asphalt cement lab sheet
TRANSCRIPT
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7/22/2019 Asphalt Cement Lab Sheet
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Experiment 1
Part 1: Penetration Test of Asphalt Cement
Objective: To determine the penetration of semisolid and solid bituminous materials
Apparatus:
1. Penetration apparatus and needle2. sample container, water bath, transfer dish, thermometers
Test Procedure:
1. Heat the asphalt binder sample until it has become fluid enough to pour.2. Pour the sample into the sample container and let it cool for at least 1 hour.3. Place the sample, together with the transfer dish in the water bath at a temperature
of 250C (770C) for 1 hour to 2 hours.4. Clean and dry the needle with a clean cloth, and insert the needle into the
penetrometer.5. Position the needle by slowly lowering it until its tip just makes contact with the
surface of the sample. This is accomplished by bringing the actual needle tip into
contact with its image reflected by the surface of the sample from a properly
placed source of light.6. Turn on the penetrometer, and press the switch once.7. Wait until the light is off. Adjust the instrument to measure the distance
penetrated.
8. Record the readings in appropriate units.9. Make at least three determinations at points on the surface of the sample.
Results:
Tabulate the readings and find the average value.
Discussions:
1. What is the significance of the penetration test?2. What is the grade for the asphalt tested?3. Why are there deviations from the grade measured to the real value?4. What is the precaution steps required to improve the accuracy of the test?
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7/22/2019 Asphalt Cement Lab Sheet
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Part 2: Viscosity Test of Asphalt
Objective: To determine the absolute viscosity of asphalt by vacuum capillary viscometer
at 600C.
Apparatus:
Viscometers, Bath, Thermometers, Vacuum system, Stop watch
Procedure:
1. Maintain the bath at a temperature of 600C.2. Charge the viscometer by pouring the prepared asphalt sample to the fill line.3. Insert the viscometer in a holder, and position the viscometer vertically in the bath
so that the uppermost timing mark is at least 20mm below the surface of the bath
liquid.
4. Connect the vacuum system to the viscometer.5. After the viscometer has been in the bath for 30 min, start the flow sample upward
through capillary by opening the toggle valve to the vacuum system.6. Measure to within 0.1 second the time required for the leading edge of the
meniscus to pass between successive pairs of timing marks.
7. Repeat the procedure for second run.Results:
1. Tabulate the flow time for each of the bulb.2. Depends on the size of viscometer used, the viscometer constant of the asphalt for
each bulb is given as follows:
Calculate the viscosity of asphalt for each bulb.
Discussions:
1. What is viscosity of asphalt?2. What are the precaution steps taken to improve the accuracy?3. What are the limitations of Viscosity Grading System?
Viscometer No. 200
Bulb Viscometer
Constant
(Poise/second)
B 121.5
C 61.42
D 41.46
E 31.31
F 25.04
Bulb Viscometer
Constant
(Poise/second)
B 35.19
C 16.90
D 10.96
E 7.594
F 6.279
Viscometer No. 100 Viscometer No. 50
Bulb Viscometer
Constant
(Poise/second)
B 8.263
C 3.948
D 2.624
E 1.959
F 1.568