Settling of Loose-Fill Insulations Due to Vibration

Abstract

Vibration and impact testing of loose-fill cellulosic, fiberglass, and rock wool insulations has been carried out to provide a data base for settled density tests. The ratio of final density to initial density for the three materials has been determined for repeated 19-mm (0.75-in.) drops, repeated 152-mm (6.0-in.) drops, and vibrations at frequencies from 10 to 60 Hz with displacements from 0.1 mm (0.004 in.) to 6.35 mm (0.25 in.). Repeated 19-mm or 152-mm drops increased the density ratio for rock wool insulation specimens the most, while the cellulosic insulation specimens were affected the least. Density ratios after 200 19-mm drops averaged 1.75 for loose-fill rock wool, 1.45 for loose-fill fiberglass, and 1.27 for loose-fill cellulosic insulations. Vibration tests for 7200 s at 0.1-mm displacement and 15 Hertz produced negligible changes in the densities of all three loose-fill insulations. An 1800-s vibration test at 2.5 mm (0.1 in.) and 10 Hz resulted in average density ratios of 1.05, 1.11, and 1.18 for specimens of loose-fill cellulosic, rock wool, and fiberglass insulations, respectively. Changes in either frequency of vibration, displacement, or test duration can be used to achieve a wide range of laboratory results. Efforts to correlate laboratory results with inmore » situ density measurements are presented.« less