Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/712836
August 2016 | EquipmentWorld.com 54 road science | continued Selecting a plant Cliff Mansfi eld of C.M. Consulting in Odell, Oregon, has been working in the paving industry for more than 40 years and travels the world in- stalling and repairing asphalt plants, as well as training personnel how to use them. For contractors looking to invest in their own plants, he offers a series of considerations including the type of plant, portability and size. The two main types of asphalt plants include batch and drum, and the decision on which to choose depends on a contractor's needs, he says. For example, batch plants are good for contractors who need to change their mix frequently, or those who need to stop and restart frequently through the day. A drum plant is best for contractors who pro- duce the same mix design continu- ously and for longer periods of time. Batch plants also are generally Washington State DOT P roducing asphalt isn't as easy or simplistic as merely dumping binder and aggregate together and expecting a dead-on-to-spec mix. It requires careful monitoring by well-trained personnel. Problems with mix at the plant level can include the clearly visible segregation, but also inconsistency in binder content. The "garbage in, garbage out" adage holds true. Astec's Renegar boils down asphalt plant trouble shooting for contractors into three basic tips. 1. Be your own police. Don't wait to be caught if you know something isn't right. 2. Listen to your own folks. They probably know what's wrong. 3. Don't wait until you are desperate to call the manufacturer for help. Quality management of the asphalt plant can prevent a host of problems. A contractor needs to: • Manage their aggregate stockpiles to avoid both material comingling or running out of material • Maintain the conveyors and gates in the silo • Maintain and calibrate the binder pump • Maintain heating systems • Match the speeds of the plant output to the speed of the pavers and rollers at the jobsite. Asphalt plant troubleshooting Mix must be handled properly when placed in a truck at the plant so that it doesn't segregate before it's dumped in the hopper of paver.