The former Workers Hospital was designed by architect Antonio Palacios in the Northern enlargement of Madrid at the beginning of the 20th century. The building and its surrounding wall are mostly built with limestone masonry. It remained abandoned almost during 25 years, and the Government of Madrid purchased the property at the beginning of the eighties of the last century. It commissioned the building restoration, and the works were carried out between 1984–1986. The main decay forms that exist on the stone façades are related to soiling processes, with the development of black crusts in some specific areas. The main causes responsible for this soiling are the urban environment that surrounds the Hospital -with intense traffic-, the façades and the wall design with many set backed elements that makes very difficult their washing by rain water, the rusticated finishing ashlars and the own passage of time.
Mokattam limestone is the most frequent building stone used in the cultural heritage buildings in Historic Cairo (Egypt) and it is susceptible to the ongoing effects of salt weathering. A purpose-made simulation chamber was used to test in the laboratory the salt weathering on limestone samples from an active quarry at Helwan area (30 km, south Cairo) at different temperature regimes (20, 30 and 40°C). To assess the extent of the resulted decay, mechanical properties of the fresh quarry and tested samples after different regimes were investigated with non-destructive techniques (P-wave velocity and Leeb rebound hardness) and destructive techniques (uniaxial compression strength). The different mechanical measurements of the tested samples were notably affected after the different temperature regimes. Uniaxial compressive strength is highly correlated with Leeb rebound hardness while P-wave velocity showed a low relevance for the prediction of the strength of the tested samples. ; This study was supported by the Mission Sector of the High Education Ministry, Egypt and the Regional Government of Madrid and the European Social Fund under the project entitled Geomateriales 2 S2013/MIT-2914.
Nondestructive in situ analysis of materials is highly desirable in cultural heritage studies, because it precludes the need for intensive sampling. The present study focused on the usability of Raman spectrometers, which can provide such analysis, in the identification of conservation treatments applied to stone materials forming part of the architectural heritage. Two products commonly used to conserve stone monuments, an ethylmethacrylate copolymer and an ethyl orthosilicate, were analyzed with a Raman spectrometer, both as supplied and after application to limestone. The main conclusion was that portable Raman analyzers can detect the presence and—in some cases—identify the nature of products on stone substrates. The latter is not always possible due to product-stone substrate interaction. The study clearly showed that a product and substrate database is needed for portable Raman spectroscopy to be usable in the analysis of conservation products, both before and after application to stone substrates. ; This research was funded by the Spanish Government's CONSOLIDER-INGENIO 2007 (CSD2007-0058) project and GEOMATERIALES (S2009/MAT-1629/GEOMATERIALES), a project sponsored by the Regional Government of Madrid. ; Peer Reviewed
The effect of high relative humidity (90% and 75% RH) on phase transformation and stability of CaCO3 polymorphs has been studied based on the structural and morphological changes from a colloidal solution based on Ca(OH)2 nanocrystals. Carbonation process has been confirmed indicating differences in nucleation and stability of CaCO3 polymorphs as a function of RH. Local fluctuations in the water/alcohol ratio significantly affect the precipitation/dissolution of anhydrous and hydrated polymorphs that are reflected in the particle size. Changes in lattice parameters and particle size are related to surface tension fluctuations, release of residual water and time of exposure. These results highly contribute to evaluate the stability of the Ca(OH)2 nanoparticles in high humidity conditions. ; This work was supported by the Government of the Community of Madrid (Spain), the GEOMATERIALES (S2009/MAT-1629/GEOMATERIALES) and CONSOLIDER-TCP (CSD2007-0058) programmes and by the JAE-Doc CSIC contracts. ; Peer Reviewed
The Church of the Assumption of Our Lady, in Valdemorillo (Madrid, Spain) is almost entirely built with granitoids. The studies and analyses were focused on the oldest part of the building (Ghosts Corner), which will be restored and rehabilitated in the near future. Homogeneous monzogranite is the predominant granitoid used in the Ghosts Corner, followed by granitic porphyry, porphyrytic monzogranite, gneiss and leucogranite. The original quarries that supplied homogeneous monzogranites for the first construction stages correspond to blocks present in the monument's surroundings. Quarries that supplied the granitic porphyries correspond to the dykes located to east–southeast of Valdemorillo, which are oriented N–S in relation to their intrusion direction. The combined use of ultrasonic velocity and Schmidt hammer techniques allowed, first, selection of the most representative blocks and ashlars for sampling. This reduced sampling to a minimum, but yielded representative results for the whole building. Second, the combined values were used to compare results for the building stones of the church to rocks from the surrounding quarries. Stones from the building showed lower ultrasonic and Schmidt hammer values, and higher porosity and water saturation values compared to the original quarry rocks. The anisotropy indices are directly related to the decay processes in the stone: spalling of homogeneous monzogranite and grain disintegration in granitic porphyries. Finally, the methods applied are inexpensive, easy to use and non-destructive techniques, very advisable properties when working with built heritage. ; This study was financed by the Heritage General Directorate of Comunidad de Madrid (Regional Government of Madrid). The authors are also grateful to the MATERNAS programme (Durability and Conservation of Natural Traditional Materials for Architectural Heritage), which is also financed by Comunidad de Madrid (0505/MAT/94), to the CONSOLIDER programme (Technologies for the preservation and revalorisation of Cultural Heritage, CSD2007-0058) and to the Research Group financed by the Complutense University of Madrid "Alteration and Conservation of heritage stone materials (ref. 921349). ; Peer reviewed
Attached files: Extended abstract (3 pages) and PDF-PPT Presentation (24 slides).-- Communication presented at: 7th International Symposium on the Conservation of Monuments in the Mediterranean Basin, Water and Cultural Heritage (Orléans, June 6-9, 2007). ; The former Workers Hospital was designed by architect Antonio Palacios in the Northern enlargement of Madrid at the beginning of the 20th century. The building and its surrounding wall are mostly built with limestone masonry. It remained abandoned almost during 25 years, and the Government of Madrid purchased the property at the beginning of the eighties of the last century. It commissioned the building restoration, and the works were carried out between 1984–1986. ; The main decay forms that exist on the stone façades are related to soiling processes, with the development of black crusts in some specific areas. The main causes responsible for this soiling are the urban environment that surrounds the Hospital -with intense traffic-, the façades and the wall design with many set backed elements that makes very difficult their washing by rain water, the rusticated finishing ashlars and the own passage of time. ; This work has been carried out as part of a Special Intramural Project, supported by the Spanish Council for Scientific Research. We would like to thank the architect of the Regional Ministry of Culture José María la Calle and the companies Proliser and FTB the facilities and assistance provided, and to the Regional Government of Madrid for the financial support Durability and Conservation of Natural Traditional Materials of the Architectural Heritage (MATERNAS_CM, 0505/MAT/0094). ; Peer reviewed
This article reports on a compositional investigation of stone patinas: thin colored layers applied for protective and/or aesthetic purposes on architectural or sculptural substrates of cultural heritage. The analysis and classification of patinas provide important information of historic and artistic interest, as their composition reflects local practices, the availabilities of different materials, and the development of technological knowledge during specific historical periods. Model patinas fabricated according to traditional procedures and applied onto limestone, and a historic patina sample from the main façade of the San Blas Monastery in Lerma (a village in the province of Burgos, Spain), were analyzed by laser-induced fluorescence and Fourier transform Raman spectroscopy. The results obtained demonstrate the ability of these two analytical techniques to identify the key components of each formulation and those of the reaction products which result from the chemical and mineralogical transformations that occur during aging, as well as to provide information that can aid the classification of different types of patinas. ; This work has been funded by the Madrid Regional Government project Geomateriales (S2009/Mat-1629) and by the Ministerio de Ciencia e Innovación under projects CTQ2010-15680 and CONSOLIDER CSD2007-00058. ; Peer Reviewed
Slaked lime (Ca(OH)2) nanoparticles were exposed at 33% and 75% relative humidity (RH) to consolidate dolostone samples used in historical buildings. Non-destructive techniques (NDT) were applied to determine the chemical, morphological, physical and hydric properties of the stone samples, before and after 20 days treatment. Morphological and mineralogical characterisation of the nanoparticles was performed. 75% RH favors the consolidation process studied under Environmental Scanning Electron Microscopy (ESEM-EDS), spectrophotometry, capillarity, water absorption under vacuum, ultrasound velocity, Nuclear Magnetic Resonance (imaging and relaxometry) and Optical Surface Roughness analyses. At 75% RH the nanoparticles fill the pores and inter-crystalline dolomite grain contacts but do not favor calcite re-crystallization as it occurs at 33% RH. The ESEM, XRD and TEM analyses under 75% RH reveal the fast transformation of portlandite (Ca(OH)2) into vaterite (CaCO3), monohydrocalcite (CaCO3 · H2O) and calcite (CaCO3), and eventually the physical and hydric properties of the stones significantly improve. New insights are provided for the assessment of consolidation effectiveness of porous carbonate stones with calcium hydroxide nanoparticles under optimum RH conditions combining several NDT. ; This study was funded by the Government of the Community of Madrid under the project "Durability and conservation of traditional natural materials in heritage architecture" (MATERNAS CM 0505/MAT/0094) and the Spanish Ministry of Science and Innovation as part of the Consolider-Ingenio 2010 programme (CSD2007-0058) ; Peer reviewed
