BITUMINOUS MATERIALS



DETERMINATION OF SOFTENING POINT OF BITUMEN 

IS: 1205 

1.  Introduction

This method covers the determination of the softening point of bitumen in the range of 30 to 157°C using ring and ball apparatus immersed in distilled water (30 to 80°C). USP glycerin (above 80 to 157°C) or ethylene glycol (30 to 110°C). The softening point is the temperatures at which the substance attains a particular degree of softening under specified conditions of test. Softening point is useful in establishing the uniformity of the bitumen delivered at site and also indicates the level of tendency to flow at elevated temperatures.

2. Apparatus

(i) Two square shouldered brass rings conforming to the dimensions specified.

(ii) A flat, smooth brass plate approximately 50 by 75 mm size.

(iii) Two steel balls 9.5 mm dia having mass of 3.50 ± 0.05 gm.

(iv) Two brass guides for centering the steel balls, one for each ring.

(v) A brass holder having a bottom plate of 16 mm thickness with two vertical supports to hold the rings in a horizontal position. The bottom of the shouldered rings shall be 25 mm above the top surface of the bottom plate.

(vi) A thermometer capable of reading from 0°C to 250°C. The thermometer is suspended in the assembly such that the bottom of the bulb is in level with the bottom of the rings. Substitution of other thermometers is not permitted

(vii) Heat resistant glass vessel not less than 85 mm in dia and 120 mm depth for the water bath.

(viii) A stirrer to ensure uniform heat distribution at all times during the test.

3. Reagents and materials

a) The use of freshly boiled distilled water is essential to avoid trapping of air bubbles on the surface of the specimen which may affect the result.

b) If USP glycerin is used it shall be kept in mind that its flash point is 160°C.

4. Sampling

a) Heat the bitumen preferably using an electric hot plate to a temperature 75 to 100°C above the expected softening point.

b) Bitumen shall not be heated more than 2 hours.

c) Take no more than 30 minutes to heat a coat-tar pitch sample to its pouring temperature and this shall be not more than 55°C above the expected softening point.

d) For repeating the test, start from fresh sample. Do not reheat the previous sample.

e) Stir until the sample is fluid and free from air bubbles and water.

f) Heat the two brass rings close to the pouring temperature of the specimen and place over the plate coated with the releasing agent made of equal parts of glycerin and dextrin.

g) Pour slightly excess heated bitumen into each ring and cool in ambient air for at least 30 minutes.

h) After cooling, cut away the excess bitumen with a clean hot knife or spatula so that the top of specimen is in level with the top of its ring.

i) Test should be completed within 240 minutes after the discs have been poured.

5. Procedure

a) Carry out the test with the appropriate bath liquid and thermometer.

b) Generally all softening points up to 80°C shall be determined in a water bath and all softening points above 80°C shall be determined in glycerin bath.

c) Assemble the apparatus with the specimen rings, ball entering guides and the thermometer in position.

d) Fill the bath liquid to a height of 50 mm above the upper surface of the rings.

e) Place the two balls inside the bath so that they are also at the same starting temperature as with the rest of the apparatus.

f) Cool the bath to reach the starting temperature for the test (5°C) and maintain it for 15 minutes.

g) Now place the balls gently over the specimen in the rings.

h) Gently heat the bath from below such that the rate of increase is uniformly at 5°C.

i) At any one minute period, after the first three minutes, the rate of rise shall not vary by ± 0.5°C.

j) Record the temperatures at which the bitumen surrounding the ball just touches the bottom plate as shown in the figure.

6. Report

The mean temperature from the two readings rounded to the nearest 0.5°C is reported as the softening point

PENETRATION TEST OF BITUMEN

IS: 1203 

1. Introduction

This method covers the determination of the penetration of bitumen, fluxed native asphalt and blown type bitumen. The penetration of a bituminous material is the distance in tenths of a millimetre that a standard needle will penetrate vertically into the sample of the material under specified conditions of test.

2. Apparatus

(i) A metal or glass cylindrical container conforming to the dimensions specified.

(ii) A straight highly polished cylindrical hard steel rod of specified dimensions with conical and parallel portions co-axial. The needle is provided with a shank to which it is fixed.

(iii) A water bath containing not less than 10 litres of water with thermostatic control to maintain the temperature at 25±0.1°C. The sample shall be immersed to a depth of not less than 100 mm from top and supported on a perforated shelf not less than 50 mm from the bottom of the bath.

(iv) A transfer dish or tray with a firm base to prevent rocking of the test container and ensure full immersion of the test container during the test.

(v) Penetration apparatus to allow the vertical penetration of needle without any friction and calibrated to provided readings to tenths of a millimetre.

(vi) Thermometer capable of reading from 0°C to 44°C, length 340±10 mm with 0.2°C graduation. Substitution of other thermometers is not permitted.

(vii) A stop watch or electric timer for hand operated apparatus. If the apparatus is attached with automatic timer, it shall be properly calibrated.

3. Preparation of test sample

a) Heat the material preferably using an electric hot plate to a temperature not more than 90°C above the approximate softening point for bitumen and not more than 60°C for tars and pitches.

b) Stir it thoroughly to make it homogeneous and free from air bubbles and water.

c) Pour the hot material into the test cup to a depth at least 10 mm above the expected penetration.

d) Protect the sample from dust and allow it to cool for 90 to 120 minutes.

e) Place the cup in the transfer dish and keep both in a water bath maintained at 25±0.1°C.

4. Procedure

a) Unless otherwise specified the test shall be done at 25±0.1°C.

b) Fill the transfer dish with water from water bath to cover the container completely. Place the test cup under the penetrometer needle

c) Ensure that the needle is properly cleaned with a suitable solvent, washed and dried properly.

d) The needle is adjusted to make contact with the surface of the specimen in the cup.

e) A source of light may be conveniently used to make the needle point just to touch its reflection.

f) Load the needle holder with the specified weight to make the total weight of 100±0.25 gm.

g) Note the reading of the dial or set the pointer to zero.  

h) Make three penetrations by releasing the needle holder for 5 seconds.

i) Each test point shall be 10 mm apart and not less than 10 mm from the side of the test cup.

j) After the first reading, the test sample with transfer tray shall be returned to the water bath.

k) The needle shall be cleaned and dried before taking each of the succeeding reading.

5. Report

(i) The penetration of the needle expressed as tenths of a millimetre is noted.

(ii) The mean of three readings is taken as the penetration value.

(iii) The difference in readings shall not be more than 4, if the penetration is between 49 and 149.

DUCTILITY OF BITUMINOUS MATERIALS  

IS: 1208

1. Introduction

The ductility of a bituminous material is measured by the distance to which it will elongate before breaking when two ends of a briquette specimen of the material are pulled apart at a specified speed of 5 cm/min and specified temperature of 25±0.5°C. This property indicates the tensile strength of the material and may be used for specification requirements.

2.  Apparatus

(i) The mould for casting briquettes is made of brass with two end clips, two side plates of prescribed dimensions.

(ii) Constant temperature water bath specifically designed for the test and capable of maintaining the temperature within 0.1°C of the test temperature. The volume of the bath shall not be less than 10 lit. The specimen shall be supported on a perforated shelf not less than 5 cm from the bottom. The specimen shall be immersed to a depth not less than 10 cm.

 (iii) The standard apparatus for ductility test shall pull the clips of the briquette mould at a uniform speed while the specimen is kept continuously immersed in water at the required temperature.

(iv) A thermometer having the range of 0°C to 44°C with graduations of 0.2°C.

3. Procedure

a) Assemble the mould on a brass plate. Thoroughly coat the surface of the plate and the interior surfaces of the mould with a thin layer of glycerin-dextrin mixture or talc or kaolin (China clay) to prevent the material from sticking to the plate and the mould.

b) Bottom plate shall be level and the bottom of the mould shall be in full contact with the plate.

c) Carefully heat the bitumen in to a pouring consistency with out over heating, preferably using an electric hot plate. Strain the material through a 300 micron sieve if necessary.

d) Pour the material into the mould in a thin stream from end to end moving back and forth until the mould is slightly more than level.

e) Cool the sample in the mould for 30 to 40 minutes.

f) Transfer the plate and mould with specimen to the water bath maintained at the test temperature and keep for 30 minutes.

g) Then cut off the excess bitumen with a hot spatula or putty knife so that the mould is just filled level.

h) Keep the brass plate and mould with briquette specimen in water bath at test temperature for 90±5 minutes.

i) Now remove the briquette from the plate

detach the side plates and carry out the test immediately.

j) Attach the rings of the end clips to the pins or hooks in the testing machine.

k) Pull apart the clips at the specified uniform speed with the speed variation not exceeding ±5% till the briquette ruptures.

l) Maintain the temperature of the bath within 0.5°C of the test temperature during the entire test period.

m) The water level shall be minimum 2.5 cm above the specimen.

4. Report

(i) The average of three normal tests is reported as the ductility of the sample.

(ii) The test shall not be considered normal if the bituminous material comes in contact with the surface of water or the bottom of the bath. If this occurs, adjust the specific gravity of water by adding either methyl alcohol or sodium chloride and repeat the test.

(iii) If a normal test is not obtained after three trials, report the ductility of the material as not obtainable

FLOAT TEST FOR BITUMINOUS MATERIALS

IS: 1210 

1. Introduction

This method covers the float test for bituminous materials. A plug of bitumen is cast in a tapered collar. The assembled float and collar is floated in a water bath of prescribed temperature. The time in seconds between placing the apparatus on the water and the water breaking through the material is taken as a measure of the consistency of the material.

2. Apparatus

(i) The float shall be of aluminum and aluminum alloy conforming to the figure shown above and the requirements given in table 1 below

Table 1: Requirements for float 

Item Minimum Normal Maximum
Mass of float, gm 37.7 37.9 36
Total height of float, mm 34 35                     27.5
Height of rim above lower side of the shoulder, mm 26.5 27
Thickness of shoulder, mm 1.3 1.4 1.5
Diameter of opening, mm 11 11.1 11.2

(ii) The collar shall be made of brass in accordance with the requirements given in table 2.

Table 2: Requirements for collar 

Item Minimum Normal Maximum
Mass of collar, gm 9.6 9.8 10
Overall height of collar, mm 22.3 22.5 22.7
Inside dia at bottom, mm 12.72 12.82 12.92
Inside dia at top, mm 9.65 9.7 9.75

(iii) The top of the collar shall screw up tightly against the lower side of the shoulder.

(vi) Low softening point thermometer having the range from -2 to +80 °C conforming to the requirements as specified in IS: 1210 clause 2.3.

(vii) A circular test water bath of at least 185 mm in internal diameter containing at least 185 mm depth of water or a rectangular bath with internal dimensions 150 mm x 300 mm size and 150 mm height containing at least 100 mm depth of water.  The water bath shall be heated by suitable means like heater or gas stove.

(viii) A stand for holding the thermometer in position to check the bath temperature during heating.

(ix) A brass pouring plate 50 mm x 75 mm size treated to prevent sticking of material. 

(x) A water bath of suitable dimensions maintained at a temperature of 5.0±1.0°C which may be accomplished by melting of ice.

3. Calibration of the assembly

a) The depth of immersion of the assembly in the bath shall be constant.

b) The assembled float and collar filled flush with bottom and weighed to a total mass of 53.2 gm shall float upon water with the rim 8.5±1.5 mm above the surface of water.

c) Fix the collar tightly to the bottom of the float and ensure that no water is trapped between the collar and float during the test.

4. Sample preparation

a) Place the brass collar with the smaller end on the coated brass pouring plate.

b) Melt the solid bitumen sample completely at the lowest possible temperature for pouring.

c)  For cutbacks, heat the residue at the lowest possible temperature to bring it to a sufficiently fluid condition for pouring.

d) Stir thoroughly until it is homogeneous and free from air bubbles.  e) Fill the material into the collar slightly more than level with the top.

5. Procedure

a) For bitumen and bituminous products, cool the collar and plate to room temperature for 15 minutes and then place them for 5 minutes in the water bath at 5°C.

b) Trim the excess material with a hot knife or spatula to make it flush with the top of the collar. Again keep it in the water bath at 5°C for 15 to 30 minutes.

c) When tar products are tested, immediately after pouring, place the collar and plate for 5 minutes in the water bath at 5°C.

d) Trim the excess material with a slightly heated knife or spatula to make it flush with on the top of the collar.

e) Place them in the water bath at 5°C for 15 to 30 minutes.

f) Heat the water bath to the test temperature using any suitable means without stirring.

g) This temperature should not vary more than 0.5°C from the test temperature throughout the testing period.  

h) Determine the temperature by immersing the bulb at a depth of 40±2 mm below the surface

 i) After the collar with the test specimen has been kept in the water bath at 5°C for 15 to 30 minutes, screw the collar to the bottom of the aluminum float.

j) Completely immerse the assembly for 1 minute in the water bath at 5°C. Transfer the float assembly to the water bath after removing the water inside the float.

k) Ensure that no spinning is imparted to the float assembly though lateral motion is permitted.

l) The temperature of the water bath will make the plug warm and fluid which will be forced upward by water from below causing the float to sink.

m) Using a stop watch, find of the time interval between, placing the float in the bath and the water forcing through the material.

6. Report

The time in seconds, between placing the float in the bath and the water forcing through the material, is considered as an indication of the consistency of the material

DETERMINATION OF ABSOLUTE VISCOSITY OF BITUMINOUS MATERIALS

 IS: 1206 - Part II 

1. Introduction

Absolute or Dynamic Viscosity of a Newtonian Liquid is an internal friction, such that, if a tangential force of one dyne (0.00001 N) acting on planes of unit area separated by unit distance of the liquid produces unit tangential velocity.  A liquid in which the shear stress is directly proportional to the rate of shear strain is called a Newtonian liquid. The constant ratio of shear stress to the rate of shear strain is called the coefficient of viscosity of the liquid. If the ratio is not constant, it is called a non-Newtonian liquid.  This method is used for the determination of absolute viscosity of bitumen and cutbacks by vacuum capillary viscometers at any specified temperature. It is applicable to materials having a viscosity range of 42 to 200,000 Poises.

2. Apparatus

(i) A capillary type viscometer like Cannon-Manning Vacuum Capillary Viscometer as shown in figure.

(ii) Glass thermometer with cylindrical bulbs. (iii) A suitable water bath with accuracy of ±1°C for immersion of viscometer.

(iv) Thermostatically controlled oven, with non-corroding material interior, capable of maintaining temperature of bituminous materials for testing.

(v) A suitable device for heating bitumen. (vi) A Vacuum system capable of maintaining a vaccum to within ±0.05 cm of the desired level of mercury up to and including 30 cm.

(vii)  A stop watch or stop clock capable of reading up to half a second.

3. Procedure

a) The bitumen sample is heated to pouring temperature not exceeding 90°C above the approximate softening point

b) Transfer about 20 ml of the sample to a container and then place it in oven maintained at 135±5.5°C.

c) Stir the sample occasionally to prevent overheating and allow the entrapped air to escape.

d) Charge the viscometer by pouring the prepared sample into the filling tube of the viscometer until the level of the bitumen reaches with in 2 mm of the „fill line? shown in figure.

e) The charged viscometer is placed in the oven or bath maintained at 135±5.5°C for 10±2 minutes to allow large air bubbles to escape.

f) The viscometer is now transferred vertically to the water bath maintained at test temperature of 60±0.1°C. 

g) The viscometer is fixed in the bath in vertical position with the help of the holder such that the upper most timing mark is at least 20 mm below the surface of the bath liquid.

h) The vacuum unit with its suction pressure maintained at a vacuum pressure of 30± 0.05 cm of mercury is connected to the vacuum tube of the viscometer with the valve closed. i) After being in the water bath for a period of 30±5 minutes, the valve is opened and the liquid bitumen is allowed to flow into the viscometer

 j) The time taken for leading edge of the meniscus to pass between successive pairs of timing marks is recorded within 0.5 seconds.

k) After completion of the test, remove the viscometer from the water bath and keep in the inverted position in the oven maintained at 135±5.5°C, till all the bitumen is drained off thoroughly. l) Rinse the viscometer with appropriate solvent till it is clean. m) Dry the tube by passing dry air through the capillary for 2 minutes.

4. Calculation

The absolute viscosity is calculated by the following equation: Viscosity Poises = Kt where K= Selected calibration factor, in poise per second and t = Flow time, in seconds. The calibration factor is selected that corresponding to the pair of timing marks used for the determination of viscosity. While reporting the viscosity, the test temperature and vacuum pressure should be mentioned and the value must be reported to three significant decimal places

DETERMINATION OF KINEMATIC VISCOSITY OF BITUMINOUS MATERIAL 

IS: 1206 - Part III

1. Introduction

Kinematic Viscosity of a Newtonian Liquid is defined as the quotient of the absolute or dynamic viscosity divided by the density of the liquid under test; both at the same temperature.  A liquid in which the shear stress is directly proportional to the rate of shear strain is called a Newtonian liquid. The constant ratio of shear stress to the rate of shear strain is called the coefficient of viscosity of the liquid. If the ratio is not constant, it is called a non-Newtonian liquid.  The CGS unit of kinematic viscosity is stoke, which is cm2 per second. For petroleum products, kinematic viscosity is usually expressed in centistokes (cSt) which is 1/100th of a stoke. This method is used for the determination of kinematic viscosity of paving grade and cutback bitumen and distillation residues of cut-backs. It is applicable to the materials having viscosity range of 30-100,000 cSt.

2. Apparatus

(i) Cannon-Fenske Opaque Viscometer as shown in figure.

(ii) Thermometer.

(iii) A suitable water bath with accuracy of ±1°C for immersion of viscometer.

(iv) Thermostatically controlled oven, with non-corroding material interior, capable of maintaining temperature of bituminous materials for testing.

(v) A Vacuum system capable of maintaining a vaccum to within ±0.05 cm of the desired level of mercury up to and including 30 cm.

(vi) A stop watch or stop clock capable of reading up to half a second.

3. Calibration of Viscometer

a) Any liquid of known viscosity may be used for calibration purposes.

b) Charge the clean dry viscometer by pouring the reference material.

c) Transfer the charged viscometer to the water bath maintained within ±1°C of calibration temperature.

d) Keep the charged viscometer in the water bath long enough to reach the test temperature.

e) Measure the time within 0.1 seconds required for the leading edge of the meniscus to pass from the first timing mark to the second.

f) The calibration constant C is given by: C = V/t where V = Viscosity in centistokes (cSt) for the standard liquid. t = Efflux time in seconds.

g) If the viscometer is used in a location than the calibrating laboratory, the constant C should be corrected for the difference acceleration due to gravity as given below: C2 = [g2/g1] x C1 where 

C2 = Calibration constant for the testing laboratory. C1 = Calibration constant for the calibration laboratory. g2 = Acceleration due to gravity at the location of testing laboratory. g1 = Acceleration due to gravity for calibration laboratory. 

4. Procedure

a) The bitumen sample is heated to pouring consistency and temperature not exceeding 90°C above the approximate softening point.

b) Stir the sample throughly and about 20 ml of the fluid binder is transferred in a 30 ml container ensuring that entrapped air is avoided. Seal the container immediately.

c) To charge the viscometer, it is inverted immersing tube N in the liquid bitumen sample to be tested.

d) Suction pressure is applied to the tube L of the viscometer.  e) The sample starts rising in the tube and when bulb is filled up and it reaches the mark „G? the viscometer is taken out, inverted again so that it is in the normal position. f) The excess bitumen at the end of the tube N is wiped clean. Stoppers are placed to close the ends of both the tubes.

g) The viscometer is then placed vertically in the bath for sufficient time to ensure that sample reaches equilibrium temperature. Normally it takes about 20 minutes for 38°C, about 25 minutes for 100°C and 30 minutes for 135°C.

h) When the test temperature is reached, the stoppers of the tubes are removed and the sample of bitumen binder is allowed to flow from bulb to the capillary tube under gravity

 i) The time required for the leading edge of the meniscus to pass from mark E to mark F is measured accurately with the timer unit. j) If the time required is less than 60 seconds, another viscometer of smaller capillary diameter is selected and the experiment is repeated.

k) After completing the test the viscometer is immediately cleaned with suitable solvents.

5. Calculation

Calculate the kinematic viscosity up to three significant figures using the following equation: Kinematic viscosity cSt = Ct C = Calibration constant of the viscometer in centistokes per second. t = Efflux time in seconds.  While reporting the viscosity, always indicate the test temperature and the value must be reported to three significant decimal places.   

SAYBOLT VISCOSITY OF PETROLEUM PRODUCTS 

ASTM Designation: D 88-94 & AASHTO Designation: T 72-90 

1. Introduction

This test covers the empirical procedures for the determination of Saybolt Universal or Saybolt Furol viscosities of petroleum products at specified temperatures between 21°C and 99°C.  Furol is the acronym for fuels and road oils. The Saybolt Furol viscosity is the corrected efflux time in seconds of 60 ml of sample flowing through a calibrated Furol orifice under specified conditions. The viscosity value is reported in Saybolt Furol seconds abbreviated as SFS at a specified temperature. Saybolt Universal viscosity is the corrected efflux time in seconds of 60 ml of sample flowing through a calibrated Universal orifice under specified conditions. The viscosity value is reported in Saybolt Universal seconds abbreviated as SUS at a specified temperature. The efflux time in seconds of 60 ml of sample flowing through a calibrated orifice is measured under specified conditions. This time is corrected by an orifice factor and reported as the viscosity of the sample at that temperature. The Saybolt Furol viscosity is approximately one tenth of Saybolt Universal viscosity is recommended for characterization of petroleum products such as fuel oils and other residual materials having Saybolt Universal viscosities greater than 1000 seconds.

2. Apparatus

(i) Saybolt Viscometers with Universal or Furol orifices and bath with dimensions detailed in annexure A1 of ASTM D 88-94.

(ii) Withdrawal tube to use with Saybolt viscometer.

(iii) Thermometer support of suitable design.

(iv) Saybolt viscosity thermometers or any other temperature indicating means of equivalent accuracy as bath thermometers.

(v) Filter funnel equipped with interchangeable 150-µm (No. 100) and 75-µm (No. 200) wire-cloth inserts.

(vi)  Receiving flask to use with Saybolt viscometer.

(vii) Timer graduated in tenths of a second and accurate within 0.1% over a 60 minute interval. Electric timers are acceptable if operated on a controlled frequency circuit.

(viii) ASTM Saybolt viscosity thermometers 17C/F to 22C/F to suite the material tested as listed in table 

Table 1: ASTM Saybolt viscosity thermometer

Standard test

ASTM thermometer

Thermometer

Sub divisions

temperature oC

number

range oC

oC

21.1

17C (17F)

19 to 27

0.1

25.0

17C (17F)

19 to 27

0.1

37.8

18C (18F)

34 to 42

0.1

50.0

19C (19F)

49 to 57

0.1

54.4

19C (19F)

49 to 57

0.1

60.0

20C (20F)

57 to 65

0.1

82.2

21C (21F)

79 to 87

0.1

98.9

22C (22F)

95 to 103

0.1

3. Preparation of the apparatus

(i) Use a Universal orifice or tip for lubricants and distillates with efflux time greater than 32 seconds. This orifice is not suitable for liquids with efflux time greater than 1000 seconds.  

(ii) Use a Furol orifice or tip for residual materials with efflux time greater than 25 seconds to give the desired accuracy

 (iii) Clean the viscometer with a proper solvent of low toxicity. Remove all traces of the solvent from the viscometer and its gallery. Remove the receiving flask in the same manner. The plunger normally supplied with the viscometer should never be used for cleaning as it may damage the apparatus.

(iv) Set up the viscometer and bath in an area where they will not be exposed to drafts or rapid change in air temperature and dust or vapours that may contaminate the sample.

(v) Place the receiving flask below the viscometer such that the stream of oil will just strike the neck of the flask. The graduation mark of the flask shall be at 100 to 130 mm below the viscometer tube.

(vi) Fill the bath to at least 6 mm above the overflow rim of the viscometer. Select the appropriate bath medium from table 2. 

(vii)  Provide adequate stirring and thermal control for the bath so that the temperature of the test sample will not vary more than 0.03 oC, after the test temperature is reached.

(viii) Do not make viscosity measurements at temperatures below the dew point of the room?s atmosphere.

 (ix) For calibration and referee tests, keep the room temperature between 20 and 30°C and record the temperature. Researches show that the error induced will be within 1% up to temperature of 38°C. 

4. Calibration of equipment

a) Calibrate the Saybolt Universal viscometer at periodic intervals by measuring the efflux time at 37.8°C using standard viscosity oil. The efflux time of the standard viscosity oil shall be same as the certified Saybolt viscosity value.  b) If the efflux time differs by more than 0.2%, calculate the correction factor F for the viscometer as below: F = V/t where V = Certified Saybolt viscosity of the standard and   t = Measured efflux time at 37.8°C in seconds c) Calibrate the Saybolt Furol viscometer at 50°C in the same manner as above, using a viscosity oil standard having a minimum efflux time of 90 seconds.  d) Viscometers or orifices requiring corrections greater than 1.0% shall not be used in referee testing.

5.  Procedure

a) Establish and maintain the bath temperature at the selected test temperature. Standard test temperatures for measuring Saybolt Universal viscosities are 21.1, 37.8, 54.4 and 98.9°C. For Saybolt Furol viscosities the standard measurement temperatures are 25.0, 37.8, 50.0 and 98.9°C. Other standard measurement temperatures used include 60.0 and 82.2°C.

b) Insert a cock stopper, having a cord attached for its easy removal, into the air chamber at the bottom of the viscometer tube. The cork shall tightly fit to prevent the escape of air.  This can be verified from the absence of oil when it is removed for the test.

c) If the selected temperature is above the room temperature, the test may be expedited by preheating the sample in its original container to not more than 1.7°C above the test temperature. Never preheat the sample within 28°C of its flash point to prevent loss of volatile matter.

d) Stir the sample well and strain through the 150-µm (No. 100) wire cloth in the filter funnel directly into the viscometer until the level is above the overflow rim.

 e) The viscosities of steam-refined cylinder oils, black lubricating oils, residual fuel oils, and similar waxy products can be affected by their thermal histories. Use the following preheating procedures with such products to obtain uniform results below temperature 93°C.

(i) Heat the sample to 50°C in its original container. During heating stir and shake well to dissolve and blend waxy materials.

(ii) Pour about 100 ml into a 125 ml Erlenmeyer flask. Close loosely with a cork or rubber stopper.

(iii) Immerse the flask in a boiling water bath for 30 minutes

(iv) Mix well, remove from the boiling water bath, wipe outside dry and strain the sample through the 75 micron wire cloth in the filter funnel directly into the viscometer until the level is above the overflow rim.

f) Stir the sample in the viscometer with the appropriate viscosity thermometer. Use a horizontal circular motion of 30 to 50 rpm.

g) When the sample temperature is steady within 0.03°C of the test temperature during 1 minute of continuous stirring, remove the thermometer. Never adjust the temperature by immersion hot or cold bodies into the sample. 

h) Immediately place the tip of the withdrawal tube at one point in the gallery and apply suction to remove oil until the level is below the overflow rim. Do not touch the overflow rim with the withdrawal tube.

i) Check whether the receiving flask is in position.

j) Snap the cork attached to the viscometer tube by pulling the chord and start the timer at the same instant. Stop the timer at the instant the bottom meniscus of the oil reaches the graduation mark of the receiving flask.

k) The efflux time in seconds is recorded to the nearest 0.1 second.

6.  Calculation and report

(i) Multiply the efflux time by the correction factor as determined during calibration.

 (ii) Report the corrected efflux time as Saybolt Universal or Saybolt Furol viscosity at the test temperature.

(iii) The values below 200 SUS or SFS are reported to the nearest 0.1 seconds. Values above 200 are reported to the nearest whole second

DETERMINATION OF SOLUBILITY OF BITUMINOUS MATERIALS 

IS: 1216

1. Introduction

This method of test determines the degree of solubility of asphalt materials, having little or no mineral matters, in trichloroethylene or carbon disulphide. Pure bitumen is fully soluble in carbon disulphide and carbon tetrachloride. If some quantity remains un-dissolved, it exhibits the quantity of inert mineral present in the bitumen.

2. Apparatus

(i) Gooch crucible.

(ii) Conical glass flask of 200 ml capacity.

(iii) Filter flask.

(iv) Filter tube.

(v) Desiccator

 (vi) A thermostatically controlled oven.

(vii) Carbon Disulphide (Redistilled grade conforming to IS: 717-1969).

(viii) Trichloroethylene conforming to IS: 245-1970.

3. Preparation of Gooch crucible

a) Heat the sample by stirring quickly, to a temperature not exceeding 130°C until the water has been removed.

b) Insert the filter tube in the stopper of the filtering flask, set the Gooch crucible in the filter tube, and connect the flask to the suction pump using a rubber hose.

c) Fill the crucible with the suspension of asbestos in water and allow it to settle partly.

d) Apply a light suction to draw off the water, leaving a firm mat of asbestos in the crucible.

e) Add more suspended asbestos and repeat the process until a mat weighing 0.5±0.1 gm is built up after drying

 f) Wash the asbestos mat thoroughly with water and dry in the oven at a temperature of 150°C.

g) Cool the crucible in the desiccator and then weigh and replace it in the dry filter tube supported in the clean dry filtering flask.

4. Procedure

a) Take 2 g of the dry material in a 200 ml conical flask

 b) Add 100 ml of carbon disulphide or trichloroethylene.

 c) Stir the contents of the flask, and then allow it to stand, loosely corked, for a period of one hour.

d) Filter the contents of the flask through the Gooch crucible prepared as described under item 3 above.

e) Moisten the asbestos pad with carbon disulphide before filtration, and filter at a rate of not more than two drops per second at first.

f) Transfer the insoluble matter remaining in the flask to the crucible by washing out the flask with a stream of carbon disulphide or trichloroethylene

g) Wash the material retained in the crucible with successive small amounts of carbon disulphide or trichloroethylene until non-discolored filtrate is obtained.

h) Allow the crucible to dry in air for 30 minutes and after that place it in an oven at 100 to 110°C for one hour. i) Allow the crucible to cool in a desiccator and then weigh.

5. Calculation and report

The total percentage matter soluble in carbon disulphide or trichloroethylene is calculated as below: Matter soluble in carbon disulphide or trichloroethylene = [A-B/A] x 100 where,

A = weight of dry sample in gm and

B = weight of insoluble material retained in the Gooch crucible.

The result is reported to the nearest 0.05 percent. 

 

BULK SPECIFIC GRAVITY OF COMPACTED BITUMINOUS MIX SPECIMENS 

ASTM Designation: D 2726/AASHTO Designation: T 166-00 

1. Introduction

This method test covers the determination of the bulk specific gravity of specimens of compacted bituminous mixes. This method is not applicable to mixes with open or interconnected voids and/or which absorbs 2.0% or more water. The bulk specific gravity is used for volumetric analysis in the Marshall method of mix designs and to compute the unit weight of the mixture.

2. Preparation of test sample  

i) The test specimens may be either from bituminous mixes moulded laboratory or cored from paved bituminous layer. The mix may be bituminous base, binder, wearing or leveling course.

(ii) It is recommend that the diameter of cored/moulded specimens or length of the sides of the sawed specimens shall be minimum four times the maximum size of the aggregate and the thickness of specimens shall be at least one and a half times the maximum size of the aggregates.

(iii) Specimens from pavement shall be taken with a core drill, diamond or carborundum saw or by other suitable means. Proper care shall be exercised to avoid damage to the specimens by distortion, bending or cracking during and after the extraction process.

(iv) The specimens shall be free from foreign materials such as tack coat, soil, paper, foil etc. If required, these shall be removed by sawing, without damaging the specimens.

3. Apparatus:

(i) A balance or scale, readable to 0.1 gm. The weighing device shall be provided with a suitable suspension device to allow weighing in water (Buoyancy balance as shown in figure).

(ii) The wire for suspending the container shall be the smallest practical size to minimize any possible effects of a variable immersed length. While weighing in water ensure that no trapped air bubbles exist under the specimen.

(iii) Water bath for immersing the specimen in water while suspended under the weighing device, equipped to allow overflow to maintain a constant water level.

(iv) Damp cloth towel to surface dry the specimens.

(v) Thermostatically controlled oven capable of maintaining a temperature of 110±5°C for drying the specimen to constant weight.

(vi) Pan large enough for holding the specimens while drying in the oven.

(vii) Thermometer having a range of 10 to 30°C with divisions of 0.2°C.

4. Procedure

a) Dry the specimen to a constant mass at 52±3°C till further drying will not change the mass of the specimen by more than 0.05% of its weight. The weighing is done at 2 hours interval. 

b) Cool the specimen to 25±5°C before weighing and record this reading as A.

c) Immerse each specimen in water bath at 25±1°C for 4±1 minute suspended from the bottom of the buoyancy balance and record this submerged weight as C.

d) Remove the specimen from water. Dry the surface to dampness by carefully blotting with a damp towel as quickly as possible and find the weight in air to get the surface-dry weight B. Any water seeping out from the specimen is considered as part of the saturated specimen.

5. Calculation

a) Calculate the bulk specific gravity of the specimen to the nearest three decimal places as below: Bulk specific gravity = A/(B-C) where

A = Mass of the specimen in air in gm.

B = Mass of the saturated surface dry specimen in air in gm.

C = Mass of the sample suspended in water in gm.

b) Calculate the percentage of water absorbed by the specimen (on a volume basis) as follows: Percentage of water absorbed by volume = (B-A)/(B-C). c) If the percentage of water absorbed by the specimen is more than 2.0%, then bulk specific gravity is determined as per ASTM D 1188–Bulk specific gravity of compacted bituminous mixtures using paraffin coated specimens. 

BULK SPECIFIC GRAVITY OF COMPACTED BITUMINOUS  MIX USING PARAFFIN WAX COATED SPECIMEN

ASTM Designation: D 1188/AASHTO Designation: T 175-00 

1. Introduction

This method test covers the determination of the bulk specific gravity of specimens of compacted bituminous mix specimens coated with paraffin wax. This method applicable to mixes with open or interconnected voids and/or which absorbs 2.0% or more water. The bulk specific gravity is used for volumetric analysis in the Marshall method of mix designs and to compute the unit weight of the mixture.

2. Preparation of test sample

 (i) The test specimens may be either from bituminous mixes moulded laboratory or cored from paved bituminous layer. The mix may be bituminous base, binder, wearing or leveling course.  (ii) It is recommend that the diameter of cored/moulded specimens or length of the sides of the sawed specimens shall be minimum four times the maximum size of the aggregate and the thickness of specimens shall be at least one and a half times the maximum size of the aggregates.

(iii) Specimens from pavement shall be taken with a core drill, diamond or carborundum saw or by other suitable means. Proper care shall be exercised to avoid damage to the specimens by distortion, bending or cracking during and after the extraction process.

(iv) The specimens shall be free from foreign materials such as tack coat, soil, paper, foil etc. If required, these shall be removed by sawing, without damaging the specimens.

3. Apparatus

(i) A balance or scale, readable to 0.1 gm. The weighing device shall be provided with a suitable suspension device to allow weighing in water.

(ii) The wire for suspending the container shall be the smallest practical size to minimize any possible effects of a variable immersed length. While weighing in water ensure that no trapped air bubbles exist under the specimen.

iii) Water bath for immersing the specimen in water while suspended under the weighing device, equipped to allow overflow to maintain a constant water level.

(iv) Damp cloth towel to surface dry the specimens.

(v) Thermostatically controlled oven capable of maintaining a temperature of 110±5°C for drying the specimen to constant weight.

(vi) Pan, large enough for holding the specimens while drying in the oven.

(vii) Thermometer having a range of 10 to 30°C with divisions of 0.2°C.

(viii) Paraffin wax to coat the test specimens.

4. Procedure

a) Dry the specimen to a constant mass at 52±3°C till further drying will not change the mass of the specimen by more than 0.05% of its weight. The weighing is done at 2 hours interval.

b) Cool the specimen to 25±5°C before weighing and record this reading as A.

c) Coat the specimen completely using molten paraffin wax sufficiently thick to seal all voids.  

d) Cool the specimen to 25±5°C and weigh again. Record the weight of paraffin coated specimen as D.

e) Immerse each specimen in water bath at 25±1°C for 4±1 minute suspended from the bottom of the buoyancy balance and record this submerged weight as E.

f) Remove the specimen from water. Determine the specific gravity F of paraffin wax at 25±1°C from manufacturer?s literature or other sources.

5. Calculation

Calculate the bulk specific gravity of the paraffin coated specimen to the nearest three decimal places as below:

Bulk specific gravity = A/D-E-[(D-A)/F]

 where A = Weight of the uncoated specimen in air in gm.

D = Weight of the paraffin coated specimen in air in gm.

E = Submerged weight of the coated specimen suspended in water in gm.

F = Specific gravity of the paraffin wax used for coating. 

DETERMINING BITUMEN CONTENT BY EXTRACTION 

ASTM Designation: D 2172 & AASHTO Designation: T 164 

1. Introduction

This method covers the quantitative extraction of bitumen from hot-mixed paving mixes and pavement samples. Aggregate recovered from this test may be subjected to sieve analysis to check the grading. The result of the test is affected by the age of the material tested. Best quantitative results are obtained when the test is made on mixtures and pavements shortly after their preparation.  It may be noted that it is difficult to remove asphalt completely from certain aggregates and also some solvent may remain within the mineral matter which could affect the measured asphalt content.  The common solvents used for extraction are benzene, trichloroethylene and methyl chloride. The asphalt content is calculated by the differences from the mass of the aggregate extracted, moisture content and mineral matter in the extract.  The asphalt content is expressed as a mass percent of moist-free mixture.

2. Apparatus

(i) A thermostatically controlled oven capable of maintaining temperatures at 110±5oC.

(ii) Extraction apparatus consisting of a bowl which can be rotated at variable speeds up to 3600 revolutions per minute. The apparatus is provided with a tight fitting lid which will prevent the solvent from throwing out.  The solvent with dissolved binder is collected through a drain pipe fitted at the bottom of the bowl.

(iii) Paper filter rings to fit the rim of the bowl.  (iv) Flat pans of appropriate sizes to warm the test specimens.

(v) A balance of suitable capacity at least readable to 0.1 percent of the sample mass.

(vi) Electric hot plate with adjustable heating range.

(vii) Cylinders, graduated, 1000 ml or 2000 ml capacity and another one of 100 ml capacity as optional.

(viii) Ignition dish at least 125 ml minimum capacity.

(ix) Desiccators.

(x) Reagents such as Benzene or Trichloroethylene, Ammonium Carbonate.

3. Preparation of test specimens

a) If the mixture is not sufficiently soft to separate with a spatula or trowel, place it in a large flat pan and warm at 110±5°C in an oven till it can be separated easily. Quarter the material till sufficient sample required for the test is obtained.

b) The size of the test sample is governed by the nominal maximum aggregate size of the mixture and conforming to the mass requirements specified below: 

Nominal maximum 

aggregate size, mm

Minimum mass of

 sample in kg

4.75

0.5

9.5

1.0

12.5

1.5

19.0

2.0

25.0

3.0

37.5

4.0

Note: When mass of the test specimen exceeds the capacity of the equipment used, the test specimen may be divided into appropriate fractions; the test carried out separately for each fraction and combined for arriving at the bitumen content.

c) Unless the mixture is free from moisture, a test specimen is collected from the same sample selected for extraction test for moisture content determination.

d) The extraction test is intended to recover the binder only, then moisture content determination is not necessary. At the other hand, if recovery of bitumen from the extract is not required, the entire sample maybe dried in an oven at 149 to 163°C for 2 to 2.5 hours and proceeded with the extraction test.

4. Procedure

a) Place the test sample into the bowl. Cover the test portion with the approved solvent and allow sufficient time, not more than one hour, for disintegration of the mixture.

b) Place the bowl with the mixture and solvent in the extraction apparatus. Weigh the previously weighed filter ring dried in the oven at 110±5°C to a constant mass. Place the ring on the bowl mouth to fit around the edge of the bowl. Clamp the top lid over the bowl tightly. Place a container of suitable size below the drain pipe to collect the extract.

c) Start the centrifuge revolving slowly and gradually increase the speed to 3600 rpm until the solvent ceases to flow. Stop the machine, add 200 ml of the solvent and repeat the process.

d) Continue adding solvent and centrifuging till the extract is not darker than light straw color. Collect the extract and washings in an appropriate container for determination of the mineral matter.

e) Carefully transfer the filter ring and mineral aggregates in the bowl to a tared metal pan.  

f) Dry in air under a hood until the fumes dissipate and then in an oven at 110±5°C to constant mass.

g) The mass of the extracted aggregate (W3) will be equal to the mass of the contents in the pan minus the initial dry mass of the filter ring.

h) Brush the mineral particles sticking on the filter ring to the extracted mineral aggregate for further testing. Alternately the filter and aggregates may be dried in the oven along with the bowl. Sometimes the filter ring is dried separately in the oven at 110±5°C to constant mass. In such cases the aggregate may be transferred to a pan and dried in an oven or a hot plate. This will enable to continue the extraction test with another sample. 

Note: When low-ash paper filter rings are used, the filter paper is burned in the pan using a Bunsen burner or match after drying in the oven.  

i) The extracted aggregate is weighed and the mass of the aggregate is recorded as W3.

Note: The dry aggregate may absorb moisture from the atmosphere. Hence the mass of the aggregate shall be determined immediately after cooling to a suitable temperature.  

j) The amount of fines washed away by the solvent needs to be determined. To determine this amount of mineral matter W4 present in the extract, measure the total mass or volume of the extracted liquid. Weigh a clean dry ignition dish. Pour 100 ml or 100 gm of the extract into it. Ensure that the extract is adequately stirred to get a uniform specimen.

k) Evaporate the liquid to dryness on a steam bath or hot plate. Burn the residue to ash at a dull red heat (500 to 600°C) and cool. Find the mass of the ash and add 5 ml of saturated ammonium carbonate per gram of ash. Keep at room temperature for one hour. Dry in an oven at 110±5°C to constant mass and cool. Determine the mass of ash Q, to the nearest 0.001 gm. The mass of total mineral matter in the extract W4 is calculated as shown below:  

W4 = Q x [Wa / (Wa-Wq)] where  

Wa = Total volume or weight of extract (ml or gm)

 Wq = Volume or weight of aliquot (100 ml or 100 gm)   Q = Ash in aliquot in gm (nearest 0.001 gm)

 5.  Calculation

Calculate the percentage of bitumen (binder content) in the bituminous mix as below

 Bitumen content % = 100 x [(W1-W2) – (W3+W4)] / (W1-W2),

where W1 = Mass of the test portion in gm

 W2 = Mass of the water in the test portion in gm.

W3 = Mass of the extracted mineral aggregate in gm.

W4 = Mass of the mineral matter in the extract in gm. 

STABILITY AND FLOW TEST ON BITUMINOUS MIXES USING  MARSHALL APPARATUS 

ASTM: D 1559/AASHTO Designation: T 245-97 

1. Introduction

Marshall Stability and Flow test have been developed by Bruce Marshall as part of a procedure for Marshall method of mix design. The procedure described in the Asphalt Institute Manual MS-2, is followed generally in India for the design of bituminous mixes. This method of test covers the measurement of the resistance to plastic flow of cylindrical specimens of compacted bituminous mixtures by circumferential loading using Marshall Apparatus. This method is applicable to mixes containing bitumen, cut back or tar with the maximum size of the aggregate in the mix being 26.5 mm.  The bulk specific gravity of the specimen is also determined for volumetric analysis in the Marshall method of mix design and to compute the unit weight of the bituminous mix

2. Apparatue

 (i) The specimen mould assembly consist of mould cylinders 101.6 mm diameter and 76.2 height, base plate and extension collar. Normally three specimens are cast for the selected binder content.

(ii) The specimen extractor consists of a steel disc not less than 100 mm diameter and 12.7 mm thick. A hydraulic jack is used to apply the required pressure for extracting the compacted specimen from the mould with the use of collar.

(iii) The compaction hammer shall have a flat circular tamping face with a sliding weight 4536 ± 9 gm having a free fall of 457.2 ± 1.524 mm.

(iv) Instead of a hand operated compaction hammer, a properly calibrated mechanically operated hammer can be used.

(v) The compaction pedestal shall consist of a 203.2 mm x 203.2 mm x 457.2 mm wooden block capped with a steel plate 304.8 mm x 304.8 mm size and 25.4 mm thick to hold the mould assembly. The wooden block is secured to a solid concrete base by means of four angle brackets. The steel cap must be firmly fastened to the block. The pedestal assembly shall be installed so that the post is plumb and the steel cap is level.

(vi) The specimen mould holder is fitted centrally to the steel cap so as to hold the specimen mould, collar and the base plate securely in position during compaction of the mixture.

(vii) The Marshall testing head for applying circumferential load on the compacted specimen consists of upper and lower cylindrical segments or test heads having an inside radius of curvature of 50.8 mm. The lower head is mounted on a base having two perpendicular guide rods or posts extending upward.

(viii) The loading jack shall consist of a screw jack mounted in a testing frame and shall produce a uniform vertical movement of 50.8 mm per minute. An electric motor may be attached to the jacking mechanism. Instead of the loading jack, a mechanical or hydraulic loading system to produce the above uniform rate of movement can be used.

(ix) The load measuring device such as proving shall have a capacity of about 25 kN with sensitivity of 50 N and shall be equipped with a dial gauge graduated in 0.0025 mm divisions. Attachments are required at top and bottom of the proving ring for fixing to the load frame and testing head respectively. (x) The flow meter consists of a guide sleeve and a gauge. The pointer of the gauge shall be placed freely over the guide rod of the breaking head and shall slide inside the sleeve with a slight amount of frictional resistance. The flow meter dial shall indicate divisions of 0.25 mm.

(xi) Ovens or hot plates thermostatically controlled are needed for heating aggregates, bituminous materials, moulds, base plate, compaction hammer etc. If a hot plate is used, a wire mesh or similar material shall be placed over the hot plate to prevent direct contact of the flame with the mixing bowl.

(xii) Mechanical mixing of the materials is recommended. A metal pan or bowl of sufficient capacity and hand mixing may also be used.

(xiii) The hot water bath shall be 152.4 mm deep, thermostatically controlled to maintain a temperature of 60±1°C. The tank shall have a perforated false bottom or a shelf for supporting the specimens fixed at 50.8 mm above the bottom of the bath.

(xiv) The air bath for bitumen cutback mixtures shall be thermostatically controlled to maintain the air temperature at 25 ±1°C.

(xv) Balance 2.0 kg capacity sensitive to 0.1 gm for weighing moulded specimens. (xvi) Balance 5.0 kg capacity sensitive to 1.0 gm for weighing mix ingredients.

(xvii) Armored-glass, dial type or digital thermometers for determining the temperature of aggregate, bitumen and bitumen mixture with sensitivity 1.0°C with the range 0 to 200 ºC.

(xviii) Thermometers for water/air baths sensitive to 0.2°C with the required range. (xix) Containers suitable for heating aggregates and bituminous material.

(xx) Mixing tools, either a steel trowel or spatula for spading and hand mixing

 (xxi) Miscellaneous tools like hot gloves for handling hot equipments, rubber gloves for removing specimens from water bath, marking crayons for identifying specimens, scoop for batching aggregates, spoon for placing mixture in the specimen moulds etc.

3. Mixing and compacting

temperatures The mixing temperature is determined from the viscosity of the binder. The temperature to produce a viscosity of 170±20 cSt shall be the mixing temperature. The temperature to produce a viscosity of 280±30 cSt shall be the compacting temperature for bitumen cement

4. Procedure

a) Dry the aggregates to a constant mass at 105 to 110°C and carry out dry sieving. Find the proportion the aggregates to get the desired grading. b) Mix the aggregates (about 1200 gm) required to produce a batch that will result in a compacted specimen of 63.5±1.27 mm in a pan.

c) Place the pan over a hot plate or in oven and heat to a temperature not exceeding the mixing temperature determined earlier by 28°C for bitumen and 14°C for cutback bitumen.  d) Heat the binder for one batch in a separate container. Transfer the heated aggregate mix to the mixing bowl.

e) Make a crater in the mixing bowl and pour the required amount of heated bitumen into it. Mix the aggregate and bitumen thoroughly till complete coating is achieved, ensuring no loss of material.

f) Clean the specimen mould assembly and face of the compaction hammer and heat them in boiling water, oven or hot plate to a temperature between 93.3°C and 148.9°C.

g) Fix the mould with base plate over the compaction pedestal. Place a filter paper at the bottom of the mould before the hot mixture is introduced. Place the entire batch in the mould and stir vigorously with a hot spatula or trowel 15 times around the perimeter and 10 times interior. Smooth the surface of the mixture to a slightly rounded shape. Temperature of the mixture immediately prior to compaction shall be the compaction temperature already established.

h) Replace the collar and place a filter paper or paper toweling cut to size, on the top of the mixture. Apply the specified number of blows with the hammer with a free fall of 457.2 mm. During compaction, hold the axis of the hammer perpendicular to the base of the mould assembly. Apply the same number of blows to the other side also after reversing the mould.

 i) Allow the specimen to cool. Carefully remove the specimen from the mould using sample extruder

 j) Specimens prepared with bitumen are placed in a water bath for 30 to 40 minutes kept at 60±1ºC. For specimens with tar, the bath temperature is 37.8±1°C. The specimens prepared with cutback bitumen are kept in air bath at 25±1°C for 2 hours

 k) Clean the guide rods and inner face of the test head prior to making the test. Lubricate the guide rods so that the upper head slides freely. The testing head temperature shall be maintained between 21.1°C to 37.8°C using a water bath, if required.

l) Remove the specimen from bath and place centrally on the lower segment of the testing head. Place the upper segment over the specimen and place the assembly in position on the testing machine.

m) Place the flow meter over the testing head tightly clamped to one of the guide rod. Adjust the dial of the meter to zero before start of the test. Hold the flow meter in position at the time of loading.

n) Apply the load to the specimen at the constant rate of 50.8 mm per minute until the maximum load is reached. Calculate load from the dial reading of the micrometer.

o) Note the flow dial reading at the failure load when the load starts decreasing.  The elapsed time from removal of the specimen from water bath to maximum load determination shall not exceed 30 seconds. 

p) If the specimen thickness differs from 63.5 mm, apply correction to the load using the correction factors.

5. Report

The report shall include the following:

(i) Type of sample – laboratory or pavement core sample

 (ii) Average height of specimen for each sample

 (iii) Average maximum load of at least three specimens, corrected if required.

(iv) Average flow value of at least three specimens, in the required unit

 (v) Test temperature. The format QC-B6/2014 included in Appendix A - Bituminous mix design may be used for recording the test data

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