ROAD MATERIAL TESTING

BITUMEN TESTING1. Penetration Tests2. Ductility Tests and Elastic Recovery3. Softening Point Tests4. Viscosity Tests5. Specific Gravity Test6. Flash and Fire Point Test7. Solubility Test

AGGREGATE TESTING1. Impact Test2. Los Angeles Abrasion Test3. Stripping Test4. Crushing Test

Note: - The bitumen is semi-liquid in nature and it obtained from the fractional distillation of crude petroleum. In factional distillation the various volatile constituents are separated at successively higher temperatures without substantial chemical change. The successive fractions obtained yield gasoline, naptha, kerosene and lubricating oil; the residue would be petroleum bitumen.

1. Penetration Test

Aim: - To determine the Consistency of the bitumen.

Apparatus required: - Penetrometer apparatus, thermometer, stopwatch, transfer dish, containers, and water cooling bath.

Figures:-

Procedure: -1. Soften the material to a pouring consistency at a temperature not more than 900C for bitumen above the approximate softening point and stir it thoroughly until it is homogenous and is free from air bubbles and water. Pour the melt into the container to a depth atleast 10-15mm in excess of the expected penetration. Protect the sample from dust and allow it to cool in an atmosphere at a temperature between 150 to 300C for one hour. Then place it along with the transfer dish in the water bath at 25.00 0.10C and allow it to remain for 1hr to1hr 30min or 2hr. The test is carried out at 25.00 0.10C, unless otherwise stated. 2. Clean the needle with benzene, dry it and load with weight. The total moving load required is 100gms, including the weight of the needle, carrier and super-imposed weights. After that the sample container is taken out of water bath for testing. 3. Adjust the needle to make contact with the surface of the sample. This may be done by placing the needle point with its image reflected by the surface of the bituminous material. 4. Make the pointer of the dial to read zero or note the initial dial reading. 5. Release the needle for exactly five seconds. 6. Adjust the penetration machine to measure the distance penetrated. 7. Make at least 3 reading at points on the surface of the sample not less than 10mm apart. Other samples are then tested with same procedure stated above. The needle should be cleaned with benzene and dried after each test.

Observation Table: - ReadingsTrial 1Trial 2Trial 3Mean value

Penetrometer dial initial readings000-

Penetrometer dial final readings51535353

Penetration value @ 100g, 250C, 5 sec,1/10mm Average value = 53(Grade VG 30 )

Result: - The penetration value of sample taken is 53. Hence the bitumen is of grade VG 30.

2. Ductility Test

A certain minimum ductility is necessary for a bitumen binder. This is because of the temperature changes in bituminous mixes and the repeated deformations that occur in flexible pavements due to the traffic loads. It is of significant importance that the binders form ductile thin films around the aggregates. The binder material which does not possess sufficient ductility would crack and thus provide previous pavement surface. This is in turn results in damaging effect to the pavement structure. The ductility is expressed as the distance in centimeters to which a standard briquette of bitumen can be stretched before the thread breaks. The test is standardized by the IS: 1208. The test is conducted at 27O.5C and a rate of pull of 502.5 mm per minute.Aim: - To measure the adhesion property of bitumen and its ability to stretch.

Apparatus Required: - Briquette mould, (length 75mm, distance between clips 30mm, width at mouth of clips 20mm, cross section at minimum width 10mm x 10mm), Ductility machine with water bath and a pulling device at a pre calibrated rate, a putty knife, thermometer.

Figures: -

Procedure: - 1. Melt the bituminous test material completely at a temperature of 750 C to 1000 C above the approximate softening point until it becomes thoroughly fluid 2. Strain the fluid through IS sieve 30. 3. After stirring the fluid, pour it in the mould assembly and place it on a brass plate 4. In order to prevent the material under test from sticking, coat the surface of the plate and interior surface of the sides of the mould with mercury or by a mixture of equal parts of glycerin and dextrin 5. After about 30 40 minutes, keep the plate assembly along with the sample in a water bath. Maintain the temperature of the water bath at 270 C for half an hour. 6. Remove the sample and mould assembly from the water bath and trim the specimen by leveling the surface using a hot knife. 7. Replace the mould assembly in water bath maintained at 270 C for 80 to 90 minutes 8. Remove the sides of the moulds 9. Hook the clips carefully on the machine without causing any initial strain 10. Adjust the pointer to read zero 11. Start the machine and pull two clips horizontally at a speed of 50mm per minute 12. Note the distance at which the bitumen thread of specimen breaks. 13. Record the observations in the proforma and compute the ductility value report the mean of two observations, rounded to nearest whole number as the Ductility Value

Observations: -Test PropertyTrial 1Trial 2Trial 3Mean value

Ductility Value71cm75cm 75cm75cm

Result: - The Ductility Value of the given sample is 75cm.

3. Softening Points Tests

Theory and Scope: Bitumen does not suddenly change from solid to liquid state, but as the temperature increase, it gradually becomes soften until it flows readily. The softening point is the temperature at which the substance attains particular degree of softening under specified condition of test. For bitumen it is usually determined by Ring and Ball apparatus. The test is conducted as per IS: 1205.

Aim: To determine the softening point of given paving bitumen as per IS: 1205.Apparatus: Ring and Ball apparatus, Water bath with stirrer, Thermometer, Glycerin, etc. Steel balls each of 9.5mm and weight of 2.50.08gm.Figures:

Procedure:1. Sample material is heated to a temperature between 75 and 100C above the approximate softening point until it is completely fluid and is poured in heated rings placed on the metal plate.2. To avoid sticking of the bitumen to metal plate, coating is done to this with a solution of glycerin and dextrin.3. After cooling the rings in air for 30 minutes, the excess bitumen is trimmed and rings are placed in the support.4. At this time the temperature of distilled water is kept at 5C. This temperature IS maintained for 15 minutes after which the balls are placed in position.5. Then the temperature of water is raised at uniform rate of 5C per minute with a controlled heating unit, until the bitumen softens and touches the bottom plate by sinking of balls. At least two observations are made. For material whose softening point is above 80C, glycerin is used for heating medium and the starting temperature is 35C instead of 5C.6. The temperature at the instant when each of the ball and sample touches the bottom plate of support is recorded as softening point valueObservations: -Observation TableTest PropertyTrial 1Trial 2Trial 3Mean value

Temperature(0C) at which 1st ball touches the bottom plate51.2050.6050.8050.87

Temperature (0C) at which 2nd ball touches the bottom plate50.5050.8051.1050.80

Final Softening Point temperature(0C) Average Value = 510C

Result: - The Softening Point the given bitumen sample is 510 C. softening point of the bitumen shows the nature of bitumen (Bingham Plastic) at which point it start melting/ softening or at which it attends sufficient degree of softening.