Hygrothermische simulatie van vorstschade in metselwerk

: effecten van klimaatverandering

Abstract

According to the KNMI (Royal Netherlands Meteorological Institute) climate change will result in an increase of air temperature and rainfall intensities for the Netherlands in winter. Climate change also threatens cultural heritage. The European project "Climate for Culture" (CfC) investigates this impact. Not only the interior and the collection are important to preserve for future generations, but also monumental buildings themselves. The risk of frost damage to an external building envelope will become less due to the increase in air temperature. However, the risk of frost damage rises as a construction will be wet for a longer time due to the increase in rainfall intensities. In this study, a statement will be made about these conflicting frost damage effects. Research will be done on the following topics: a) the type of material that is sensitive to frost, b) the conditions under which the material damage occurs, c) the outside climate conditions in future (frost damage winters) and d) the possibility to predicted frost damage with a multiphysical model. The methodology was: 1) literature review on frost damage; 2) verification of a coupled heat-moisture model; 3) simulation of case studies to predict frost damage; 4) analysis of the external climate; 5) drawing of conclusions from literature and case studies. Frost damage in a frost-sensitive material may occur after long-term rainfall, immediately followed by severe frost, as excessive internal stresses arise caused by the volume increase due to the phase change of water into ice. Analysis of the external climate for winter periods from 1) data of the past till the present and 2) future data indicate that monthly average air temperatures increase. Also rain intensities increase in the future for winter months. Simulations with a hygrothermal model of external building envelopes with the frost-sensitive material calcium silicate brick show a reduction of the risk of frost damage in order of magnitude of 70%.

Date of Award	30 Jun 2013
Original language	Dutch
Supervisor	B. Blocken (Supervisor 1), Henk L. Schellen (Supervisor 2) & A.W.M. van Schijndel (Supervisor 2)