Building Defects Research Articles

Bounding-box object augmentation with random transformations for automated defect detection in residential building façades

This study proposes a novel bounding-box object augmentation (BoxAug) method to improve the performance of deep learning models in detecting defects in residential building façades. The most significant characteristic of the method is that it augments objects in images, rather than augmenting images, to solve the data imbalance problem. Moreover, it employs the bounding-box form for object detection, instead of the segmentation mask form. To evaluate the method, 7635 images obtained using unmanned aerial vehicles were utilized as the original training dataset. The faster region-based convolutional neural network model trained with the augmented training dataset using the method exhibited better performance than the model trained with the original dataset. Particularly, the class with the least objects in the original dataset displayed a markedly improved performance. Thus, the method can serve as an auxiliary method for effectively augmenting real-world image datasets with an unbalanced number of objects.

Evaluation of defect in hospital buildings

There are many complaints and criticisms in media and research literature on defects in hospital buildings despite the consistent increase in maintenance expenditures. This research investigated the nature of defects in private hospital buildings. Primary data for the study were collected through a survey questionnaire administered to hospital building users. Based on the findings, the defects that often require frequent maintenance are leaky faucets, defective doors, defective windows, broken lights, and faulty ventilation. The major conclusion drawn from the survey was that although there are many different defects in the buildings, the urgency at which they require maintenance interventions varies. Therefore, in order to avoid value mismatch and resource misallocations, resources and attention should be directed to the defects that are more important to the users and the other should be included in the next maintenance rolling programme. Maintenance management should be implemented to achieve good maintenance, capable to meet the expected requirements of the end-user and increase building performance and reduce the maintenance backlog.

Defects in Concrete Elements: A Study of Residential Buildings of 30 Years and above in Onitsha Metropolis, Anambra State, Nigeria

Building defect is an issue in existing buildings that needs urgent tackling to prevent further problems. This study assessed the defects in concrete elements in residential buildings of 30 years and above in the Onitsha metropolis of Anambra State, Nigeria. Data collection instruments in the study include structured questionnaire, interviews, visual inspection/observations, archival records, recordings, photographs; and non-destructive testing of the concrete elements in an existing building in the study area. The population of this study constituted of the construction registered professionals and the existing buildings in study area. The sample for the study was based on the calculated sample size using Taro Yamani Formula. A total of 158 registered professionals were sampled from the population of 260. The questionnaires were purposively distributed to the registered professionals up to the required sample sizes of 158 and 129 questionnaires were properly filled and returned. The study used the SPSS and Microsoft Excel to analyze the data. The results were analyzed in percentages and figures using descriptive statistics and presented in the form of pie charts and tables. The finding of the study revealed that the causes and effects of structural defects on the concrete elements in existing buildings in the study area according to the rating are; exposed/corrosion of the embedded metals, faulty workmanship, overload and impacts, chemical attack, freeze-thaw deterioration, fire/heat, restraint to volume change. The visual observation revealed that the structural elements are characterized by heavy defects such as deep vertical, horizontal and diagonal cracks, exposed/ corrosion of the embedded metals, spalling of the concrete slabs. The existence of defects in the concrete members led to the low compressive strength of the concrete elements and the structural instability of the existing buildings as revealed by the non-destructive test. The non-destructive test result revealed that most of the tested concrete elements have low compressive strength value and such were remarked poor as they did not satisfy the assumed value. Essentially, the study concluded by recommending that regular monitoring, inspections and non-destructive testing of concrete elements should be conducted on existing aged and defected buildings to detect the structural stability of the buildings; and it is imperative to evacuate occupants from heavy structurally deteriorated and defected buildings since most of them have lost their residual design life span and ability to sustain imposed loads.

Case analysis of thermal defect detection of near-zero energy building envelope based on infrared thermography

The thermal performance of the envelope structure is one of the important components of the performance design of near-zero energy buildings. Minimizing envelope heat loss is the key to improving building energy efficiency. A necessary first step in the building envelope optimization process is the assessment of its actual thermal performance. This paper summarizes the application status of infrared thermography in thermal defect detection of building envelopes and common forms of thermal defects in near-zero energy buildings. Taking a near zero energy building in Shenyang area as the target object, an efficient and non-destructive infrared thermal image measurement method is applied to determine the thermal defect rating of the building from both qualitative and quantitative aspects. The results show that the building has high thermal performance. The temperature field distribution of the building envelope could be quickly obtained by using the infrared thermal imaging instrument. In this way, it can accurately identify the location of thermal bridges and air tightness defects, and provide an efficient and accurate detection method for building energy-saving diagnosis and evaluation.

Assessment of Public Building Defects and Maintenance Practices: Cases in Mettu Town, Ethiopia

Assessment of Public Building Defects and Maintenance Practices: Cases in Mettu Town, Ethiopia

Defect management of hospital buildings

Healthcare organisations are increasingly recognising the need to improve building performance in order to improve health care delivery, profits, and to reduce penalties. Hospital maintenance organisations are under constant pressure to plan maintenance work due to a shortage of funds on account of huge catalogues of defects in hospital buildings. While investments in hospital building maintenance are increasing, the requirement to increase building performance and user satisfaction is also increasing. The nature of building faults and the factors that influence hospital building maintenance management in Malaysia were explored. Primary data were collected through structured interview techniques involving six hospital maintenance organisations. According to the results of a survey interview involving six hospitals, water seepage, cracks, peeling paint, broken ironmongery, pipe leakage, damaged plasterboard, and discoloured paint are all widespread in hospital structures, according to the results of a survey interview involving six private and public hospitals. The key aspects that determine the maintenance management practise of hospital buildings are user attitudes, misuse/abuse, weather, and bad maintenance practice. The data revealed that hospital building users are demanding improved building performance through enhanced maintenance management service delivery. Implicit in the findings of this research is the lack of effective maintenance organisations. It is necessary to reorganise the hospital's maintenance organisations. From an ontological standpoint, the main findings of this study are generalizable to other hospitals and building typologies in and outside of Malaysia.

Critical Insight into Defects in Malaysia Hospital Buildings Maintenance Management

Healthcare buildings require efficient maintenance management to afford patients, visitors, and other users of hospital buildings such as healthcare professionals a serene and safe environment that accelerates wellbeing and provides maximum comfort. To achieve this goal, hospital buildings must adopt effective maintenance management approaches and services. Apart from ensuring the safety of the environment, users of the buildings must be satisfied with the quality of available services, particularly, those offered to patients. Against this backdrop, this study assesses the effects of defects on hospital buildings and analyzes the practicality of maintenance best practices such as sufficient allocations of funds and appropriate management of resources (including time and labor) towards the improvement of the prevalent status quo. This is important because the maintenance practices employed in hospitals intrinsically impact the performance of the hospital buildings as a result of defects. Survey questionnaires were administered to users of hospital buildings in Malaysia. The most significant defects reported concerned Algae on concrete floors, weather and climate conditions, and sanitary appliance & fittings damages. These defects depreciate the appearance, functionality and utility of hospital buildings thereby lessening their performance and efficiency. Therefore, this study asserts the pertinence of reevaluating the maintenance management approaches employed towards the rectification of the highlighted defects in hospital buildings across Malaysia. The study posits the adoption of systemic proactive maintenance procedures to preempt decay, causalities and reduce cost implications.

Building and Infrastructure Defect Detection and Visualization Using Drone and Deep Learning Technologies

This paper presents an accurate and stable method for object and defect detection and visualization on building and infrastructural facilities. This method uses drones and cameras to collect three-dimensional (3D) point clouds via photogrammetry, and uses orthographic or arbitrary views of the target objects to generate the feature images of points’ spectral, elevation, and normal features. U-Net is implemented in the pixelwise segmentation for object and defect detection using multiple feature images. This method was validated on four applications, including on-site path detection, pavement cracking detection, highway slope detection, and building facade window detection. The comparative experimental results confirmed that U-Net with multiple features has a better pixelwise segmentation performance than separately using each single feature. The developed method can implement object and defect detection with different shapes, including striped objects, thin objects, recurring and regularly shaped objects, and bulky objects, which will improve the accuracy and efficiency of inspection, assessment, and management of buildings and infrastructural facilities.

An analysis of the Causes of Building Defects in Residential Properties in Diobu area of port Harcourt, River State, Nigeria.

Abstract: Currently, derelict buildings with little or no amenities have remained a challenge to the physical fabric of properties in Diobu in Port Harcourt. These derelictions are observed to be affecting the economic and physical functionality of these buildings. Therefore, the paper aims to investigate the causes of the dereliction in the buildings in Diobu area in Port Harcourt Rivers State of Nigeria. A survey research design was adopted where 153 questionnaires was administered to the resident of the study area and another 56 questionnaires to property managers in Port Harcourt. Out of the 209 (Nr) questionnaires administered, a total of 197 was retrieved representing a response rate of 94%. Data gathered were analyzed using Relative Important Index, mean and percentages and presented in tabular and pictorial formats. The paper’s finding revealed and confirmed that wall cracks, wall/floor dampness, roof leakages, faulty plumbing fittings, poor ventilation and peeling/faded wall paints are some of the defects in the properties in Diobu. A further investigation revealed that poor building designs, old age, poor maintenance culture, adverse climatic condition, misuse, overcrowding and insect attack are among the causes of these defects on the buildings. This research work is original and has not been previously published anywhere; its reflection is that effective maintenance culture, good occupancy ratio, use of skilled personnel and quality building materials should be encouraged by residents, property managers and landlords in order to check the menace of building defects in the study area. Keywords: Residential Buildings, Defects, causes, Analysis, Diobu.

Enhancement of Multi-Class Structural Defect Recognition Using Generative Adversarial Network

Recently, in the building and infrastructure fields, studies on defect detection methods using deep learning have been widely implemented. For robust automatic recognition of defects in buildings, a sufficiently large training dataset is required for the target defects. However, it is challenging to collect sufficient data from degrading building structures. To address the data shortage and imbalance problem, in this study, a data augmentation method was developed using a generative adversarial network (GAN). To confirm the effect of data augmentation in the defect dataset of old structures, two scenarios were compared and experiments were conducted. As a result, in the models that applied the GAN-based data augmentation experimentally, the average performance increased by approximately 0.16 compared to the model trained using a small dataset. Based on the results of the experiments, the GAN-based data augmentation strategy is expected to be a reliable alternative to complement defect datasets with an unbalanced number of objects.

Process induced building defects in Norway – development and climate risks

The SINTEF building defects archive is an important source to knowledge on building defects in Norway. This study presents a review of defects investigated by SINTEF in the period 2017–2020, including 175 defect cases registered in 125 reports. The main goal is to understand the primary causes of process induced building defects today and which building elements may be considered as risk spots. The review shows that almost 3 of 4 defects is related to moisture, caused by sources as precipitation, condensation of humid indoor air or built-in moisture. Defects associated with the building envelope make up more than 70% of the cases, of which most defects are linked to exterior wall or roof constructions. The results from the present study have been compared to a review of defects reported in the archive during the period 1993–2002. The comparison reveals that the share of damages caused by precipitation is almost doubled, while the share of damages caused by humid air from the interior is approximately halved. The results imply that climate adaptation of buildings is important. As climate change causes more precipitation with higher intensities, the load on buildings increases and a larger focus on risk reduction and protection towards penetration of water from the outside is required.

Spatial inhomogeneity of build defects across the build plate in laser powder bed fusion

The population of build defects as a function of position on the build plate was examined in Ti-6Al-4V specimens fabricated on two common commercial laser powder bed fusion (LPBF) systems. Using standard build parameters, X-ray computed tomography revealed that spatial heterogeneity of the defect population can be substantial, relative to the variations in defect population that can occur due to other parameters, e.g. part geometry, build orientation, and laser power schedule. To understand the potential importance of such variability, its impact on fatigue performance is considered. Asymmetries inherent to LPBF fabrication are investigated as potential sources of the spatial heterogeneity, with shielding gas flow simulations providing an explanation.

ДЕФЕКТЫ И ПОВРЕЖДЕНИЯ МЕТАЛЛИЧЕСКИХ ПОДКРАНОВЫХ БАЛОК ПРОИЗВОДСТВЕННЫХ ЗДАНИЙ

The article provides an analysis of typical and unique defects and damages of crane beams, which is a continuation of the series of articles by the authors about defects and damages of industrial buildings. Previously, articles on typical defects of industrial buildings have already been published: ground bases, foundations, reinforced concrete columns, metal columns, vertical connections and wall panels. Most of the defects are explained by photos. At the end of the article, an analysis of the characteristic zones of defect formation in the metal crane beams of industrial buildings is given, which allows laying the foundation for the development of an automated control system (ACS) for the life cycle of an industrial building.

Classifying apartment defect repair tasks in South Korea: a machine learning approach

ABSTRACT Managing building defects in the residential environment is an important social issue in South Korea. Therefore, most South Korean construction companies devote a large amount of human resources and economic costs in managing such defects. This paper proposes a machine learning approach for investigating whether a specific defect can be autonomously categorized into one of the categories of repair tasks. To this end, we employed a dataset of 310,044 defect cases (from 656,266 validated cases of 717,550 total collected cases). Three machine learning classifiers (support vector machine, random forest, and logistic regression) with three word embedding methods (bag-of-words, term frequency-inverse document frequency, and Word2Vec) were employed for the classification tasks. The highest yielded results showed more than 99% accuracy, precision, recall, and F1-scores for the random forest classifier with the Word2Vec embedding. Finally, based on these findings, the implications and limitations of this study are discussed. Representatively, the findings of this research can improve the defect management effectiveness of the apartment construction industry in South Korea. Moreover, to contribute to future research, we have made the dataset publicly available.

Factors affecting the number of building defects and the approaches to reduce their negative impacts in Malaysian public universities’ buildings

PurposeThe largest share of a building maintenance budget goes towards preventing or repairing building defects. Also, building defects shorten a building’s lifetime, impact the user’s safety and health, prevent the buildings from performing their functions well and repairing building defects generates waste. Therefore, this study aims to specify the factors that affecting the number of building defects and how to reduce their negative impacts.Design/methodology/approachA case study was used as a research strategy and convergent parallel mixed methods were used as research design. Quantitative and qualitative data were collected concurrently, followed by independent analyses of the quantitative and qualitative data, and then merged the two sets of results according to the procedure of using the convergent parallel design. Descriptive statistics analysed quantitative data, whilst qualitative data was analysed by the content analysis technique.FindingsThe findings of this study explored the factors that affect the number of defects in buildings, the significant factors were related to the building’s life cycle in terms of design, construction, operation and maintenance phase; relevant attributes were construction teams, building users and maintenance teams. The study also addressed the approaches to minimise the negative impacts of those factors. Their negative impacts mainly contributed to increased building defects that increase maintenance costs, affect users’ safety and health, reduce buildings’ lifespan and cause environmental impact due to resource extraction.Originality/valueThe existing studies have not adequately addressed the significant factors that affect the number of building defects. Also, emerging technologies and environmental sustainability considerations related to building defects have not been linked in previous related work. Therefore, the present study has contributed to filling this gap.

Mapping External Mortar Render (RAF) defects: case study in multi-storey residential buildings

This study aims to identify, map, and quantify the external mortar render (EMR) defects of 22 multi-storey buildings located in the Fernandópolis city, Brazil. Incidence (M-INC) and intensity (M-INT) methods were used to quantify the building defect (BD) of five typified facade regions: continuous wall (1-OCW), around openings (2-OOP), top of parapets and eaves (3-TOP), below balconies, soffits or ledges (4-BCE), and on corners and edges (5-OCE). In addition, three degradation pattern maps were created. We observed 4351 and 481 BDs by M-INT and M-INC, respectively. The most frequent problems were stains and cracks. The most affected regions by M-INT were 2-OOP (34.5%), 1-OCW (23.3%), and 4-BCP (21.6%) while by M-INC were 1-OCW (39.9%), 3- TOP (29.3%), and 2-OOP (16.6%).

Investigation of construction material quality and workmanship defects of RC buildings collapsed and severely damaged in the 6.8 Mw Sivrice, Elazığ, Turkey earthquake, January 2020

In the Sivrice, Elazığ, Turkey earthquake on January 24, 2020, 41 people lost their lives, more than 1600 people were injured, 672 buildings collapsed, and around 12600 buildings were severely damaged due to poor construction quality. After such devastating earthquakes, damage assessment and forensic investigations are normally carried out quickly for a judicial process, and material qualities are revealed. However, emotional sensitivity of the victims in the earthquake affected zone and disruptions in key lifeline services such as transportation, electricity supply often make these processes difficult. After the Elazığ earthquake, along with the conventional in-situ core sampling method, concrete pieces were collected from columns of collapsed and severely damaged buildings and transported out of the earthquake zone to overcome these adverse conditions. Unlike in the conventional method where the whole sampling process is carried out in the earthquake zone, the core extraction from the transported concrete pieces was carried out outside the earthquake-affected area. The extracted concrete samples were checked for compliance with the prevailing material standards. Moreover, multiple reinforcing bars of various diameters were also extracted and tested to check their compliance with the standards. Besides, the results of examination of the quality of materials and workmanship used in the construction are also discussed, along with the precautions required to minimize fatalities and damage from similar buildings.

Residential building defects investigation and mitigation – a comparative review in Victoria, Australia, for understanding the way forward

PurposeThe issue of building defects is a growing concern that affects all major construction stakeholders as a result of costs and time implications of reworks. The magnitude of the problem is severe with statistics highlighting defects often result in 4% of the total cost of construction of a building. Despite the importance of this problem, studies have seldom considered development of systematic approaches to enhance the quality control process in construction.Design/methodology/approachBuilding defects is a growing concern that affects all major construction stakeholders because of costs and time implications of reworks. Magnitude of the problem is severe with statistics highlighting defects often result in 4% of the total cost of construction of a building. Despite the importance, studies have seldom considered development of systematic approaches to enhance the quality control process in construction.FindingsResults indicated that poor workmanship is the main cause of building defects and incomplete works is a frequently detected defect type. Results categorised defects based on cost and frequency to identify the severity. Findings also identified four focus areas including control measures, technology use audit and inspections and promotion of best knowledge.Research limitations/implicationsThe study lacks generalisation as it covers only Victorian scenario and further studies are needed to generalise the findings.Originality/valueThe study provides a deeper understanding of the challenges currently facing the residential construction industry in Victoria, Australia, and underlines the need for developing quantitative models and methodologies to improve current processes, practices and policies for effective defects minimisation in Victoria, Australia. The systematic methodological framework can also be adopted by researches across the globe to effectively analyse the options for minimising residential building defects.

Comparative case study research: an international analysis of nine home warranty schemes

PurposeConstruction defects in residential buildings are causing significant impacts both on consumers and the industry. As a consequence, several countries have established new home warranty schemes. However, designing a public policy for domestic building warranties can become a difficult task. In fact, many of these programs in the past have failed, collapsed or gone bankrupt. Therefore, the purpose of the current research is to provide a systematic comparative representation of various active programs internationally.Design/methodology/approachThe methodology relied on a multiple-case study research design. The case selection covered a total of nine jurisdictions with compulsory home warranty programs. Those included Japan, France, United Kingdom, three provinces in Canada (Ontario, British Columbia and Alberta), and three states in Australia (New South Wales, Victoria and Queensland). The study applied a data collection protocol to gather all the evidence in a replicable manner for each individual case. Subsequently, a cross-case analysis was conducted to identify similarities and variations between programs.FindingsThe findings unveiled institutional practices that aimed to resolve, compensate, or rectify defects in residential constructions within these countries. The review mostly suggested that every home warranty program presents certain unique characteristics. At the end, this paper proposed an analytical illustration representing the diversification of components adopted by each jurisdiction.Originality/valueNowadays, there is still not a consensus within the academic community on what is an optimal solution when conceiving a new home warranty program. Hence, the current study aims to fill this knowledge gap by presenting the plurality of methods employed by several countries. This paper seeks to help policy makers and industry leaders to improve their home warranty scheme based on awareness derived from observations and analyses of what has been accomplished elsewhere in the world.

Detection of Building Defects Using CNN

Detection of defects together with cracks and spalls on wall surface in high-rise buildings may be a crucial task of buildings’ maintenance. purchasers area unit progressively searching for quick and effective suggests that to quickly and often survey and communicate the condition of their buildings in order that essential repairs and maintenance work will be tired a proactive and timely manner before it becomes too dangerous and big-ticket. If left unseen and untreated, these defects will considerably have an effect on the structural integrity and also the aesthetic side of buildings, timely and efficient strategies of building condition survey area unit of active want for the building house owners and maintenance agencies to switch the time- and labour-consuming approach of manual survey. so mistreatment the applying of deep learning technique of convolutional neural networks (CNN) in automating the condition assessment of buildings. the main target is to automatic detection and localisation of key defects arising from damp, patches, stains, cracks in buildings from pictures.