KOD ETIKA PELAJAR (KEP) JABATAN KEJURUTERAAN JALAN RAYA & TRAFFIK FAKULTI KEJURUTERAAN AWAM & ALAM SEKITAR UNIVERSITI TUN HUSSEIN ONN MALAYSIA BATU PAHAT JOHOR "Saya dengan ini mengaku bahawa saya telah menyediakan laporan ini dengan daya usaha saya sendiri. Saya juga mengaku tidak menerima atau memberi sebarang bantuan dalam menyediakan laporan ini dan membuat ikrar ini dengan kepercayaan bahawa apa-apa yang tersebut di dalamnya adalah benar"
(TANDATANGAN PELAJAR) NAMA NO. MATRIK •........ TARIKH
1. AIM / PURPOSE Skid Resistance Test a. To determine that slippery is one of the main cause of accident. b. To know the road surface condition that danger to users. c. Indentify and make investigation to confirm that slippery is one of the main cause of accident. d. To determine the temperature of the road e. To know the friction of the road in dry f. To know the friction of the road in wet g. Produce skid resistant (high friction) surfaces for sites with known skidding and braking problems. h. Inadequate skid resistance will lead to higher incidences of skid related accidents Sand Patch Test a.
To know the surface texture of a pavement.
b.
Texture depth determined by the Sand Patch Method is a measure of the surface macrostructure.
c.
To fine the texture depth.
d.
This test method describes the procedure for determining the average texture depth.
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2. HYPOTHESIS/THEORY
Skid Resistance Test The polished-stone value gives a measure of the resistance of roadstone to the polishing action of vehicle tyres under conditions similar to those occurring on the surface of a road. Where the surface of a road consists largely of roadstone the state of polish of the sample will be one of the main factors affecting the resistance of the surface to skidding. The actual relationship between PSV and skidding resistance will vary with the traffic conditions, types of surfacing and other factors. All factors together with the reproducibility of the test should be taken into account when drawing up specifications for road-works which include test limits for PSV. The test is in two parts: a) First part: Samples of stone are subjected to a polishing action in an accelerated polishing machine. b) Second part: The state of polish reached by each sample is measured by means of a friction test and is expressed as a laboratory-determined PSV. Sampling : The sample used in the laboratory for the test shall be taken in accordance with Clause 5 of MS 30 : Part 3. The sample shall be taken from the normal run of production from the plant.
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Sand Patch Test In order to achieve a good skid resistance value, it is necessary for the surface course to have a ‘roughed’ surface. For coated macadams, this can be achieved by the careful choice of aggregate grading and size. On fine graded macadam and hot rolled asphalt this roughing is provided by coated chippings. The ‘roughness’ is measured and referred to as ‘texture depth’. A typical value for high speed road is 1.5 mm. the measurement of texture depth is done either by the sand patch method or by use of mini texture meter. The method is known as ‘Sand Patch’ because fine sand was used. However, the size of the sand particles needed was only generally available in the UK. For the test to be global, glass beads are now manufactured which usually replace the sand particles.
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3. MATERIALS & EQUIPMENT
APPARATUS Skid Resistance Test
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1. Ruler
2. Thermometer
3. Odometer
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4. Water
5. Traffic cone
6. Safety Helmet
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Sand Patch Test; 1. Sand
2. Soft Brush
3. Measuring Cylinder
4. Tyre to protect wind
5. Ruler
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6. Sand Spreading Tool.
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4.
PROCEDURE
Skid Resistance Test 1. The test was carrying out on the road ACW 20 and ACW 14 for the 4 point of the each road by two conditions of road such as in dry and wet condition. The first test was carrying out on the road ACW 14.
2. The tester was resting upon a firm level surface and the leveling screw was adjusting so that the column is vertical. Then, the axis of suspension of the pendulum was rising so that the arm swing freely and the friction in the pointer was adjusting are released from the right-hand horizontal position the pointer comes to rest at zero position on the scale. 10
The track of the slider was ensuring is parallel to the long edge of the specimen across the skidding distance.
3. The following procedure was using to ensure that the rubber slider is correctly conditioned. a) A stock of Criggon specimens was maintaining for calibration purposes. These shall be made from stone from Criggon Quarry and shall be made and polished as in an actual determination. When tested they shall yield a value in the range 58 to 66. The values and air-dry the specimens was recorded and store them in a sealed container for future use. b) Before using a new slider, swing it five times over the dry surface of a polished Criggion specimen following with a further 20 swings on its wetted surface. The Criggion specimen was keeping used for this purpose apart from the Criggion calibration specimen tested in (c); it may be used repeatedly provided it value (when wet) does not fall below 55.
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c) Before measuring the set of specimens polished on each test run, the performance of the slider was checking by testing a Criggion calibration specimen. The resulting value was recording. Additional polishing through testing yield was repeating progressively lower value and the control shall be discarded when its value falls below 57. A new control shall then be drawn from the stock. If a check value is more than 2 units lower (or one unit higher) than the last recorded value for the control, discontinue testing and rectify any fault in the instrument or its operation or due to changes in the slider. It is recommended that more than one slider be kept in use to help differentiate between a faulty slider and a defective instrument. d) Discard any slider that develops excessive burring and scoring through prolonged use. 4. The first test specimen was locating rigidly with its longer dimension lying in the track of the pendulum, and centrally with respect to the rubber slider and to the axis suspension of the pendulum. Locate it in such a way that the slider of the pendulum will traverse it in the same direction as the specimen travelled in the polishing machine.
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5. The height of the axis of suspension was adjusting of the pendulum so that in traversing the specimen the rubber slider is in contact with it over the whole width of the slider and over a length of 76.0 mm, as accurately as can be visually gauged. 6. Then, wet the surfaces of the specimen and the rubber slider with a copious supply of clean water, being careful not to disturb the slider from its set position.
7. The pendulum was releasing and pointer from the horizontal position and the reading of the pointer was recording to the nearest whole number. This operation was performing five times, rewetting the specimen each times and the mean of the last three readings was recording to the nearest 0.1 unit. Sand Patch Test 1) The surface to be measured must be dry and should first be swept with a soft brush.
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2) A cylinder (3.5 cm high with an are of cross section is 4.5cm 2) was filling with beads and level off with a straight edge.
3) The bead was pour into a heap on the surface to be tested. If in windy conditions, a tyre or similar item may be used to protect the pile.
4) The beads was spreading over the surface, working the material into a circular patch – using a flat wooden disc of 65 mm diameter (this has a hard rubber disc 1.5 mm thick, stuck to one face and usually a handle on the wooden side). The beads are spread so that the surface depressions are filled to the level of the peaks.
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5) Using dividers, the radius of the patch formed by the beads was measured and this to be recorded to the nearest millimeter.
6) A number of tests was carry out at intervals along the road surface, ideally along a line parallel to the kerb, in order to obtain an average value.
5. RESULT & ANALYSIS 15
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6. DISCUSSION
Safety characteristics of a pavement are another measure of its condition, and highway agencies continually monitor this aspect to insure that roadway sections are operating at the highest possible level of safety. The principal measure of pavement safety is its skid resistance. Other elements contributing to the extent in which pavements perform safely are rutting (which causes water to collect that creates hydroplaning) and adequacy of visibility of pavement markings. Skid resistance data are collected to monitor and evaluate the effectiveness of a pavement in preventing or reducing skid-related accidents. Skid data used by highway agencies to identify pavements sections with low skid resistance, to develop priorities for rehabilitation, and to evaluate the effectiveness of various pavement mixtures and surface types. The coefficient of sliding friction between a tire and pavement depends on factors such as weather conditions, pavement texture, tire condition, and speed. Since skidding characteristics
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are not solely dependent on the pavement, it is necessary to standardize testing procedure and in this way eliminate all factors but the pavement. Skid resistance is an important pavement evaluation parameter because: • •
Inadequate skid resistance will lead to higher incidences of skid related accidents. Most agencies have an obligation to provide users with a roadway that is "reasonably" safe.
•
Skid resistance measurements can be used to evaluate various types of materials and construction practices.
The skid resistance value of the completed material on carriageway shall have a minimum average value of 46 (corrected to 35oC) as measured by the SRT pendulum device or equivalent for a number of tests to be agreed by S.O. and the Contractor, depending on the size and type of site involved (JKR specification). skid resistance = microtexture & macrotexture
Microtexture From crystalline structure of agg.particles,Interacts with tyre to generate adhesive forces and Gradually polished away by action of traffic Macrotexture Generated by size, shape & spacing of coarse aggregate particles (also, purpose made grooves in concrete surface) The test procedure covers the determination of the average texture depth of paved surface sand to give the volume of voids. The method is suitable for the measurement of surface with average surface texture depth greater than 0.45mm (i.e. less than 350mm sand circle diameter). The lab and research our group do at surrounding in UTHM, the first location at the main road behind with highway laboratory was using the RW20 type of road surface (Old type of road surface) and the main road in front of Faculty electrical and electronic was using the RW14 type of road surface (New type road surface). Each location, we do 4 times to get the value of skid resistance and the value of sand patch diameter of sand. The sand patch testing are to determine the depth bituminous are be can consider to use for motorist with knowing the area of sand, when the value of diameter of sand is big so the road surface is polished and when the value of diameter of sand is small, so the road surface quiet coarse and can grip the tire of car. From the 18
result, we can analyzed the road are absolutely harm and danger because the roughness of surface road.
ACW 20 Location : Junction of Faculty Electric Time : 4.00 pm -5.00 pm Condition : Wetted Point
1
2
3
4
Temperature :
35º
36º
35º
36º
Average Skid Resistance Value
51
50
47
50
Condition : Dry
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Point
1
2
3
4
Temperature :
39º
39º
39º
39º
Average skid resistance value
102
99
100
90
Point
1
2
3
4
Temperature :
38º
37º
39º
38º
Average skid resistance value
96
96
87
95
ACW 14 Location : Corner of road highway and traffic lab Time : 3.00 pm -4.00 pm
Condition : Dry
20
Condition : Wetted Point
1
2
3
4
Temperature :
26º
38º
35º
35º
Average skid resistance value
70
51
64
55
If the difference between the two mean values of the PSV control specimens for each test run is greater than 4.7, the result for the test shall be rejected. If the mean value of PSV control specimens for either test run does not lie within the range 49.5 to 55.5 the test results shall be rejected. The whole test procedure shall then be rejected. The whole test procedure shall then be examine and modified as necessary to ensure that these requirement for range and mean are satisfied. Value represents the performance of a patterned tire, majority of even with values above 55. Smooth looking roads maybe sllippering to vehicle having smooth tyres and this is danger and must to rehabilitation and maintainance of road surface. During our group do the test of skid and sand patch at surround which has we receive the 2 location, we in danger if the safety precaution has not safety first, as a example the 1 st and 2nd, the road actually is main and many car and motorist through that road, that why the safety must take serious, and Alhamdulillah our group used safety vest, cone, and must have one person to manage the traffic. Besides that, the lecture should to visit when the experiment doing to check the experiment procedure and safety checking.
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For sand patch testing, the value obtained for each road show that the condition of road surface with the texture depth same like what we had predicted. Both locations give us a bigger diameter of sand patch. This reading is due to frequent usage of the road, should be considered, it is an old road.
7. CONCLUSION 22
Road are plays vital rolet o given the vehicle are move place to another place with suitable for motorist, so the related in pavement of top the surface are wheels for any type for vehicle wwither car, lorry, van hence the motorcycle the surface for road are very important to knowing and indentified once road weather the road are good given safety during drive especially at corner road which are very sharp, these wolud be dangerous for motorist. Skid resistance is a method for us to know the pavement surface roughness. Based on our result experiment, the result shows that the values of reading are quite high with 2 condition wetted average in 47-70 and dry road surface average in 87-102. From 2 location we can analyzed the road are absolutely harm and danger because the roughness of surface road. Another factor that should be rememberd is the condition of the existing road. The first location using ACW14 the old surface and 2nd location using ACW 20 the new road surface. So, looked at the esult, the reading dows make sense and logic referring to the age and usage of those roads. 8. REFERENCE
Book a. Highway Engineering, Paul H. Wright; New York;John Wiley,1996 b. Taffic And Highway Engineering, Nicholas J.Garber, Lester A. Hoel. Australia: Brooks/Cole,2002 Website a. http://training.ce.washington.edu/WSDOT/Modules/09_pavement_evaluation/094_body.htm b. http://www.munro-group.co.uk/skid/index.html c. http://www.asphaltwa.com/wapa_web/modules/08_evaluation/08_categories.htm d. http://www.mastrad.com/pendul.htm
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