SOFTENING POINT OF BITUMENReference Standard: ASTM (1998).ASTM D36-95, Millard, R.S (1993)

INTRODUCTION

Unlike some substances for example water which changes from solid to liquid at 0℃ bituminous materials do not have a definite melting point. Instead, as the temperature raises these materials slowly changes from brittle or very and slow flowing materials to softer and less viscous liquids. For this reason the determination of softening point must be made by affixed, arbitrary and closely defined method if results are to be comparable.

Being very simple in concept and equipment the ring and bell has remained a valuable consistency test for control in refining operations particularly in the production of air blown bitumen. It is also an indirect measure of viscosity or rather the temperature at which the given viscosity is evident. The softening point value has particular significance for materials which are to be used as thick films such as joint and crack fillers and roofing material. A high softening point ensures that they will not flow in service. For bitumen of a given penetration determined at 25℃ the higher the softening point the lower the temperature sensitivity.

OBJECTIVE

The objective of the experiment is to determine the temperature at which given bitumen reaches a certain degrees of softness.

APPARATUS

i. Steel ball of diameter 9.53mm and weighing 0.05gii. Tapered ring made of brass and conforming to the standard BSI

iii. Ball guide and ring holderiv. Thermometerv. Beaker

vi. Burner

PROCEDURES

1The bitumen was melted and the liquid was poured into a pair of ring placed on plate.

2After specimen had cold, ring was suspended in the distilled water in the beaker at 5 2.

3Bath temperature is maintained at that temperature for 15 minutes.

4The steel balls were put on the surfaced of the bitumen in the ring.

5The bath liquid was stirred and heated to 5 2 per minutes.

6Temperature was noted just after the ball was passed and dropped into the base plate.

RESULT

Record the temperature indicated by the thermometer at the beginning of the heating and at the end of each 1 minute interval.

Timer reading (min)

Temperature (°C)

Timer reading (min)

Temperature (°C)

0 5.6 15 29.11 7.4 16 30.62 8.4 17 32.23 9.6 18 33.84 11 19 35.45 12.5 20 36.96 14.2 21 38.47 15.8 22 39.88 17.6 23 41.39 19.3 24 42.910 21 25 44.411 22.6 26 4612 24.3 27 47.513 25.9 28 49.114 27.5 29 -

The mean temperature of the two specimens (which shall not differ by more than 1℃) is recorded as the softening point.

Number of Test Softening Point (℃)

1 48.40

2 49.10

Average 48.75

DISCUSSION

Based on the results that we obtained from the experiment, the temperature of bitumen to become soft for test number 1 is 48.40℃ while for the test number 2, the temperature is 49.10℃ . Besides that, the average temperature of softening point that we calculated is 48.75℃ . The theoretical value of the optimum temperature of bitumen softening point is between 48℃ to 52℃ according to Jabatan Kerja Raya (JKR) standard. The temperature than we recorded is 48.75℃ which is situated in the theoretical standard.

Cause and error during experimental;

i. The bath temperature not maintained for 15minutes.ii. The bath temperature is not in the 5℃ ± 2℃ range.iii. Surrounding temperature may affect the water temperature.

While doing the experiment, some safety measures have to be follow. Be alert and make sure your hand doesn’t touch the hot burner while taking the reading as it may cause minor severe burn. After the experiment, the apparatus are washed using hazards chemical. Ensure that you wash the apparatus in a fume chamber with your gloves on.

CONCLUSION

To conclude, the final temperature of the softening point is 48.75℃ which match the theoretical value which is 48℃ to 52℃. The objective of this experiment was achieved. During conducting the experiment, there are some errors that occurred which will affect the final result. In order to prevent this from happening, there are methods to improve the experiment’s result. Before doing the experiment, make sure the Ring holder does not hold the Ball guide in stationary. Adjust the ring until the ball can pass through freely. In addition, to get good results, ensure you conduct the experiment in room temperature condition. The purpose of this test in the industry is to estimate viscoelastic properties of both asphalt and a paving mixture especially in road design. This is to test the consistency of bitumen.

REFERENCES

1. http://encyclopedia2.thefreedictionary.com/ring-and-ball+test 2. http://wiki.answers.com/Q/

How_do_you_perform_a_ring_and_ball_test_on_bitemun3. composite.about.com/library/glossary/b/bldef-b523.htm