Natur / Stein / Kultur / Wein: Siegesmund, S., Hoppert, M., Epperlein, K. (eds.), 2014
Pori suntian dicita cones eicias molupta tureperiosam la consequ isimodist, simaio que conest ell... more Pori suntian dicita cones eicias molupta tureperiosam la consequ isimodist, simaio que conest ellut omni in essunde ipsum.
Uploads
Papers by Wanja Wedekind
In this case study a stone staircase with a balustrade was employed to perform a directed moisture. The procedure can be used with thin-walled parapets of histor- ical buildings, which often have a decorative function as well. The treatment presented in this article was realized on the staircase of the medieval town hall of the UNESCO World Heritage city of Goslar in Germany. The staircase with or- namental decoration was heavily affected by road salt.
Here, too, a desalination process with a directed water transport was used over a large area. In this case a hot lime mortar was applied as the poultice material. The rock properties and preliminary investigations of the salt content are present- ed and the desalination results are specified both qualitatively as well as quantitatively.
In the course of restoration of antique tombs no. 825 and 826 in the world he- ritage site of Petra the role of salt in the weathering process was fully taken into account and the restoration process exe- cuted accordingly.
With regard to the desalination two different methods were applied: the poul- tice method and the sprinkling method. The degree of desalination was in both cases intermittently measured until the concentration of the rock was evaluated to be low enough to initiate the restorati- on process with application of the selec- ted restoration mortar. Its condition was then probed by long term successive in- spections.
This study discusses the results and limits of both procedures and the techniques and methods applied in the course of the restoration of the two mo- numents.
Keywords: Petra, sandstone, salt weathe- ring, desalination procedures, restorati-
on mortar, restoration procedures, control of success
Keywords: tuff, Mexico, deterioration, porosity, pore distribution
The rock cut architecture of the Lycian culture in Turkey, created from around 500 BC to 400 AC, is one of the most fascinating remains of humanity’s ancient building heritage. The Lycian builders created monumental sarcophagi and tomb facades with unique forms and aesthetic styles which are never found twice in the Mediterranean world. Most of these magnificent monuments are cut into different limestone formations located in the area along the southern coast of Turkey, known as Lycia after its creators. The rocks as well as the monuments are affected by weathering and disasters, such as the dissolution and precipitation of calcite, biological growth and cracks due to earthquakes. To characterise the weathering forms and processes onsite investigations were done on rock cut monuments at the outstanding site known as Myra. Field investigations included quantitative mapping of damage phenomena, pointing surface hardness measurements utilizing a Schmidt pendulum hammer, water absorption using Karsten test pipes and closer surface observations using a digital microscope. The limestone varieties were characterised by petrophysical measurements and mineralogical analysis of thin sections.
Keywords: rock cut architecture, limestone, weathering, micro-climate, microbiology
Similar to many other buildings constructed with this material, the cut stones of the church also show back-weathering concentrated in the basement area, which can be traced to wet and dry cycles and the accumulation of salt. Conservation by desalination of the basement area was undertaken by cyclical sprinkling and measuring of the electrical conductivity of the excess water runoff. Using this method around 3000 grams of soluble salts could be extracted. During the restoration, diagnostic investigations were done consisting of mapping the deterioration, determining the moisture content and measuring the temperature as well as evaluating the salt accumulation by drilling powder analysis.
The mineralogical composition of the original stone material was determined by thin sections and X-ray diffraction (XRD) measurements. Investigations on the petrophysical properties focussed on the impact of wet conditions. Compressive and tensile strength tests were done under dry and water-saturated conditions as well as hygric and thermal dilatation, swelling pressure, water uptake, and sorption. To evaluate the impact of the inhomogenous internal structure, experimental testing of hygric swelling on a cubic stone block were performed.
The results from the study show that a reduction of the mechanical properties up to 40% by water saturation could be detected. Back-weathering is probably due to the inhomogenous internal structure, resulting from the interaction of clastic material and the fine-grained ash-matrix induced by different swelling intensities and swelling pressure.
Keywords: tuff stone, desalination, moisture expansion, critical values.
pot bricks was developed and implemented.
groin vaults of the church were exposed to bad weather conditions.
Along with the structural problems, the structurally damaging salts, principally magnesium sulfate, were regarded as the main cause of damage to the historical substance of the building. In many areas, the painting on the ashlar blocks and mortar was already lost or in acute danger of loss due to salt degradation.
After making a map of the damages and prior testing, the ribs and the vault stones were extensively desalinated by cyclical sprinkling in order to ensure a contact-free treatment.
In this case, the sprinkling proved to be both an economical procedure for a sustained salt reduction.
In this case study a stone staircase with a balustrade was employed to perform a directed moisture. The procedure can be used with thin-walled parapets of histor- ical buildings, which often have a decorative function as well. The treatment presented in this article was realized on the staircase of the medieval town hall of the UNESCO World Heritage city of Goslar in Germany. The staircase with or- namental decoration was heavily affected by road salt.
Here, too, a desalination process with a directed water transport was used over a large area. In this case a hot lime mortar was applied as the poultice material. The rock properties and preliminary investigations of the salt content are present- ed and the desalination results are specified both qualitatively as well as quantitatively.
In the course of restoration of antique tombs no. 825 and 826 in the world he- ritage site of Petra the role of salt in the weathering process was fully taken into account and the restoration process exe- cuted accordingly.
With regard to the desalination two different methods were applied: the poul- tice method and the sprinkling method. The degree of desalination was in both cases intermittently measured until the concentration of the rock was evaluated to be low enough to initiate the restorati- on process with application of the selec- ted restoration mortar. Its condition was then probed by long term successive in- spections.
This study discusses the results and limits of both procedures and the techniques and methods applied in the course of the restoration of the two mo- numents.
Keywords: Petra, sandstone, salt weathe- ring, desalination procedures, restorati-
on mortar, restoration procedures, control of success
Keywords: tuff, Mexico, deterioration, porosity, pore distribution
The rock cut architecture of the Lycian culture in Turkey, created from around 500 BC to 400 AC, is one of the most fascinating remains of humanity’s ancient building heritage. The Lycian builders created monumental sarcophagi and tomb facades with unique forms and aesthetic styles which are never found twice in the Mediterranean world. Most of these magnificent monuments are cut into different limestone formations located in the area along the southern coast of Turkey, known as Lycia after its creators. The rocks as well as the monuments are affected by weathering and disasters, such as the dissolution and precipitation of calcite, biological growth and cracks due to earthquakes. To characterise the weathering forms and processes onsite investigations were done on rock cut monuments at the outstanding site known as Myra. Field investigations included quantitative mapping of damage phenomena, pointing surface hardness measurements utilizing a Schmidt pendulum hammer, water absorption using Karsten test pipes and closer surface observations using a digital microscope. The limestone varieties were characterised by petrophysical measurements and mineralogical analysis of thin sections.
Keywords: rock cut architecture, limestone, weathering, micro-climate, microbiology
Similar to many other buildings constructed with this material, the cut stones of the church also show back-weathering concentrated in the basement area, which can be traced to wet and dry cycles and the accumulation of salt. Conservation by desalination of the basement area was undertaken by cyclical sprinkling and measuring of the electrical conductivity of the excess water runoff. Using this method around 3000 grams of soluble salts could be extracted. During the restoration, diagnostic investigations were done consisting of mapping the deterioration, determining the moisture content and measuring the temperature as well as evaluating the salt accumulation by drilling powder analysis.
The mineralogical composition of the original stone material was determined by thin sections and X-ray diffraction (XRD) measurements. Investigations on the petrophysical properties focussed on the impact of wet conditions. Compressive and tensile strength tests were done under dry and water-saturated conditions as well as hygric and thermal dilatation, swelling pressure, water uptake, and sorption. To evaluate the impact of the inhomogenous internal structure, experimental testing of hygric swelling on a cubic stone block were performed.
The results from the study show that a reduction of the mechanical properties up to 40% by water saturation could be detected. Back-weathering is probably due to the inhomogenous internal structure, resulting from the interaction of clastic material and the fine-grained ash-matrix induced by different swelling intensities and swelling pressure.
Keywords: tuff stone, desalination, moisture expansion, critical values.
pot bricks was developed and implemented.
groin vaults of the church were exposed to bad weather conditions.
Along with the structural problems, the structurally damaging salts, principally magnesium sulfate, were regarded as the main cause of damage to the historical substance of the building. In many areas, the painting on the ashlar blocks and mortar was already lost or in acute danger of loss due to salt degradation.
After making a map of the damages and prior testing, the ribs and the vault stones were extensively desalinated by cyclical sprinkling in order to ensure a contact-free treatment.
In this case, the sprinkling proved to be both an economical procedure for a sustained salt reduction.