Een plaag van alle tijden: zout: Over oude en toekomstige schade, oud en toekomstig onderzoek

In deze bijdrage wordt nader ingegaan op de achtergronden van zoutschade, de vraag of we er in de toekomst meer last van zullen krijgen, en op oud, nieuw en gewenst onderzoek.

Effect of moisture on tuffstone weathering

Tuffstone elements with a large length/width ratio, as e.g. mullions, often suffer damage in the form of cracks parallel to the surface and spalling of the outer layer. The response of tuff to moisture might be a reason for this behaviour. This research aimed at verifying if a differential dilation between parts with different moisture content ...

Salt crystallization damage: How realistic are existing ageing tests?

Salt crystallization is a major cause of damage in porous building materials. Notwithstanding the extensive research in this field, the complexity of the problem has hindered the use of mathematical models for forecasting ageing and damage due to salt crystallization. Nowadays, the durability of materials with respect to salt crystallization is...

Van de symmetrie van diamant naar steenkeuze op de steiger

Bij grote restauraties aan gebouwen zijn tegenwoordig niet alleen architecten, historici en aannemers betrokken, maar ook specialistische adviseurs, waaronder geologen. In Nederland begon de betrokkenheid van aardwetenschappers bij de Delftse mijningenieur Abraham Louis Willem Eduard van der Veen, die in 1920 onderzoek ging doen voor de twee...

Petrographic characterization of renders from the Lucchesian Villas

Around the Tuscan city of Lucca, a complex system of about 300 villa has developed between 15th and 19th centuries in a ring of territory called the Six Miles District. Nowadays, many of the buildings inside the villas enclosures are damaged and their materials – in particular renders -­ need to be restored. A research program was developed...

Historic lime-binders: An example of the 19th century Dutch military plain concrete

Before the general acceptance of Portland cement as the main binder for concrete in the late 19th century, other, locally available binders were occasionally used. In the case of the Netherlands, which did not produce Portland cement, traditional lime-based binders were not uncommon. With a strong tradition of trass production, trass-lime...

Delft: Nieuwe natuursteen in een oude stad

Delft is alom bekend van de Oude en de Nieuwe Kerk, beiden (deels) opgetrokken door bouwmeesters/steenhouwers van het roemruchte Brabantse geslacht Keldermans en deels in de onvermijdelijk met deze bouwmeesters verbonden witte zandige kalksteen, meestal Lede of Balegemse steen genoemd. Met name aan de Oude Kerk is echter ook nogal wat Gobertange...

High filler concrete using fly ash: Chloride penetration and microstructure

Most high filler concrete studies are based on relatively high contents of powder (cement + filler) (>400 kg m-3). This paper aims to increase the total fly ash content relative to the clinker content, while simultaneously minimizing the total powder content in the concrete to values lower than 300 kg m-3. The motivation for decreasing the total...

Simulation of self-healing of dolomitic lime mortar

In the present research a test procedure was set up to reproduce self-healing on lime-based (both pure calcium and magnesium-calcium) mortar specimens in laboratory. After few months testing, during which the specimens were subjected to wet-dry cycles, thin sections of the specimens were prepared and observed by Polarization and Fluorescence...

Self-healing of lime based mortars: Microscopy observations on case studies

Lime mortars have, up to a certain extent, a self-healing capacity which may contribute to their durability. Self-healing in lime mortars consists of a process of dissolution, transport and re-precipitation of calcium compounds to heal cracks and fissures. The spontaneous occurrence of self-healing in lime-based mortars is a well known...

Assessment of the state of conservation of a Middle Neolithic flint mine in Maastricht limestone

Upper Cretaceous Maastricht limestone ("mergel") outcrops in the provinces of Dutch and Belgian Limburg. The Upper Cretaceous in the Netherlands consists of the geological Maastricht Formation and the upper part of the Gulpen Formation. Limestones from the Maastricht Formation represent one of the few native Dutch natural stones used for...

Salt decay of Morley limestone

Salt weathering is one of the main causes of decay of natural stone, and by consequence a major problem to the conservation of cultural heritage. In the present case, the performance of Morley limestone from the Département Meuse, France, as a replacement stone under saltloaded conditions is evaluated. Morley limestone was used in the...

Decay of Rhenish Tuffs in Dutch Monuments. Part 2: Laboratory Experiments as a Basis for the Choice of Restoration Stone

Rhenish tuffs (Eifel, Germany), have been used as building material in the Netherlands since Roman times. They were the most important natural building stone in the Netherlands in early medieval times. In addition, tuff was used as raw material for production of trass, that served as a pozzolanic addition for mortars. Rhenish tuffs, notably...

Black Weathering of Bentheim and Obernkirchen Sandstone

Black weathering of sandstone in monuments is widespread. Some objects owe their name to it, like the Porta Nigra in Trier (Germany). Other than the black gypsum crusts common on limestone, the black weathering layer on sandstone is rather thin and well adherent. Formation of such layers on Bentheim and Obernkirchen sandstone, both widely used...