ABSTRACT
To analyse the influence of a finishing coat on the hygric buffering capacities of gypsum board, dynamic experiments are performed on uncoated and coated gypsum board samples. In these experiments a harmonically changing relative humidity is imposed, while the mass response of the sample is measured quasi-continuously. The measured response is compared with a numerically predicted response. To do so, gypsum board is implemented as a composite material in a finite element model with sorption isotherm and vapour permeability determined for each layer of the board separately. It is found that hysteresis on the sorption isotherm plays an important role on the dynamic response of coated gypsum board.
