Paper 2: Climatic Study of the Underground Archaeological Site Coudenberg

Abstract

The excavation and valorization of subterranean archaeological remains, and eventually opening a site to the public, required a proper management and conservation strategy. This strategy was based on the evaluation of the delicate balance between the requirements for public health and safety, and the protection of the archaeological remains from future degradation. Controlling the climate can be essential for a preventive conservation strategy, which can be defined as an indirect action to increase the life expectancy of the archaeological remains, and by doing so keeping them in a preferred state of conservation to mitigate damage and/or deterioration.

Potential risks and possible interventions are outlined to avoid climatic conditions which are in conflict with the requirements for the visitors’ comfort while preventing damage phenomena to the materials.     

Paper 4: Mechanical Properties of Bricks of the Coudenberg Archaeological Site in View of a Proper Conservation Strategy

Abstract

Archaeological sites are essentially submitted to decay phenomena inherent on their history as well as the environment to which they are exposed after excavation. The history of such archaeological sites is particularly related to their long-term underground conservation conditions during which they were subject to salt migration into the architectural remains. This paper describes the results of drill resistance measurements using a drill resistance measurement (DRMS) device to evaluate the mechanical damage resulting from salt crystallization pressures. Further tetraethoxysilane (TEOS) was applied on powdered bricks of often moist archaeological remains. It was noticed that TEOS serves as potential nutrient for present moulds. The mechanical consolidation effect was evaluated by comparing the hardness profiles after treatment with the reference ones. Bricks used for the construction of the Aula Magna, situated underneath the Royal Square, are characterized by severe patterns of fissures for which the damage diagnosis was built up.     

Paper 5: Historic Mortars from the Coudenberg Archaeological Site: Characterization and Source of Raw Materials

Abstract

The characterization of historic mortars by means of a concise methodology of material analyses can provide crucial information with regard to the origin of the raw materials and the ancient mortar technology. For the analysis of the historic mortars of the Coudenberg archaeological site, the methodology consists of optical and scanning electron microscopy, simultaneous thermal analysis, and an acidic treatment. These analyses were carried out on a total of seventeen samples lifted from various areas in the site, in function of the building chronology resulting from a historic built investigation. The type of binder and aggregate as well as their volumetric ratio were determined.

Both binder and aggregate present distinctive features, which made it possible to identify the probable geological provenance of the raw materials. The observations are verified with available historical records regarding the construction of the main banqueting hall — the Aula Magna — and the use of raw materials such as limestone and sand for the production of lime and construction purposes.     

Offspring sex preference in frontier America

Analysis of the fertility histories of women born between 1850 and 1900, as given in the Utah Population Database (UPDB), reveals the effect of the number, as well as the sex composition, of previous children on birth-stopping and birth-spacing decisions. Specifically, agricultural and Church of Jesus Christ of Latter-day Saints (LDS) households—two sub-populations that might have placed different values on male and female children for economic, social, and/or cultural reasons—showed a distinct preference for male children, as expressed by birth stopping after the birth of a male child and shorter birth intervals in higher-parity births when most previous children were female. Remarkably, women in both the early "natural fertility" and the later contraceptive eras used spacing behavior to achieve a desired sex mix. Although the LDS population had relatively high fertility rates, it had the same preferences for male children as the non-LDS population did. Farmers, who presumably had a need for family labor, were more interested in the quantity than in the sex mix of their children.     

Mission Impossible: UN Special Representative Gunnar Jarring and His Quest for Peace in the Middle East

On 23 November 1967, Gunnar Jarring, a Swedish diplomat, was appointed the United Nations Special Representative to the Arab-Israeli conflict. The Security Council had decided to launch a peace effort in the Middle East following the Six-Day War in June 1967. Israel had won a sweeping victory, and the Arab states had suffered a devastating loss. After the war, Israel controlled a territory almost three and a half times the size of the country itself. But what should be done with these newly conquered territories? Should Israel be allowed to keep them? Over the course of some three and a quarter years, Jarring shuttled between the representatives from the three countries involved in the peace endeavour: Israel, Egypt, and Jordan. (Syria refused to participate.) Despite his arduous efforts, he failed miserably to produce viable progress in the Arab-Israeli conflict.     

Paper 6: Grouting Mortars for Fragmented Bricks and Repair Mortars for Tiles in the Archaeological Site Coudenberg

Abstract

Different grouting and repair mortars were developed and evaluated for the conservation and restoration of fragmented bricks in the walls and floors of the remaining cellars underneath the Aula Magna, the palace’s main banqueting hall, and to fill the lacunae and perform edge repairs of red and blue-grey ceramic floor tiles in the remaining cellars underneath the chapel of the former Palace of Coudenberg in Brussels, Belgium.

To prevent the deposition of lime bloom at the surface of the masonry and to achieve an acceptable colour match of the grout in harmony with the bricks of the Aula Magna, the effect of brick powder added to natural hydraulic lime was studied. The pozzolanic properties and colour match of several historic and modern powdered bricks were investigated. Surprisingly, ancient bricks do not seem to possess higher pozzolanic properties than the more modern ones, although it is supposed that they were fired at lower temperatures. Additional evidence for the pozzolanic reaction of the different brick powder materials was obtained from a simple visual observation of stored samples. After eight weeks all of the samples containing brick powders, fired at low and high temperatures, added to putty lime had hardened under water and were transformed into a remarkably tough material. These results are important, as modern bricks are readily available in large quantities and different colours, which are hence in favour of being used instead of historical material from the site.

For the repair of the ceramic floor tiles different mortars were investigated with mixtures containing talcum, stone or brick powder, pigments, and chalk added to an epoxy binder. The mortars were tested in the laboratory and in situ for their workability and resemblance with the historic floor tiles. The finished mortars showed excellent aesthetic properties with the tiles in situ and good properties to prevent further loss due to human interaction.     

Paper 3: Impact of the Indoor Climate on the Performance of Building Materials Contaminated with Salt Mixtures

Abstract

Archaeological sites are essentially submitted to decay phenomena inherent on their history as well as the environment to which they are exposed after excavation. The history of such archaeological sites is particularly related to their long-term underground conservation conditions during which they were subject to salt migration into the architectural remains.

It is well known that soluble salts present in building materials can cause damage, mainly by producing stresses in the substrate. A lot of research has been done in the past concerning the behaviour of salts in built constructions. However, most studies include single salts, of which the deliquescence points are well documented, while in situ one mostly finds complex salt mixtures, which makes the conservation strategy much more intricate.

The environmental conditions to minimize damage of salt-laden porous building materials can be modelled using a computer program ECOS capable of predicting the crystallization behaviour of salt mixtures. To use the model data of quantitative salt analyses are required as input. The program is then able to predict from a thermodynamic point of view which minerals will exist in the solid state under specified climatic conditions.

This paper deals with the results of a systematic investigation of the salt contamination of the building materials of the Coudenberg site and a prediction of the behaviour of the salt mixture related to the actual climate, as part of the environmental assessment.