Short description
(English)
|
The project aims to establish a scientific basis for museum guidelines as to which fluctuations of relative humidity are tolerable for the conservation of historic cultural objects made of wood. The kinetics of humidity absorption / desorption and the mechanical response of wood to fast and slow RH fluctuations will be investigated through environmental chamber experiments, neutron radiography and numerical model calculations.
|
Partners and International Organizations
(English)
|
AT, BE, CH, CZ, DE, DK, ES, FI, FR, GR, HU, IT, LV, MK; MT, NL, NO, PL, PT, RO, SE, SI, TR, UK
|
Abstract
(English)
|
Fluctuations of relative humidity result in difficulties in the conservation of wooden cultural heritage objects. Shrinkage and swelling due to changes of moisture content may lead to irreversible damages like cracking, warping and delamination. In order to prevent these, guidelines about the amount of tolerable fluctuations of relative humidity should be set up. The current project aims at establishing a scientific basis for the latter by providing data about diffusion and sorption processes as well as about the behavior of naturally aged wood, traditional coatings and adhesives. The guidelines based on this data will help to choose appropriate, but also economic conditioning devices for museums. At ETH Zurich, sorption and diffusion properties of aged wood and historic adhesives were studied in various experiments. To investigate the long term sorption behavior, sorption isotherms of aged and recent wood were recorded through several cyclic climate changes. The influence of historic adhesives on diffusion and sorption processes was observed as well. The water vapor diffusion-equivalent air layer thickness was determined and 'in situ' investigations of capillary water uptake were carried out with neutron radiography at the Paul Scherrer Institute (PSI) in Villigen. Based on data from these and from earlier experiments - regarding the physical-mechanical porperties of aged wood and soprtion and diffusion behavior of historical coatings - numerical models of different diffusion processes will be calculated. At AHB Biel, to learn more about crack formation and propagation mechanisms, elastic, viscoelastic and mechano-sorptive behavior of aged and recent wood was investigated on micro specimens and structural microscopic investigations were carried out.
|
