Document 281931

AIM :- To perform water absorption test on given aggregate sample by oven d rying
APPARATUS :Measurin g weights , aggregates immersed in water for 24 hrs , oven .
FORMULA :Water absorption in %
[ ( W1- W3 ) / ( W2- W1 ) ] x 100
Weight of empty container
Weight of soaked aggregate + Weight of container
= W1 = _____ Gm
= W2 = _____ Gm
Weight of oven dried aggregate + Weight of container = W3 = _____ Gm
FIGURE :THEORY :Stones having higher water absorption values are porous
and hence weak . They are generally suitable unless found acceptable based
on crushing and grinding . The sample is weighted on water and the
buoyant weight is found . The aggregate is taken out and weighted after th e
surface is dried . The specific gravity can be calculated by diving dry
weight of aggregate by weight of equal volume of water.
The water absorption is expressed as percentage water absorption in terms
of oven dried weight of aggregate . The specific gravity of rock varies fro m
2.6 to 2.9 . Rock specimen having more than 0.6 percent of water
absorption are considered unsatisfactory values found acceptable based
upon strength tests . However slightly higher value of porosity may be
acceptable for aggregate used in bitumen pavement construction of the
aggregate are otherwise suitable
PROCEDURE :1)About 2 Kg of dry aggregate sample is placed in wire basket and
immersed in water for 24 Hrs.
2) The weight of the sample is taken .
3)The aggregate sample is placed in oven ( 100 – 110 0 C ) for 24 Hrs.
4)After complete drying dry weight of the sample is taken .
5)Percentage of water absorption is calculated .
Weight of empty container
= W1 = _____ Gm
Weight of soaked aggregate + Weight of container
= W2 = _____ Gm
Weight of oven dried aggregate + Weight of container = W3 = _____ Gm
Water absorption in %
[ ( W1- W3 ) / ( W2- W1 ) ] x 100
RESULT :Percentage of water absorption for a given sample of aggregate is found to
be _________ %.
PRECAUTION :1) The aggregate must be immersed properly in water for 24 Hrs .
2)The water from surface of aggregate must be dried .
3)Weight the aggregate carefully in spring balan ce.
DISCUSSION :Rock specimen having more than 0.6 % water absorption
values are considered unsatisfactory unless found acceptable based on
strength test . However slightly higher value of porosity may be acceptable
for aggregate used in bituminous pavement construction if aggregate is
found otherwise suitable.
AIM :- To determine flakiness index of aggregate .
APPARATUS :Aggregate, set of sieves, tray, weight box etc.
FORMULA :flakiness index = [
W ] X 100
w = Weight of aggregateWhere,
W = Weight of aggregate retained
FIGURE :THEORY :The principal shape of Aggregate mass is determine by the
percentage of flaky and elon gated particles contained in it and by its
angularity . The evaluation of shape of particles made of flakiness index
and elongated index and angularity numbers .
The flakiness index of aggregate is the per centage by
weight of aggregate particles whose least dimensional thickness is less
than 0.6 times their mean dimension. The test is applicable to size larger
than 6.3 mm standard thickness is used to guage the thickness of sample .
PROCEDURE :1) The sample of aggregate to b e tested is sieved through a set of sieves and
separated into a specified size ranges.
2) Now to separate the flaky material , the aggregate which pass through
the appropriate elongated slot of thickness guage are found .The width of
the appropriate slot would be 0.6 of the average of the sieve size range.
3) The flaky material passing the appropriate slot from each size range of
test aggregate are added up and let the weight be W1.
4) If the total weight of sample take from different size range is w, the
flakiness index is given by
Flakiness Index = [ W1 / W ] X 100
Weight of
Aggregate passing
appropriate slot (gm)
F. I. = [ w /
X 100
CALCULATION :flakiness index = [
W ] X 100
RESULT :The Flakiness Index of a given aggregate sample is found to be _______ %.
DISCUSSION :Elongated aggregate are less workable , they are also likely to
break under smaller load s than the aggregate which are spherical or cubical
, flakiness index values in excess of 15 % are generally consider
undesirable . If is desirable that flakiness index of aggregate used in road
construction is less than 15 % and normally does not exceed 25 %.
APPLICATION :If the flakiness index is more than the aggregate can take less
loads and are liable to fail under less load . So it is not desirable to use
aggregate of higher flakiness index is permanent .
AIM:- To determine specific gravity of a given aggregate sample by Pycnometer
Pycnometer balance, Weight –box, aggregate
Specific gravity =
(W2-W1) – (W3-W4)
(W2-W1 )
Weight of empty Pycnometer
= W1 gms
Weight of Pycnometer + aggregate
= W2 gms
Weight of Pycnometer + aggregate +Water
= W3 gms
Weight of Pycnometer + Water
= W4 gms
Weight of aggregate
= (W2-W1) gm.
Weight of equal volume of distilled water = (W2-W1) – (W3-W4)
FIGURE :THEORY :Specific gravity is the ratio of the weight of given volume of
dry aggregate to the weight of equal volume of distilled water.
Let (i) Weight of empty Pycnometer
= W1 gms
(ii) Weight of Pycnometer + aggregate
= W2gms
(iii)Weight of Pycnometer + aggregate +Water = W3 gms
(iv)Weight of Pycnometer + Water
= W4 gms
Weight of aggregate
= (W2-W1) gm.
Weight of equal volume of distilled water = (W2-W1) – (W3-W4) gms
(W2-W1 )
Specific gravity =
(W2-W1) – (W3-W4)
PROCEDURE:(1)Make the Pycnometer dry &Weight it with its cap &rin g
(2)Unscrew the cap &Rut 200 gms of aggregate &Weight it
(3)Add water to the top of brass cap. Remove all the trapped dir by pouring
additional water
(4)Dry the Pycnometer & fell it to the top with & weight it
(5)Repeat the Pro cedure
(6)Find the average specific gravity by using formula
Weight of Weight of
aggregates empty
Weight of
(W2) gm
Weight of
(W3) gm
Weight of
(W4) gm
Average specific gravity =
Specific gravity
(W2-W1) – (W3-W4)
RESULT:Average specific gravity is found to be ___________
PRECAUTIONS:(1) Take the weight carefully.
(2) Pycnometer must be dry for use.
(3) There should be no air bubble inside the bottle.
DISCUSSIONS:The value of specific gravity of aggregate is required for
concrete mix design and useful for calculating water content. Stone having
higher water absorptions values are porous and this weaker specific gravity
also indicates strong specimen.
AIM: -
To determine the Flash &Fire point for the sample of bitumen taken.
APPARATUS: Flash point set up, thermometer, heating arrangement etc.
FIGURE:THEORY: This test gives up the indications of the critical temperatur e
at which the suitable precautions should be taken while heating bitumen .
Flash Point:-The temperature at which the volatile material i.e. bitumen
emits vapours and it catches fire momentarily in the form of flash.
Fire Point :-The temperature at which the volatile nature i.e. bitumen emits
vapours get ignited and burns
PROCEDURE: The material is filled up to the mark of filling in the cup
liquid is placed too dose to the cup .All accessories including thermometers
are fixed .The sample is heated at rate of 50to60 0C/min. The first flash as
applied at test 170 C below actual flash point.
The flash point as taken as the temperature reading on the
thermometer at the time of applications of flame that causes bright flash in
the interior of cup. The heating is continuous till the material’s ignited. This
gives the fire point.
- =
i) Flash Point
ii) Fire Point =
DISCUSSION:The bitumen material leaves out volatile at high temperature
depending up on their grades. These volatile catch fire causing a flash. This
condition is very hazardous.
PRECAUTION: If the candle is used as a flame then it should be seen that
flame should not fall in the bitumen, otherwise it would give flame at less
Temperature as wax will catch fir e.
APPLICATION: Bitumen is used in construction of pavements so the flash & fire
point is determined to check for the amount of heating to avoid any
To Determine the impact value of a given a aggregate sample
APPARTAUS:Impact testing machine, aggregates, sieves, weight box, weighing balance
FORMULA:Impact Value = W3 / (W2 – W1) X100
W1 = empty wt of cylinder.
W2= wt of Cylinder + aggregate.
W3= wt of fines passing through 2.25 mm sieve
THEORY: A test designed for to evaluate the toughness of stone or the
resistance of aggregate to fracture under repeated impact is called impact
test. The aggregate impact value indicates relative measur es of resistance of
aggregate to impact, which has different effect then the resistance to
gradually incr easing compression stress. The aggregate impact testing
machine consists of a metal case and a cylindrical cap of internal dia of 10.2
cm and a depth of 5 cm in which the aggregate specimen is placed A
hammer of weight 13.5 to 14 kg having a free fall from height 38 cm is
arran ged to drop through a vertical height.
PROCEDURE: (1)Aggregate specimen passing throu gh 12mm sieve retained on 10mm
sieve is filled in the cylinder in 3 layers by tampin g each other or each layer
by 25 flows and then measures it.
(2)The sample is transferred from balance to cap of the aggregate impacttesting machin e. The metal hammer is raised to a height of 38cm.Above th e
upper surface of the aggregate in the cap and is allowed to fall freely on the
cap specimen After subjected to15blows of metal hammer, the crashed
aggregate is sieved from 2.36 mm sieve and the sieved weight is noted.
OBSERVATION:(1)Weight of empty mould
= W1 =
(2)Weight of mould + aggregate
= W2 =
(3)Weight of tines passing through = W3 =
CALCULATION:Impact Value = W3 / (W2 – W1) X100
RESULT: The impact value of given sample of aggregate found out to be
PRECAUTIONS:(1)The aggregate used should be of good quality.
(2)Hammer should be p roperly handed otherwise it may cause physical
damage or injury.
DISCUSSION:The impact value indicates the relative measurement of
resistance of aggregate to impact, which has a different effect then th e
r istance to gr adually increased compressive stress. The value less then 10
% to 20 % is satisfactory for wads. The aggregates should not have impact
value more then 30 % & if it is used to say to be weaker for base course the
value should not exceed 40%
To Determine California Bearing ratio [CBR] value and sub grade thickness
for compacted soil under given traffic load.
APPARTAUS:CBR apparatus consisting of mould of 150mm dia with a base plate and a
collar, a 50mm dia, gauge for measuring expansion soaking and penetration
This method was originally devised by O. J. Parter, then the
California State Highway, by other authority in USA, notably the US
Corporation Of Engineering. The method combines a load penetration test
perform in a lab. This is probably the most widely used method for the
design of flexible pavement.
The thickness of various elements comprising a p avement is
determine by CBR values. It is a small scale p enetration test in which a
cylindrical plunger 5 mm dia. is pen etrated into a soil mass. The
observation are taken between the penetr ation resistance into a soil mass at
the ratio of 0.05 inch / min [1.25 mm / min ]. The observations are tak en
between the penetration resistance verses the penetration of plunger. The
California Bearin g Ratio is defined as the ratio of test load to the standard
load expressed in percentage
CBR = [Test Load / Standard load ] x 100
WORKING :The CBR test is carried on a compacted soil in a CBR 150
mm dia. and 175 mm height provided with a detachable collar of 50 mm
deep to be kept in the mould during the sp ecimen penetration which
enables a specimen of 1 25 mm deep to be obtained .
The moulding dry density and water content should be same
as it should be maintained during field compaction. To estimate th e worst
moisture condition of the field, the specimen is submerged in water for
about 4 days before testing. Generally CBR value for both soaked and
unsoaked sample and determined both during soaking and penetration the
specimen is carried with equal surcharge weights to estimate the effect of
overlying parameters or particular layer under construction . Each
surcharge weight 147 mm dia with a general hoe of 153 mm in did and
weighing 2.5 kg is considered approximately equivalent to 6.5 cm of
construction . A minimum of two weights are placed as sp ecimen load is
applied on the penetration piston to obtained the penetration of 1.25 mm /
min . The max imum load and penetration is recorded if it occurs for
penetration less than 7 mm.
PROCEDURE :The soil sample approximately 2000 gm is weighted and
transformed in a tray . About 7 % of water of total weight of soil sample is
added in the soil and mix it properly This moisturized sample is compacted
in the CBR in different layers . Each layer is compacted by giving 56 no of
blows by tamp ering rod . After compaction the mould is placed under CBR
testing machine and adjusted properly . The load is applied gradually by
this pressure testing machine and various sets of r eadin g are taken until soil
specimen fails.
OBSERVATIONS:(i) Weight of rammer
(ii) Drop of rammer
(iii) No. Of layers computed =
(iv) Blows per layers
(v) Wt. of empty mould =
(vi)Wt. of mould + compacted soil =
(vii) Volume of mould
(viii)Water content of soil =
(by oven dried method)
(ix) Wt. of empty tray
Plunger Dia
Surcharge Wt.
Test end of specimen = 1 div
Proving ring constant = 1 div =
(KG )
X 100
CALCULATION:(1) For penetration 2.5 mm (corrected) CBR
X 100 =
(2) For penetration 5mm (corrected) % CBR
X 100 =
The sub grade thickness is given by
t =
Sub grade thickness
CBR Value
Wheel Load = 4500 kn
Area of sub grade contact
p = 6.5kg/cm2
RESULT:(1) The CBR value for 2. 5mm penetration is found to be = _______
(2) The CBR value for 5 mm penetration is found to be
= ________
APPLICATION :This test is meant for soils and also carried out on the sub
base and granular base coarse material . The CBR Test values are made use
if an imperial method of flexible pavement design
Grade of load Depth of construction on
in cm
Traffic density No. of commercial
vehicle per day exceeding 3 + loaded
0 - 15
15 - 45
45 - 150
150 - 450
450 - 1500
1500 - 4500
Above 4500
AIM: -
To perform penetration test on the given sample of bitumen
Penetrometer is penetration test apparatus
FIGURE :THEORY :The penetration test determines the hardness and so ftness
of bitumen by measuring the depth of needle in mm to which a standard
loaded needle penetrates vertically 5 sec . The sample is maintained at 250
PROCEDURE :A bitumen sample of depth about 15mm. is taken into a
container . The sample is arranged on the instrument that the standard
needle just touches the surface of the bitumen sample . The dial is set to
zero . Now initial reading is taken and the needle is released for 5 sec. and
the final reading is taken on the dial gauge . Three reading should be tak en.
Each test should be performed for at least 10 min apart from each other and
the mean value is taken .
Initial Reading
1/10 mm
Final Reading
1/10 mm
Differ ence
1/10 mm
RESULT :The average penetration of the given sample (bitumen ) is
found to be _____________ mm.
PRECAUTION :1)The needle should be cleared properly before taking nex t reading .
2)The needle should just touch the bitumen.
3)Minimum 10 min should be maintained between the reading .
APPLICATION :It is the most adopted test for bitumen depending on climate
condition , type of construction Various bitumen used in permanent constant range
between 20 to 25 .
AIM :- To determine the crushing value of aggregate by aggregate crushed test
APPARATUS :Steel cylinder of 152 cm diameter with a base plate and and plunger
compression testing machine , sieves , aggregate etc.
% Crushing Value = [W3 / (W2 – W1 )] x 100
W1 = Weight of empty mould
= __________ Kg
W2 = Weight of mould + Aggregate
= __________ Kg
W3 = Weight of pan + crushed aggregate = ___________ Kg
THEORY :The strength of coarse aggregate may be determine by
aggregate crushing strength test . The aggregate crushing value provides a
relative measure resistance to the crushing order .Gradually applied
compression load , to achieve a high resistance to crushing or low aggregate
crushing value are performed .
PROCEDURE :Dry aggregate passin g through 12.5 mm sieve and retained
on 10 mm sieve is filled in the cylinder in three layers . Each layer being
compacted b y 25 blows of tamping rod of diameter 16 mm.Then the
plunger is placed on the top of the specimen and a load of 40 ton es/ min is
applied b y the compression machine .The crushed aggregate are removed
and sieved in 2.35 mm sieve . The material which passes through this sieve
is weighed (Ws ). The value of aggregate is in percentage o f crushing
material passing through 2.35 mm sieve in term of original weight of
specimen .
OBSERVATION :W1 = Weight of empty mould
= ___________Kg
W2 = Weight of mould + Aggregate
= __________ Kg
W3 = Weight of pan + crushed aggregate = ___________Kg
% Crushing Value = [W3 / (W2 – W1 )] x 100
RESULT :The crushing value of the given aggregate is found to be ___________ %
PRECAUTION :1)Length of the three layers should be approximately equal .
2)Aggregate should be perfectly dry .
3)Mould should be perfectly dry and clean .
4)Sieving should be done carefully.
APPLICATION :Stone aggregate gives low crushing value . The crushing
value of good quality aggregate to be used in base coarse should not ex ceed
45 % and the value for the surface co arse should not be less than 30 %.
AIM :- To determine ab rasion value of coarse aggregate by Los Angelis Abrasion
Testing Machine.
APPARATUS :Los Angelis Abrasion Testing Machine , aggregate , cast iron , spear , 17
mm sieve
THEORY :The principle of Los Angelis Abrasion Test is to find out
percentage valu e due to the relative rubbing action between the aggregate
and the steel ball which are used as an ab rasion char ge .
PROCEDURE :The test procedure co nsists of a rotating drum . It is rotated
at a speed of 20 – 30 rpm . In this cylinder the sample along with the balls
is added . The total weight of sample depends upon the size of aggregate
and number of steel balls and weight of each steel balls . Maximum weight
of steel ball is limited to 5 Kg . The sample and the steel ball are rotated
upto 500 revolution . After completion of revolution , the sample is taken
out . It is allowed to pass through 1.7 mm sieve size . The percentage
weight passing is called abrasion value of aggregate.
OBSERVATION TABLE :Weight of aggregate = _________ gm (W1 )
Sieve Size
Weight retained
% Finess
Weight of sample passing through 1.7 mm Sieve (W2 ) = _________ gm
CALCULATION :Abrasion value of a given aggregate sample =
RESULT :Abrasion value is found to be _________ % of given
aggregate sample by Los Angelis Abrasion Testing Machine.
PRECAUTION :1) Aggregate should be taken by specific size because number and weight
of steel balls depends upon size of aggregate .
2) Revolution of rotating drum should be rotated and noted perfectly.
APPLICATION :Abrasion are carried out to test the hardness properly of
coarse aggregate and d ecide wheth er they are suitable for different road
The Los Angelis Abrasion
value of good quality accepted for cemen t
concrete , bituminous concrete or other high quality bituminous material
should be less than 30% . Here percentage of fines or abrasion value is 10
% , which is less than 30 % and hence given specimen is accepted .
This test is carried out to test the hardness properly of
coarse aggregate and to decide whether they are suitable for road
construction work The test is the best to found out the hardness of
AIM :- To determine the softening point for the given sample of bitumen
APPARATUS :Softening point test set up .
THEORY :The softening point of any substance is the temperature at
which the substance attain a particular degree of softening under specified
condition of test . The softening point of bitumen is generally found o ut
by using ring and ball apparatus.
PROCEDURE :A brass ring containing test sample of bitumen is suspended
in liquid like water . Some times glycerin can be taken at a given bitumen
sample and set up is placed in liquid . The liquid is heated after due coarse
of time the steel ball fall down because the bitumen is very soft . Th e
temperature at which the ball falls is called as softenin g point . Hard
bitumen softens at high temperature.
Temperature at which b all falls
CALCULATION :Softening Point =
RESULT :The softening point of given of bitumen sample is found to be ______ 0C .
PRECAUTION :1)The rate of increase of temperature should be uniform .
2)The stirrer should be used.
DISCUSSION :Temperature at which the substance attends a particular
degree of softening , This temperature must be kept in mind by the engineer
while construction works. Hard grade bitumen posses higher softening than
soft grade bitumen . Therefore the grade of bitumen can be determine by the
test .
APPLICATION :The softening point of bitumen is found to check whether is
above the highest surface temperature ,else the bitumen may get slippery .
In slippery the bitumen may even slide down if the softening point is less .