20-10-2014, 10:01 AM
Abstracts: ? This production process is same for all the Road Construction Equipment products. The process is begun to raw-material such as iron plates, pipe, angle, channel, guder. First of all iron plates is going to cut. These cutting plates are used in body making of the equipment. After completing cutting process next is welding. All the material which are necessary in equipment are joint through welding process. Than next is grinding and finishing. This process removes all the dots which are done by welding and give proper shape to the equipment. Now it is going to paint. Basically there are three colours are used yellow, black and white. Than all the parts are to be joint. This process is assembly process. Now the equipment is prepared and ready to sale. ? Hot mix asphalt paving materials are a mixture of graded, high quality aggregate (which may include reclaimed or recycled asphalt pavement) and liquid bitumen, which is heated and mixed in measured quantities to produce hot mix asphalt materials. Aggregate and recycled asphalt pavement, if used, constitute over 92% by weight of the total hot mix asphalt mixture. Aside from the relative amounts and types of aggregate and recycled asphalt pavement used, mix characteristics are determined by the amount and grade of bitumen used. Additionally, the bitumen may be blended with petroleum distillates or emulsifiers to produce cold mix asphalt, often referred to as cutback or emulsified bitumen, respectively. ? The process of producing hot mix asphalt involves drying and heating the aggregate to prepare it for the bitumen coating. In the drying process, the aggregate is dried in a rotating, slightly inclined, direct-fired drum dryer. The aggregate is introduced into the higher end of the dryer. The interior of the dryer is equipped with flights that veil the aggregate through the hot exhaust as the dryer rotates. After drying, the aggregate is generally heated to temperatures ranging from 250 to 300 ?C and then coated with bitumen in one of two ways. In most drum mix plants, the bitumen is introduced directly into the dryer chamber to coat the aggregate. In batch mix plants, the mixing of aggregate and asphalt takes place in a separate mixing chamber called a pug mill. ? The following types of plants primarily define the variations in the hot mix asphalt manufacturing process: ? batch mix plants; • parallel flow drum mix plants; and • counter flow drum mix plants.