Band 3, Heft 4

Currently, there are a great amount of cultural and historical important structures in East Germany, where maintance and refurbishment is necessary. Therefore refurbishment work is more often the business of the local engineer. The refurbishment concept of a small church will be presented. Under consideration of the main aspects as maintance of historical features, statical safety and economical belongings the design documents have been created

Moisture transport in porous building materials is described by a transport model that expresses the action of the several transport mechanisms of liquid water and water vapor in the porous system by a single material specific transfer coefficient. This parameter has to be determined by experimental measurement of moisture distributions inside samples exposed to known initial and boundary conditions. Neutron radiography is employed as experimental method because of its high sensitivity and good spatial resolution. The moisture distribution is determined from the raw data obtained in the measurement by a calculation procedure based on a signal transfer model of the neutron transmission. This approach is illustrated by two examples: the drying of a plain brick sample and the drying of a composite sample consisting of two brick elements separated by a layer of mortar.

In this report the behaviour of cementitious materials especially high performance concrete under the attack of ammoniumnitrate solutions is described. From the experimental data concerning the loss of weight and strength of concrete specimens under the chemical attack simple formulas were derived. The formulas enable the estimation of the effect of an chemical attack by solution on cementitious materials. Further within the range of data the duration of experimental programs can be determined in advance.

Interior plaster from the Abbot's Palace of the Abbey of Villers-la-Ville, Brabant Wallon province, Belgium has been investigated. It is done by using chemical analysis, x-ray diffraction analysis, scanning electron microscopy, energy dispersive electron spectroscopy, and transmission electron microscopy. It is found that the rendering was made with lime rich mortar and animal hairs. The sand used was very fine and the hairs were very short. The solid constituents and the hairs were uniformly dispersed, which could have been obtained by the addition of some other natural polymer, containing protein.

Different methods to dry moist masonry are presented. Effectless methods are mentioned in this context, too. Some specific risks are outlined. Finally, the difficulty to select the best method for a given building is discussed.