construction material, concrete can be cast in almost any shape

desired, and once hardened, can become a structural (load bearing) element.

Portland cement may be gray or white.

Portland cement blends

y These are often available as inter-ground mixtures from cement manufacturers, but

similar formulations are often also mixed from the ground components at the

concrete mixing plant.

Portland Blastfurnace Cement

y Contains up to 70% ground granulated blast furnace slag, with the rest Portland

clinker and a little gypsum. All compositions produce high ultimate strength, but as

slag content is increased, early strength is reduced, while sulfate resistance



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increases and heat evolution diminishes. Used as an economic alternative to

Portland sulfate-resisting and low-heat cements.

Portland Flyash Cement

y Contains up to 30% fly ash. The fly ash is pozzolanic, so that ultimate strength is

maintained. Because fly ash addition allows a lower concrete water content, early

strength can also be maintained. Where good quality cheap fly ash is available, this

can be an economic alternative to ordinary Portland cement.

Portland Pozzolan Cement

y Includes fly ash cement, since fly ash is a pozzolan, but also includes cements made

from other natural or artificial pozzolans.

Portland Silica Fume cement

y Addition of silica fume can yield exceptionally high strengths, and cements

containing 5-20% silica fume are occasionally produced. However, silica fume is

more usually added to Portland cement at the concrete mixer.

Colored cements

y Are used for decorative purposes. In some standards, the addition of pigments to

produce "colored Portland cement" is allowed. In other standards (e.g. ASTM),

pigments are not allowed constituents of Portland cement, and colored cements are

sold as "blended hydraulic cements".

Non-Portland hydraulic cements



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Pozzolan-lime cements. Mixtures of ground pozzolan and lime are the cements used

by the Romans, and are to be found in Roman structures still standing (e.g. the

Pantheon in Rome). They develop strength slowly, but their ultimate strength can be

very high. The hydration products that produce strength are essentially the same as

those produced by Portland cement.

Slag-lime cements. Ground granulated blast furnace slag is not hydraulic on its own,

but is "activated" by addition of alkalis, most economically using lime. They are similar to

pozzolan lime cements in their properties. Only granulated slag (i.e. water-quenched,

glassy slag) is effective as a cement component.

Supersulfated cements. These contain about 80% ground granulated blast furnace

slag, 15% gypsum or anhydrite and a little Portland clinker or lime as an activator. They

produce strength by formation of ettringite, with strength growth similar to a slowPortland cement. They exhibit good resistance to aggressive agents, including sulfate.

Calcium aluminate cements are hydraulic cements made primarily from limestone and

bauxite. The active ingredients are monocalcium aluminate CaAl2O4 (CA in Cement

chemist notation) and Mayenite Ca12 Al14O33 (C12 A7 in CCN). Strength forms by hydration

to calcium aluminate hydrates. They are well-adapted for use in refractory (high-

temperature resistant) concretes, e.g. for furnace linings.

(B) Gravel

Gravel is rock that is of a specific particle size range.

Gravel is an important commercial product, with a number of applications. Many roadways

are surfaced with gravel, especially in rural areas where there is little traffic. Globally, far

more roads are surfaced with gravel than with concrete or tarmac



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Multiple types of gravel have been recognized, including:

y Bank gravel: gravel intermixed with sand or clay.

y Bench gravel: a bed of gravel located on the side of a valley above the present stream

bottom, indicating the former location of the stream bed when it was at a higher level.

y Lag gravel: a surface accumulation of coarse gravel produced by the removal of finer

particles.

y Pay gravel: also known as "pay dirt"; a nickname for gravel with a high concentration of

gold and other precious metals. The metals are recovered through gold panning.

y

Pea Gravel: gravel that consists of small, rounded stones used in concrete surfaces. Also used for walkways, driveways and as a substrate in home aquariums.

(C) Sands

Sandstone

Sedimentary Rock

Prepared sample of sandstone

Composition

Typically quartz and/or feldspar (on earth); lithic fragments

are also common. Other minerals may be found in

particularly immature sandstone.



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Sandstone composed mainly of quartz grains

Sandstones fall into several major groups based on their mineralogy and texture.

y Quartz arenites are made up almost entirely of quartz grains, usually well sorted and

rounded. These pure quartz sands result from extensive weathering that occurred before

and during transport and removed everything but quartz, the most stable mineral.

y Arkoses are more than 25 percent feldspar.T he grains tend to be poorly rounded and

less well sorted than those of pure quartz sandstones. These feldspar-rich sandstones

come from rapidly eroding granitic and metamorphic terrains where chemical weathering

is subordinate to physical weathering.

y Lithic sandstones contain many lithic fragments derived from fine-grained rocks, mostly

shales, volcanic rocks, and fine-grained metamorphic rocks.

y Graywacke is a heterogeneous mixture of lithic fragments and angular grains of quartz

and feldspar, and/or grains surrounded by a fine-grained clay matrix. Much of this matrix

is formed by relatively soft fragments, such as shale and some volcanic rocks, that are

chemically altered and physically compacted after deep burial of the sandstone

formation.

Gallery

Sandstone with ironoxide bands A sandstone quarry atJodhpur, India A natural sandstoneformation composed of cemented quartz sand

Sandstone patterns on achamber wall in Petra

(D) Water



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Water is the another important material to form the blocks

The function of water is to mix another material that form blocks like cements,gravel and

sandstone

The insufficient of using of water in making of blocks will causes the blocks become

unstable

In conclusion, the using water must be balance/parallel with the quantity of another material in order to from very strong/stable blocks

TYPES OF BLOCKS

Actual and Nominal Sizes. Concrete blocks come in specific sizes. The 3/8-inch mortar joint

has been adopted as the standard-size joint for joining blocks. The actual dimensions of the

block are fractional; when combined with a 3/8-inch mortar joint, the dimensions will come out

even in inches or nominal sizes. Therefore, a 15 5/8-inch stretcher block with a 3/8-inch mortar

joint equals 16 inches. The same explanation holds true for heights and widths.

Typical Sizes and Shapes. Blocks come in both heavyweight and lightweight materials with

full- and half-length sizes. The three-core block can also be obtained as two-core blocks. Figure

2.1, illustrates some of the typical sizes and shapes of concrete blocks.

Figure 2.1 Types of Concrete Blocks



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Types of Concrete blocks come in several different types:-

STRECHER. A stretcher block is the most commonly used block in construction. It is

laid with its length parallel to the face of the wall.

CORNER. A corner block is used for corners at simple window and door openings.

Double Corner or Pier. A double-corner or pier block is used for constructing piers

pilasters or for any other purpose where both ends of the block would be visible.

BULL NOSE. A bull-nose block serves the same purpose as a corner block, but it is

used where round corners are desired.

JAMB. A wood-sash jamb block is used with a stretcher and a corner block around

elaborate window openings. The recess in the block allows room for the various casing

members, as in a double-hung window.

Most Common Block. The most common concrete block is the hollow, load-bearing stretcher

block, which is 8 by 8 by 16 inches nominal size, but 7 5/8 by 7 5/8 by 15 5/8 inches actual size.

The heavyweight load-bearing stretcher block weighs from 40 to 50 pounds.

In Figure 2.2, the cores taper toward the top of the block, providing a wider face shell. Always

lay this block with the wider face up to allow for a greater area on which to lay a bed of mortar.

Figure 2.2 Hallow load-bearing stretcher block



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MANUFACTURING PROCESS

The production of concrete blocks consists of four basic processes: mixing, molding,

curing, and cubing. Some manufacturing plants produce only concrete blocks, while

others may produce a wide variety of precast concrete products including blocks, flatpaver stones, and decorative landscaping pieces such as lawn edging. Some plants

are capable of producing 2,000 or more blocks per hour.

The following steps are commonly used to manufacture concrete blocks:-



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Mixing

y

1 . The sand and g rave l a re s t o red ou t s ide i n p i l es and a ret rans fe r red i n t o s t o rage b ins i n t he p lan t b y a conveyor be l t as t hey

a re needed . The po r t l and cemen t i s s t o red ou t s ide i n l a rge ve r t i ca l

s i l os t o p ro tec t i t f r om mo is tu re .

y 2 . As a p roduc t i on run s t a r t s , t he requ i red amoun t s o f sand , g rave l ,

and cemen t a re t r ans fe r red by g rav i t y o r by mechan i ca l means t o a

we igh ba t che r wh i ch measures t he p roper amoun t s o f e ach ma te r i a l .

y 3 .The d ry ma te r i a l s t hen f l ow i n t o a s t a t i ona ry m ixe r where t hey

a re b lended t oge the r f o r seve ra l m inu tes . There a re two t ypes o f

m ixe rs common ly used . O ne t ype , ca l l ed a p lane ta ry o r pan m ixe r ,

resemb les a sha l l ow pan w i t h a l i d . M ix ing b lades a re a t t ached t o a

ve r t i ca l r o t a t i ng sha f t i ns ide t he m ixe r . The o the r t ype i s ca l l ed a

hor i zon ta l d rum m ixe r . I t r esemb les a co f f ee can t u rned on i t s s i de

and has m ix ing b lades a t t ached t o a ho r i zon ta l r o t a t i ng sha f t i ns ide

the m ixe r .

y 4 . A f t e r t he d ry ma te r i a l s a re b lended , a sma l l amoun t o f wa te r i s

added t o t he m ixe r . I f t he p lan t i s l oca ted i n a c l ima te sub jec t t o

t empera tu re ex t remes , t he wa te r may f i r s t pass t h rough a hea te r o r

ch i l l e r t o regu la te i t s t empera tu re . Adm ix tu re chem ica l s and

co lo r i ng p igmen ts may a l so be added a t t h i s t ime . The conc re te i s

t hen m ixed f o r s i x t o e igh t m inu tes .



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Molding

y 5 . O nce t he l oad o f conc re te i s t ho rough l y m ixed , i t i s dumped i n t o

an i nc l i ned

bucke t conveyor and t ranspor t ed t o an e leva ted hopper . The m ix ing

cyc le beg ins aga in f o r t he nex t l oad .

y 6 . F rom the hopper t he conc re te i s conveyed t o ano the r hopper on

top o f t he b lock mach ine a t a measured f l ow ra te . I n t he b lock

mach ine , t he conc re te i s f o r ced downward i n t o mo lds . The mo lds

cons i s t o f an ou te r mo ld box con ta in ing seve ra l mo ld l i ne rs . The

l i ne rs de te rm ine t he ou te r shape o f t he b lock and t he i nne r shape o f

t he b lock cav i t i es . As many as 15 b locks may be mo lded a t one

t ime .

y 7 . When t he mo lds a re f u l l , t he conc re te i s compac ted by t he we igh t

o f t he upper mo ld head com ing down on t he mo ld cav i t i es . Th i s

compac t i on may be supp lemen ted by a i r o r hyd rau l i c p ressu re

cy l i nde rs ac t i ng on t he mo ld head . Mos t b lock mach ines a l so use a

shor t bu rs t o f mechan i ca l v i b ra t i on t o f u r t he r a id compac t i on .

y 8 . The compac ted b locks a re pushed down and ou t o f t he mo lds

on to a f l a t s t ee l pa l l e t . The pa l l e t and b locks a re pushed ou t o f t he

mach ine and on to a cha in conveyor . I n some opera t i ons t he b locks

then pass under a ro t a t i ng b rush wh ich removes l oose ma te r i a l f r om

the t op o f t he b locks .



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Curing

y 9 . The pa l l e t s o f b l ocks a re conveyed t o an au tomated s t acke r o r

l oader wh i ch p laces t hem in a cu r i ng rack . Each rack ho lds seve ra l

hundred b locks . When a rack i s f u l l , i t i s r o l l ed on to a se t o f r a i l sand moved i n t o a cu r i ng k i l n .

y 10 . The k i l n i s an enc losed room w i t h t he capac i t y t o ho ld seve ra l

racks o f b l ocks a t a t ime . There a re two bas i c t ypes o f cu r i ng k i l ns .

The mos t common t ype i s a l ow-p ressu re s t eam k i l n . I n t h i s t ype ,

t he b locks a re he ld i n t he k i l n f o r one t o t h ree hours a t r oom

tempera tu re t o a l l ow t hem to ha rden s l i gh t l y . S team i s t hen

gradua l l y i n t roduced t o ra i se t he t empera tu re a t a con t ro l l ed ra te o f

no t more t han 60°F pe r hou r (16°C pe r hou r ) . S tandard we igh tb locks a re usua l l y cu red a t a t empera tu re o f 150 -165°F (66 -74°C) ,

wh i l e l i gh twe igh t b locks a re cu red a t 170 -185°F (77 -85°C) . When

the cu r i ng t empera tu re has been reached , t he s t eam i s shu t o f f , and

the b locks a re a l l owed t o soak i n t he ho t , mo is t a i r f o r 12 -18 hours .

A f t e r soak ing , t he b locks a re d r i ed by exhaus t i ng t he mo is t a i r and

fu r t he r ra i s i ng t he t empera tu re i n t he k i l n . The who le cu r i ng cyc le

takes abou t 24 hours .

Ano the r t ype o f k i l n i s t he h igh -p ressu re s t eam k i l n , somet imes

ca l l ed an au toc lave . I n t h i s t ype , t he t empera tu re i s ra i sed t o 300 -

375°F (149-191°C) , and t he p ressu re i s ra i sed t o 80 -185 ps i ( 5 . 5 -

12 .8 ba r ) . The b locks a re a l l owed t o soak f o r f i ve t o 10 hours . The

pressu re i s t hen rap id l y ven ted , wh i ch causes t he b locks t o qu i ck l y

re lease t he i r t r apped mo is t u re . The au toc lave cu r i ng p rocess

requ i res more energy and a more expens i ve k i l n , bu t i t can p roduce

b locks i n l ess t ime .



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Cubing

y 11 The racks o f cu red b locks a re ro l l ed ou t o f t he k i l n , and t he

pa l l e t s o f b l ocks a re uns tacked and p laced on a cha in conveyor .

The b locks a re pushed o f f t he s t ee l pa l l e t s , and t he empty pa l l e t sa re f ed back i n t o t he b lock mach ine t o rece i ve a new se t o f mo lded

b locks .

y 12 I f t he b locks a re t o be made i n t o sp l i t - f ace b locks , t hey a re f i r s t

mo lded as two b locks j o i ned t oge the r . O nce t hese d oub le b locks a re

cu red , t hey pass t h rough a sp l i t t e r , wh i ch s t r i kes t hem w i t h a heavy

b lade a long t he sec t i on be tween t he two ha l ves . Th i s causes t he

doub le b lock t o f r ac tu re and f o rm a rough , s t one - l i ke t ex tu re on one

face o f each p iece .y 13 The b locks pass t h rough a cuber wh i ch a l i gns each b lock and

then s t acks t hem in t o a cube t h ree b locks ac ross by s i x b locks deep

by t h ree o r f ou r b locks h igh . These cubes a re ca r r i ed ou t s ide w i t h a

fo rk l i f t and p laced i n s t o rage .

Quality Control

The manu fac tu re o f conc re te b locks requ i res cons tan t mon i t o r i ng t o

p roduce b locks t ha t have t he requ i red p roper t i es . The raw mate r i a l s a re

we ighed e lec t ron i ca l l y be fo re t hey a re p laced i n t he m ixe r . The t rapped

wate r con ten t i n t he sand and g rave l may be measured w i t h u l t r ason i c

sensors , and t he amoun t o f wa te r t o be added t o t he m ix i s au tomat i ca l l y

ad jus ted t o compensa te . I n a reas w i t h ha rsh t empera tu re ex t remes , t he

wa te r may pass t h rough a ch i l l e r o r hea te r be fo re i t i s used .

As t he b locks emerge f rom the b lock mach ine , t he i r he igh t may be

checked w i t h l ase r beam sensors . I n t he cu r i ng k i l n , t he t empera tu res ,

p ressu res , and cyc le t imes a re a l l con t ro l l ed and reco rded au tomat i ca l l y

t o ensu re t ha t t he b locks a re cu red p roper l y , i n o rde r t o ach ieve t he i r

r equ i red s t reng th .



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SELECTION OF BLOCKS



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Mate r i a l s se lec t i on i s a c ruc ia l f ac to r i n de te rm in ing t he cos t ,

qua l i t y , and co r ros ion p ro tec t i on f o r eve ry eng ineer i ng p ro jec t . The

var i e t y o f i nc reas ing l y du rab le ma te r i a l s and t he i r comb ina t i ons ,

coup led w i t h t he r i se o f ne w and more c r i t i ca l se rv i ce requ i remen ts

and t he demand f o r l ower cos t s , have expanded upon t r i a l - and -

e r ro r c r i t e r i a i n t o me thod i ca l , mu l t i - d imens iona l app roaches t o

mate r i a l s se lec t i on .

The se lec t i on o f a spec i f i c b lock was genera l l y made by t he c l i en t ,

t ha t choose i t by economic reasons , i ns tead o f t echn i ca l r easons .

An t i c i pa t i ng f u t u re t r ends and p rospec t s , t he book a l so exam ines

the f ounda t i ons t o seve ra l i nnova t i ve t echno log ies , i nc lud ing t he

po ten t i a l o f t a i l o r -made mate r i a l s , va r i ous t ypes o f f ue l ce l l s , and

the p roper t i es o f FG Ms in cu r ren t and f u t u re me ta l l i c and non-

meta l l i c s ys tems and mode ls . I n i t s f i na l chap te r , t he book

h igh l i gh t s p rocesses t ha t a re po i sed f o r p roduc t i on as we l l as

p rospec t s s t i l l i n exper imen ta t i on and t es t i ng phases .

New Mate r i a l s , P rocesses , and Me thods Techno logy p rov ides

today ' s sc ien t i s t s , t echn i c i ans , and eng ineer i ng depar tmen t s

devo ted t o reso l v i ng app l i ca t i on requ i remen ts w i t h pe r f o rmance

proper t i es us ing a we l l - execu ted ma te r i a l se lec t i on p rocess .



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A Foursquare -s t y l e house des ign , appear i ng i n t he Rad fo rd

A rch i t ec tu ra l Company ' s 1908 ca ta log Cement Houses and How to

Bu i l d Them. I t was one o f hundreds o f canc re te b lock house

des igns o f f e red by t he Rad fo rd company . They es t ima ted t ha t t h i s

des ign cou ld be bu i l t f o r abou t $2 ,250 .00 , much l ess t han

t rad i t i ona l s t one masonry houses o f t he t ime . When manu fac tu re rs des ign a new b lock , t hey mus t cons ide r no t

on l y t he des i red shape , bu t a l so t he manu fac tu r i ng p rocess requ i red

to make t ha t shape .

Shapes t ha t requ i re comp lex mo lds o r add i t i ona l s t eps i n t he

mo ld ing p rocess may s low p roduc t i on and resu l t i n i nc reased cos t s .

I n some cases , t hese i nc reased cos t s may o f f se t t he be ne f i t s o f t he

new des ign and make t he b lock t oo expens i ve .



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Page | 23

SUITABILITY

Design Flexibility

Concrete block is an extremely flexible building material. Building with concrete block means

you have the flexibility to do just about anything you want. Whether it be a one- story home or a

three story home with such options as columns, arches, high ceilings and tall windows concrete

block provides the needed flexibility for every type of job.

Durability

Beauty That Lasts

Concrete is one of the most durable materials on Earth. There¶s no rotting or wall warping. Noextensive maintenance or upkeep requirements. Your home retains it curb appeal and its value

± beautifully.

Energy Efficiency

Attractive Energy Savings

Concrete block homes are more energy efficient than wood homes, especially in hot, humid,

sun baked climate. That¶s because the mass factor of block acts as a reservoir to trap and store

heat from the sun, so that interiors stay cooler longer.

Another point: air infiltration from ³wall leaks´ is estimated to cause up to 39% of home energy

loss. Concrete block walls, which are more airtight than wood frame walls, seal in air

conditioned air far better ± while keeping out hot, humid air.



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Page | 24

Fire Resistant

You Won't Get Burned with Concrete Block

Concrete block is a non-combustible material. Resistance to fire is of particular importance

since fire services in the countryside tend to be further away and take longer to arrive at the

scene of the fire. Concrete blocks are incombustible and will not burn, so the house

structure will stay intact in the event of fire. In contrast, if a timber frame structure catches fire it

will burn to the ground quickly.. In addition, concrete block significantly reduces unwanted noise

pollution.

Termite Resistant

Concrete Block terminates Problems

Wood frame homes are tasty targets for these destructive insects, but not block homes. What¶s

more, block homes are virtually immune to dry rot,

Weather & Storm Resistance

A Beautiful Choice in Ugly Weather

After a hurricane passes, weather resistance may be the most important benefit to a home

buyer nowadays. In a concrete block home you and your family will enjoy increased safety and

peace of mind during dangerous weather. Moreover, block does not deteriorate in any way.



BLOCKS

Page | 25

SUMARRY

Block walls are noted in this structure. There are many factors involved in the proper

construction of block and walls. This inspection cannot ascertain whether reinforcing bars are

properly installed or whether block cells are properly filled with concrete.

The only way to know if the reinforcing bars are properly installed is destructive testing.

Very little, if any maintenance considerations are necessary with this type construction. If

efflorescence, a "whitish" material, is seen on the wall, we could expect a water problem on the

opposite side, especially if the wall has earth against it, such as in basement construction.

The waterproofing agent used may be breaking down or the wall may be cracked. This

inspection will not ascertain whether water problems exist in this type construction if the

problems are not readily visible. Contact the inspector for further information regarding this

inspection limitation if necessary.



BLOCKS

REFERENCES

INTERNET :

www.hometips.com

www.ehow.com

www.concretebolckshome.com

www.askthebuilder.com

http://en.wikipedia.org

http://commons.wikimedia.org

http://cementamericas.com/mag/cement_chinas_cement_demand/

http://www.litebuilt.com/table3.html

http://www.concreteresources.net/categories/4F26A962-D021-233F

The Physics Factbook . http://hypertextbook.com/facts/1999/KatrinaJones.shtml.

http://www.fhwa.dot.gov/infrastructure/materialsgrp/silica.htmThe Physics Factbook .

http://hypertextbook.com/facts/1999/KatrinaJones.shtml.

FURTHER READING:

Hornbos te l , Ca leb .

C ons t ruc t ion Mate r ia ls , 2nd Ed i t ion . J o h n W i l e y

and Sons , I nc . , 1991 .

Kosk i , John A . "How Conc re te B lock A re Made . " Mason ry

C ons t ruc t i on , O c tober 1992 , pp .374-377 .

Sch ie rhom, Caro l yn . "P roduc ing S t ruc tu ra l L i gh twe igh t Conc re te

B lock . " C onc re te Jou rna l , Februa ry 1996 , pp . 92 -94 , 96 , 98 , 100 -

1 0 1 .

Warde l l , C . "O pera t i on Founda t i on . " Popu la r Sc ience , December

1995 , p . 31 .

Yeap le , Jud i t h Anne . "Bu i l d i ng B locks G row Up . " Popu la r Sc ience ,

June 1991 , pp . 80 -82 . 108 .

Documents

Penauk Assigment - About Block