Equipment World Digital Magazine
Issue link: https://read.dmtmag.com/i/726012
EquipmentWorld.com | September 2016 73 S tringless paving isn't just for concrete contractors. The asphalt guys are in on it as well, but with a few slight twists on the methods used. As with concrete paving, string- less asphalt paving offers the ben- efi t of eliminating the costly step of bringing in a survey crew to set up the stringline. Eliminating that step also removes the physical ob- stacles of the string and posts that get in the way of the paving crews and the workers running ancillary equipment. But when we talk about stringless paving in asphalt, the conversation turns to 3D paving, which involves not just the 3D positioning systems, but also 3D machine control. 3D vs. 2D In 2D paving, the action is about controlling grade. In 3D paving, it may include steering as well as automatic screed width control. The system works with a known 3D model, which specifi es what grade and slope should be at a given point. In 2D, it's more about setting up and paving away. Systems for 2D paving consist of a single display, sonic sensor, contact sensor or sonic averag- ing beam. In 3D paving, the same components are there, but the 3D system talks to the 2D system so they work in conjunction. "When you're talking about 3D paving, people generally don't un- derstand what's all involved," says highway contractor | by Chris Hill | ChrisHill@randallreilly.com STRINGLESS 3D PAVING FOR ASPHALT 3D machine control provides the highest accuracy and smoothness levels possible for asphalt pavement – no strings attached. Caterpillar equipment paving in echelon on a curve while using Trimble's stringless 3D system for guidance. 3D machine control is designed to handle curves such as this without diffi culty.