INTRODUCTION Skid resistance is important for road safety. With skid resistance it allows for better ‘grip’ between tire and road surfaces. Most road surfaces have adequate skid resistance in the dry as compared during wet condition. The presence of water between tire and road surface reduce the contact are which are needed to create the ‘grip’. This method describes the procedure for determining the frictional properties (skid resistance value) of a pavement surface using a Portable Skid Resistance Tester. OBJECTIVE To determine the skid resistance value of road pavement surface.
SKID RESISTANCE PROCEDURE
APPARATUS A Portable Pendulum Skid Resistance Tester, a rubber slide, a scale ruler, brush, water container and thermometer. CONCLUSION
DISCUSSION
I. The skid resistance tester was set up so that Based on the result of the experiment, the center column is vertical by adjusting the differences between Skid Resistance leveling screws. Value (SVR) for each type of surface are obviously varied, depending on its II. The height of the pivot was adjusted so that surface texture and also its condition, the arms swing freely without touching the either wet or dry. road surface. The pivot was checked to swing freely right through to the zero on the scale. The surface which turned out to have the highest Skid Resistance Value (SVR) is III. The pivot height was lowered so that the the rough road pavement; with the friction foot is in contact with the road surface average wet SVR of 48 and dry of SVR over the precise distance (150mm) as shown by 88.67. Road surface which represent the gauge (scale rule) which is placed smooth texture is having wet SVR of alongside. 29.67 and dry SVR of 54.67. The IV. The pendulum arm was raised to the pavement which is classified as medium starting position and the retaining catch was rough texture is having wet SVR of 35.33 and dry SVR of 70.33. Based on the engaged. value, the readings of the skid resistance V. The road surface was wetted with water value are decreasing as the surface where the readings of skid resistance will be texture changing from rough texture to taken. the smoother texture. It is because the SVR is depends on the pavement VI. The maximum swing indicator was surface’s micro texture. Micro texture checked to be set to the vertical position. refers to the small-scale texture of the pavement aggregate component. VII. The pendulum arm was released. VIII. The pendulum arm was caught after it The experiment is implemented in swings through to prevent back swing which highway engineering in order to evaluate the surface friction between the road and could disturb reading. vehicles’ tires, which enable more research to be made to maximized road IX. The reading on the scale was recorded. safety, primarily during the rain. X. The test was repeated to obtain a minimum Rougher surface will have larger micro of three readings. textures which produce larger force to prevent rotating slides along the pavement. With the presence of water, the SVR value.
The skid resistance test is important in highway engineering since inadequate skid resistance will lead to higher incidences of skid related accidents. Surface with rougher texture will have higher friction value compared to smoother surface texture. Besides, skid resistance measurements can be used to evaluate various types of materials and construction practices of highway and road. Meanwhile, the skid resistance test with wetted surface was done to illustrate the road condition during rain, where it is dangerous for any vehicle to travel in high speed.
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MOHAMAD HAQIMI BIN AWANG MOHAMAD ZAHIR BIN ABDUL RAZAK SITI NAZIHAH BINTI IBRAHIM
