Plaster Ceilings Research Articles

Concorde noise and historic structures

The probability of failure of structural elements from vibration induced by noise from subsonic Concorde overflights was calculated for five historic sites near Dulles and Kennedy Airports. The structural elements investigated included windows, brick chimmeys, stone bridges, and plaster ceilings. Breakage probabilities were calculated using the response probability density function technique, which had been used in previous structural response studies for sonic boom and subsonic aircraft noise. The calculated breakage probabilities were generally less than 0.001 per year of Concorde operations. The only exceptions were some cracked windows at Sully Plantation, which were slated to be replaced anyway; these had a predicted breakage rate of once every five years. The failure rates of all elements were found to be considerably below those that would be expected just from exposure to the weather. [Work supported by Federal Aviation Administration.]

Problems of Field Measurement of Transmission Loss as Illustrated by Data on Lightweight Partitions Used in Music Buildings

Field measurements of airborne sound-transmission loss involve several practical difficulties and limitations as compared to the laboratory standard test procedures for such measurements. Data from field measurements are valuable to architects and acoustical consultants, in spite of these limitations. A workable procedure for field measurements is described, along with a discussion of the difficulties. Measured transmission loss data are presented for double plaster walls on cork isolation, double plaster walls on concrete slabs, double concrete block walls, double brick walls, single concrete block walls, and a floor slab with resiliently suspended plaster ceiling.