30-01-2015, 05:17 PM
road roller ppt
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road roller ppt
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road roller ppt
13-04-2017, 09:04 AM
A road roller (sometimes called roller compactor, or simply roller) is a type of engineering vehicle compactor used to compact soil, gravel, concrete or asphalt in road construction and foundations. Similar rollers are also used in landfills or in agriculture. In some parts of the world, road rollers are still known colloquially as steam rollers, regardless of their method of propulsion. This usually only applies to larger examples (used for road construction).
Since the effectiveness of a roller depends largely on its weight, self-propelled vehicles replaced the horse-drawn rollers of the mid-nineteenth century. The first vehicles of this type were the steam rollers. Single cylinder steam rollers were generally used for compacting the base and operate at high engine speeds in low gear to promote rebound and vibration from the crankshaft to the rollers in the same way as a vibratory roller. The double cylinder or composite steam rollers became popular from around 1910 onwards and were mainly used for hot surface lamination due to their smoother running motors, however both types of cylinders are capable of laminating the finished surface . Steamrollers were often given a task by their gear, since the slower motors were for compacting the base, while the higher gear models were often known as "chip chasers" that followed behind Hot tar laying and chipping machines. Some highway companies in the United States used tamping machines during the 1950s, and in the United Kingdom some remained in commercial service until the early 1970s.
As the technology of internal combustion engines improved during the 20th century, kerosene, gasoline and diesel rollers gradually replaced their steam counterparts. The first internal combustion road rollers were very similar to the steam rollers they replaced. They used similar mechanisms to transmit engine power to the wheels, typically large straight gears exposed. Some users did not like it in their childhood, since the engines of the time were usually difficult to start, particularly those of kerosene. Virtually all road rollers in commercial use now use diesel power.
Since the effectiveness of a roller depends largely on its weight, self-propelled vehicles replaced the horse-drawn rollers of the mid-nineteenth century. The first vehicles of this type were the steam rollers. Single cylinder steam rollers were generally used for compacting the base and operate at high engine speeds in low gear to promote rebound and vibration from the crankshaft to the rollers in the same way as a vibratory roller. The double cylinder or composite steam rollers became popular from around 1910 onwards and were mainly used for hot surface lamination due to their smoother running motors, however both types of cylinders are capable of laminating the finished surface . Steamrollers were often given a task by their gear, since the slower motors were for compacting the base, while the higher gear models were often known as "chip chasers" that followed behind Hot tar laying and chipping machines. Some highway companies in the United States used tamping machines during the 1950s, and in the United Kingdom some remained in commercial service until the early 1970s.
As the technology of internal combustion engines improved during the 20th century, kerosene, gasoline and diesel rollers gradually replaced their steam counterparts. The first internal combustion road rollers were very similar to the steam rollers they replaced. They used similar mechanisms to transmit engine power to the wheels, typically large straight gears exposed. Some users did not like it in their childhood, since the engines of the time were usually difficult to start, particularly those of kerosene. Virtually all road rollers in commercial use now use diesel power.
It can be understood in the following video:
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