Entire Building Research Articles

Foundation Protection of Buildings in Coastal Areas Using Cathodic Protection

Foundation of the building plays a major role in proving stability to the entire structure. Foundation soil in the Coastal region having lot of sea water intrusion. The salt content and several minerals present in the sea water having the tendency to erosion of materials like metals and non-metals. The pile foundation present in the coastal region will have reinforcement incorporated on it. It should be strong enough to sustain the entire building loads until its service life. This reinforcement may continuously be exposed to the sea water intrusion on the underground, and it will cause deterioration of reinforcement and it leads to durability issues. The entire structure will be unstable if the foundation is damaged, or it can’t take the building load. In several cases, entire building is collapsed due to the uneven settlement caused by the foundation failure. This can be prevented by using an Anti-corrosion method called Cathodic Protection. A demonstration is made on this idea with an electrical voltage supply by using battery.

К ПРЕДЕЛЬНОМУ РАВНОВЕСИЮ МОНОЛИТНЫХ ЖЕЛЕЗОБЕТОННЫХ ПЛИТ ПЕРЕКРЫТИЙ КАРКАСНЫХ ЗДАНИЙ В АВАРИЙНЫХ СИТУАЦИЯХ, ПРИВОДЯЩИХ К ПРОГРЕССИРУЮЩЕМУ ОБРУШЕНИЮ КОНСТРУКЦИЙ

A brief analysis of current standards concerning calculations of the resistance to progressive structural collapse of frame buildings in case of an accidental destruction is presented. Two analysis methods concern the resistance to progressive collapse of the slabs of monolithic frame buildings in case of accidental failure of one column are considered: direct method in which the entire building is calculated with a modified analysis scheme followed by checking the strength of structures with increased efforts, and calculating the slab located over the destroyed column by the ultimate equilibrium method with determination the slab destroying load. It is shown that the slab destroying load greatly depends on the model of its destruction. General equation of the ultimate equilibrium of the slab is written down. It includes not only the formation of plastic hinges in the slab, but also taking in account pushing through the slab by the column located on it. There are three possible options for an emergency destruction of the slab: from the formation of plastic hinges in the plate only, the slab pushing through by a column and formation of plastic hinges at the same time and situation when the slab is pushed through by the column. A criterion of the destruction option determination is offered. An example of calculation is given.

Assessing embodied carbon of flat slab buildings – An ANN-integrated optimization methodology

Currently, there is a scarcity of studies that comprehensively address all structural components in the building's overall environmental performance. Although mathematical optimization has shown its great effectiveness, the prevailing iterative design approach continues hindering the simultaneous optimization of building structural performance and its sustainability. This research aims to address this gap by introducing an innovative optimization framework that integrates optimization concepts into the design process using Artificial Neural Networks (ANNs). The proposed framework includes a carbon-optimization problem for flat slab buildings, which is validated with manual designs, and a surrogate modelling stage employing ANNs to predict optimal design solutions. The best network demonstrates remarkable predictive power, yielding minimal errors and high fitness (>0.96) for all variables, except slab thickness. Sensitivity analysis identifies the building's height and dimensions as the most influential factors on the slab reinforcement, column reinforcement, and carbon footprint. While span length and slab concrete strength greatly impact slab and drop depths, column size is primarily controlled by span length and building's height. This research not only provides crucial insights into sustainable design solutions but also paves a clear pathway towards achieving decarbonization and cleaner production across the entire building sector.

Retraining surrogate models in increasingly restricted design spaces: a novel building energy model calibration method

Surrogate (i.e. meta) models can approximate building energy models (BEMs) accurately and quickly, hence they have been widely used in BEM calibration studies. Typically, the surrogate models are trained a single time over the entire unknown building parameter space with a design such as Latin hypercube sampling. In this article, a multiple polynomial regression surrogate model is, instead, retrained with increasingly restricted designs. In each training repetition, the bounds of the design narrow around the unknown building parameter values that minimize the error between the surrogate model’s predictions and the measured energy. This ‘cascading surrogate’ calibration method finds CVRMSE values that are much lower than those of a powerful black box optimizer in a case study with simulated ‘measured’ data. However, the method has similar performance to the black box optimizer in a case study with real hourly measured energy, probably since the BEM was not configured accurately enough.

Evaluation of Deep Learning-Based Non-Intrusive Thermal Load Monitoring

Non-Intrusive Load Monitoring (NILM), which provides sufficient load for the energy consumption of an entire building, has become crucial in improving the operation of energy systems. Although NILM can decompose overall energy consumption into individual electrical sub-loads, it struggles to estimate thermal-driven sub-loads such as occupants. Previous studies proposed Non-Intrusive Thermal Load Monitoring (NITLM), which disaggregates the overall thermal load into sub-loads; however, these studies evaluated only a single building. The results change for other buildings due to individual building factors, such as floor area, location, and occupancy patterns; thus, it is necessary to analyze how these factors affect the accuracy of disaggregation for accurate monitoring. In this paper, we conduct a fundamental evaluation of NITLM in various realistic office buildings to accurately disaggregate the overall thermal load into sub-loads, focusing on occupant thermal load. Through experiments, we introduce NITLM with deep learning models and evaluate these models using thermal load datasets. These thermal load datasets are generated by a building energy simulation, and its inputs for the simulation were derived from realistic data like HVAC on/off data. Such fundamental evaluation has not been done before, but insights obtained from the comparison of learning models are necessary and useful for improving learning models. Our experimental results shed light on the deep learning-based NITLM models for building-level efficient energy management systems.

Insulation performance evaluation of stone-finished exterior insulation systems with insulation frames for green remodeling of concrete exterior walls

This study aimed to evaluate the thermal bridge reduction effect of insulation frames applied to a stone-finished exterior insulation system, which is commonly used in green remodeling projects. The insulation performance of the exterior walls and the energy performance of the building in a baseline case in which an existing steel pipe frame was applied were compared with those in cases alt 1 and alt 2, which included application of double- and single-wired truss-shaped insulation frames, respectively. First, a three-dimensional steady-state heat transfer simulation was conducted for the exterior wall-floor joint of the model building, and the effective U-factor was obtained. Next, mock-ups were constructed and the U-factor was tested to verify the insulation performance of cases alt 1 and alt 2. The heat loss decreased as the effective U-factors of alt 1 and alt 2 decreased by 19.0 % and 19.7 %, respectively, compared to the baseline case, according to the heat transfer simulations. In the mock-up test, the U-factors of alt 1 and alt 2 were similar to design U-factor, indicating almost no heat loss caused by the thermal bridges. Notably, the U-factor of alt 2 was 2.4 % lower than that of alt 1. Finally the energy performance of the entire building was compared through dynamic building energy simulations by reflecting the thermal bridging effect. The annual heating and cooling energy use of alt 1 and alt 2 were 2.5 % and 2.6 % lower than those of the baseline case, respectively, confirming the energy-saving effect of reducing thermal bridges.

Typhoon Guard: Windows Protection System for Typhoon

Typhoons are hazard that is threatening the Philippines every year. Design and construction of the houses and shelter in Catanduanes changes rapidly incorporating provision against wind speed. The effect of typhoon become the basis in the design of structures and the windows components. The study sought to answer what is the type of house built in Catanduanes, what is typical window system used for houses/building in Catanduanes, what are the protection and provision being implemented to withstand the effect of high winds pressure, and what are the safety practices to counter the effect of high winds of typhoon? Most designs and houses constructed in the late 80’s already introduced these provisions that make them easy to install the windows shutter locally termed as “typhoon guard”. This was also implemented by architects, engineers, and owners as a mandatory inclusion in the building construction and design. The selection criteria for designer and owner include the budget, structural integrity of the window, and aesthetical appearance. Respondents acknowledge that windows must be protected from the force of gusty winds and debris impact and this will also ensure that your entire house or building stays safe and intact. Many respondents agree that it is vital to protect the window from breakage by using materials that can withstand the full force of the wind pressure or employing protection components to keep the window intact and safe. However, most owners of nipa hut and a handful of owners of bungalow houses suffer minor and major damages during super typhoon Rolly, and they have common concerns about their safety and evacuation to safe buildings is the ultimate safety practice to mitigate the risk pose by the typhoon. It is recommended that typical windows systems to be used in homes and buildings must be rigid enough to withstand wind forces. Safety practices to counter the effect of high winds of typhoon includes removal of possible debris and projectile must be practiced. Also, Integrated windows protection design such as windbreaker must be re-integrated into the design of the building and adopt new window design to mitigate typhoon wind forces.

ESTABLISHING THE RELIABILITY LEVEL OF MASONRY BEARING STRUCTURES BASED ON ITS COMPONENT STRENGTH ANALYSIS

The article discusses aspects related to assessing the reliability of masonry structures. The authors present methods for determining the compressive strength of masonry in existing structures, taking into account reliability theory. We also consider practical solutions for calculating the design strength of masonry, which may help to assess the safety of massive brick walls and pillars that act as core structural elements of existing buildings. Thus, walls and pillars operating in compression are vital elements of stone buildings and require special attention when analysing and assessing their strength. They carry enormous loads and are critical to the stability of the entire structure. There are cases when it may be hard to obtain safe samples for testing masonry mechanical performance, making the analysis of existing masonry structures difficult. However, building codes and methods provide specific methods for determining the strength of existing structures based on reliability theory. These methods assume uniformity of masonry with regularly spaced brick layers. Although such assumptions may simplify the analysis, they can still provide sufficiently accurate results for making decisions about the safety and reliability of the building. It is essential to consider all possible factors and limitations when using these methods to ensure a reliable assessment of the condition of masonry structures. Stone materials are among the most traditional in various areas of construction production. Buildings with brick load-bearing walls represent the lion’s share of the existing housing development in Ukraine. Ensuring its high-quality operation and the safety of residents during the life cycle of such buildings are priority areas. However, changes occurring in the external environment and the state of regulatory support for construction production require a periodic return to the issues of assessing the load-bearing capacity of both previously erected building structures and those under design. Thus, lately, the territories with previously unusual force impacts on building structures, such as horizontal displacements of the base of the building, have significantly expanded. The reasons for this include seismic activity in certain regions of the country and the results of anthropogenic factors, particularly the areas with unstable soils. We should note that many buildings and structures are subject to external influence due to military operations on a large territory of Ukraine. So, in the event of a hit by warheads or the action of a blast wave, they generate new, non-typical, but dangerous effects on the load-bearing structures of the entire building. Keywords: reliability theory, reliability assessment, structural safety, stone structures, masonry strength.

Virtual Building Models in built environments

The global building sector plays a pivotal role in addressing sustainability, climate change, and carbon neutrality. This study introduces the original concept of virtual building models (VBMs) throughout the lifecycle of the building industry, considering the unique characteristics of this industry. VBMs are defined as mathematical models that represent the physical behavior of buildings throughout their lifecycle. These models consist of subvirtual models that represent the physical operational environments of the target building, encompassing physical variables, equipment, systems, indoor environments, and structural and material behaviors. This concept can contribute to achieving the existing concepts of building information modeling, digital twins, and cyber-physical systems within building operations, communities, and environments. In this study, building models are categorized into five aspects: virtual model environments, types, interactions, integrations, and levels of detail (LODs). The LODs are classified into five levels (LOD100, LOD200, LOD300, LOD350, and LOD400) depending on the primary environments of the virtual models and their coverage across the entire building. Virtual modeling methodologies are proposed considering the virtual model aspects to achieve higher or intended LOD states from both academic and industrial perspectives. Finally, future research directions are discussed to drive the concept of virtual buildings to shape the future of the building industry through digital transformations.

Public health risk assessment and speciation of air-borne microorganisms in an office building

This study focuses on speciation of air borne microbes in an office building and health impacts of these microbes in terms of Quantitative Microbial Risk Assessment (QMRA), Hazard Quotient (HQ) and Hazard Index (HI). This is important in the wake of Sustainability Development Goal 3 (Public Health and well-being) specially when there is a lack of standards in terms of microbial air quality in office buildings where people spend 8–10 h indoors. Air borne bacterial and fungal species in different floors of the office building with varying occupancy and work profile were identified. The load of bacterial count on an average for the entire building was found to be 1917 CFU/m3. Overall, Gram-positive bacteria were predominant (>53%). Based on V3–V4 sequencing Staphylococcus scuiri (causing UTIs) was the most abundant (93.7%) and other bacterial species found were Lactobacillus hamsteri, Prevotella copri, Bacteroides plebeius Faecalibacterium prausnitzii, Bacillus coagulans (gut commensals), Shigella boydii (causes bacillary dysentery), and Propionibacterium acnes (acne producing). Fungal load was 4000 CFU/m3. Based on ITS sequencing Aspergillus (45.6%) was the dominant fungus and other fungi found were Cunninghamella, Lichtheimia, Fusarium, and Circinella Grammothele, Chondrostereum, and Pseudolagarobasidium, Candida sp., Chondrostereum, Sarocladium. The QMRA of gram-negative air borne bacteria showed a high disease burden, well over the WHO benchmark values even though Hazard Quotient (HQ) and Hazard Index (HI) was found to be negligible. These findings can contribute to the development of guidelines for seemingly safe workplaces that may harbour disease-causing microbes and calls for an immediate attention from policy makers as it is a major cause of concern for public health.

Glass Fibre Reinforced Concrete (GFRC) Materials and Its Applications

In the 1940’s, potential of glass as a construction material was realized and improvement continued with the addition of zirconium dioxide in 1960's for harsh alkali conditions. The development of new glass fibre generations is focused on improving the process of material durability. In order to meet various needs, glass fibre reinforced concrete, or GFRC, was thus introduced into production. Research and experiments conducted on GFRC have demonstrated that the material quality and production precision have an impact on the material's mechanical and physical characteristics. GFRC can be applied anywhere an impermeable, weather-resistant, fire-resistant, light-weight, and robust material is required. With the development of technology, it may be possible to construct sophisticated freeform structures and entire buildings at a reasonable cost. Recently, research has been done on the impact of glass fibres in hybrid mixtures for high-performance concrete (HPC), a newly developed technology that is gaining popularity in the building sector.

Circular Renovation of an Apartment Building with Prefabricated Additional Insulation Elements to Nearly Zero Energy Building

Construction and demolition waste constitute more than one-third of the total waste generated in the European Union. The pursuit of sustainable renovation must progress further to encompass elements that ensure reuse or recyclability. A fundamental transformation, involving extensive renovation and a transition to circular renovation practices, is indispensable in effectively addressing the pressing challenge of decarbonization for the entire building stock in Europe. In this study, we have developed a circular deep renovation solution using prefabricated modular external additional insulation elements to achieve a nearly Zero Energy Building (nZEB). Circular prefabricated modular external additional insulation elements were formulated, manufactured, and installed. The potential for disassembly and reutilization of materials was developed and demonstrated for both a prototype and the complete deep renovation. The analysed prefabricated modular solutions exhibited greater potential for circularity compared to the traditional External Thermal Insulation Composite System (ETICS) due to their superior demountability and reusability characteristics. The overall cost of the renovation, which included the installation of a new heating system, replacement of water and sewer pipes, addition of 50 kW photovoltaic (PV) panels on the roof, installation of new balconies, addition of a balanced ventilation system with heat recovery, and replacement of the electricity system in common areas, amounted to 505 €/m². Following the deep renovation, the Energy Performance Value was measured to be 92 kWh/(m²·a), resulting in an EPC class of A. This implies that the building now meets the requirements for nZEB in accordance with Estonian legislation, with no performance gap.

An experimental analysis of full scale light-frame timber modules

Prefabricated timber modules are being increasingly used in the load-bearing structure of entire residential buildings reaching heights up to six stories. The development is driven by the demand of high-quality housing that remains affordable while fulfilling tough environmental requirements imposed on modern construction. To enable further development of this type of buildings additional research is needed despite the considerable number of studies previously performed. This study provides an extensive experimental investigation by subjecting three modules to three different load cases. In each load case, the modules were initially loaded with dead-load placed atop of the module. Thereafter the modules were laterally loaded at the top using a servo hydraulic piston in displacement control. The main aim of the study was to assess the structural behavior of these modules under combined lateral and vertical loading, and also to generate experimental data suitable for verification of finite element models. Results from the test series reveal significant variation in racking stiffness and racking strength depending on the module’s design. Furthermore, in some cases more stiff and stronger mechanical inter-module connections are needed to enhance their global structural performance. Finally, the experimental results reveal that the modules are relatively ductile in their shear response when subjected to horizontal load.

Freezing and Thawing of Enclosing Structures and Foundation Soils Taking into Account the Effects of Solar Energy: Part 1. Theoretical Foundations of Freezing Wet Soils

The temperature and humidity state of the foundations and foundations in the climatic conditions of the Russian Federation is decisive in their design,it affects the bearing capacity, operational reliability, and durability of the foundations and the entire building. When designing foundations and foundations, they solve a set of tasks that are subordinated to one idea, so that the soil (base) he carried the load from the building or structure proposed to him, and the foundation structure itself would ensure reliable operation of the building or structure for the entire life cycle, since the foundations belong to permanent structures, and their repair is associated with large material costs. Existing modern calculation methods assume that the heat transfer process is stationary and do not consider real processes – seasonal and daily fluctuations in outdoor air temperature, heating on and off modes, temperature changes in the depth of the soil, wet structures due to accidents of heating plants, the absence (or destruction) of a blind area, etc. Freezing of soils, as a rule, occurs in autumn-winter period, when the soil is saturated with moisture. Thawing of the soil occurs in the spring-summer period. These processes are non-stationary in nature, which is influenced by many factors, including solar radiation. The work is devoted to modelling and calculation of these real processes. The process of freezing and thawing of the foundation soils is influenced by many factors: the composition of the soil, water, ice, snow, solar radiation, fluctuations in outdoor temperature. The paper provides general information about some of the physical properties of water, ice, and snow, necessary for understanding the processes under consideration.

Research on Traditional Reinforcement Techniques for Rammed Earth Walls in China

ABSTRACT Rammed earth is typically a material with a high compressive capacity and low tensile and shear strength. In traditional Chinese architecture, reinforcing rammed-earth walls with ties and beams is common. This study offers insights into the characteristics of reinforcement methods applied to rammed earth walls in houses and forts. After analyzing the mechanical failure of the walls, the article suggests that reinforcement can enhance mechanical performance by reducing shrinkage cracks, enhancing the bearing capacity of walls, and increasing the integrity of the entire building.

Reusability assessment of reinforced concrete components prior to deconstruction from obsolete buildings

A large part of building demolitions is motivated by purely socio-economic reasons. Hence, about-to-be-demolished structures, commonly made of reinforced concrete, very often present no or little degradation. When adaptive reuse of the entire building is not possible anymore, its deconstruction and the reuse of its load-bearing components elsewhere in new structures maximize the reclamation of preexisting structural qualities. This strategy drastically decreases the environmental burden of both demolition and subsequent new construction. However, its efficient implementation requires a careful preliminary assessment of the existing structure, including the inventory of its components, and the evaluation of their reuse potential in relation with their pre-existing damages and possible future uses. Currently available procedures are not exhaustive and focus solely on precast components. This paper thus introduces a specific methodology for the reusability assessment of load-bearing reinforced concrete components, focusing in priority on their long-term durability. It first proposes a systematic protocol to classify and quantify the components, investigate their geometrical and material properties and evaluate their preexisting damages. Then, the paper develops a new procedure to grade the reusability of the components for future projects. Finally, the whole methodology is tested on three case studies in Switzerland, demonstrating its robustness and repeatability. In these three case studies, 95 % of reinforced concrete components are graded as reusable.

Climate Resilience through AI-Driven Hurricane Damage Assessments

Evolving hurricane patterns intensified by climate change are expected to exacerbate economic hardships on coastal communities. Climate resilience for these communities requires both the capability to recover rapidly from devastating storms, and the ability to develop an accurate and actionable understanding of vulnerabilities to reduce the impact of future storms. Available data from past storms can provide invaluable insight in addressing both these requirements. Post-disaster preliminary damage assessments (PDAs) are a crucial initial step toward a rapid recovery. They also provide the most accurate information on the performance of various types of dwellings after the storm. Traditional door-to-door inspection methods are time-consuming and can hinder efficient resource allocation by governments in the aftermath. To address this, researchers have proposed automated PDA frameworks, often utilizing data from satellites, combined with deep convolutional neural networks. However, before such frameworks can be adopted in practice, the accuracy and fidelity of predictions of damage level at the scale of an entire building must be comparable to human assessments. To bridge this gap, we present an innovative PDA framework that leverages Ultra-High-Resolution Aerial (UHRA) images alongside state-of-the-art transformer models for multi-class damage predictions across entire buildings. Our approach leverages vast amounts of unlabeled data to enhance accuracy of prediction and generalization capabilities. Through a series of experiments, we evaluate the influence of incorporating unlabeled data, and transformer models. By integrating UHRA images and semi-supervised transformer models, our findings indicate that this framework overcomes critical limitations associated with satellite imagery and traditional CNN models, achieving an 88% multiclass accuracy, ultimately leading to more precise, efficient, and reliable damage assessments that are a first step towards building more climate resilient societies.

Horizontal displacement at the top of the building with frame and shear walls structures according to TCVN 2737:2023

When designing the structure of a high-rise building, it is important to consider not only the load-bearing capacity of the entire building but also the issue of limiting horizontal displacement at the top of the building. In this study, the author used Etabs software to analyze and compare the horizontal displacement at the top of a building. The study focused on two different types of structural system: frame system (consisting of columns, beams, and floors) and shear walls (which consists just of reinforced concrete walls). The analysis was conducted in accordance with Vietnamese standards on loads and impacts, specifically TCVN2737:2023. The wind loads were applied to the geometric center of the structure. Research results suggest the impact of horizontal displacement at the top of high-rise buildings is significant. Additionally, it has been observed that the shear walls system shows an increased horizontal displacement value compared to the frame system.

Thermal Transmittance in Roof–Wall Structural Junction Areas Insulated with a Hemp–Lime Mixture

The junction between the roof and the external wall is a sensitive area within the building envelope; here, increased heat flow often takes place. In the case of partitions insulated with materials based on plant ingredients, thermal bridges are particularly dangerous due to the possibility of condensation and, consequently, mold. The present article analyzed the connection of the roof with the knee wall made of a hemp–lime composite and the ridge in terms of the occurrence of thermal bridges. The following factors that may affect heat transfer in the junction were taken into account: the location of the load-bearing wooden frame, the roof slope, and the presence of internal plaster in the junction. Two-dimensional heat transfer analysis was performed based on the finite element method using THERM 7.4 software. All of the studied thermal bridges had ψ values below 0.10 W/(m·K). Calculations of heat losses through a roof with different slopes were also presented, taking into account the considered thermal bridges. As the roof slope decreases, the heat flow through the roof decreases, despite the increasing value of the linear thermal transmittance. The share of the considered thermal bridges in the total heat loss from the roof reached up to 15%. To verify the obtained results, in further analysis, it would be necessary to calculate the impact of the roof–knee wall bridge variants on heat losses throughout the entire building.

The warning and security system of the multifunctional complex

This article describes the warning and security system in the building of a multifunctional complex located in the city of Rostov-on-Don. The project includes the positioning of radio and telephone equipment, the installation of an Internet transmission network, as well as an alarm system for the entire building. The building must be a subscriber in order to gain access to one of the Internet networks and cable operators that can connect the transmitted object and the Internet. A radio network and a telephone network have been designed, as well as the reception of radio waves has been provided. A bell alarm system of the building is provided and installed. There are many different public multifunctional buildings in Rostov-on-Don, but there was a clear shortage of it in this area of the city. Moreover, this facility is distinguished by the fact that it has not only the usual shopping and entertainment areas for the city, but also a business space, which is now very much in short supply to many, as work at home and online is gaining more and more momentum.