Abstract Colors are frequently defined by three points on the L*a*b* coordinates of the CIELAB color space, and the distance between two colors can be expressed as the total color difference ΔE. In particular with respect to reproducibility of print media color differences are an important parameter, as well as for car finishes and textile dyes. Color changes are also the result of ageing and weathering which is an issue for art objects and in the building and restoration sector. However, the subjective perceptibility of color differences depends on numerous factors and general thresholds are difficult to define. This study aimed therefore on defining tolerance levels for color changes in dependence of color tones and color tone combinations as well as their resolution. In total 30 test persons evaluated samples, which had been painted with acrylic artist colors with defined color differences (ΔE = 0–7). The test subjects realized color differences already at ΔE = 1–4 for the highest resolution. Threshold values have been identified for different tones as well as the effect of interdependencies between tones and the level of color heterogeneity between adjacent areas.
{"title":"Subjective Sensation of Color Differences – Determination of Thresholds Depending on Color Tones and Resolution","authors":"C. Brischke, Tanja Borcharding, U. Mengel","doi":"10.1515/rbm-2015-0003","DOIUrl":"https://doi.org/10.1515/rbm-2015-0003","url":null,"abstract":"Abstract Colors are frequently defined by three points on the L*a*b* coordinates of the CIELAB color space, and the distance between two colors can be expressed as the total color difference ΔE. In particular with respect to reproducibility of print media color differences are an important parameter, as well as for car finishes and textile dyes. Color changes are also the result of ageing and weathering which is an issue for art objects and in the building and restoration sector. However, the subjective perceptibility of color differences depends on numerous factors and general thresholds are difficult to define. This study aimed therefore on defining tolerance levels for color changes in dependence of color tones and color tone combinations as well as their resolution. In total 30 test persons evaluated samples, which had been painted with acrylic artist colors with defined color differences (ΔE = 0–7). The test subjects realized color differences already at ΔE = 1–4 for the highest resolution. Threshold values have been identified for different tones as well as the effect of interdependencies between tones and the level of color heterogeneity between adjacent areas.","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"9 1","pages":"21 - 27"},"PeriodicalIF":0.0,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75481439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The Italian standards, formerly NORMAL, define Extraordinary Maintenance as those where a major intervention on the building is carried out, usually referred to as a conservation intervention. These receive much attention from the media thus prompting the interest of NGO and for non-profit organizations which take an interest in funding such projects. Conservation interventions are critical for the preservation of our architectural heritage;however, the trigger for their undertaking, as well as their timing, is mainly determined by political interests. Because of the lack of ordinary maintenance, conservation interventions have to address heightened material deterioration problems thus increasing the complexity and invasiveness of the required operations, as well as an overall higher cost. The most worrisome issue is that once the intervention is completed, the building or monument is considered as being in a stable condition and not requiring any further action. Only in few cases is the most ordinary maintenance regularly carried out but what is neglected is the monitoring, the early identification of those “symptoms” revealing that a problem is present and should be addressed before more damage occurs. The paper uses various examples to illustrate the above points.
{"title":"The Relevance of Maintenance and Monitoring in Architectural Conservation","authors":"A. Elena Charola, F. Henriques, M. L. Magadán","doi":"10.1515/rbm-2015-0001","DOIUrl":"https://doi.org/10.1515/rbm-2015-0001","url":null,"abstract":"Abstract The Italian standards, formerly NORMAL, define Extraordinary Maintenance as those where a major intervention on the building is carried out, usually referred to as a conservation intervention. These receive much attention from the media thus prompting the interest of NGO and for non-profit organizations which take an interest in funding such projects. Conservation interventions are critical for the preservation of our architectural heritage;however, the trigger for their undertaking, as well as their timing, is mainly determined by political interests. Because of the lack of ordinary maintenance, conservation interventions have to address heightened material deterioration problems thus increasing the complexity and invasiveness of the required operations, as well as an overall higher cost. The most worrisome issue is that once the intervention is completed, the building or monument is considered as being in a stable condition and not requiring any further action. Only in few cases is the most ordinary maintenance regularly carried out but what is neglected is the monitoring, the early identification of those “symptoms” revealing that a problem is present and should be addressed before more damage occurs. The paper uses various examples to illustrate the above points.","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"44 1","pages":"1 - 8"},"PeriodicalIF":0.0,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89084430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Van Gemert, S. Ignoul, K. Brosens, E. Toumbakari
Abstract: Mass consolidation of stone and brick masonry is considered, with exclusion of pure crack repair. Damage and specific failure mechanisms in multiple leaf masonry are presented. The aims of consolidation are explained, and the inherent advantages and disadvantages of distinct strengthening and consolidation techniques are given. An historical overview of consolidation methods and of development of consolidation grout materials is given, which explains how technology evolved to the actual procedures.
{"title":"Consolidation and Strengthening of Historical Masonry by Means of Mineral Grouts: Grout Development","authors":"D. Van Gemert, S. Ignoul, K. Brosens, E. Toumbakari","doi":"10.1515/rbm-2015-0004","DOIUrl":"https://doi.org/10.1515/rbm-2015-0004","url":null,"abstract":"Abstract: Mass consolidation of stone and brick masonry is considered, with exclusion of pure crack repair. Damage and specific failure mechanisms in multiple leaf masonry are presented. The aims of consolidation are explained, and the inherent advantages and disadvantages of distinct strengthening and consolidation techniques are given. An historical overview of consolidation methods and of development of consolidation grout materials is given, which explains how technology evolved to the actual procedures.","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"43 1","pages":"29 - 45"},"PeriodicalIF":0.0,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88404074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Rodriguez-Navarro, F. Jroundi, M. T. González-Muñoz
Abstract Precipitation of calcium carbonate minerals by bacteria, the so-called bacterial carbonatogenesis, is a promising method for the consolidation of decayed stone. Despite extensive laboratory testing that has demonstrated the efficacy of this method, little is, however, known regarding the medium- and/or long-term performance of this bacterial conservation treatment once applied in situ, on stone buildings. Here, we report on the evaluation of the performance of bacterial consolidation treatments applied in three different historical buildings placed in an urban environment and built using a highly porous, easily decayed calcarenite stone. Peeling tape tests show a significant long-lasting (up to four years) strength improvement following treatment with either a Myxococcus xanthus bacterial culture or a sterile nutritional solution that selectively activates the carbonatogenic bacteria inhabiting the stone. Total color changes, measured before and after treatment using a spectrophotometer, are systematically below the acceptable value of ΔE ≤ 5. Culture-dependent analysis of the microbiota shows that 100% of the culturable bacteria collected before and after treatment is carbonatogenic, and the total count of fungi spores remains constant or diminishes, while the population of acid-producing bacteria decreases over time after treatment application. Culture-independent microbial analyses show that no deleterious microbiota develops after treatment, being carbonate-producing Proteobacteria, Firmicutes and Actinobacteria the most abundant phyla both before and after treatment. Overall these results show that the in situ application of the bacterial consolidation method shows no detrimental side effects and is highly effective in the medium- and long-term.
{"title":"Stone Consolidation by Bacterial Carbonatogenesis: Evaluation of in situ Applications","authors":"C. Rodriguez-Navarro, F. Jroundi, M. T. González-Muñoz","doi":"10.1515/rbm-2015-0002","DOIUrl":"https://doi.org/10.1515/rbm-2015-0002","url":null,"abstract":"Abstract Precipitation of calcium carbonate minerals by bacteria, the so-called bacterial carbonatogenesis, is a promising method for the consolidation of decayed stone. Despite extensive laboratory testing that has demonstrated the efficacy of this method, little is, however, known regarding the medium- and/or long-term performance of this bacterial conservation treatment once applied in situ, on stone buildings. Here, we report on the evaluation of the performance of bacterial consolidation treatments applied in three different historical buildings placed in an urban environment and built using a highly porous, easily decayed calcarenite stone. Peeling tape tests show a significant long-lasting (up to four years) strength improvement following treatment with either a Myxococcus xanthus bacterial culture or a sterile nutritional solution that selectively activates the carbonatogenic bacteria inhabiting the stone. Total color changes, measured before and after treatment using a spectrophotometer, are systematically below the acceptable value of ΔE ≤ 5. Culture-dependent analysis of the microbiota shows that 100% of the culturable bacteria collected before and after treatment is carbonatogenic, and the total count of fungi spores remains constant or diminishes, while the population of acid-producing bacteria decreases over time after treatment application. Culture-independent microbial analyses show that no deleterious microbiota develops after treatment, being carbonate-producing Proteobacteria, Firmicutes and Actinobacteria the most abundant phyla both before and after treatment. Overall these results show that the in situ application of the bacterial consolidation method shows no detrimental side effects and is highly effective in the medium- and long-term.","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"197 3 1","pages":"20 - 9"},"PeriodicalIF":0.0,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76605403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Van Gemert, E. Toumbakari, S. Ignoul, K. Brosens
Abstract Development of mineral grouts for consolidation and strengthening of historical masonry was discussed in Ref. [1]. The properties of the injection grout must counteract the elements that initiate the failure mechanism of multiple leaf historical masonry and lead to its collapse. This paper presents a macro-approach to model the structural behavior of three-leaf masonry. A global approach is used, based on the properties and the behavior of the external leafs, in combination with the properties and behavior of the central core of the three-leaf wall. Evaluation of the models is made by comparison with experimental data.
{"title":"Consolidation and Strengthening of Historical Masonry by Means of Mineral Grouts: Modeling Structural Behavior of Grouted Three-Leaf Masonry","authors":"D. Van Gemert, E. Toumbakari, S. Ignoul, K. Brosens","doi":"10.1515/rbm-2015-0005","DOIUrl":"https://doi.org/10.1515/rbm-2015-0005","url":null,"abstract":"Abstract Development of mineral grouts for consolidation and strengthening of historical masonry was discussed in Ref. [1]. The properties of the injection grout must counteract the elements that initiate the failure mechanism of multiple leaf historical masonry and lead to its collapse. This paper presents a macro-approach to model the structural behavior of three-leaf masonry. A global approach is used, based on the properties and the behavior of the external leafs, in combination with the properties and behavior of the central core of the three-leaf wall. Evaluation of the models is made by comparison with experimental data.","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"3 1","pages":"47 - 54"},"PeriodicalIF":0.0,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81006917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Preventive Conservation is argued to improve preservation of heritage at large. The UNESCO chair on Preventive Conservation, monitoring and maintenance of monuments and sites (PRECOM3OS) has pushed research and collaboration to understand the nature of preventive conservation in the field of built heritage. The study of the concepts and practices of prevention in public health helps to understand the systemic nature of prevention and how they can be transferred to the conservation world.
{"title":"Preventive Conservation of Historic Buildings","authors":"K. van Balen","doi":"10.1515/rbm-2015-0008","DOIUrl":"https://doi.org/10.1515/rbm-2015-0008","url":null,"abstract":"Abstract Preventive Conservation is argued to improve preservation of heritage at large. The UNESCO chair on Preventive Conservation, monitoring and maintenance of monuments and sites (PRECOM3OS) has pushed research and collaboration to understand the nature of preventive conservation in the field of built heritage. The study of the concepts and practices of prevention in public health helps to understand the systemic nature of prevention and how they can be transferred to the conservation world.","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"93 1","pages":"104 - 99"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73654345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract High-performance fiber-reinforced cement-based composites (HPFRCC) can be characterized by low porosity and fine pores as compared to normal concrete and therefore this interesting material absorbs little water or aqueous salt solutions if exposed to aggressive environment. These properties are indications for excellent durability and long service life of structural members or structures made with this high-performance material. In practice, however, most structures and structural elements are designed to be load bearing. The influence of an applied tensile stress on capillary absorption was investigated and results are presented in this contribution. It was found that the coefficient of capillary absorption increases rapidly if a tensile stress exceeding half of the tensile strength is applied. This observation has to be taken into consideration if HPFRCC is to be applied in aggressive environment. The maximum admissible stress must be reduced accordingly.
{"title":"Capillary Absorption and Chloride Penetration into High-Performance Fiber-Reinforced Cement-Based Composites (HPFRCC) as Influenced by Tensile Stress and Self-Healing","authors":"F. Wittmann, Penggang Wang, Peng Zhang, T. Zhao","doi":"10.1515/rbm-2015-0009","DOIUrl":"https://doi.org/10.1515/rbm-2015-0009","url":null,"abstract":"Abstract High-performance fiber-reinforced cement-based composites (HPFRCC) can be characterized by low porosity and fine pores as compared to normal concrete and therefore this interesting material absorbs little water or aqueous salt solutions if exposed to aggressive environment. These properties are indications for excellent durability and long service life of structural members or structures made with this high-performance material. In practice, however, most structures and structural elements are designed to be load bearing. The influence of an applied tensile stress on capillary absorption was investigated and results are presented in this contribution. It was found that the coefficient of capillary absorption increases rapidly if a tensile stress exceeding half of the tensile strength is applied. This observation has to be taken into consideration if HPFRCC is to be applied in aggressive environment. The maximum admissible stress must be reduced accordingly.","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"88 1","pages":"75 - 80"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90594602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Restoration of Buildings and Monuments","authors":"Ö. Cizer","doi":"10.1515/rbm-2015-1000","DOIUrl":"https://doi.org/10.1515/rbm-2015-1000","url":null,"abstract":"","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"30 1","pages":"v - v"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91518633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhancement of Theory and Practice in Restoration and Renovation of Buildings and Monuments needs Attitude, Knowledge and Skill: Contribution of a Man and a Journal","authors":"D. Van Gemert","doi":"10.1515/rbm14.20.6-0035","DOIUrl":"https://doi.org/10.1515/rbm14.20.6-0035","url":null,"abstract":"","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"134 1","pages":"379 - 382"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81279516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The evaluation of nano-particle based products to protect granite surfaces from water absorption is presented. Wettability, water absorption, drying behaviour and water vapour transfer were considered as the most relevant parameters for this evaluation. The effect of the application methods on the final performance was also tested. The results allow to consider that nanostructured products may present some advantages when compared with conventional water repellent products, namely on some common relevant harmful effects, such as colour changes, water vapour or liquid transfer during drying, but their effectiveness as barriers against water absorption upon longer contact time may not be equally satisfactory.
{"title":"Testing New Water Repellent Solutions to Protect Deteriorated Granite","authors":"D. Costa, J. Delgado Rodrigues","doi":"10.1515/rbm14.20.6-0040","DOIUrl":"https://doi.org/10.1515/rbm14.20.6-0040","url":null,"abstract":"Abstract The evaluation of nano-particle based products to protect granite surfaces from water absorption is presented. Wettability, water absorption, drying behaviour and water vapour transfer were considered as the most relevant parameters for this evaluation. The effect of the application methods on the final performance was also tested. The results allow to consider that nanostructured products may present some advantages when compared with conventional water repellent products, namely on some common relevant harmful effects, such as colour changes, water vapour or liquid transfer during drying, but their effectiveness as barriers against water absorption upon longer contact time may not be equally satisfactory.","PeriodicalId":20957,"journal":{"name":"Restoration of Buildings and Monuments","volume":"89 1","pages":"413 - 422"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79736742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：