Study on Properties of Blue-Brick Masonry Materials for Historical Buildings

There are a large number of historic buildings which were mainly made of blue-brick masonry in today’s world.However,for the natural and man-made reasons,these historic buildings have been damaged in different degrees.In order to protect historic buildings more scientifically and learn about the preservation state of existing historic buildings,it is necessary to ascertain the material properties of blue brick in historic buildings.The article takes the blue bricks of historical buildings in Kaifeng area of the Central Plains as an example to study.Through the analysis of physical properties,X-ray fluorescence spectroscopy,X-ray diffraction and scanning electron microscopy of blue brick specimens,the physical properties such as the apparent density,moisture content,porosity,and material structure composition are understood.The results show that the apparent density of blue brick is 1.64 g/cm^(3),the moisture content is 10.23%,the 24 h atmospheric water absorption is 17.86%,and the porosity is 20.99%.The smaller the apparent density is,the larger the porosity is,and the water absorption performance is better.From the microscopic point of view,bonding ability between blue brick mineral particles is relatively weak.The pores between skeletons are large and the pore structure is obvious.From the perspective of material phase,the elements of blue brick are mainly O,Si,Al,Fe,and the composition of blue brick is mainly composed of quartz and feldspar.The softening coefficient of blue brick is 0.80,and the deformation and stability of the structure should be paid special attention in the rainy season or wet environment.Through the frost test,there are salt substances in the internal pores of the brick,and the surface of the blue brick is eroded and pulverized.In this paper,the experimental process and analysis methods for testing the material properties of blue brick can provide reference for the research on the material properties of the same kind of blue-brick masonry in historic buildings and masonry relics.The relevant material property parameters obtained in this paper can provide guidance for making protection schemes and scientific repairs for historic buildings in Central China,enrich the evaluation criteria for maintaining and reinforcing historic buildings,and provide theoretical support for studying the damage and health detection technology related to historic buildings.

Analysis of the Influence of New Usages on the State of Conservation of Historical Buildings through Microclimate Characterization

Recycling is an alternative for preserving historical heritage buildings. Through such process, buildings are occupied by new usages that assure they are not abandoned. However, conservation issues, like pathological manifestations by filamentous fungi, are common even in buildings receiving new uses. Thus, it is extremely important to know the microclimate behavior of these buildings and analyze if there are usages that favor the appearance of filamentous fungi or not. This study aims to verify if new usages modify the microclimate in historical buildings and if such possible change favors the appearance of pathological manifestations by filamentous fimgi in some specific use. To achieve the results, three buildings that have gone through recycling processes were chosen in the city of Pelotas, in Southernmost Brazil. The city possesses a large number of buildings with historical value and its climate conditions are propitious for appearance of filamentous fungi. For 12 months, microclimate was monitored, the environments modus operandi was characterized and there was a survey on the pathological manifestations by filamentous fungi in the three buildings with two different uses： administration offices and exhibition rooms. Conclusion was that usages that allow natural ventilation and lighting favor conservation, which is what happens in the ones used as administration offices. Besides that, it was noticed that the construction system also influences, since buildings with a high cellar that is being used did not present filamentous fungi, which also shows the influence of ascending humidity on the appearance of such pathological manifestations.

Ambient Vibration Testings and Field Investigations of Two Historical Buildings in Europe

In this study,the methodology and results of ambient vibration-based investigations of the historical Tash Mosque in Kosovo and a 3-story historical building in Bulgaria are presented.The investi gations include full-scale in situ testing of both structures due to ambient vibrations induced by micro-seismic,wind,traffic,and other human activities.To this aim,Ranger seismometers and Kinemetric products were used.Measurements were performed in both horizontal directions in several points along the structures'height utilizing a high-speed data acquisition device.All recorded data have been analyzed and processed by the software developed at IZIIS,and then the processed data were used as input for modal analysis.The basic assumption is that the excitation can be considered as a stationary random process to have a relatively flat spectrum.The paper clearly describes the procedure used for investigations and presents the dynamic properties of the whole structures.The inv estigated structures are both historical buildings and defined as architectural heritage and the outcome of this study including the natural vibration frequencies and mode shapes)can be very benefi-cial for the verification stage of the analytical/numerical models for future retro-fiting/rehabilitation schemes.

A novel approach for assessing color harmony of historical buildings via street view image

While new buildings continue to emerge in the process of urbanization,historical buildings,as valuable legacies carrying national historical memory,play an important role in the urban landscape.Previous studies have shown that color harmony is a crucial factor in coordinating urban landscapes.However,the evaluation of color harmony in historic areas and buildings lacks effective quantitative standards,often overlooking factors such as complementary color harmony and the compatibility of analogous colors.This study aims to build a new method to evaluate the color harmony of historical buildings through street view technology,semantic segmentation algorithms,quantification of color harmony methods based on image property detection and classification,questionnaire verification,and takes Shanghai’s historical buildings as an example to explore.Our study categorizes six types of color harmony indexes for Shanghai street-facing historic buildings into three levels,with the top tier serving as a benchmark for excellence and the lowest tier highlighting areas in need of urban environmental improvement.This study uniquely considers color compatibility within hue ranges and expanded relationship types like complementary harmony.This approach,applicable to cities globally,offers practical tools for urban planners and conservators in managing and preserving historic areas and buildings.

Assessment and Rehabilitation of Damaged Buildings in Historic Benghazi City

The primary focus of the study is to assess and classify the damage in the old Benghazi City.Specifically,it aims to evaluate buildings within a designated area,which is bordered by Umar Ibn Al-Aas Street to the south,Omar Al-Mukhtar Street to the north,Ben Issa Street to the east,and the extension of Gamal Abdel Nasser Street to the west.The main objective is to gather valuable insights and data that can support effective rehabilitation or reconstruction efforts.By comprehending the extent of the damage and categorizing it accordingly,the study seeks to provide essential information for decision-making processes and determine the most appropriate approach for restoration.The ultimate aim is to ensure the safe return of residents to the affected area.In addition to this,the restoration process aims to preserve and revitalize the city’s religious,historical,and distinctive features.This includes safeguarding religious structures,landmarks,and elements that contribute to the city’s unique identity.To achieve this,the study proposes separate rehabilitation schemes tailored for ordinary buildings and historic buildings.

Protection of Historical Buildings in Metro Line Construction:A Case Study in Shanghai,China

This research presents a holistic approach to the protection of historical building group adjacent to metro line construction,in which health investigation,protection criterion determining,numerical simulation analyses,corresponding protection measures and field monitoring analyses are incorporated as main procedures.A case relating to the conservation of a seven-storey brick-wood pagoda,Longhua Pagoda,adjacent to the construction of Shanghai Metro Lines 11 and 12 in China,is presented.A reasonable protection criterion is determined rationally by means of numerical simulation based on the health investigation results combined with related standards,which can help to achieve a fine balance between system safety and cost constraints in protection measures determining.A full numerical model is developed to analyze the effect of dewatering,excavation,tunneling,and shield departure/reception,and corresponding measures are adopted to ensure the safety of the pagoda.Especially a brand new method,steel jacket method,is introduced in detail,which has a good performance on decreasing the amount of dewatering and maintaining a stable working face.Results demonstrate the application potential of the proposed approach,as well as its feasibility.The proposed approach can be used in the industry by practitioners to provide positive guidelines on the conservation of historical building group against metro line constructions.The reliable and detailed data in this case can also provide verification for subsequent research.

Urban Public Spaces and Design of Historical and Cultural Buildings——Series II of Urban Public Space Design

This paper summarized concept and role of urban public space, highlighted its role in emotional exchange, cultural exchange, and business communication, and the significance of showing inside image of the city in terms of morality and residents' quality. Combining with design of historical and cultural buildings, the paper explored the forms of historical and cultural buildings in urban public spaces from the perspectives of administration square, religious square, cultural square and commercial street, so as to design "human-concerned" urban public spaces that meet human needs and reflect personality of the city.

Evolution of Damage on Historical Heritage Buildings in Presence of Catastrophic Events and Aggressive Natural Phenomena

The feasibility analysis of projects for the preservation of the historical heritage buildings is an important problem concerning the evaluation of ＂the total cost of intervention＂, which includes all the future damage costs. The total cost of intervention represents a suitable measure of the expected deterioration risk and its evolution obviously depends on the damage process which buildings are subjected to. That damage phenomena affecting masonry buildings pleased into an aggressive environment are suitably modelled by renewal processes： this happens both in the case of catastrophic events, or in the case of the so-called ＂natural aging＂, in which damage comes off gradually in time. In the hypothesis ofa Markovian renewal process （Mrp） describing the damage process, the total cost of all the future damage is evaluated taking into account both the damage aspects： damages due to catastrophic aspects and damages due to aggressive environment, supposing different maintenance and/or rehabilitation scenarios. A semi-Markov process （s-Mp） is defined to model the damage rehabilitation history of buildings in presence of seismic events, natural ageing and rehabilitation strategies. The expected rewards connected to the process are defined; they represent a significant measure of the risk.

Preliminary Research on Water Supply,Drainage,and HVAC Equipment in Shanghai Historic Buildings During the Northern Warlord Period

During the Northern Warlord Period(1912–1928),the construction industry in Shanghai underwent robust development.As an integral element of buildings,equipment served both functional purposes and stood witness to the evolution of the economy and society,thus earning its place as part of the architectural heritage.However,due to various reasons,there are many loopholes in the protection of these building equipment.This paper examines the development of building equipment in Shanghai during the Northern Warlord Period,using water supply,drainage,and heating,ventilation,and air conditioning(HVAC)systems as examples.Through historical context analysis,it summarizes this development from a social-spatial perspective,infers the reasons behind it,and analyzes the importance of preserving such equipment,considering both past and present viewpoints.In this research,the importance of protecting historical building equipment is emphasized,which aims to give people a deeper understanding of their cultural value,and suggests that scholars conduct more practical research on their protection.

Adaptive-Reuse of Historic Industrial Buildings and Sites in China

The paper analyzes the definite place of industrial building in the history of urban development. Due to the development of urban economy and the transition of the traditional industrial structure, many historic cities and towns both at home and abroad have witnessed a large scale "demolition" and abandonment of industrial buildings in urban renewal during last 30 years. Consequently, it has been leading to the discontinuity of urban cultural and historic context. The paper discusses and expounds the clas...

Design between Architecture and Structure: Case Studies of Pilot Interventions on Italian Monumental Buildings

Two case studies,referring to historic Italian buildings housing city halls,provide an opportunity to investigate the design of non-standard elements aimed at protecting masonry vaults,with particular reference to the preliminary works prior to the actual structural restoration work.There is in fact a phase in which it is a priority to secure the vault to avert possible risks to the users of that portion of the building.This phase is temporarily intermediate between the detection and aggravation of injuries and the renovation and consolidation project.Although these are provisional works,they are intended for buildings that are often public and therefore intended for a wide range of users,such as schools,offices or monumental buildings.In analyzing traditional techniques and systems used in similar cases,the possibility of developing evolutionary aspects with respect to,above all,simple shoring techniques emerged.In these areas,hybrids between a structural and architectural project,it is possible to reconcile static requirements with architectural techniques of space management,attentive to the quality of the interior and the integration of the provisional work with the reference context.

The Reuse of Historic Buildings as a Preservation Practice

This paper aims to discuss the concept of reuse as a preservation practice for historic buildings.One of the inherent characteristics of architecture is use.It is among the necessary conditions for its preservation.Thus,considering cultural assets and the architectural heritage of different historical moments,currently recognized as depository of artistic,social and memory values,worthy of being preserved,the issue of reuse assumes relationships that go beyond pragmatic aspects to become a cultural matter.To this end,it can be observed the debate about the reuse of heritage buildings has been gaining prominence in the academic and technical sphere of construction.In May 2018,the 5th International Forum on Architectural Heritage Brazil-Portugal(FIPA)took place in the city of Rio de Janeiro,Brazil.This event had as a study dimension the reuse while a preservationist practice.That is why the methodology used to structure this text is bibliometrics,in other words,this study was based on papers presented at the event in direct dialogue with the concept under analysis.In this context,it is observed the attribution of a new use,compatible with the characteristics of pre-existing structures,which becomes an important preservation tool.

Case Study of Indirect Adiabatic Cooling System in Historical Building

The objective of the present study is to investigate the efficiency of indirect adiabatic chiller-based cooling system efficiency dependence of outdoor air humidity. The system is located in historical building, in temperate climate of Latvia. The data about electricity consumption, water consumption, chiller operation stages, cooling average temperatures and outdoor air parameters have been acquired for the period of 2.5 month, during the cooling season. Using data collected by BACnet based BMS controllers and adiabatic chiller control system, we have analyzed operation efficiency of the chiller and its dependence of outdoor air humidity. Data range for the period from August 1st till October 13th, 2011 was taken for deeper analysis, which showed that in temperature range 22.0 ± 0.5 ℃ for the studied period of time chiller＇s COP is slightly dependent on the outdoor air moisture.

Characteristics and Protection of Historic Blocks in the Downtown of Quanzhou City:A Case Study of the Blocks along Zhongshan Road

Historic block records the historic development and changes of a city,contains rich cultural resources,and is an important product in the process of urban development.Historic block of Zhongshan Road has a long history,so there are many historical buildings with local characteristics and traditional style of commercial market,and it is an important window of refl ecting characteristics and regional culture of Quanzhou ancient city.However in long-period development process,historic buildings and blocks in the block along Zhongshan Road of Quanzhou City were destroyed.We initially study how to rationally develop and protect these precious historic and cultural relics,and the methods,principles and countermeasures of protection are put forward.

Dynamic response analysis of train-induced vibration impact on the Probhutaratna pagoda in Beijing

Train-induced vibration exhibits a potential dynamic impact on historic buildings and especially on those with high historical and cultural value.Under the long-term reciprocating load of train vibrations,structural fatigue damage can occur,and thus,a significant problem involves effectively evaluating and mitigating vibration impact on historic buildings while developing a rail transit system.In the present study,train-induced vibration impact and dynamic behavior of Probhutaratna pagoda in the suburb of Beijing,which has a history of approximately 1000 years,was investigated.To examine the dynamic behavior of the Probhutaratna pagoda and determine the weakest position in its architectural damage under train loads,its dynamic characteristics were measured.The free vibration modes were identified based on the dynamic measurement results.Subsequently,a finite element(FE)model of the Probhutaratna pagoda was constructed and the models and train-induced structural responses were compared with measured results.Finally,the structural dynamic responses to moving train loads were analyzed in detail.The results indicate the following conclusions.(1)The dominant frequency of the ambient vibration is below 4 Hz,and the dominant frequency of the train-induced vibration is between 8 and 16 Hz.(2)The first,second,and third order natural frequencies are 1,3.25,and 6 Hz,respectively,in the west-east direction,and are 1,3.25,and 6.25 Hz,respectively,in the north-south direction.(3)The two weakest locations(A and B)of the Probhutaratna pagoda are observed at the spire bottom and west gate of the first floor.At location A,the maximum principal stress reached 243.6 N/m^2 and the corresponding maximum tensile strain reached 3.74×10^-7.

Introspection on improper seismic retrofit of Basilica Santa Maria di Collemaggio after 2009 Italian earthquake

The 2009 L’Aquila, Italy earthquake highlighted the seismic vulnerability of historic masonry building structures due to improper ＂strengthening＂ retrofit work that has been done in the last 50 years. Italian seismic standards recommend the use of traditional reinforcement techniques such as replacing the original wooden roof structure with new reinforced concrete （RC） or steel elements, inserting RC tie-beams in the masonry and new RC floors, and using RC jacketing on the shear walls. The L’Aquila earthquake revealed the numerous limitations of these interventions, because they led to increased seismic forces （due to greater additional weight） and to deformation incompatibilities of the incorporated elements with the existing masonry walls. This paper provides a discussion of technical issues pertaining to the seismic retrofit of the Santa Maria di Collemaggio Basilica and in particular, the limitations of the last （2000） retrofit intervention. Considerable damage was caused to the church because of questionable actions and incorrect and improper technical choices.

Conservation of Building and Decorative Elements of Ottoman Architecture in the Medieval City of Rhodes

The transformation of the medieval city of Rhodes and the modification of its buildings since the siege of 1522 by Suleiman the Magnificent up to the 20th century, were imposed by the social and religious needs of each of its conquerors. In particular, during the period of the Ottoman rule （1522-1912）, most of the churches were converted into mosques while new buildings like public baths and mansions were constructed, resulting in alterations in the morphological characteristics of the city. Although the buildings of the Hospitalier＇s period （1307-1522） were preserved, the additions and adjustments resulted into a mixture of western and oriental architecture, which today determines the multicultural identity of the city. In 1988, UNESCO （United Nations Educational, Scientific, and Cultural Organization） designated the medieval city of Rhodes as a world heritage city for its exemplary architectural complexity and variability, which perfectly reflects the complex historical phenomena and the unique integration of various cultures for more than seven centuries. In this paper, the management of the modifications and the restoration approach of four representative mosques are presented.

Optimal retrofitting scenarios of multi-objective energy-efficient historic building under different national goals integrating energy simulation,reduced order modelling and NSGA-II algorithm

Retrofitting a historic building under different national goals involves multiple objectives,constraints,and numerous potential measures and packages,therefore it is time-consuming and challenging during the early design stage.This study introduces a systematic retrofitting approach that incorporates standard measures for the building envelope(walls,windows,roof),as well as the heating,cooling,and lighting systems.Three retrofit objectives are delineated based on prevailing Chinese standards.The retrofit measures function as genes to optimize energy-savings,carbon emissions,and net present value(NPV)by employing a log-additive decomposition approach through energy simulation techniques and NSGA-II,yielding 185,163,and 8 solutions.Subsequently,a weighted sum method is proposed to derive optimal solutions across multiple scenarios.The framework is applied to a courtyard building in Nanjing,China,and the outcomes of the implementation are scrutinized to ascertain the optimal retrofit package under various scenarios.Through this retrofit,energy consumption can be diminished by up to 63.62%,resulting in an NPV growth of 151.84%,and maximum rate of 60.48%carbon reduction.These three result values not only indicate that the optimal values are achieved in these three aspects of energy saving,carbon reduction and economy,but also show the possibility of possible equilibrium in this multi-objective optimization problem.The framework proposed in this study effectively addresses the multi-objective optimization challenge in building renovation by employing a reliable optimization algorithm with a computationally efficient reduced-order model.It provides valuable insights and recommendations for optimizing energy retrofit strategies and meeting various performance objectives.

Metro train-induced vibrations on historic buildings in Chengdu,China

In this paper, the vibration influence on a monument caused by Chengdu Subway Line 2 is analyzed. Due to its elaborate and unique design, both structural and architectural damages should be avoided. First, the allowable root mean square （RMS） velocity at the foundation of the monument is derived and a site measurement is performed to obtain the background vibrations induced by road traffic. In addition, a train-track coupled model and 3D tunnel-soil-structure coupled finite element models are built to predict the dynamic response of the monument. Prediction models are checked by site measurement in Beijing Subway Line 5. Different kinds of fasteners and train speeds are compared and discussed as well. Results show that： （1） At a train speed of 72 km/h, all the traffic vibrations exceed the low limit no matter what kind of fastener is used, which is mainly due to the contribution of road traffic. Slowing down train speeds can cause effective vibration attenuation; （2） Vibrations drop dramatically with the train speed from 65 to 58 km/h. When the train speed is lower than 58 krn/h, vibrations are lower than allowable value even if the contribution of road traffic is considered.

The Old and the New: Designs to Enhance Cesano Maderno Old Town through a Regenerative Structure

The relationship between the old and the new is a specific theme of architecture that bears witness not so much to the original appearance of the old but to its enduring meaning in historic Italian and European cities.The complex palimpsest of signs,memories,and overwriting that time has layered on built forms opens questions of meaning that can be untangled only in the relationship between history,site and design.The investigation of structural characters of places and their relationships with cultural assets and heritage provides a layered set of readings,which is itself the forerun of an urban landscape design action.Beyond preserving the integrity of the material traces,there can only be the new.The test bench is therefore the project as a cognitive act around which to build‘case by case’the strategies for recovering urban identity.The series of projects for Cesano Maderno old town,north of Milan,exemplifies a design-led approach to the built heritage and historic urban landscape in which reading tools,conservation and design are shown in their mutual relationship.In this dialectic between the old and the new,the design is part of the architecture of time where the new,working through light reversible overwriting and measured grafting,becomes a further layer in the historical palimpsest and the authentic form of its enhancement and reuse.Integrating project strategies-from pure conservation to new architectural grafting,from reuse to overwriting-the sequence of designs give shape to a‘regenerative structure’that enhances as a system and for public use a set of introverted Baroque buildings and spaces along a historical promenade,re-centring the city around its brownfield core.