Conservation Of Buildings Research Articles

Application of Femtosecond Laser Processing Method in the Sustainable Conservation of Stone Cultural Relics: An Example of Green Schist in Wudang Mountain, China

The ancient building complex in Wudang Mountain, China, is known as the “Museum of Ancient Chinese Architectural Accomplishments”. However, the valuable stone components are preserved in open or semi-open environments and environmental factors such as rain seriously threaten its sustainable conservation. In this context, a femtosecond laser processing method has been demonstrated to be able to prepare hierarchical micro-nano structures on the stone surface to regulate its wettability, achieving the purpose of sustainable conservation. In this paper, the processing mechanism and performance of the femtosecond laser on green schist, a local stone material in the Wudang Mountain, are systematically investigated. It is found that green schist, as a typical non-homogeneous material, exhibits significant differences in its absorption of femtosecond laser with different compositions. Among them, quartz, chlorite, and muscovite are the three main compositions, and they are mainly characterized by cold ablation, thermal melting, and expansion under the irradiation of the femtosecond laser (238 fs, 100 kHz, 40 μJ, 33 μm, 500–40,000 pulses), respectively, and it is difficult to achieve a uniform and stable surface structure. Based on this, we prepared grooves with a spacing of 100–400 μm by scanning the femtosecond laser. Through the characterization of surface morphology, elemental composition, and three-dimensional structure, the processing mechanism of the hierarchical micro-nano structures of green schist under the irradiation of the femtosecond laser is comprehensively revealed. Finally, the wettability modulation result of water contact angle up to 147° is achieved by processing the grooves with an optimal spacing of 400 μm. The results of this research are of guiding significance for the sustainable conservation of ancient buildings and cultural relics.

Analysis of the Current Status of Sensors and HBIM Integration: A Review Based on Bibliometric Analysis

This article presents a bibliometric analysis conducted on the implementation of sensor-extracted data in the context of Historical Building Information Modeling (HBIM) with a focus on the conservation of heritage buildings. The study utilized recognized databases, namely, Web of Science (WoS) and Scopus. A bibliometric analysis methodology was applied, employing the VOSviewer 1.6.19 software. The results obtained provide a robust overview of the current state and trends in HBIM and sensor research and enabled the identification of emerging trends in the field of preventive conservation. Three promising trends were identified, establishing connections between this field and 4D spatial data management, energy performance, and artificial intelligence. Additionally, relations with climate change were also detected. These trends underscore a significant convergence of technologies and methodologies in the realm of heritage building conservation. The conclusions serve as a valuable contribution to guiding future research in the field of built heritage conservation.

Rural Residents’ Willingness to Adopt Energy-Saving Technology for Buildings and Their Behavioral Response Path

There is an urgent need to promote the technical means of energy conservation in rural buildings. However, it is difficult to inspire enthusiasm among rural residents to implement the mandatory building energy conservation policy, resulting in invisible and avoidable waste. Based on the characteristics of energy-saving technology for buildings and the theory of planned behavior, structural equation modeling was adopted to explore the transformation process of the “cognition–willingness–behavior” of rural residents. The model results validate the hypothesis that behavioral attitudes, subjective norms and perceived behavioral control influence the adoption of energy-efficient building technologies by rural residents. The results show that in terms of the factors influencing rural residents’ willingness to adopt building energy-saving technology, behavioral attitudes have the greatest impact, followed by subjective norms and perceived behavior control, and that rural residents’ subjective norms can indirectly promote their willingness to adopt building energy-saving technology, which is mediated through their behavioral attitudes. The paper concludes with suggestions for countermeasures to enhance buildings’ energy efficiency and energy management in rural areas.

A Review of Metaheuristic Optimization Techniques for Effective Energy Conservation in Buildings

The built environment is a significant contributor to global energy consumption and greenhouse gas emissions. Advancements in the adoption of environmentally friendly building technology have become crucial in promoting sustainable development. These advancements play a crucial role in conserving energy. The aim is to achieve an optimal design by balancing various interrelated factors. The emergence of innovative techniques to address energy conservation have been witnessed in the built environment. This review examines existing research articles that explore different metaheuristic optimization techniques (MOTs) for energy conservation in buildings. The focus is on evaluating the simplicity and stochastic nature of these optimization techniques. The findings of the review present theoretical and mathematical models for each algorithm and assess their effectiveness in problem solving. A systematic analysis of selected algorithms using MOT is conducted, considering factors that influence wellbeing, occupant health, and indoor environmental quality. The study examines the variations among swarm intelligence MOTs based on complexity, advantages, and disadvantages. The algorithms’ performances are based on the concept of uncertainty in consistently providing optimal solutions. The paper highlights the application of each technique in achieving energy conservation in buildings.

The critical issues in the conservation of Heritage building: Masjid Mahabat Khan Peshawar, Pakistan

The critical issues in the conservation of Heritage building: Masjid Mahabat Khan Peshawar, Pakistan

Isolation and identification of fungal biodeteriogens from the wall of a cultural heritage church and potential applicability of antifungal proteins in protection

Fungi are able to permanently damage cultural heritage buildings and stone monuments. Protection against these biodeteriogen fungi is challenging because it may require the use of drastic techniques to remove fungal colonies and chemicals, which can cause further damage, especially on mural paintings. Natural biocides are less damaging, greener, and safer and mainly include essential oils and plant-derived substances. Studies on the applicability of purified antifungal proteins in the conservation of cultural heritage buildings are lacking. In this study, we isolated mold mycoflora from the biodeteriorated inner walls of the Calvinist church of Kézdialbis (Kézdialbis, Romania) and investigated the in vitro antifungal efficacy of Neosartorya (Aspergillus) fischeri antifungal proteins, NFAP and NFAP2 against them. Antifungal susceptibility testing revealed that these proteins inhibited the growth of the most commonly isolated indoor biodeteriogen fungi from the site (Aspergillus creber, Aureobasidium pullulans, Cladosporium sp., Penicillium chrysogenum, and Parengyodontium album) and not common ones (Mucor hiemalis, Sarocladium kiliense) with different spectra and efficacies. A phytopathogen and an entomopathogen species (Pseudopithomyces chartarum and Beauveria pseudobassiana, respectively) were also isolated and described first as fungal biodeteriogens of the inner walls. Among them, P. chartarum was susceptible to NFAP2. Next, we tested the applicability of NFAP and NFAP2 in protecting cultural heritage buildings in a wall model experiment against A. creber. Topical application of both antifungal proteins significantly decreased the area infected by fungi. Scanning electron microscopy of the wall models showed that A. creber had reduced growth and conidiation in the presence of NFAP and NFAP2. This inhibitory activity was maintained for a long time. Strong UV irradiation decreased the protective effect of both proteins in the wall model. Taking into account these results, the high stability of NFAP and NFAP2 in harsh environments, and their bulk recombinant producibility, we suggest that both can be used in the protection and posttreatment of painted walls of cultural heritage buildings to clean up mural painting or to inhibit mold recolonization after mechanical, physical, or chemical decontamination.

Historic Building Information Modeling for Conservation and Maintenance: San Niccolo’s Tower Gate, Florence

In the field of conservation and protection of heritage buildings, knowledge plays a fundamental role, emphasized by national and international rules and regulations. This aspect becomes fundamental when conducting the structural assessment of a historical building. This study envisaged a cognitive phase via the application of advanced survey and diagnostic methodologies to define the materials, construction techniques, and state of conservation of the structural system of a specific building forming part of Florence’s heritage. The information complex produced formed the basis for the structural assessment and for the experimentation of the BIM methodology within the creation of databases for the management of cognitive processes of historical buildings. The case study is one of the gates of the last circle of walls of the 14th century and is the only one that has maintained its original height, despite modifications: the gate/tower of San Niccolò. The research conducted, in addition to achieving a structural assessment of the tower, has allowed the creation of a dynamic model for organizing and consulting the information, laying the groundwork for the creation of a conservation and maintenance plan.

Single drone-based 3D reconstruction approach to improve public engagement in conservation of heritage buildings: A case of Hakka Tulou

Public engagement in protecting architectural heritage is a critical component of sustainable development. This study has developed an innovative single drone-based 3D reconstruction (SD-3DR) approach for public-involved architectural heritage conservation. A new software tool named after CU-Recon is also developed to enable easy access and efficient 3D reconstruction using drone photography. Unlike traditional photogrammetry-based reconstruction, CU-Recon adopts our unique deep learning-based multi-view stereo network named LCM-MVSNet, enabling the public to employ only one drone for image capture and 3D reconstruction. LCM-MVSNet applies a learnable cost metric (LCM) to adaptively aggregate multi-view matching similarity into the 3D cost volume by leveraging sparse point hints. Its outstanding reconstruction performance for building scale applications is proved by the extensive experiments on the DTU training dataset and BlendedMVS dataset. A remarkable architectural heritage Hakka Tulou is selected to verify the effectiveness of the SD-3DR on large-scale heritage buildings. The results show our approach outperformed the other four 3D reconstruction tools. Moreover, the reconstruction quality in CU-Recon is evaluated from a perspective of heritage conservation using the concept of satisfaction. Practitioners expressed an overall satisfaction score of 4.175 (out of 5) for the reconstruction quality of the method. Survey results reveal a higher level of satisfaction with single drone photography for architectural heritage conservation compared to LiDAR-based scanning in terms of portability, operability, and cost. The research outcome changes the current situation of government-led top-down architectural heritage conservation by providing valuable insights for individual practitioners in creating bottom-up heritage conservation routes.

The Influence of Visitors on Heritage Conservation: The Case of the Church of San Juan del Hospital, Valencia, Spain

One of the greatest challenges in heritage management is to find a balance between the demands of visitor access and heritage conservation. The income generated prevents decay and benefits the conservation of buildings. At the same time, cultural tourism can accelerate the deterioration of buildings from increased use and an increase in agents harmful to conservation. This unique research analyses the influence of building use at San Juan del Hospital, the oldest church in the city of Valencia. Its architectural characteristics and the climate of the city mean that visits to the building put the conservation of its heritage assets at risk. Monitoring data from the summer months were put into a digital twin generated from a heritage building information model (HBIM), and the modelling of visitor numbers and the impact on indoor environmental quality was conducted. Monitoring and simulations confirmed that visitor numbers need to be reduced or mechanical conditioning systems need to be installed to prevent damage to the heritage artefacts within the building. This research provides building managers with information to make informed decisions about the preventive maintenance of heritage buildings. This research also demonstrates for the first time the value of using monitoring and a digital twin for conservation management.

Analysis of Diseases and Conservation of Modern Residential Buildings in Macao: A Case Study of the Lou Family's Big House

The Lo Family Building is a typical representative of modern residential architecture in Macao, which has its own characteristics in terms of architectural history, culture, spatial layout and fittings. In recent years, many scholars have been carrying out research on the Lu Family's Great House. At present, there is insufficient research and protection on the disease analysis and architectural protection related issues of the restored Lu Family's Great House. This paper through the literature research, field research methods on the Lu family house specific investigation and research, analysis of existing disease phenomena, concluded that the Zheng family house is currently the main external finishes discolouration, cracking, weathering, plant erosion and human factors and other types of disease, and its characteristics and causes of a brief collation of the analysis; and finally, based on the above materials, put forward the subsequent protection measures. To a certain extent, it provides some new thoughts for the conservation of modern residential buildings in Macao.

Energy efficiency retrofitting measures of an institutional building: A case study in eastern India

Increasing energy demand and greenhouse gas emissions are major concerns in India. Building energy use in India accounts for 33 % of total energy consumption and is growing at an annual rate of 8 %. In order to save energy, energy conservation in buildings should be given primary importance. Energy conservation practices can reduce energy use in buildings while maintaining thermal comfort. This can be achieved by optimising existing energy use or lowering consumption. One such initiative was undertaken by Siksha 'O' Anusandhan Deemed to be University. It analysed the energy consumption pattern and possible energy conservation opportunities (ECOs) to lower energy usage in its buildings at campus 1 in Bhubaneswar. The Energy Conservation Building Code Odisha (OECBC) was followed to reduce energy use by replacing all the damaged windows with efficient glazing. By following OECBC guidelines, we can save up to 30 % of the energy consumed by an existing building. Besides, energy conservation measures were performed by replacing ceiling fans with brushless direct current (BLDC) fans, existing lights with LED bulbs, and using variable speed drives instead of induction motors. This study will help to define the most efficient energy conservation measures for existing buildings in terms of cost and energy savings. Retrofitting the present building with energy-saving devices will cost INR 21, 32, 90,152 with an overall annual energy savings of 47, 28,177 kWh and a yearly cost saving of INR 319,66,703.

A robust superhydrophobic coating of siloxane resin and hydrophobic calcium carbonate nanoparticles for limestone protection

Hydrophobic calcium carbonate (CaCO3) nanoparticles (NPs), modified with dodecanoic acid (DA), are produced and dispersed in solutions of KSE 100, which is a silicic acid ester base product used for the conservation and maintenance of heritage and modern buildings. The dispersions are sprayed on limestone and marble specimens. By adjusting the relative concentrations of DA and NPs, the treated stones obtain superhydrophobic properties. Focusing on limestone it is reported that the treatment has negligible effects on the colour and vapour permeability of the original stone and offers protection against water capillary rise. Several studies are performed to test the durability of the composite (KSE + CaCO3-DA NPs) coating against rain impact, freezing and thawing, salt attack and UV radiation. Moreover, the mechanical, chemical and thermal durability of the coating is studied according to the tape peeling test, contact angles of drops which correspond to a vast range of pH, and heat treatment. The results of the aforementioned tests reveal the very good stability of the composite coating. In sum, it is reported that the wetting properties of the KSE 100 stone strengthener, which is used in building conservation, can be highly improved by adding a small amount of modified CaCO3 NPs. The latter are chemically compatible with calcareous stones.

Research on wind pressure characteristics of traditional timber buildings: a case study of the main hall of Shisi Temple

Traditional timber buildings are sensitive to wind action. Studying the wind pressure characteristics is the premise for the preventive conservation of traditional timber buildings. To investigate the computational fluid dynamics (CFD) numerical simulation method for wind pressure on traditional timber buildings, a typical traditional timber building, the main hall of Shisi Temple, is chosen as a case to carry out the study. A comparative analysis is conducted to examine the effects of curve simplification of the roof slope, as well as the Dougong (bracket sets) and roof tile components, on the numerical simulation results of wind pressure on the building surface. Additionally, simplification schemes of geometric modeling are provided for the efficient and accurate simulation. The results indicate that moderate simplification of the roof curve has a relatively minor impact on the overall calculation of wind pressure, and the difference between the drag coefficients of the simplified model and the accurate model is no more than 3%. However, excessive simplification can lead to distorted simulation results, and a three-segment curve simplification method is recommended for roof cornices. The influence of Dougong on the wind pressure calculation results is negligible (within 5%), whereas roof tiles significantly reduce the drag coefficient, with an impact of over 30% at various wind directions. The impact of roof tiles on wind pressure distribution in traditional timber buildings lies in their alteration of the building aerodynamic shape rather than an increase in roof thickness. The findings can provide a basis for assessing the wind resistance of traditional timber buildings and helpful insights for improving the efficiency of wind pressure analyses of traditional timber structures.

Mass transfer research on the regeneration process of an air-conditioning battery system

Developing a sustainable and low-carbon society calls for energy conservation of buildings. On this purpose, green air-conditioning systems driven by renewable energy have been encouraged as alternative to the present vapor-compression air-conditioning system. Absorption system is one promising representative, but relatively lower performance impedes its application. To improve, we propose an air-conditioning battery system (ACBS) that evolves from the traditional absorption system. Its COP attains four by incorporating a refrigeration cycle with a battery cycle, realizing energy storage when producing cooling effect. Driven by renewable energy, ACBS is a green air-conditioning system for being environmental friendly with refrigerant water and avoiding the combustion of fossil fuels that emits a large amount of CO2 bringing in environmental issues. The critical part of ACBS is the capacitive deionization (CDI) regeneration process, which concentrates absorbent by electrical adsorption. The mass transfer mechanism of regeneration is important for system optimization. Simulation investigation has been made in this paper to reveal the mechanism. A two-dimensional model has been established and validated to depict the dynamic response at different electric adsorption stages. Analysis has been conducted based on the models to expose the influence of some critical parameters. The results show that the enhancement of COP could exceed 50% with optimum design parameters.

Heritage buildings management: the role of situational awareness and cyber-physical systems

AbstractSafeguarding and conservation of cultural heritage is an important issue that requires both theoretical knowledge and practical implementation to effectively protect this valuable asset. In recent years, new technologies have enabled the development of advanced monitoring and control systems that can provide more precise and timely information about the condition of heritage buildings. Additionally, these systems can collect and analyze a large amount of data, allowing decision-makers to make informed decisions regarding maintenance and other management processes. With a situational awareness model proposed for heritage building conservation as a starting point, this work outlines how the design and implementation of a cyber-physical system to support conservation processes can be done. The model combines decisional processes that involve both humans and automated systems and can be used as a guideline for the realization of decision support systems for the management of heritage buildings. The paper provides a case study describing the steps for the realization of a cyber-physical system for automated monitoring and control at the Royal Palace of Carditello, a prominent cultural attraction in Italy.

A comprehensive investigation of zeolite/polyurea cooling coating on concrete for building energy conservation

Passive daytime radiative cooling (PDRC) materials are beneficial to energy conservation and emission reduction of buildings. Currently, the design of PDRC coatings for exterior walls and roofs of buildings places excessive emphasis on improving the solar reflectance (Rs) and infrared emissivity (Ei) of the coating, while neglecting other important properties of building coatings, such as adhesion, waterproofness, corrosion resistance, and weather resistance. To address these deficiencies, this work developed a (calcined zeolite)/polyurea (CZ/PU) PDRC coating with excellent comprehensive performance for building exterior walls and roofs, using CZ and PU as raw materials. The CZ/PU coating is prepared using a method that is completely consistent with existing paint production and construction techniques, and can be applied to large-area building surfaces at scale. The Rs of the CZ/PU coating is 97.4 %, and the Ei is 94.4 %. Under direct sunlight in summer, the CZ/PU coating achieved significant PDRC effects under both adiabatic conditions (using test equipment to reduce heat conduction and convection) and natural conditions. The corresponding radiative cooling temperatures are 14.9 °C and 4.4 °C, respectively. In addition, the CZ/PU coating also exhibits excellent water resistance, reducing the capillary water absorption rate of a cement block by 78 %. In addition, the adhesion strength of the CZ/PU coating to the substrate reached the highest rating (rating 0). In particular, the optical properties, radiative cooling function, water absorption, and adhesion force of the CZ/PU coating showed ultra high stability in ultraviolet aging experiments. Energy consumption simulations show that the average energy saving efficiency of the CZ/PU coating on the annual total building energy consumption of ten typical Chinese cities is as high as 13.3 %. The CZ/PU-based coating developed in this work comprehensively considers various issues that may be faced in the practical application of radiative cooling architectural exterior wall coatings, providing an experimental foundation for promoting the application of radiative cooling coatings in buildings.

Carbon-negative heat-stored limestone calcined clay cement mortar containing form-stable phase change materials

Heat-stored cement-based materials (HSCMs) with form-stable phase change materials (PCMs) have exhibited tremendous opportunities for energy conservation and emission reduction in buildings. In this study, a novel HSCM system was designed by incorporating form-stable PCMs into limestone calcined clay cement (LC3) mortar, in which a highly compatible form-stable PCM was constructed by the three-step method including the synthesis of red mud-based geopolymer hollow microsphere (RMHM), the impregnation of n-Octadecane (ODE) into RMHM and the surface precipitation of CaCO3. The microstructures, phase transition properties, chemical compatibility and thermal stability of the two resulting form-stable PCMs (namely ODE/RMHM and ODE/RMHM@CaCO3) were evaluated. A comparative analysis was conducted to reveal the influence mechanism of ODE/RMHM and ODE/RMHM@CaCO3 on the microstructural evolution, hydration reaction, mechanical and thermal properties of LC3 mortar. Moreover, the numerical model method confirmed the significant role of the prepared LC3-based in temperature control and energy conservation in building. In addition, the obtained LC3-based HSCM could achieve a short dynamic payback period and sequestered huge of carbon emissions for service life. In overall, this work opened up a novel path of economically feasible carbon-negative building materials with form-stable PCM.

Boosting the electrochromic performance of P-doped WO3 films via electrodeposition for smart window applications.

Electrochromic smart windows have attracted more attention from researchers due to their potential applications for energy conservation in buildings. As the most key component, the electrochromic layer is still limited by the complexity of the preparation process and poor performance, such as lower stability, slow response time, and low coloration efficiency. In this study, as a simple and expedient method, electrodeposition is successfully used to prepare amorphous WO3 films doped with P. By optimizing the amount of P in the PW-2 film, a large optical modulation of 80.8% at 550 nm is achieved, and the P-doped amorphous WO3 film also shows a fast response time, a high CE, and good cycling stability. The mechanism of the P-doped amorphous WO3 films to improve the electrochromic properties is as follows. Firstly, by appropriate phosphorus doping, the stress of the film is released, and the binding force is improved. Secondly, the films possess proper cracks, which accelerate the diffusion of ions. Thirdly, the films make the nanoparticles more uniform, and provide more active sites. Furthermore, the electrochromic smart windows based on the P-doped amorphous WO3 film display a large temperature difference of 11 °C, which indicates good solar thermal regulation ability, and promises practical applications for building energy conservation.

Thermochromic Smart Windows with Ultra-High Solar Modulation and Ultra-Fast Responsive Speed Based on Solid–Liquid Switchable Hydrogels

Thermo-responsive hydrogels can dynamically modulate incident light, providing a broad prospect for development of smart windows, which are of pivotal importance for energy conservation in buildings. However, these hydrogels normally exhibit slow response speed and tend to contract over extended phase transition, compromising structural integrity of smart windows. In this study, a solid–liquid switchable thermochromic hydrogel, denoted as SL-PNIPAm, was synthesized by cross-linking PNIPAm with AMEO through dynamic imine bonds. Due to its distinctive solid–liquid transformation characteristics, SL-PNIPAm demonstrates rapid response time (within 5 s) and retains structural integrity without undergoing shrinkage during heating/cooling and freezing/thawing cycles. SL-PNIPAm can also be encapsulated within 2 glass panels to prepare smart windows, which showed extraordinary luminous transmittance ( T lum = 96.8%) and solar modulation ability (Δ T solar = 89.7%) and effectively reduced the indoor temperature (22 °C) in a simulated indoor experiment. Energy consumption simulation investigations are performed in diverse cities. The results reveal that SLW is capable of achieving a remarkable 54% reduction of HVAC energy consumption, leading to substantial decrease in CO 2 emissions by up to 40 kg m −2 annually. This work develops a new hydrogel system with outstanding durability for smart windows and will promote the development and renovation of thermochromic smart windows.

The Practice of Digital Technology in the Conservation and Restoration of Historical Buildings

The Practice of Digital Technology in the Conservation and Restoration of Historical Buildings