Our Airports team in the US has completed the hot-mix asphalt paving at the Minot Air Force Base in Minot, North Dakota for Principal Contract Sundt Construction on behalf of the US Army Corps of Engineers.
Site works commenced in mid May 2014. Our crews have performed the following items and quantities of work:
- Place and compact approximately 57,000 tons (52,000 MT) of graded aggregate base course using a Vogele 1900-2 paver equipped with a TP-2 type screed.
- Produce, place and compact 37,000 tons (34,000 MT) of polymer-modified hot-mix asphalt (HMA) along both sides of the runway centre keel concrete section.
Hot-mix asphalt paving was completed in August 2014 resulting in LC crews laying and compacting 94,000 tons of material over 88 calendar days, while battling difficult and extreme weather conditions which varied from 32°F to over 90°F (0° – 32° Celsius).
We purchased, set-up and operated a portable asphalt drum-mix plant to produce the hot-mix asphalt on site rather than purchase from a third party supplier. Operating our own asphalt plant gave LC the flexibility to work when the weather permitted.
The drum-mix plant purchased by LC is a Voyager model, manufactured by ASTEC/Dillman and is rated at 250 tons/hour. ASTEC are one of the leading manufacturers of asphalt plants and paving equipment in the US. The portable plant components are constructed on heavy-duty chasses which streamline the set up process and makes the plant highly portable, with no hydraulics on the drum. The plant utilizes the ASTEC proprietary control system, PMII Continuous Mix Blending Controls with a 30 inch console, similar to most on ASTEC/Dillman equipment.
In addition to the sophisticated control system, the Unified Counterflow drum itself is at the heart of the plant and is the primary factor in mix design control and production rates. The drum on our plant is 7 foot in diameter and 46 foot in length and includes a drying and mixing section. The Voyager plant features four 20-hp drives, ¼ inch flighting, and recycled asphalt product (RAP) capabilities up to 40%. The cold feed centre is a portable 8 foot x 11 foot five-bin system with a 24 foot x 52 foot collecting conveyor.
The control house is mounted on a chassis with the 50 ton self-erecting surge bin which provides for storage of material and loading into the haulage trucks.
We managed and controlled the aspect of haulage / trucking by dry-hiring dual-axle dump trucks from local equipment suppliers.
During production and placement of the hot-mix asphalt, we were required to comply with strict quality control standards. As such, it was mandatory to have an approved QC laboratory on site. In order to achieve this, we constructed a modern laboratory facility. The laboratory then achieved accreditation by the U.S. Army Engineer Research and Development Centre prior to being used on the project and is accredited to provide aggregate and bituminous testing for US Army Corp of Engineer projects through to April 2016.
In addition to the laboratory material testing, we also conducted in-house quality control tests such as smoothness testing using a California profilograph and material density testing using a non-nuclear gauge. The non-nuclear density gauge is a reasonably new technology which uses an electromagnetic field to measure asphalt density rather than a radioactive field used in most nuclear density gauges. The non-nuclear density gauge provided our QC and management teams with immediate information on mat temperature, density and roller pattern effectiveness.
Click here for more information: http://www.nwo.usace.army.mil/Media/NewsStories/tabid/1834/Article/494066/runway-replacement-project-nearing-completion.aspx
