A critical factor with the Superpave™ Gyratory Compactor (SGC) is the angle of gyration during the compaction cycle. The DAV II with Hot Mixed Simulator (HMS) is making the process of checking and adjusting the angle much easier and more reliable. Several years ago the Federal Highway Administration (FHWA) determined that a key factor in agreement between gyratory compactors was the internal-mold angle of gyration.
Tom Brovold of Test Quip, Inc. worked with FHWA and invented the DAV specifically for this purpose. Now this concept has been improved with the development of DAV II – HMS. Troxler has joined with Mr. Brovold to make this new device available for all compactor owners.
The DAV II with HMS works without mix (simulating mix properties); the DAV II can also be used with hot mixed asphalt. The Hot Mixed Simulator (HMS) replaces hot mixed asphalt to simulate the forces applied directly inside the compaction mold. An asphalt mix has a shear factor that is different for the type and size of aggregate being used.
The HMS measured angle needs to be compared to the angle measured with the actual hot mixed asphalt that will be produced to ensure the compactor is set with the appropriate angle of gyration. The DAV is the only internal-angle-measuring device that gives you the option of measuring angle with or without hot mixed asphalt.
A single replaceable battery that will give the user years of service life powers the DAV II. The circuitry and mechanical parts are designed for the elevated temperatures encountered with hot mixed asphalt. The DAV II with HMS can be used in a cold gyratory mold or, preferably, in a hot mold. You do not use a cold mold when you compact specimens, so why use a cold mold during the angle check? Go ahead and use a hot mold, DAV II can take it!
43.2 W x 35.6 D x 17.8 H cm
(17 W x 14 D x 7 H in.)
Safe in 149°C (300°F) mold for 60 minutes
The DAV II offers the following advantages: Works in any brand of gyratory compactor Measures the angle with or without hot mixed asphalt Light weight and compact Calibrates at 155 mm, same as your gyro specimen heights, with no data extrapolation required Takes less than 30 minutes to measure the internal-mold angle No disassembly required to change eccentricity plates Verifies mix stiffness Stores measurement data as a permanent record Has an extended data collection time in its memory Includes a NIST traceable verification device