Deterioration Of Buildings Research Articles

Development of a Long-Term Repair Allowance Estimation Model for Apartments Based on Multiple Regression Analysis in Korea

Buildings aged 20 years or older account for 63.34% of all edifices in Korea. To ensure sustainable construction, apartment managers must plan and allocate financial resources to maintain communal facilities. However, on the one hand, long-term repair allowances (LTRAs) can be underestimated relative to actual repair costs; consequently, apartments can rapidly deteriorate. On the other hand, the long-term allowance may exceed the actual repair expenditure, thus, wasting resources. Existing estimation methods do not consider the apartment management degree, equipment condition, time value, or the extent of building deterioration. Based on multiple regression, this study developed a repair budget estimation model that considers the influencing factors that include the main characteristics of apartments and the time value, thereby allowing apartment managers to estimate the appropriate long-term repair expenses. In the conducted experiments, the root mean square and mean absolute percentage errors of the estimation model were USD 144,587.38 and 25.6%, respectively. Further, ANOVA results showed a difference between the actual and estimated total long-term repair costs. The resulting model should support apartment managers in establishing reliable maintenance budgets and effectively prevent the functional degradation of buildings.

Climate Change Projection and Its Impacts on Building Façades in Singapore

Singapore is one of the most populous countries, and the majority of the population stays in high-rise public flats. In 2021, there were about 1.1 million public residential units, of which 79% were above 20 years old. The number of incidents of falling objects from a height has been increasing due to the aging and deterioration of buildings. The Periodic Façade Inspection (PFI) regime was enacted in 2020 to mandate façade inspections for all buildings above 13 m and exceeding 20 years old. However, the relatively new PFI regime has not considered the potential impacts of climate change on building façades. In this paper, the common root causes of façade defects that can be impacted by climate change are first identified. Based on the climate projection in Singapore to 2100, Singapore is expected to experience a higher mean temperature, a higher rainfall intensity, more extreme rainfall events, and a higher wind gust speed. Overall, these changes in the climate pattern will accelerate corrosion or degradation, material fatigue, adhesion failure, biological attack, and humidity or dampness. The impacts of climate change on vertical greeneries are also discussed. This paper provides a first insight into the key concerns to focus on for the future revision and improvement of the PFI regime to incorporate climate change impacts on façades.

МЕТОДИКА ОЦЕНКИ СОСТОЯНИЯ ОГРАЖДАЮЩИХ КОНСТРУКЦИЙ ЗДАНИЙ НА ТЕРРИТОРИИ ЖИЛОЙ ЗАСТРОЙКИ ПОДЛЕЖАЩЕЙ РЕНОВАЦИИ

The assessment of the physical deterioration of buildings and structures is an expensive, lengthy and to some extent subjective process. The process of making a decision on the need for repair, reconstruction or demolition of a building is stretched over time, sometimes dragging on for years. At the same time, the condition of a building or structure may undergo significant changes, and therefore, the efficiency of information is crucial. The authors of the article propose a method for assessing the physical wear of buildings and structures based on the results of thermal imaging, which allows you to accurately indicate the areas of heat loss. The building's enclosing structures combine load-bearing and heat-protective functions. The presence of defects (cracks, chips, soaking) lead to the formation of heat loss bridges, which are manifested in thermal imaging. The work is carried out both with stationary scanners and with the use of unmanned aerial vehicles. Thermal imaging should be carried out during the heating period. It is important to be able to obtain information about the presence of damage in a hard-to-reach part of buildings. When using stationary scanners, a combined assessment of the condition of the structure, including geometric parameters, is possible. The camera processing of the survey results is carried out on the basis of standard methods fixed by regulatory documents. Being an integral part of a complex of engineering surveys conducted to determine the physical wear of buildings and structures, this technique allows you to supplement the general situation analyzed when drawing up the final conclusion with quantitative data.

РАЗВИТИЕ КОНСТРУКТОРСКО-ТЕХНОЛОГИЧЕСКОЙ КЛАССИФИКАЦИИ ДЕТАЛЕЙ МАШИН

The assessment of the physical deterioration of buildings and structures is an expensive, lengthy and to some extent subjective process. The process of making a decision on the need for repair, reconstruction or demolition of a building is stretched over time, sometimes dragging on for years. At the same time, the condition of a building or structure may undergo significant changes, and therefore, the efficiency of information is crucial. The authors of the article propose a method for assessing the physical wear of buildings and structures based on the results of thermal imaging, which allows you to accurately indicate the areas of heat loss. The building's enclosing structures combine load-bearing and heat-protective functions. The presence of defects (cracks, chips, soaking) lead to the formation of heat loss bridges, which are manifested in thermal imaging. The work is carried out both with stationary scanners and with the use of unmanned aerial vehicles. Thermal imaging should be carried out during the heating period. It is important to be able to obtain information about the presence of damage in a hard-to-reach part of buildings. When using stationary scanners, a combined assessment of the condition of the structure, including geometric parameters, is possible. The camera processing of the survey results is carried out on the basis of standard methods fixed by regulatory documents. Being an integral part of a complex of engineering surveys conducted to determine the physical wear of buildings and structures, this technique allows you to supplement the general situation analyzed when drawing up the final conclusion with quantitative data.

Pinpointing drivers of widespread colonization of Legionella pneumophila in a green building: Roles of water softener system, expansion tank, and reduced occupancy

IntroductionLegionella pneumophila is an opportunistic pathogen that is a key contributor to drinking water-associated disease outbreaks in the United States. Prolonged water stagnation periods in building plumbing systems due to low occupancy, especially during building shutdowns, breaks, and holidays, can lead to water quality deterioration and (re)colonization of buildings with L. pneumophila. Water monitoring in buildings typically relies on grab samples with small datasets.MethodsIn this study, a larger dataset was created by sampling a Leadership in Energy and Environmental Design (LEED)-certified data-rich commercial building for L. pneumophila and physical-chemical water quality during the COVID-19 pandemic after reduced building occupancy. A proxy for human occupancy rates using WIFI logins was recorded throughout the study period.ResultsL. pneumophila was observed in grab samples taken throughout the building, where concentrations generally increased with greater distances from the building point of entry to locations throughout the building. Factors conducive to microbial growth were identified in the building including fluctuations in water temperatures, lack of chlorine residual, a low water heater setpoint, colonized water-saving fixtures, prolonged stagnation throughout the building; especially in an expansion tank designed to reduce pressure issues during demand fluctuations, and the presence of oversized softener tanks with ion exchange resin that contributed to chlorine residual removal as well as colonization of the resin with L. pneumophila.DiscussionFlushing and thermal disinfection alone did not resolve the problem, and replacement of the expansion tank ultimately resolved the L. pneumophila issue. As ad-hoc approaches are logistically- and time-intensive, more proactive approaches are needed for informing preventative and corrective actions for reducing the risk of exposure to opportunistic pathogens in the building plumbing.

A new method for assessing the physical wear of apartment buildings with defects included

The article proposes a new method for assessing the physical deterioration of residential buildings, taking into account not only the physical deterioration of structures, but also the accumulated defects in buildings. The composition of operational wear, methods for their assessment and assessment of the real technical condition of structures and buildings as a whole are analyzed. At the same time, operational wear is considered as a combination of physical and moral wear. If physical depreciation is presented as a category of technical and economic, then the assessment of the degree of this depreciation is associated with the costs spent on its elimination. The technical condition of the building structure is also affected by defects accumulated at different stages (pre-project, design stage, prefabrication stage, storage and transportation of the structure, construction and installation and operation stage) of the existence of the building. The elimination of accumulated defects also requires corresponding costs. Therefore, in the article the accumulated defects are referred to as functional deficiencies and it is accepted as functional wear and tear. And the assessment of cumulative wear in determining the real technical condition, the inclusion of this wear is necessary. This article presents an algorithm and a mathematical model for accounting for this type of (functional) wear.

Environmental Protection Solutions for Heritage Buildings from Air Pollution Impacts “Case-Study of Qasr El-Manial, Cairo, Egypt”

The current local strategies are reactive in response to risk or damage, usually in the form of treatments, repairs and retrofitting on the building scale, there is a need for proactive strategies that rely on preventive conservation concepts which can be more sustainable and cost effective as it minimizes the possibility of deterioration and risk through controlling its cause on different scales. In order to conserve historic buildings from deterioration caused by air pollution, the impact of air pollution on these buildings need specification and quantification in order to control below the tolerable thresholds using convenient strategies on the appropriate scale. The main objective is to minimize deterioration of Historic Buildings caused by Air Pollution through the development of a framework for local management preservation strategies. A survey conducted to validate the framework. This will lead to types of preventions (UNESCO PRECOMOS Chair) as follows; primary prevention by avoiding the causes of the unwanted effect (damage), secondary prevention as the means of monitoring that allow an early detection of the symptoms of the unwanted effects, and tertiary prevention that allow avoiding further spread of the unwanted effect or the generation of new unwanted (side) effects.

In‐Plane damage of partition walls with various boundaries during earthquakes

AbstractCold‐formed steel‐framed gypsum partition walls (hereinafter referred to as partition walls) sustain the seismic damage induced by small story drifts. The impacts on the functional deterioration and monetary loss of buildings are enhanced in earthquake events where structural damages are limited. Although the boundaries of partition walls vary by location in a building structure, the existing studies assume a typical partition wall surrounded by a frame consisting of columns and girders. In particular, the vertical boundary members vary from a column, stud column, and wall panel. Our present work investigates the influence of the boundaries on seismic damage and fragility assessment of partition walls using an experimental dataset of cold‐formed steel‐framed gypsum partition walls with various boundaries obtained at an E‐Defense shake table on a four‐story steel frame. A damage mechanism model considering the deformation and rigid body motion of the partition walls and boundaries suitably explains the observed damage variations and underlying mechanisms. This study also presents the non‐negligible impact of boundaries on the fragility and expected repair time and cost model of the partition walls. The presented results are critical in providing references for the layout of partition walls, damage predictions, construction improvements, and repair strategy.

Real time vibration measurement and inverse analysis for dynamic properties of an axisymmetric masonry structure

ABSTRACT Historic buildings are public symbols, standing as sacred reminders. Many of them have been recognized as World Heritage Sites. In this study, real time vibration measurement of an important axisymmetric masonry pagoda was performed. With the measured vibration data, inverse analysis was proposed to backward determine its damping and natural period. The proposed algorithm utilizes Duhamel’s time integration method for solving the equation of motion and the Gauss-Newton algorithm to minimize the sum-of-squares error between the calculated and real-time measured accelerations of the structure. Four distant earthquake-induced vibrations were recorded and used for the analysis. The results show that the dynamic parameters determined by the proposed method agree with those obtained from the previous study adopting finite element analysis. The obtained dynamic properties of the two perpendicular directions are slightly different, indicating the non-homogenous body of the axisymmetric structure or there would be a particular damage zone. From the results, an onsite damage investigation can be specifically identified. In summary, continuous structural health monitoring and time-dependent deterioration of historic buildings are possible with real time measurement and the proposed analytical algorithm.

The use of drilling test to investigate the salt distribution in air lime mortars

• Drilling test (DRMS) to map salt distribution in air lime mortars. • Processing of drilling data to detect salts within air lime mortars. • Diagnostic techniques to evaluate the presence of salts and salt damage in air lime mortars. One of the principal causes of deterioration in historic buildings is the presence of salts. Porous and low-strength materials, such as soft mortars, are particularly susceptible to the deteriorating action of salts. The most severe damage occurs when salts accumulate behind the material surface, causing crumbling, exfoliation, and spalling. For this reason, the use of minimally invasive techniques to locate the presence of salts below the surface can be helpful to make an informed decision on the best practice for conservation strategies. In this work, the effectiveness of the drilling test in investigating the sub-surface distribution of salts in two lime-based mortars was evaluated. The technique proved to be effective as the increase in the recorded drilling forces was well correlated with the salt content measured within the materials. In particular, the drilling test results showed a similar behavior between the two mortar mixes. This finding was confirmed by the ultrasonic pulse velocity tests, visual observations, and weight loss measurements performed after the salt aging test. Another aspect of the work is the contribution to the processing of drilling profiles in salt weathered soft mortars. Indeed, the results of drilling tests in soft mortars are very scattered due to the intrinsic heterogeneity of these materials. Thus, the proposed processing of drilling data was effective in evidencing the effects of salts, by reducing the influence of the chip formation on the drilling profiles.

Photocatalytic soot degradation under UV and visible light.

Particulate matter is one of the most persistent global air pollutants that is causing health problems, climate disturbance and building deterioration. A sustainable technique that is able to degrade soot using (sun)light is photocatalysis. Currently, research on photocatalytic soot oxidation focusses on large band gap TiO2-based photocatalysts and thus requires the use of UV light. It would prove useful if visible light, and thus a larger fraction of the (freely available) solar spectrum, could additionally be utilised to drive this process. In this work, a visible light-active photocatalyst, WO3, is benchmarked to TiO2 under both UV and visible light. At the same time, the versatility and drastic improvement of a recently introduced digital image-based soot degradation detection method are demonstrated. An additional step correcting for non-soot related catalyst colour changes is applied, resulting in accurate detection and quantification of soot degradation for all studied photocatalysts, even for materials such as WO3 that are inherently coloured. With this study, we aim to broaden the scope of photocatalytic soot oxidation technology to visible light-active photocatalyst. Along with this study, we provide a versatile soot degradation detection methodology based on digital image analysis that is made widely applicable.

Formation of Strontianite and Witherite Cohesive Layers on Calcite Surfaces for Building Stone Conservation

The formation of micrometric-thick mineral cohesive layers is a novel method to prevent the deterioration of historical buildings. Here, we study the formation of thin, cohesive, pseudomorphic shells of strontianite (SrCO3) and witherite (BaCO3) on the surface of calcite (CaCO3) single crystals reacted with aqueous solutions bearing Sr2+ and Ba2+, respectively. The reaction front moves inward from the calcite–solution interface through a dissolution–crystallization reaction, which stops before the strontianite and witherite shells are barely 40 thick. These shells consist of elongated crystallites that grow oriented on the calcite substrate, with which they share very small contact areas. The calcite–strontianite and −witherite epitaxies are mono-dimensional and involve a parallelism between (101̅4)Cal||(021)Str/Wth. Strontianite and witherite cohesive layers remain strongly attached to the calcite substrates, which appear crack-free even after 2 years of reaction time. The formation of thin, cohesive, and durable replacement layers of strontianite and witherite may provide a long-lasting protection for calcitic marbles and limestones used as building stones in cultural heritage.

Users’ Perception of Compliance of Security Features with Defensible Space Principles in Selected Secondary Schools in Ota, Ogun State, Nigeria

The idea of preventing crime by strategically using the environment as tool has been explored for decades. Defensible space provides architectural strategies for effectively preventing crime by reorganizing the physical environment and giving inhabitants control over their surroundings. This study seeks to examine the security features allaying with defensible space in four selected secondary schools in Ota, Ogun state, Nigeria, with a view to making contributions on how to improve security in such environments for users. The study identifies areas for further improvements based on users’ perception, towards enhancing security in the academic environments in Nigeria. Four selected secondary schools in Ota, publicly and privately owned was used for the study. The study used quantitative and qualitative research methods to obtain data from 149 students, in addition with 33 teachers from four secondary schools. The collected data were descriptively analysed with the use of SPSS (Statistical Package for Social Science) software. Results showed that there are evidences of elements of defensible space strategies, which are Territoriality and Natural surveillance that were adequately perceived and being implemented by the respondents. Deterioration of school buildings and poor road construction were seen. These were evidences of the elements of Milieu and Image, an indication of defensible space perception. Students dissatisfaction with overall school security was also revealed. The study further shows that appropriate maintenance strategies can help enhance the physical and security conditions of school environment in Nigeria.

Facile Synthesis and Characterization of CeO2-Nanoparticle-Loaded Carboxymethyl Cellulose as Efficient Protective Films for Mild Steel: A Comparative Study of Experiential and Computational Findings.

Corrosion is considered to be the most severe problem facing alloys and metals, one that causes potentially dangerous industrial issues such as the deterioration of buildings and machinery, and corrosion in factory tanks and pipelines in petroleum refineries, leading to limited lifetime and weak efficacy of such systems. In this work, novel CeO2-nanoparticle-loaded carboxymethyl cellulose (CMC) was successfully prepared by using a simple method. The structural configuration of the prepared CeO2-nanoparticle-loaded CMC was investigated by FE-SEM/EDX, TEM, FT-IR, and thermal analyses. The corrosion protection proficiency of uncoated and coated mild steel with CeO2-CMC systems in 1.0 M HCl solutions was studied by EOCP-time, EIS, and PDP tools. Moreover, the relationship between the structure of coating films and their corrosion protection was confirmed by DFT calculation and MC simulation. The obtained findings from the studied methods showed that the prepared CeO2-CMC-coated films reported high corrosion resistance. The protection capacity augmented with ceria presents an increase of up to 3% to achieve 98.4%. DFT calculation and MC simulation confirmed the influence of the chemical construction of coated films on its protection capacity, which was in accordance with the experimental results.

Tuning Ice Nucleation by Mussel-Adhesive Inspired Polyelectrolytes: The Role of Hydrogen Bonding

Tuning Ice Nucleation by Mussel-Adhesive Inspired Polyelectrolytes: The Role of Hydrogen Bonding

Investigation in manufacturing self-healing cementitious materials using microbial technology

Small cracks are inherent in cementitious-based structures. This causes deterioration of buildings, reducing the bearing capacity of structures due to the invasion of harmful substances as well as corrosion of reinforcement in cementitious material. Therefore, the cementitious material needs to be restored and these voids filled. Self-healing cementitious material has been strongly developed for long time in the world. However, this technology has not been popular in Vietnam. Therefore, the aim of this paper is to find the appropriate mix-design for creating self-healing cementitious material in Vietnam conditions. Experimental results show that the mixture including bacillus subtilis and calcium lactate can be used for creating the self-healing cementitious materials. Mixing directly the mixture in the cement is selected to manufacture the self-healing cementitious materials. It seems that the width of crack affects more on healing ability than the length of crack.

Investigation in manufacturing self-healing cementitious materials using microbial technology

Small cracks are inherent in cementitious-based structures. This causes deterioration of buildings, reducing the bearing capacity of structures due to the invasion of harmful substances as well as corrosion of reinforcement in cementitious material. Therefore, the cementitious material needs to be restored and these voids filled. Self-healing cementitious material has been strongly developed for long time in the world. However, this technology has not been popular in Vietnam. Therefore, the aim of this paper is to find the appropriate mix-design for creating self-healing cementitious material in Vietnam conditions. Experimental results show that the mixture including bacillus subtilis and calcium lactate can be used for creating the self-healing cementitious materials. Mixing directly the mixture in the cement is selected to manufacture the self-healing cementitious materials. It seems that the width of crack affects more on healing ability than the length of crack.

Investigation in manufacturing self-healing cementitious materials using microbial technology

Small cracks are inherent in cementitious-based structures. This causes deterioration of buildings, reducing the bearing capacity of structures due to the invasion of harmful substances as well as corrosion of reinforcement in cementitious material. Therefore, the cementitious material needs to be restored and these voids filled. Self-healing cementitious material has been strongly developed for long time in the world. However, this technology has not been popular in Vietnam. Therefore, the aim of this paper is to find the appropriate mix-design for creating self-healing cementitious material in Vietnam conditions. Experimental results show that the mixture including bacillus subtilis and calcium lactate can be used for creating the self-healing cementitious materials. Mixing directly the mixture in the cement is selected to manufacture the self-healing cementitious materials. It seems that the width of crack affects more on healing ability than the length of crack.

Local Management Strategies for Preventive Conservation of Historic Buildings “Controlling Deterioration Caused by Air Pollution”

The current local strategies are reactive in response to risk or damage, usually in the form of treatments, repairs and retrofitting on the building scale, there is a need for proactive strategies that rely on preventive conservation concepts which can be more sustainable and cost effective as it minimizes the possibility of deterioration and risk through controlling its cause on different scales. In order to conserve historic buildings from deterioration caused by air pollution, the impact of air pollution on these buildings need to be specified and quantified in order to be controlled below the tolerable thresholds using convenient strategies on the appropriate scale. The main objective is to minimize deterioration of Historic Buildings caused by Air Pollution through the development of a framework for local management preservation strategies. A survey was also conducted to validate the framework. This will lead to types of preventions (UNESCO PRECOMOS Chair) as follows; primary prevention by avoiding the causes of the unwanted effect (damage), secondary prevention as the means of monitoring that allow an early detection of the symptoms of the unwanted effects, and tertiary prevention that allow avoiding further spread of the unwanted effect or the generation of new unwanted (side) effects.

Geotechnical modelling and subsurface analysis of complex underground structures using PLAXIS 3D

In this study, analysis of complicated underground structure of Horemheb tomb (KV57) at Luxor, Egypt by using the software PLAXIS 3D is adopted and the deformation that occurs in the body of the underground structure after applied the failure load detected; the failure loads are obtained from the series of laboratory tests. Then, the structure is modelled by using finite element code to perform accurate three-dimensional analysis of deformation and stability in complex geotechnical engineering and rock mechanics. These underground monumental structures have been analyzed by finite element method FEM to obtain the deformation that accrued into the structure and so beneath of the surface and calculated the effective stress, shear stress and horizontal displacements. In order to modeling requires the soil parameters obtained from laboratorial tests. In the analysis elastic–plastic Mohr–Coulomb model is used as material model. It involves five parameters namely, Young’s Modulus (E) and poison’s ratio (ν) for soil elasticity, friction angle (φ) and cohesion (c) for soil plasticity. To set up the boundary condition, the standard fixities option is used. As a result a full fixity at the base and free condition at the horizontal side of geometry are generated. Numerical Engineering analysis for Horemheb tomb (KV57) in the valley of kings at the west bank of Luxor was carried out through the following four main steps: (1) Evaluation of surrounding rocks (marl limestone and marl shale) by experimental research and Roclab program to obtain the Hoek Brown and Mohr- Coulomb fit classification criterion and rock mass standards in particular the global strength and deformation coefficient. Also to specify the main characteristics of the Esna Shale using different methods such as swelling test, swelling potential, swelling pressure, in addition, discussion of the role of the expansive Esna Shale in the deterioration of archaeological buildings and sites. (2) Quantitative and qualitative estimates of the relevant factors affecting the stability of the tomb, especially overloading, fixed, geographic, and dynamic. (3) Integrated 3D geotechnical modeling of the cemetery environment for stress and displacement analysis and identification of volumetric strains and plastic points using advanced symbols and programs such as PLAXIS 3D. (4) The rapeutic and retrofit policies and techniques and the fixed monitoring and control systems needed to strengthen and stabilize the cemetery, where the rock mass classification refers to the rock mass where KV57 is excavated and it is poor rocks. The mechanical behavior of the rocks is simulated by assuming a foundational model to soften the elastic stress of the flexible plastic that captures fragile failure and the mechanisms of progressive substrate failure. In addition, rock pillar treatments and ground support strategies are discussed. This article represents the second phase of the numerical analysis of KV57 using PLAXIS 3D.