A vibrations approach to determining batch-to-batch changes in poured gypsum used in flooring systems

An average human spends about 87% of their time indoors and it is very important to make this a comfortable experience. The noise coming from upstairs as people walk is annoying to the residents, especially in multi-family apartments. The Impact Insulation Class (IIC) rating is used to characterize the transmission loss in the floor-ceiling assembly. Designers can run into problems when characterizing a frequency dependent spectrum with a single curve. The individual parts that make up the assembly should be studied to predict its performance and design for a target IIC rating. Gypsum poured floors are important in new construction due to their prominence and an underlayment for hard flooring options. The field performance of gypsum panels has several manufacturing-related uncertainties. The focus of this paper is to characterize gypsum panels that are used in the floor-ceiling assembly using their natural frequencies and loss factor values to aid in the development of quality control measures for the manufactured panels to control variability. The comparison of natural frequencies and loss factors for seventeen gypsum panels has been presented and it has been shown that different groups of panels have different characteristics.