FACULTY OF CIVIL AND ENVIRONMENTAL ENGINEERING DEPARTMENT OF GEOTECHNICAL AND TRANSPORTATION ENGINEERING LABORATORY OF HIGHWAY
LAB REPORT Subject Code Code & Experiment Title Course Code Date Group
BFC3121 SOFTHENING POINT OF BITUMEN 3 BFF 5 APRIL 2011 6
Members of Group
1. HAFIZAN MOHD SALLEH
CF090351
2. SAIDATUL ELINA BT NEBIL
CF090156 CF090321 CF090362
3. NOOR SANAA BT MOHD BUNYAMI 4.NUR HASLIZA BT HASSAN
Lecturer/Instructor/Tutor Received Date
Comment by examiner
EN. MOHD NASIR BIN MOHD TAHIR 12 APRIL 2011
Received
FACULTY OF CIVIL AND ENVIRONMENTAL ENGINEERING DEPARTMENT OF GEOTECHNICAL AND TRANSPORTATION ENGINEERING
TRANSPORTATION ENGINEERING LABORATORY
LABORATORY INSTRUCTION SHEETS
SUBJECT CODE EXPERIMENT CODE EXPERIMENT TITTLE COURSE CODE
BFC 3121 MA6 SOFTENING
STUDENT CODE OF ETHIC (SCE) DEPARTMENT OF GEOTECHNICAL AND TRANSPORTATION ENGINEERING FACULTY OF CIVIL & ENVIRONMENTAL ENGINEERING
I, hereby confess that I have prepared this report on my own effort. I also admit not to receive or give any help during the preparation of this report and pledge that everything mentioned in the report is true.
___________________________ Student signature
___________________________ Student signature
HAFIZAN MOHD SALLEH Name : _____________________
SAIDATUL ELINA BT NEBIL Name : _____________________
CF 090 351
Matrix no :___________________
12 APRIL 2011
CF 090 156
Matrix no :___________________
12 APRIL 2011JANUARY
Date :_______________________
Date :_______________________
___________________________ Student signature
___________________________ Student signature
NOOR SANAA MD BUNYAMI
Name : _____________________
CF 090 321
Matrix no :___________________
12 APRIL 2011
Date :_______________________
NUR HASLIZA HASSAN
Name : _____________________
CF 090 362
Matrix no :___________________
12 APRIL 2011JANUARY
Date :_______________________
1.0
OBJECTIVE To determine the softening point of bitumen within the range 30 to 157 0C bye mean of the ring and ball apparatus.
2.0
BACKGROUND Unlike some substances (e.g. water which changes from solid to liquid at 0 oC) bituminous materials do not have a definite melting point. Instead, as the temperature rises, these materials slowly change from brittle or very thick and slow-flowing materials to softer and less viscous liquids. For this reason, the determination of 'softening point' must be made by a fixed, arbitrary and closely defined method if
results
are
to
be
comparable. Being very simple in concept and equipment, the Ring-and-Ball Test has remained a valuable consistency test for control in refining operations, particularly in the production of air-blown bitumens. It is also an indirect measure of viscosity or, rather, the temperature at which a 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 materials. A high softening point ensures that they will not flow in service. For a bitumen of a given penetration (determined at 25oC), the higher the softening point the lower the temperature sensitivity. Research has shown that, for conventional paving grade bitumens, the Ring-andBall softening point temperature is the same as that which would give a penetration of 800 d-mm. This, together with the penetration at 25 oC, can be used to compute the Penetration Index.
3.0
INTRODUCTION
Bitumen materials are extensively used for roadway construction, primarily because of their excellent binding characteristics and water proofing properties and relatively low cost. Bituminous materials consists of bitumen which is a black or dark colour solid or viscous cementitious substances consists chiefly high molecular weight hydrocarbon derived from distillation of petroleum or natural asphalt, has adhesive properties, and is soluble in carbon disulphide. Bitumens are viscoelastic materials without sharply defined melting points; they gradually become softer and less viscous as the temperature rises. For this reason, softening points must be determined by an arbitrary and closely defined method if results are to be reproducible. The softening tests are usually conducted to evaluate of bituminous materials. The softening point is useful in the classification of bitumens, as one element in establishing the uniformity of shipments or sources of supply, and is indicative of the tendency of the material to flow at elevated temperatures encountered in service. Softening point denotes the temperature at which the bitumen attains a particular degree of softening under the specifications of test. The test is conducted by using Ring and Ball apparatus. A brass ring containing test sample of bitumen is suspended in liquid like water or glycerin at a given temperature. A steel ball is placed upon the bitumen sample and the liquid medium is heated at a rate of 5o C per minute. Temperature is noted when the softened bitumen touches the metal plate which is at a specified distance below. Generally, higher softening point indicates lower temperature susceptibility and is preferred in hot climates.
4.0
SUMMARY OF TEST METHOD (ASTM 1988) Two horizontal disks of bitumen, cast in shouldered brass rings, are heated at a controlled rate in a liquid bath while each supports a steel ball. The softening point is reported as the mean of the temperatures at which the two disks soften enough to allow each ball, enveloped in bitumen, to fall a distance of 25 mm.
5.0
APPARATUS Thermomet
Ring Ring holder and assembly
Clipper Ice cube Bal
Bitumen
Bitumen
Figure 1. Apparatus for the bitumen Softening Point Test (Millard, 1993)
6.0
PROCEDURE
1. Specimen are prepared exactly as specified (ASTM D36-95) in precisely dimensioned brass rings and maintained at a temperature of not less than 100C below the expected softening point for at least 30 minutes before the test. 2. The rings and assembly and two ball bearings are placed in a liquid bath filled to a
depth of 105 ± 3 mm and the whole maintained at a temperature of 5 ± 10C for 15 minutes. Freshly boiled distilled water is used for bitumen with a softening point of 800C or below and glycerine is used for softening point greater.
Poured bitumen the
into
rings Hot bitumen placed into ring
Put the ring into ring holder
put an ice into the beaker and
maintain
its temperature to 5oc for 15 minutes.
Hot bitumen for cold
put the magnetic stirrer and stir it
Wait until the bitumen fall to the plate and record the temperature.
7.0
RESULT AND CALCULATION
boiled the ice until it melt
waited
Number of test 1 2 AVERAGE
Softening point (oC) 50 48 49
Table A.1: Softening Point Test (ASTM D36)
P1
Bitumen Type
-1.55
Conventional paving bitumen Table A.2: Value of penetration Index (PI)
Calculation of Penetration Index (PI) Softening Point = 49 oC Penetration
= 75 mm
∴ Based on Nomograph for the Penetration Index of bitumen below, we get the
Penetration Index (PI) is -1.
8.0
QUESTIONS
a)
Report the source and type of bitumen. Bitumen is a non-crystalline viscous material, black or dark brown, which is
substantially soluble in carbon disulphide (CS2), possessing adhesive and water-proofing qualities.It consists essentially of hydrocarbons and would typically comprise at least 80% carbon and 15% hydrogen, the remainder being oxygen, sulphur, nitrogen and traces of various metals. Asphalt is a word with different meanings. In American usage asphalt, or, in full, asphalt cement, is used to mean bitumen (or bitumen binder). In the term 'rock asphalt' it defines a mineral substance that may be impregnated with bitumen or pitch. Bitumen does occur naturally, but for all intents and purposes it is petroleum on which the world relies for its supplies of bitumen today. The bitumen content of crude can vary between 15% and 80%, but the more normal range is 25% to 40%. In fact the three broad classifications for crude oils are:
Bitumen based.
paraffin based
bitumen and paraffin based
Depending on the type of crude, bitumen is present either in the form of colloidally dispersed particles or in a true solution. During the refining process, as petroleum oils are taken away by distillation, the proportion of oil to bitumen particles changes. Instead of being dispersed and relatively few in number, the particles become closer to one another and the size of the particles increases. At the point when the distillation process is usually stopped, the petroleum bitumen is a colloidial dispersion of black solids (hydrocarbons), known as asphaltenes, in a dispersion medium, which is an oily brown yellow liquid known as malthene fraction. Also present to act as a stabilizing agent to keep the asphaltenes in suspension are another group of hydrocarbons known as resins. There are two source of bitumen which is from natural sources is a bitumen which is located in geological stratum and can be obtained in the hard and soft form.
Meamwhile, the second sources of bitumen are from petroleum bitumen is a bitumen in colloidal form obtained from refinery process of crude oil and has been widely used in the road construction. There are three types of bitumen such as asphalt, tar and pitches. Asphalt consists primarily of bitumen. Tar is obtained from natural organic materials such as coal or wood are carbonized or destructive distillation of coal in the absence of air. Pitches can be made from petroleum products or plants which are also known as resin. The type of bitumen is temperature susceptible bitumen (Tar).
Paving grade bitumen is refined and blended to meet road engineering and industrial specifications that take into account different climatic conditions. As a product it is the most widely used bitumen. It may also be considered as the parent bitumen from which the other types, listed below, are produced.
Cutback bitumens consist basically of bitumen that has been diluted in order to make it more fluid for application, mainly in road making. Their fluidity depends on the degree of hardness of the bitumen base and the proportion of diluent (or flux) to bitumen. They are classified according to the time it takes them to become solid, as rapid curing (RC), medium curing (MC) or slow curing (SC) cutbacks. The cutback varies according to the flux, white spirit commonly being used for RC grades, kerosene for MC and diesel for SC. They set as the fluxevaporates. This evaporation is currently regarded as a potentially undesirable characteristic from the point of view of the environment and health and safety, so cutback bitumens are looked upon less favourably than the more modem bitumen emulsions.
bitumen emulsions the basic bitumen has also been diluted in order to facilitate application. Hot bitumen, water and emulsifier are processed in a high-speed colloid mill thatdisperses the bitumen in the water in the form of globules that are normally in the 5-10 micrometre size range but may be even smaller. The emulsifier produces a system in which fine droplets of bitumen, of between 30%
and 80% of the volume, are held in suspension. If they separate in storage, the emulsion can easily be restored by agitation. Bitumen emulsions have a low viscosity and can be workable at ambient temperatures, which makes them ideal for use in roadbuilding. This application requires controlled breaking and setting. The emulsion must not break before it is laid on the road surface but, once in place, it should break quickly so that the road can be in service again without delay. b)
Report the bath liquid in the test and quote the mean softening point of your specimen. Comment on the value obtained. From the test 1 experiment that we do, the bitumen will start to soften when the temperature increases and drops each ball enveloped in the bitumen at a distance 25mm. We have got 45 0C as the mean softening point. Then, for the test 2 experiment, we got 46 0C as the mean softening point. The average softening point is 45.5oC. For the value of the penetration index (PI) based on the experimental is -2 and it include in conventional paving bitumen type. The liquid that we use in softening point test is water. The ring and assembly and two ball bearings are place in water to a depth of 105 ± 3 mm. and the whole maintained at a temperature of 5± 1 oC. Freshly boiled distilled water is used for bitumen with a softening point of 80 oC or below and glycerin is used for softening point greater. The mean softening point is 45.5 oC and it still in range between 44 oC and 45 oC . So the mean temperature of the two specimen is not differ by more than 1 o
C. The value for this temperature is not differ than 1 oC because we make the
experiment using the same of sample bitumen. This value is to be used to define the Penetration Index (PI) c)
If the two test temperature differ by more than 1 0C, offer an explanation.
Based on the experiment, we can see that he causes of temperature differ by more than 1°C because of the volume of bitumen in ring are not the equal. It happens because of same error and it maybe became from personal errors like does how are not familiar with the apparatus or the way to put the bitumen in to the ring. Besides that, the other causes that lead to differ temperature is also of external factors such as temperature, pressure or physical condition of the apparatus may cause some errors in the experiment. Besides that, the two samples are different because the softening points are different. Therefore, the consistency changes as temperature, so the types of bitumen of two samples are different type. Others than that, the two test temperature differ by more than 1°C due to the bitumen condition which becomes soft in irregular state. It causes the balls to fall at different temperature. Deep water temperature in the beaker has been irregular because the bitumen softens at different state.
9.0
DISCUSSION
Based on the experiment conducted the bitumen in BS 4692. While doing this test, preparation of this sample must be done under controlled condition as mentioned in BS 4692. So this test is to be done with high consistency. From the test, two values are recorded, which could be identified at the same time. Insulated water is used at temperature of 0.5 oC. Two bearings with 9.53 mm diameter are put on top of the samples. Softening point is a temperature where the bitumen specimen fall and touch on the base plate which is 25mm under the ring. For this experiment that we have done, we used two ball bearings to determine the mean temperature in effort to get an exactly value. A different temperature between both specimens that fall on the base is 0.50C because both specimens fall at temperature 450C and 490C. The objective of the softening point is to determine temperature where tie materials or bitumen achieve soft level in the condition that already decided. A ball bearing in 9.5 mm diameters and 3.5 g was put on the specimen. For this test, we used water as a medium (bath liquid) because the softening point cannot greater than 800C. Base on the bitumen grade by JKR specification: Softening point (0C), ASTM D36 Not less than 48 and not more than 56 Not less than 45 and not more than 52
Penetration Grade 60 – 80 80 - 100
The softening point that we get is 470C. Thus this value is not fulfilling the bitumen grade of Malaysia JKR specification.
Our mean temperature was 47 0C where both specimens touched the base plate. The different values between both specimens are 40C. This is because those specimens not touched the base at the same time. If the different temperature was more than 1 0C, it
may be because of the heat for the medium is not uniformly. Thus, we need to stir the medium in effort to make sure the temperature is uniformly and with use magnetic stir, this problem can be solve. Beside that, to heat the beaker we can use electronic heater to solve this problem. Softening point is different for different asphalt. Normally, types of asphalt are cement asphalt, emulsion asphalt, cutback asphalt, and tar. Cement asphalt always use in roads pavement. They are remainder materials from petroleum distillate process. The character of the cement asphalt is very good as a tie component. Cutback asphalt is in a liquid condition at a normal temperature and it getting by mixed cement asphalt with light dissolves. Emulsion asphalt is always use in maintaining asphalt pavement process. It is mixed from cement asphalt, water and emulsion materials. Tar is a liquid that sticky, black and have a glue characteristic that always use as tie material in bitumen pavement. Tar is get by destroy distillate charcoal, wood and syal.
10.0
CONCLUSION As a conclusion, we can see that we achieve the objective of this softening point test which is to determine the softening point of the bitumen within the range of 30°C to
157°C by means of the ring and ball apparatus. This is a basic test for the classification of bituminous materials for the road construction. From the experiment, since the softening of the bituminous material does not take place at any definite temperature, but rather involves a granular change in consistency the penetration index and in conjunction with penetration and loading time, can be used to estimate viscose elastic properties of both the asphalt and a paving mixture. This method can also be used to advantage to predict high-temperature shear resistance of the paving mixture. Bitumens are visco elastic materials without sharply defined melting points; they gradually become softer and less viscous as the temperature rises. For this reason, softening points must be determined by an arbitrary and closely defined method if results are to be reproducible. The softening point is useful in the classification of bitumen’s, as one element in establishing the uniformity of shipments or sources of supply, and is indicative of the tendency of the material to flow at elevated temperatures encountered in service. From the nomograph in figure 1, we know that the penetration (PI) is -1, so that the type of bitumen is Conventional Paving Bitumen The principle behind this test is that softening point is the temperature at which the substance attains a particular degree of softening under specified condition of the test.
REFERENCES
ASTM (1998). D36-95 Standard test method for softening point of bitumen (Ring-andBall Apparatus). 1998 Annual Books of ASTM Standards, Volume V04.04, American Society for Testing and Materials, Philadelphia, PA 19103-1187.
Millard, R.S. (1993). Road building in the Tropics. Transport Research Laboratory Stateof-the-art Review 9, HMSO, London.
PWD (1992). PWD General Specification. Public Works Department, Singapore 1987 (with amendments, 1992).
www.ntu.edu.sg/cts/tlab/002.pdf
