EFFECTS OF POLYETHYLENE AND KEROSENE ON THE PROPERTIES OF BITUMEN

TEST PROCEDURE & GRAPHICAL PRESENTATION

Specific Gravity Test

           (a)        Wt. of bottle at clean and dry condition = A gm

           (b)        Wt. of (bottle+ water full) at 25⁰ C after 30 min = B gm

           (c)        Wt. of (bottle+ bitumen) at 25⁰ C after 60 min = C gm

           (d)        Wt. of (bottle+ bitumen +water full) at 25⁰ C after 30 min = D gm

                                                    Sp. Gr. = (C-A) / ((B-A)-(D-C))

Penetration Test

(a) Bitumen at 100-1100 C was poured into the container and then cooled to room temperature for one hour.
(b) Container with bitumen was submersed in water at 250 C for one hour.

(c) At constant temp. of 250C, the sample was placed in penetrometer and then readings were recorded for a period of 5 seconds.

Ductility Test

(a) Bitumen was strained through 0.6 mm sieves and then poured into the briquette and was cooled to room temperature for 30 min.
(b) Then sample was placed in water at 25 0C for 30 min.
(c) Excess bitumen was cut off and the briquette was placed in water at 250 C for 1.5 hour. 

(d) Briquette was placed in ductility machine and recorded the reading in cm at which the bitumen threads were broken.

Result of Specific gravity, Penetration and Ductility Test.
(Modified Bitumen Sample made with mixing of Pure Bitumen,
Polyethylene and Kerosene)

Type of Sample	% of Polyethylene content	% of Kerosene content	Specific Gravity	Penetration value	Ductility value
Pure bitumen	0	0	1.020	85	100+
Sample-1	1	1	1.016	41	74
Sample-2	2	2	1.013	53	60
Sample-3	3	3	1.009	50	44
Sample-4	4	4	1.006	41	26
Sample-5	5	5	1.003	38	18

 

Result of Penetration Test (only for % of kerosene content)

Type of Sample	% of Kerosene content	Penetration value
Pure bitumen	0	85
Sample-1	1	80
Sample-2	2	60
Sample-3	3	55
Sample-4	4	54
Sample-5	5	82

 

Solubility Test

(a) 0.50 gm asbestos fiber was thoroughly shaked in 150 cc water.

(b) The crucible was filled with some of the suspension of asbestos in water and applied a light suction to draw off the water, leaving a firm mat of asbestos in the crucible.

(c) The crucible was heated for 10 to 15 min. for the constant weight of A.
(d) 2 gm bitumen was stirred in 100 cc CS2 until all lumps were disappeared and no undissolved sample was adhered to the container. (e) The prepared weighed Gooch crucible was placed in the filter flask. Decanted the solution through the asbestos mat of the crucible with light suction. Removing the crucible from the flask and then heating for 10 to 15 min. for constant weight of B gm.

 

Softening Point Test

(a) Completely fluid bitumen was poured in heated rings placed on metal plate.
(b) After cooling the rings in air for 30 min. the excess bitumen was trimmed.
(c) At this time the temperature of water was kept at 50C for 15 min. and then the balls were placed in position. 

(d) The temperature of water was raised at uniform rate of 50C/min. until the bitumen was softened and touched the bottom plate by sinking of balls.

  

Flash and Fire Point Test

(a) Bitumen was poured into the clean and dried cup up to a filling mark.
(b) Sample was then heated at the rate of 5 to 60C/ min.

(c) Test flame was applied at intervals depending upon the expected flash and fire points.

Result of Solubility, Softening, Flash and Fire Point Test.
(Modified Bitumen Sample made with mixing of Pure Bitumen,
Polyethylene and Kerosene)

Type Of Sample	% of Polyethylene content	% of Kerosene content	Solubility (%)	Softening Point (0C)	Flash Point (0C)	Fire Point (0C)
Pure bitumen	0	0	95.70	43	290	300
Sample-1	1	1	90.05	55	280	295
Sample-2	2	2	85.70	56	270	285
Sample-3	3	3	82.13	57	260	275
Sample-4	4	4	84.30	58	255	270
Sample-5	5	5	87.50	59	250	265

DUCTILITY TEST OF BITUMINOUS MATERIAL

In flexible pavement construction where bitumen binders are used, it is of significant importance that the binders form ductile thin films around the aggregates. This serves as a satisfactory binder in improving physical interlocking of the aggregates. The binder material, which does not possess sufficient ductility, would crack and thus provide pervious pavement surface. It has been stated by some agencies that the penetration and ductility properties, go together; but depending upon the chemical composition and the type of crude source of the bitumen, sometimes it has been observed that the above statement is incorrect. It may hence be mentioned that the bitumen may satisfy the penetration value, but may fail to satisfy the ductility requirements. Bitumen paving engineer would however want that both test requirements be satisfied in field jobs. Penetration or ductility cannot in any case replace each other. The ductility is expressed as the distance in centimeters to which a standard briquette of bitumen can be stretched before the thread cracks. The test is conducted at 27+/-0.5⁰C and a rate of pull of 50+/-2.5 mm per minute. The test has been standardized by the ISI.

LABORATORY TEST FOR BITUMINOUS MATERIAL

Laboratory Test on Bitumen

Crude petroleum obtained from different sources contains different proportions of different constituents. Hence its properties may differ. Therefore to judge their suitability as binders, following tests are recommended;

i)                    Penetration test

ii)                   Ductility test

iii)                 Softening point test

iv)                 Specific gravity test

v)                  Flash point and fire point test

vi)                 Float test

vii)               Viscosity test

viii)              Loss on heating test

ix)                 Solubility test

 

To determine all of these properties, a variety of tests have been specified by Institutions like ASTM, I.S.I., Asphalt institute and B.S.I. Here ASTM is followed. Prepared samples are tested to determine some of above properties. 

CHEMICAL COMPOSITION OF BITUMEN

Bitumen’s chemical composition is extremely complex. According to the most accepted analysis, bitumen can be divided into the following three main fractions.

         i.            Asphaltenes.

       ii.            Maltenes.

      iii.            Carbenes.

Asphaltenes are insoluble in light hydrocarbon solvents, such as petroleum either. Maltenes are soluble in hydrocarbon solvents but carbenes fraction is in soluble in carbon tetrachloride. Maltenes consists of four elements namely nitrogen base, first acidaffins, second acidaffins and Paraffins.

 
The malten fraction may be further sub-divided into resins and oils, and one method that have been used to absorb the resin constituent on an active power such as Fuller’s earth.

Asphaltene fraction together with a part of the maltene fraction forms the dispersed phase. The lower molecular weight maltenes are assumed to from the continuous phase.

Asphaltenes are considered to be small particles surrounded by a resin coating. The oil serves as a medium in which the asphaltene resin can exist. Asphaltenes contribute body, resins furnish adhesiveness and ductility, and oils influence viscosity and flow.