Concrete #1.pptx

Concrete Ingredients
By:
Rizwan Ullah
Chapter #1
Department of Civil Technology
GCT Peshawar

Concrete
Introduction:
 Concrete is a composite material that consists essentially of a binding
medium within which are embedded particles or fragments of aggregate.
 Concrete is an artificial stone like material used for constructional purpose
of different type of engineering structures.
 It is made by mixing Portland cement with sand, coarse aggregate, and
water.
 The most widely used construction material in world is concrete. According
to several researchers man consumes no material in such a tremendous
amount except water.
 Today, the rate at which concrete is used is much higher than it was 40 years
ago.
 It is estimated that the present consumption of concrete in the world is of the
order of 20 to 35 billion metric tonnes every year.

Why concrete is the most widely used engineering material?
First Reason:
Concrete possesses excellent resistance to water. Unlike wood and ordinary
steel, the ability of concrete to withstand the action of water without serious
deterioration makes it an ideal material for structures to control, store and
transport water.

Second Reason:
The second reason for the widespread use of concrete is the ease with which
structural concrete elements can be formed into a variety of shapes and size.
Molding property of concrete is due to it plastic consistency

Third Reason:
The third reason for the popularity of concrete with engineers is that it is
usually the cheapest and most readily available material. The principal
components for concrete aggregate, water and Portland cement are commonly
available all over the world, and having relatively low cost.

Concrete Ingredients
Concrete Mix
Binding
Materials(Cement)
Aggregates
(Fine & Coarse)
Water

Binding materials (Cement)
Introduction:
 Cement is a finely pulverized, dry material that by itself is not a binder but
develops the binding property as a result of hydration (i.e., from chemical
reactions between cement minerals and water).
 Cement produce water resisting products as a result of hydration reactions
with water.
 Calcination of Gypsum (CaSO4·2H2O) or calcium carbonate(CaCO3) is
non-hydraulic because its hydration products are not resistant to water.
 Mostly Portland cement are used in concrete mix.

Portland Cement
Definition:
According to (ASTM C 150) Portland cement are hydraulic cement produced
by pulverizing clinkers consisting essentially of hydraulic calcium silicates, and
a small amount of one or more forms of calcium sulfate as an addition. Clinkers
are 5mm to 25mm-diameter nodules that is produced when a raw mixture of
predetermined composition is heated to high temperatures.

Cement Raw Materials
The fundamental raw materials for clinker production are:
Compound Name Formula
Lime CaO
Silica SiO2
Alumina Al2O3
Iron Oxide Fe2O3

Composition of Portland cement
Chemically Portland cement are composed of:
Compound Name Formula %age
Tricalcium silicate 3CaO.SiO2 50
Dicalcium silicate 2CaO.SiO2 25
Tricalcium Aluminate 3CaO.Al2O3 10
Tetracalcium
aluminoferrite
4CaO.Al2O3.Fe2O3 10
Gypsum CaSO4. 2H2O 1 to 5

Manufacturing of Portland cement
Manufacturing
of Portland
cement
Dry Process Wet Process

Manufacturing of Portland Cement by Dry Process Flow
Chart

Manufacturing of Portland Cement by Dry Process

Manufacturing of Portland Cement by wet Process Flow
Chart

Manufacturing of Portland Cement by Wet Process

Types Of Cements
Ordinary Portland Cement Type I (OPC):
Ordinary Portland cement is the most widely used type of cement which is
suitable for all general concrete construction. It is most widely produced and
used type of cement around the world. Today use of this cement is about 90%
of the total cement. The name Portland cement was given by joseph aspadin in
1824 due to its similarity in colour and quality when hardened with Portland
stone.

Types Of Cements
Quick Setting Cement (Type-11) :
This type of cement sets very quickly. It used where quick setting is required.
Its initial setting time is 5 minutes and final setting time is 30 minutes. It cannot
be used in normal construction projects but is used in special conditions such as
construction in running water.
Phenomenon of Quick setting cement:
The cement clinkers are grinded with aluminium Sulphate(Al2SO4)3, which
accelerates the setting time of cement. aluminium Sulphate is used as
accelerating additive in the dosage range of 1% to 3% by weight of cement
clinkers . The mechanism of function of aluminium Sulphate is that it increases
the rate of hydration of tricalcium silicate (C3S) and tricalcium aluminate
(C3A) phases of cement, thereby providing earlier heat evolution and strength
development. It acts as a catalyst in the hydration of tricalcium silicate (C3S)
and tricalcium aluminate (C3A).

Types Of Cements
Rapid Hardening Cement (Type III):
Rapid hardening cement attains high strength in early days. it is used in
concrete where formworks are removed at an early stage. This cement has
increased lime content and contains higher C3S content and finer grinding
which gives greater strength development than OPC at an early stage. RHC
should not be used in large structures and in area where temperature is high.
Low Heat Portland Cement (Type IV):
These cement are developed in USA for use in large gravity dams. It has low
heat of hydration due to lower content of C3S and C3A. There is a slow
development of strength than OPC, but the ultimate strength is unaffected.

Types Of Cements
Sulphate Resisting Cement (Type V):
Sulphate Resisting Cement is a type of Portland Cement in which the amount of
tricalcium aluminate (C3A) is restricted to lower than 5% and (2C 3A +C4AF)
lower than 25%, which reduces the formation of sulphate salts. The reduction
of sulphate salts lowers the possibility of sulphate attack on the concrete.

Types Of Cements
White Portland Cement (WPC):
WPC are similar to OPC in all aspects except its high degree of whiteness.
WPC can be made in types I, II, III,V cement. WPC can be obtained by
reducing the content of oxides which make the cement color gray or slightly
brown. Manufacturing process has also affect on cement color.

Types Of Cements
Blast Furnace Cement :
Blast furnace cement can be produce by intergrinding of OPC clinker and
granulated blast furnace slag. These cement has good workability like ordinary
Portland cement. BFC has more resistance to sea water and other chemical
agent then OPC. Its 90 days strength is less then OPC.
Note: Blast furnace slag is a byproduct formed to remove nonessential
elements from the production of iron and steel.

Types Of Cements
Colored Cement:
Various colored cements are used for architectural purposes. Different suitable
pigments are used to impart desired color. Pigment should be inert and durable
under sun light and weather.

Types Of Cements
High Alumina Cement (HAC):
HAC is also known as aluminous cement. Because of high contents of Alumina
these cement can also be used as a rapid hardening cement.

Types Of Cements
Expanding Cement:
Expansive cement, when blended with water, is a particular type of cement,
forms a paste that tends to expand volume to a considerably higher degree than
cement paste from Portland after setting. The expansion of the cement mortar or
concrete is reimbursed for the shrinkage losses. In this type of cement two types
of clinker are used. First, clay and lime stone are heated and clinkers are formed
in the next batch lime stone, calcium Sulphate (CaSO4) and bauxite are heated
together where sulfoaluminate clinkers are formed. These two clinkers are
grounded together to form expansive cement. Sulfoaluminate expands in
volume when water added to this cement.

Portland Cement Testing
Introduction:
The quality of cement is vital for the production of good concrete. A number of
tests are performed on cement in the plant laboratory to insure that the cement
is of the desired quality and that it conforms to the requirements of the relevant
national standards. It is also desirable for the purchaser to make periodic
acceptance tests or to examine the properties of cement to be used for some
special purpose. Some of the quality test performed on cement are as follow:
(1) Fineness test (2) Tensile strength
(3) Setting time test (4) Consistency test
(5) Soundness test (6) Compressive strength

Fineness of Hydraulic Cement (ASTM C 184-83)
Introduction:
The degree of fineness of cement is a measure of the mean size of the particles
in cement. The rate of hydration and resultant development of strength depends
upon the fineness of cement. The finer cement has quicker action with water
and gains early strength. It's ultimate strength remains unaffected.
However the shrinkage and cracking of cement will increase with fineness of
cement.

Fineness of Hydraulic Cement by #100 or #200 Sieve
Scope:
This test method covers determination of the finesses of hydraulic cement by
means of the 150 µm (No.100) and 75µm (No.200) sieves.
Apparatus:
(1) Sieve #100 or #200
(2) Weighing balance
(3) Stop watch
(4) Cleaning brush
(5) Pan &cover for sieve

Fineness of Hydraulic Cement by #100 or #200 Sieve
Procedure:
 Place 50-gram sample of the cement on the clean, dry (No.100) or (No.200)
sieve with the pan attached
 Place the assembly in the sieve shaker and shake it for period of 15 minute.
 Carefully open the set and transfer the residue on the sieve to a white clean
paper, and record the weight.
 Calculate the percentage residue.
 Specifications requires that %retained on sieve (No.200) Shall not exceed
22% and on sieve (No.100) not more than 10%.
wt. of residue
50
x 100

Normal Consistency of Hydraulic Cement
ASTM ( C 187-86)
Scope:
This test method cover the determination of the normal consistency of
hydraulic cement. That is by determining the amount of water required to
prepare cement pastes for Initial and final setting time.
Apparatus:
 weighing devices
 Glass graduates (200 or 250) ml capacity.
 Vicat apparatus with the plunger end, 10 mm in dia.
 Electrical mixer , trowel and containers.

ASTM ( C 187-86)
Procedure:
 Prepare the mixer.
 Place all the mixing water in the bowl.
 Add the cement to the water.
 Allow it for 30 second to absorb water.
 Start the mixer at low speed for 30 second.
 Stop for (15 second) and make sure no materials have collected on the sides
of the bowel.
 Start mixing at medium speed for (1 min).
 Quickly form the cement paste into the approximate shape of a ball with
gloved hands.

ASTM ( C 187-86)
Procedure:
 Putting hand at (15cm) distance, throw the cement paste ball from hand to
hand six times.
 Press the ball into the larger end of the conical ring, completely fill the ring
with paste.
 Remove the excess at the larger end by a single movement of the palm of the
hand. Place the ring on its larger end on the base of the plate of Vicat
apparatus.
 Slice off the excess paste at the smaller end at the top of the ring by a single
sharp- ended trowel and smooth the top. (Take care not to compress the
paste).
 Center the paste under the plunger end which shall be brought in contact with
the surface of the paste, and tighten the set-screw.

ASTM ( C 187-86)
Procedure:
 Set the movable indicator to the upper zero mark of the scale or take an
initial reading, and release the rod immediately. This must not exceed 30
seconds after completion of mixing.
 The paste shall be of normal consistency when the rod settles to a point
10±1mm below the original surface in 30 seconds after being released.
 Make trial paste with varying percentages of water until the normal
consistency is obtained. Make each trial with fresh cement.
 Prepare a table data.

Initial and Final Time of Setting of Cement
(ASTM C191-08)
Scope:
This test covers determination of the time of Setting of cement by means
of the Vicat needle.
Apparatus:
 weighing devices
 Glass graduates (200 or 250) ml capacity.
 Vicat apparatus with the needle end, 1 mm in diameter.

Initial and Final Time of Setting of Cement (ASTM C191-08)
Procedure:
 Weigh (650) gram cement.
 Prepare amount of water as to that calculated in normal consistency test.
 Prepare cement paste adopting the method used for paste preparation in
consistency test.
 Allow the time of setting specimen to remain in the moist cabinet for 30 minutes
after molding without being disturbed. Determine the Penetration of the 1mm
needle at this time and every (15) minutes until a penetration of 25mm or less is
obtained.
 To read the penetration, lower the needle of Vicat Apparatus until it touches the
surface of the cement paste. Tighten the screw and take an initial reading.
Release the set screw and allow the needle to settle for 30 seconds, and then take
the reading to determine the penetration.
 Note that no penetration shall be made closer than (5mm) from any previous
penetration and no penetration shall be made closer than (10mm) from the inside
of the mold.

Initial and Final Time of Setting of Cement
(ASTM C191-08)
Calculation:
 [(H-E)/(C-D) x ( C -25)] + E
 where:
 E = time in minutes of last penetration greater than 25 mm,
 H = time in minutes of first penetration less than 25 mm,
 C = penetration reading at time E, and
 D = penetration reading at time H
Note:
 According to ASTM C150:
 Initial time of setting, not less than 45 min.
 Final time of setting, not more than 375 min.

Compressive Strength of Hydraulic Cement Mortar Using
50 mm Cube Specimens (ASTM C109-88 )
Scope:
This test method covers determination of the compressive strength of
cement mortar using 2 inch ( 50 mm ) cube specimens.
Apparatus:
 Weights and weighing device.
 Glass Graduate.
 Specimen molds: nine cube molds of (50mm) side.
 Mixer.
 Cube vibrating machine or tamping rod.
 Scoop and trowel.
 Testing machine.

Compressive Strength of Hydraulic Cement Mortars
Using 50 mm Cube Specimens (ASTM C109-88 )
Material:
Graded standard sand should be used with cement in the proportion 1 Cement :
2.75 Sand by weight. Use water to cement ratio of 0.485 for all Portland
cements and 0.460 for all air- entraining Portland cements.
Procedure:
 Weigh (300) gm of cement and Prepare the corresponding weights of
standard sand and water.
 Place all the mixing water in the bowl of mixer machine.
 Add the cement to the water, then start the mixer and mix at the low speed
(140 ± 5 r/ min) for (30 s).
 Add the entire quantity of sand slowly over a (30 s) period , while mixing at
slow speed.

Using 50 mm Cube Specimens (ASTM C109-88 )
Procedure:
 Stop the mixer, change to medium speed (285 +10 r/min) and mix for 30s.
 Stop the mixer and let the mortar stand for 1.5 min . During the first (15 s)
of this interval, quickly scrape down into the batch any mortar that may have
collected on the side of the bowl.
 Finish by mixing for (1min) at medium speed.
 Thinly cover the interior faces of the specimen molds with oil.
 Start molding the specimens within a total time of not more than 2.5 min
after completion of mixing.
 Place a layer of mortar about 25 mm (half the depth of the mold ) in all the
cube specimens.
 Tamp the mortar in each cube 32 times (4x8) , about 4 rounds , each round
to be at right angles to the other.
 The 4 rounds of taming shall be completed in one cube before going to the
next.

Using 50 mm Cube Specimens
(ASTM C109-88 )
Procedure:
 When the tamping of the first layer in all cubes is completed , fill the molds
with the remaining mortar and tamp as specified for the first layer.
 Cut off the mortar to a plane surface with a straight edge.
 Keep the molds in a moist room for 20-24 hours then open them and keep
the specimens in a water basin for a week.
 After 7 days (+ 3 hours) , take the specimens out of the basin, dry them with
a clean cloth , put them, one after the other, in the testing machine.
 The cubes must be put on one side , using extra steel plates up and down the
specimen.
 When failure, record load and the compressive strength.

Tensile Strength of Cement Mortar
(ASTM C 190-85 )
Scope:
This test method covers the determination of the tensile strength of cement
mortar employing the Briquet specimens.
Apparatus:
 weighing device.
 Tools and containers for mixing.
 Briquet molds.
 Water basin.
 Testing Machine.

(ASTM C 190-85 )
Procedure:
 The proportions of materials for the standard mortar shall be 1 part of
cement to 3 parts standard sand by weight.
 For making 3 briquets, prepare 300 gm of cement with 3x300 = 900 gm of
standard sand.
 The percentage of water used in the standard mortar shall depend upon the
percentage of water required to produce a neat cement paste of normal
consistency from the same sample of cement as in table (1).

(ASTM C 190-85 )
Procedure:

Tensile Strength of Cement Mortar (ASTM C 190-85 )
Procedure:
 Mix dry cement with dry sand and make a crater in the middle, then pour
water in the crater, and turn the material on the outer edge into the crater
within 30 seconds by the aid of a trowel.
 After an additional interval of 30 seconds for the absorption of the water,
mix thoroughly for 1.5 minutes.
 Prepare Briquet molds, clean and thinly covered with a film of mineral oil
Fill the molds heaping full without compacting, then press the mortar in,
firmly with the thumbs, applying the force 12 times to each Briquet at points
to include the entire surface.
 Heap the mortar above the mold and smooth it off with a trowel
 Keep all test specimens in moist room for 24 hours
 Open molds and immerse the specimens in water in the storage tank. Keep
them in water for a week
 Take specimens out of water, dry with clean cloth then fix them in the
testing machine (one after the other).

Soundness Test of Cement (ASTM C191-82)
Introduction:
It is essential that once the cement paste set then no large change in volume
shall occur. The appreciable expansion, could result in destruction of the
hardened cement paste. Such expansion may occur due to presence of free lime,
magnesia and calcium Sulphate in cement.
Apparatus:
 Le Chatelier apparatus
 Weighing balance

Soundness Test of Cement
(ASTM C191-82)
Introduction:
 Prepare cement paste of normal consistency.
 Fill the Le Chatelier apparatus mold with the paste while placing base plate
down the mold.
 Place another plate on the top of the mold and store the assembly in water
for 24 hours.
 After 24 hours put the assembly in water at a temperature of 80 degree
centigrade for a period of 3 hours.
 Before and after heating measure space between both the handle of le
Chatelier apparatus and find the difference, the difference must not be more
then 10mm.

AGGREGATES
Introduction:
 Granular material, such as sand, gravel, crushed stone, or iron blast-furnace
slag, used with a cementing medium to form hydraulic-cement concrete or
mortar.
 Aggregates are inert and inexpensive material dispersed throughout the
cement paste so as to produce a large volume of concrete.
 The fine and coarse aggregates generally occupy 60% to 75% of the
concrete volume (70% to 85% by mass) and strongly influence the
concrete’s freshly mixed and hardened properties, mixture proportions, and
economy.

Classification of Aggregate
Aggregates may be classified :
 According to formation:
 Natural Aggregate
 Artificial aggregate
 According to Size :
 Fine aggregate
 Coarse aggregate

Classification of Aggregate (According to formation)
Natural Aggregate:
Natural aggregate are formed by process of weathering and abrasion, or by
artificially crushing a large parent mass (rock). These parent rocks may:
 Igneous Rocks: These are the rocks which are formed by cooling and
solidification of molten materials on the earth or beneath the earth surface. A
bulk amount of concrete aggregate are obtained from igneous rocks.
 Sedimentary Rocks: Rocks which are formed through the deposition and
solidification of sediment, especially sediment transported by water.
 Metamorphic rocks: Rocks which are formed as result of change in original
rock due to high temperature and pressure are named as metamorphic rock.

Classification of Aggregate (According to formation)
Artificial aggregate:
For concrete with special properties we need to produce aggregates artificially
which is termed as artificial aggregates. Some of its types are as follow:
 Light weight aggregates: According to ASTM C 125 aggregates having bulk
density less then 1120 kilogram per meter cube is called light weight
aggregate.
 Heavy weight aggregate: These are the aggregate with bulk density about
2900 kg per cubic meter to 6100 kg per cubic meter. Primarily used for
making nuclear radiation shields.
 Blast Furnace aggregates: these are the aggregate which are formed of blast
furnace slag.

Classification of Aggregate (According to Size)
Fine Aggregate:
As per ASTM C125 Portion of aggregate passing through 4.75-mm (#4) sieve
and retained on the 75-μm (# 200) sieve is termed as fine aggregate.
Coarse Aggregate:
As per ASTM C125 Portion of aggregate that retained on the 4.75-mm (#4)
sieve.

Classification of Aggregate (According to Material)
Types of fine aggregates:
 Sand: it is categorized as fine aggregate which is formed as a result of
disintegration of rocks. It consist of small particles of silica. It reduces
shrinkage effect in concrete. On the base of source sand is classified in to pit
sand, river sand and sea sand.
 Stone Dust: it is a byproduct of crushing machine which produce during
stone crushing for aggregate production.
 Cinder: Powder obtained by finely grinding burnt coal or wood can be used
as fine aggregate
 Surkhi: Surkhi is called as brick-dust in England. Surkhi is used as a
substitute for sand for concrete and mortar, and has almost the same function
as of sand.

Classification of Aggregate (According to Material)
Types of coarse aggregates:
 Gravel: Natural aggregates obtained from sea shore, river bed river bank.
 Crushed Stone : obtained artificially or naturally by crushing rocks.
 Brick Ballast: obtained by crushing over burnt bricks in aggregate size

Bulking of sand
 Bulking of sand means increase in sand volume due to presence of water
film pushing the sand particles apart.
 This increase occur with increase in water content up to certain limit.
 The volume may increase up to 20% to 40% when moisture content is 5 to
10 percent.
 Beyond 10% water, film starts to break and volume starts to reduce.

Sand Bulking Test
Objective:
To find sand bulking value
Apparatus:
 Graduated Cylinder
 Steel Rod (6mm Diameter)
 Steel ruler
 Sand Sample
 Container

Sand Bulking Test
Procedure:
 Take the sample and fill the cylinder up to 200 ml.
 To make the necessary correction use the steel ruler but don’t compact the
sand.
 Transfer that sample to a container.
 Refill the measuring cylinder with 100ml water.
 Now refill the sand into measuring cylinder and stir it well with the help of
steel rod.
 Allow it to settle for some time.
 Note the new height of sand.

Sand Bulking Test
Procedure:
 Repeat the procedure for two more sample.
Calculation:
Bulking of sand =
𝟐𝟎𝟎 −𝒀
𝒀
x 100

Sieve Analysis Of Fine Aggregates (ASTM C-136)
Scope: This method covers the determination of the particle size distribution of
fine aggregate by sieving.
Materials: Dry sand about 500 gram
Apparatus:
• Digital balance
• Containers to carry the sample.
• Oven.
• Mechanical Sieve shaker.
• Sieve Set:-For fine aggregate
[ #4 , 8, 16 , 30, 50,100]
In addition to a pan and a cover for each set.

Procedure:
• Dry the sample to constant mass at a temperature of 110 + 5°C (230 6 9°F).
• Determine the empty weight for each sieve and record.
• Nest the sieve in order of decreasing size of opening from top to bottom
place the sample on the top sieve.
• Agitate (shake) the sieve by placing the set on the mechanical shaker for
10min.
• Open the set of sieve carefully so that no loosing of materials is expected.
• Weigh each sieve with the residue record its weight.
• Tabulate your data in a suitable shape.
• Make sure that the summation of the residue weights equals to the original
sample weight with a difference not more than 1% of the original weight.

Sieve No Weight Retained
(gram)
%age Retained Cumulative
%age passed
Cumulative
%age retained
4 0 0 100 0
8 0 0 100 0
16 18 3 97 3
30 271 45.16 51.84 48.16
50 243 40.5 11.34 88.66
100 63 10.5 0.84 99.16
200
𝐹𝑖𝑛𝑒𝑛𝑒𝑠𝑠 𝑚𝑜𝑑𝑢𝑙𝑢s =
𝑆𝑢𝑚 𝑜𝑓 𝑐𝑜𝑚𝑢𝑙𝑎𝑡𝑖𝑣𝑒 %𝑎𝑔𝑒 𝑟𝑒𝑡𝑎𝑖𝑛𝑒𝑑
100

Type of sand Fineness modulus range
Fine sand 2.2 – 2.6
Medium sand 2.6 – 2.9
Coarse sand 2.9 – 3.2

Sieve Analysis Of Coarse Aggregates (ASTM C-136)
Scope: This method covers the determination of the particle size distribution of
coarse aggregate by sieving.
Materials: Coarse aggregate
Apparatus:
• Balance: Digital balance for weighing
• Containers to carry the sample.
• Oven.
• Mechanical Sieve shaker.
• Sieve Set:-For coarse aggregate
For coarse aggregate [37.5mm , 19mm ,9.5mm, No.4 , No.8]
In addition to a pan and a cover for each set.
.

The size of the test sample of coarse aggregate shall conform with the
following
Nominal Maximum
Size,
Square Openings
(mm)
Nominal Maximum
Size,
Square Openings,
(in)
Test Sample Size in
kg
Test Sample Size in
lb
9.5 3/8 1 2
12.5 1/2 2 4
19 3/4 5 11
25 1 10 22
37.5 1.5 15 33
50 2 20 44
63 2.5 35 77
75 3 60 130
90 3.5 100 220

Sieve Analysis Of Coarse Aggregates
Procedure:
• Put the sample in the oven at 110°C.
• Determine the empty weight for each sieve and record.
• Nest the sieve in order of decreasing size of opening from top to bottom
place the sample on the top sieve.
• Agitate (shake) the sieve by placing the set on the mechanical shaker for
10min.
• Open the set of sieve carefully so that no loosing of materials is expected.
• Weigh each sieve with the residue record its weight.
• Tabulate your data in a suitable shape.
• Make sure that the summation of the residue weights equals to the original
sample weight with a difference not more than 1% of the original weight.

Aggregates Properties(testing)
Crushing strength of aggregate:
 The aggregate crushing value provides a relative measure of resistance to
crushing under a gradually applied compressive load.
 It is one of the major mechanical property of aggregate which enable it to
withstand against the crushing loads acting upon it, like load on aggregates in
road due to moving vehicle.
 With this the aggregates should also provide sufficient resistance to
crushing under the roller during construction.

AGGREGATE CRUSHING STRENGTH TEST
(IS-2386 Part- 4 )
Scope:
This test evaluates the ability of the Aggregates used in road construction to
withstand the stresses induced by moving vehicles in the form of crushing.
Apparatus:
1. A steel cylinder of internal diameter 15.2 cm
2. A square base plate, plunger having a piston diameter of 15 cm .
3. A cylindrical measure of internal diameter of 11.5 and height 18 cm
4. Steel tamping rod having diameter of 1.6 cm length 45 to 60 cm.
5. Balance of capacity 3 kg with accuracy up to 1 gm
6. Compression testing machine capable of applying load of 40 tonnes at a
loading rate of 4 tonnes per minute

(IS-2386 Part- 4 )
Procedure:
 Pass the aggregate in surface dry condition from 12.5 mm and retain it on 10
mm.
 Fill the cylindrical measure by the test sample in three layers of
approximately equal depth, tamp each layer 25 by using tamping rod.
 Level the aggregate surface in measure and weigh it. Let that be W1.
 place the cylinder on the base plate of test apparatus and transfer one third of
the sample from cylindrical measure and tamp it for 25 blows.
 Fill the cylinder using same procedure for other two layers too.
 Place plunger on the sample surface and position it in the machine.
 Apply load through the plunger at a uniform rate of 4 tonnes per minute until
the load is 40 tonnes.
 Remove the piston and sieve the aggregate through 2.36 mm IS.
 Collect the material which pass through 2.36 mm and weigh it. Let that be
W2.

(IS-2386 Part- 4 )
Procedure:
 Repeat the procedure for two more sample.
 Use the following formula :
Crushing percentage =
𝑊2
𝑊1
x 100

Aggregates Properties(testing)
Toughness of Aggregate:
Toughness is the property of material due to which it resist against failure due
to impact. Due to moving loads the aggregates are subjected to impact and
there is possibility of stones breaking into smaller pieces. A test designed to
evaluate the toughness of stones i.e., the resistance of the stones to fracture
under repeated impacts called “Impact test on aggregate”.

IMPACT TEST (IS-2386 Part IV)
Scope:
This test evaluate the ability of aggregate against impact load.
Apparatus:
 Impact testing machine: The machine consists of a metal base. A detachable
cylindrical steel cup of internal diameter 10.2cm and depth 5cm. A metal
hammer of weight between 13.5 to 14Kg, 10 cm in diameter and 5cm long.
An arrangement for raising the hammer and allow it to fall freely between
vertical guides from a height of 38cm on the test sample in the cup.
 A cylindrical metal measure having 7.5cm and depth of 5cm for measuring
aggregates.
 A tamping rod of circular cross section, lcm in diameter and 23cm long,
rounded at one end.

Apparatus:
 I.S. sieve of sizes 12.5mm (1/2 in), 9.5mm (3/8 inch) and 2.36 (#8)
 Balance of capacity not less than 500gm to weigh accurate up to 0.01gm.

Procedure:
 Take sample consisting of aggregate passing through 12.5mm sieve and
retained on 10mm sieve.
 Oven dry the sample for a period of 4 hours at a temperature of 100 C to 110
C.
 Fill the cylindrical measure in three layers while compacting each layer for
25 blows.
 Cutoff the over flow of aggregate.
 Weigh the aggregate in the measure and transfer it in the cup of machine.
Then tamp it for 25 time.
 Rise the hammer until its lower surface is 38cm above the top surface of
aggregate and allow it to fall freely on the aggregate.
 Repeat the free fall of hammer for 15 time.
 Remove the aggregate from cup and sieve it through 2.36mm sieve.

Procedure:
 Weigh the friction pass carefully.
 Let weight of oven dry sample is W1, weight of crushed portion is W2
So
Percent of crushed portion =
𝑊2
𝑊1
x 100

Hardness of Aggregate:
The property of a aggregate due to which it resist against wearing of its surface.
It is an essentially property for road aggregates especially when used in wearing
coarse. Due to the movements of traffic, the road stones used in the surfacing
course are subjected to wearing actions at the top. When traffic moves on the
road the soil particle (sand) which comes between the wheel and road surface
causes abrasion on the road stone. In order to determine resistance of aggregate
against wearing a test is performed which is named as “Los Angeles abrasion
test”.
LOS ANGELES ABRASION TEST(ASTM C-131-3)

Scope:
This test method covers a procedure for testing sizes of coarse aggregate
smaller than 37.5 mm (1.5 in.) for resistance to degradation using the Los
Angeles testing machine.
Apparatus:
 Los Angeles machine.
 Sieve with 1.7mm (#12) opening.
 Weighting Balance of O.1gm accuracy.

Table for grading, charging and mass of materials
Grade Number od sphere(charge) Mass of materials
(gram)
A 12 5000 ± 25
B 11 4584 ±
C 8 3330 ± 20
D 6 2500 ± 15

Procedure:
 Clean and dry aggregate sample confirming to one of the grading A to D.
 Take aggregate weighing 5kg for grade A , B , C and D and
 Place the sample in the cylinder.
 Choose abrasive charge in accordance from table and place it with sample in
cylinder.
 Fix the cover to make it dust free.
 Start the machine to rotate with speed of 30 to 33 rpm for revolution of 500
for A B C and D
 Discharge whole material from machine.
 Sieve the materials through a sieve larger then 1.70mm sieve and then sieve
the passing materials through 1.70mm sieve.
 Let weight of original sample is W1
 Weight of material retained on sieve 1.70mm is W2.

Formula & Value:
Los angeles abrasion value% =
W1 −W2
W1
x 100

Aggregate Specific Gravity
Specific gravity:
Natural aggregates have pores which may be permeable or impermeable.
Porosity value is different for different rocks, like up to 2 percent is common
for igneous rocks, 5 percent for dense sedimentary rocks and 10 to 40 percent
for vary porous rocks like lime stone. For the purpose of mix proportion it is
necessary to determine the space occupied by aggregate particles and pores in
it, which can be find out by determining specific gravity of aggregate.
According to ASTM C 127-07. “SPECIFIC GRAVITY” is the ratio of specific
weight of material(aggregate) to the specific weight of water.
Specific gravity =
𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙
𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟

Aggregate Specific Gravity
Specific gravity Types:
Absolute Specific Gravity:
Ratio of the volume of solid material excluding all pores to the mass of same
volume of water.
Apparent Specific Gravity:
Ratio of volume of solid material including non permeable pores to the mass of
same volume of water.

Specific Gravity Test Of Coarse Aggregate
(ASTM C 127-07)
Scope:
This test method covers the determination of the average density of a quantity
of coarse aggregate particles (not including the volume of voids between the
particles), the relative density (specific gravity), and the absorption of the
coarse aggregate.
Apparatus:
 Weighing balance
 Sample Container
 Water Tank
 Sieve # 4
 Oven

Specific Gravity Test Of Coarse Aggregate
(Designation: C 127)
Procedure:
 Dry the test sample in the oven to constant mass at a temperature of 110 + 5 °C,
cool in air at room temperature for 1 to 3 h for test samples of 37.5-mm nominal
maximum size, or longer for larger sizes until the aggregate has cooled to a
temperature that is comfortable to handle (approximately 50 °C).
 Then immerse the aggregate in water at room temperature for a period of
24 ± 4 h.
 Remove the test sample from the water and roll it in a large absorbent cloth until
all visible films of water are removed. Find weight of aggregate in SSD form.
 After determining the mass in air, immediately place the saturated-surface-dry
test sample in the sample container and determine its apparent mass in water.
 Dry the test sample in the oven to constant mass at a temperature of 110 ± 5 °C,
cool in air at room temperature 1 to 3 h, or until the aggregate has cooled to a
temperature that is comfortable to handle (approximately 50 °C), and determine
the mass.

Specific Gravity Test Of Coarse Aggregate(ASTM C 127)
Calculation:
1. Relative density( specific gravity)(OD) =
𝑨
𝑩−𝑪
Where
A = mass of oven-dry test sample in air.
B = mass of saturated-surface-dry test sample in air.
C = apparent mass of saturated test sample in water.
2. Relative Density (Specific Gravity) (SSD) =
𝐵
𝑩−𝑪
3. Apparent relative density ( apparent specific gravity) =
𝐴
A−𝑪
4. Absorption (%) =
𝐵 −𝐴
𝐴
x100

Mixing water for concrete
 Water is required for mixing with cement powder to form a paste which hold the
aggregates together like glue.
 Almost any natural water that is drinkable and has no pronounced taste or odor
can be used as mixing water for making concrete.
 Water that are not suitable for drinking may also be used as mixing water , if
mortar cubes (ASTM C 109) made with it have 7 days strength to at least 90%
to the specimens made with drinkable or distilled water.

Admixture
 Admixtures are the material other than cement, water, and aggregates which
are used in concrete batch immediately before or after mixing.
 This ingredient is added to modify the mixing, setting, or hardened
properties.
 Note: When the same ingredient is added to a cement during the
manufacturing process, will be additive

Reasons for using admixtures
 To reduce the cost of concrete construction.
 To achieve certain properties in concrete more effectively than by other
means.
 To maintain the quality of concrete during the stages of mixing, transporting,
placing, and curing in ad-verse weather conditions.
 To overcome certain emergencies during concreting operations.

Admixture Types
 Chemical Admixtures:
• Plasticizers (water reducers)
• Retarders
• Accelerators
• Air-entraining Admixtures
• Damp-proofing and Waterproofing Admixtures
• Fungicidal, Germicidal, Insecticidal Admixtures
 Mineral Admixtures:
 Fly Ash
 Silica Fume
 Blast furnace Slag

Chemical Admixtures
Plasticizers (water reducers)
The organic substances or combinations of organic and inorganic substances,
which allow a reduction in water content for the given workability, or give a
higher workability at the same water content, are termed as plasticizing
admixtures.
Some basic plasticizer are as follow:
lignosulphonates and their modifications and derivatives, salts of sulphonates
hydrocarbons
Non ionic surfactants, such as polyglycol esters, acid of hydroxylated
carboxylic acids and their modifications and derivatives

Chemical Admixtures
 Retarders:
Retarder are admixtures that slows down the chemical process of hydration so
that concrete remains plastic and workable for a longer time than concrete
without the retarder.
• Retarders are used to overcome the accelerating effect of high temperature
on setting properties of concrete in hot weather concreting.
• Very useful when concrete has to be place in very difficult conditions and
delay may occur in transporting and placing.
• Gypsum and Calcium Sulphate are well known retarders.
Other examples are: starches, cellulose products, sugars, acids or salts of acids

Chemical Admixtures
 Accelerators:
• Accelerating admixtures are added to concrete to increase the rate of early
strength development
• Reduce the required period of curing
• In the emergency repair work
• Permit earlier removal of formwork

Chemical Admixtures
 Air-entraining Admixtures:
• Admixtures which produces minute air bubbles in concrete are termed as
air-entraining admixtures.
• Minute spherical bubbles of size ranging from 5 microns to 80 microns
distributed evenly in the entire mass of concrete.
• These incorporated millions air bubbles act as flexible ball bearing which
modify the properties of plastic concrete regarding workability, segregation,
bleeding and finishing quality of concrete.
• It also modifies the properties of hardened concrete regarding its resistance
to frost action and permeability.

Mineral Admixtures
 Fly Ash:
Fly ash is finely divided residue resulting from the combustion of powdered
coal and transported by the flue gases and collected by;
• Electrostatic
• Precipitator
Fly ash is the most widely used pozzolanic material all over the world.
Pozzolans are a broad class of siliceous or siliceous and aluminous
materials which, in themselves, possess little or no cementitious value but
which will, in finely divided form and in the presence of water, react
chemically with calcium hydroxide at ordinary temperature to form compounds
possessing cementitious

Mineral Admixtures
Silica Fume:
It is an ultrafine powder collected as a by-product of the silicon and ferrosilicon
alloy production and consists of spherical particles with an average particle
diameter of 150 nm It is highly pozzolanic in nature.
• It increase water demand for concrete.
• Reduce bleeding and permeability of concrete

Admixture Types
 Blast furnace slag:
Blast-furnace slag is a nonmetallic product consisting essentially of silicates
and aluminates of calcium and other bases.
The molten slag is rapidly chilled by quenching (rapid cooling of a work piece)
in water to form a glassy sand like granulated material.
Rice Husk Ash:
Burning rice husk in a controlled manner without causing environmental
pollution.
10% by weight of cement
It greatly enhances the workability and impermeability of concrete.
Reduces large pores and porosity resulting very low permeability.

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