Building Industry Research Articles

Leveraging BIM for Sustainable Construction: Benefits, Barriers, and Best Practices

The building sector is still criticized for its excessive energy use and negative environmental effects, even with significant improvements in recent years. It makes a major contribution to the world’s energy, waste, and water use. This study investigates the possible benefits of using Building Information Modeling (BIM) technology in environmentally friendly building methods. It also seeks to identify and rank the major obstacles to the industry’s integration of sustainability and BIM. The study aims to accomplish its research objectives by means of a questionnaire survey approach. The three primary categories of the possible benefits associated with BIM are social, economic, and environmental, which correspond to the generally acknowledged elements of sustainable development. The provision of a centralized database that facilitates the administration of the full building lifetime, less material waste, and increased design efficiency have all been noted as key benefits. In the building industry, BIM approaches have shown to be quite successful in improving sustainable practices. The study does, however, point out a few difficulties. The number of people with a BIM degree has increased significantly, but there are still not enough qualified professionals with the necessary knowledge and experience. Project managers with the necessary skills are needed to oversee BIM deployment successfully. They should be able to advice and counsel clients and other stakeholders on the benefits of BIM. Building professionals may maximize the environmental performance of structures across their lifetimes and make well-informed decisions by integrating sustainability concepts into the BIM process.

Analysis of the form, construction, and structural conception of Silberkuhl shells through construction history and advanced HBIM

In the 20th century, the development of industrial buildings featured a strong relationship between form, conception, needs of production processes, and advanced structural solutions. The knowledge, safeguard, and valorization of the industrial heritage structures, of the 20th century, requires a multidisciplinary approach, including construction history, structural analysis, and advanced 3D modeling. In particular, the study of shape-resistant structures in reinforced concrete – such as thin shells – needs to consider the deeply intertwined aspects of form, construction, and structural conception. The main aim of the present paper is to set a methodological workflow based on the combination of archival research, Historic/Heritage Building Information Modeling (HBIM), and numerical structural analysis to support the knowledge, safeguard, and valorization of the thin shells in reinforced concrete. The effectiveness of the proposed methodology, scalable for the analysis of historical shell structures in reinforced concrete, is tested on the noteworthy case study of the so-called Silberkuhl shells. According to their convenience in terms of structural efficiency and economy of construction, this system stood out worldwide for industrial roofing in the second half of the 20th century, exploiting the possibility of both industrial production and on-site precast, adapting to different economic and technological backgrounds.

Safety Management System in Pune Metro Rail Projects

The construction industry continues to grow as the demand for infrastructure, homes, and officespaces grows by the day. Since the construction industry is so dynamic, it is vulnerable to a range ofhealth risks. As a result, protection is a top priority in the construction sector to ensure a healthy workingenvironment. Safety experts have determined that risky behaviours cause the majority of workplaceinjuries, and that controlling these behaviours is one of the keys to effective accident prevention and a lowaccident rate on construction sites. Safety in construction industry is much more important. This reviewpaper is about to increase safety in the building industry performance. The study's primarily is to definethe critical success factors that affect the implementation of construction safety management. Thisreview paper is to recognize and solve major problems in the infrastructure sector with varioussolutions related to work situations that affect project safety performance. Due to lake of knowledge andawareness large number of people’s deaths and long-term injuries occurs. in order to reduce andcontrol construction worker health and safety.The construction industry has the largest number of injuries compared to other industries. Thus,reducing accidents and determining construction risks are extremely important. One of the essentialsteps for construction safety management is hazard identification, since the most unmanageable risksare from unidentified hazardsPune metro project is the key project for city the accident at going site may causes the break inprogress of work ultimately it casues the increases the duration of project as well as cost of projects.The various safety and control measures of accidents in Pune Metro projects will outlined in thisproject in order to mitigate accidents

A Novel Approach for Predicting CO2 Emissions in the Building Industry Using a Hybrid Multi-Strategy Improved Particle Swarm Optimization–Long Short-Term Memory Model

The accurate prediction of carbon dioxide (CO2) emissions in the building industry can provide data support and theoretical insights for sustainable development. This study proposes a hybrid model for predicting CO2 emissions that combines a multi-strategy improved particle swarm optimization (MSPSO) algorithm with a long short-term memory (LSTM) model. Firstly, the particle swarm optimization (PSO) algorithm is enhanced by combining tent chaotic mapping, mutation for the least-fit particles, and a random perturbation strategy. Subsequently, the performance of the MSPSO algorithm is evaluated using a set of 23 internationally recognized test functions. Finally, the predictive performance of the MSPSO-LSTM hybrid model is assessed using data from the building industry in the Yangtze River Delta region as a case study. The results indicate that the coefficient of determination (R2) of the model reaches 0.9677, which is more than 10% higher than that of BP, LSTM, and CNN non-hybrid models and demonstrates significant advantages over PSO-LSTM, GWO-LSTM, and WOA-LSTM hybrid models. Additionally, the mean square error (MSE) of the model is 2445.6866 Mt, and the mean absolute error (MAE) is 4.1010 Mt, both significantly lower than those of the BP, LSTM, and CNN non-hybrid models. Overall, the MSPSO-LSTM hybrid model demonstrates high predictive accuracy for CO2 emissions in the building industry, offering robust support for the sustainable development of the industry.

Biocomposites reinforced with wood flour and eggshell powder: production and properties

Abstract Wood plastic composite (WPC) is one example of a biocomposite that has been applied commercially as structural materials either in the building industry and in the automobile interior parts. In this work, WPC was developed based on polypropylene (PP) from used medical mask, polyethylene (PE) from plastic pocket reinforced with wood flour mixed with eggshell powder (ESP). The study aims to target similar properties as commercial WPC with its tensile strength of 14.27 MPa, flexural strength of 37.57 MPa, water absorption 2.61 %, and flammability (burning rate) < 100 mm/min. The composition of the composites investigated was PP (45 wt. %), PE (5 wt. %), wood flour (30 wt. %), ESP (20 wt. %). The effect of calcined and uncalcined ESP on the properties was first studied and the results show no significant differences in their properties. That finding leads to prepare biocomposite samples using hot press with various applied pressures, i.e. 0.55; 0.65; and 0.75 MPa. The tests show that the samples prepared with hot press pressure of 0.55 MPa can meet all the limit target of the above properties.

Research of electrode materials for the creation of multifunctional current sources with increased capacity as a components of the energy sector of an efficient urban environment

As part of creating a comfortable and safe environment, constructing energy-efficient residential and industrial buildings and structures that meet modern requirements and standards, the development of the production of environmentally friendly renewable and new individual energy sources is becoming especially relevant. In this regard, there is a need to increase the energy capacity of electrochemical cells. Research has been carried out on the metallized conductive materials creation based on rolled carbon non-woven material “Busofit” with the sequential application of metal coatings of titanium and silver using ion-plasma sputtering and electric pulse dispersion methods. It has been shown that surface layer metallization of the electrode material with titanium can improve the electrochemical cell characteristics. Additional silver film deposition leads to further cell performance improvement. It has been confirmed that the multilayer structure interfacial resistance between the carbon and the current collector has a significant effect on the conductivity of the electrochemical cell and the stability of its operation. The contact area increase of the electrode with the electrolyte leads to an increase in the rate processes occurring on the electrode surface and in the near-electrode space, which opens up prospects for increasing the energy intensity of the electrochemical system. A significant capacity increase of a water-based capacitor structure is achieved by the formation of a nanostructured dielectric layer of potassium titanate in the interelectrode space. It has been confirmed that the cell voltage cycling helps to stabilize the processes occurring in the surface layer of the electrode material at the interface and determining the range of mechanisms for transmitting electrical energy, which makes it possible to achieve higher energy intensity of the samples. Improvement of technological solutions in the field of ion-plasma technologies and the use of new perspective nanostructured materials creates the prerequisites for the creation of advanced automation and energy supply systems with a higher resource, which expands the possibilities of their use in various construction projects.

Прогнозирование безопасной эксплуатации сооружений при вибрационных динамических воздействиях работающего промышленного оборудования и транспорта

Vibrational process excited in foundation soils by the operation of industrial equipment and transport traffic causes dynamic vibrations of building structures located in proximity to industrial enterprises and transport communications, which leads to additional dynamic force in building structures and violations of sanitary and hygienic norms when operating premises designed, inter alia, for working personnel and passenger services. This causes the reduction of operational characteristics of structures such as cracking and local destructions. A computational model «the source of dynamic load (equipment of industrial buildings, moving automotive and railroad transport) — medium of load transfer (soil) — building structure (receiver of impacts)» to assess such impacts has been proposed. When formating computational schemes, a simplifying assumption on the discretization of the computational scheme based on the Dalembert principle has been taken into account. Solution of the motion equations must be sought in the decomposition by appropriate vibration forms. Some simplifications of the computational model to obtain numeric engineering observable results have been substantiated. The simplified methodology to solve the problem of vibrations of bearing and enclosing structures of buildings and facilities impacted by vibrations spread in foundation soils under operating industrial equipment wheeled and railroad transport has been theoretically substantiated. The suggested methodology is based on the division of the structural scheme into separate core structures, dynamic support deviation calculation of which is to be performed sequentially. The calculation of building structures for vibrations caused by dynamic impacts of transport traffic and equipment operation can be used as a theoretical basis for the design and construction of buildings and facilities in order to ensure their safe operation.

Assessment of the Mechanical and Microstructural Performance of Waste Kraft Fibre Reinforced Cement Composite Incorporating Sustainable Eco-Friendly Additives

This study investigates the influence of limestone powder and metakaolin as sustainable eco-friendly additives on the properties and behavior of cementitious composite boards, with a focus on mechanical strength, physical properties, and microstructural characteristics. The experimental investigation begins with the characterization of the raw materials, including limestone powder, and metakaolin, to assess their particle sizes, elemental composition, and microstructural features. Cement composite boards were fabricated using an innovatively developed lab-simulated vacuum dewatering process, by varying the proportions of limestone powder and metakaolin as partial replacements for cement, along with waste kraft fibres as reinforcement. Mechanical testing was conducted to evaluate the flexural strength and behaviour of the composite boards according to standardized procedures. A microstructural analysis was performed using scanning electron microscopy (SEM) to examine the effect of additives on the cementitious matrix, fibrematrix interaction, and hydration products. The findings from the experimental study reveal insights into the influence of limestone powder and metakaolin on the mechanical properties and microstructure of waste kraft fibre-reinforced cement composite boards. Our analysis of the results shows that adding 9% limestone powder as partial cement replacement produces a 24% and 50% enhancement in flexural strength at 7 and 28 days of hydration, while that of metakaolin as partial cement replacement was optimum at 6% with an enhancement of 4% and 36%, respectively, at 7 and 28 days of hydration. The implications of these findings for the development of sustainable cementitious composite are discussed, including the potential benefits of using limestone powder and metakaolin as supplementary cementitious materials in waste kraft fibre-reinforced cement composite boards. Finally, recommendations for optimizing additive proportions are also provided to enhance the understanding and application of these materials in the construction and building industries.

Experimental and analytical investigation of bracket moment connection for precast concrete beam-to-composite column joints

In large industrial buildings, precast prestressed concrete beams and composite columns are appealing to achieve longer span and higher story height, with temporary supporting and scaffolding minimized. To facilitate field erection of moment connection between precast beams and composite columns, a bracket connection transferring beam loads to the column by connecting the beam to a composite bracket attached to the column has been developed. Since precast beams are lap-spliced and integrated with the bracket by concrete engagement at the interfaces, the connection performance depends on beam lap length and load transfer details (i.e., concrete shear keys). In this study, the seismic performance of precast prestressed concrete beam-to-composite column joints with the bracket connection was experimentally and analytically investigated. Cyclic loading tests were conducted on four full-scale specimens with different beam lap lengths and load transfer details. For the specimens with a longer beam lap length, the bracket connection successfully transferred the beam flexural strength to the column with the connection barely damaged. The governing failure mode was beam flexural yield occurring at the bracket end. However, for the specimen with a shorter beam lap length, relative slips at the interfaces of the beam and bracket occurred and thus the strength was governed by the bracket connection. Excellent ductility satisfying the acceptance limit of special moment frame in AISC 341 was achieved in all specimens. The load transfer at the bracket connection through concrete shear keys and other details were further investigated through finite element analysis. Design models to predict the connection strength were proposed and the validity of the models was verified through comparisons with the tests and analyses.

A Reusable Past. Opportunities for the Utilization of Industrial Heritage in Salgótarján, Hungary

AbstractIndustrial heritage is not just the industrial landscape, buildings, and material objects, but also the highly complex cultural heritage created by industrial society, with many unique features. The former industrial towns of East-Central European countries have little memory of their early capitalist industrial past, and their socialist legacy is mostly seen as an unwanted and unwelcome burden. Industrial heritage preservation in Hungary was also adversely affected by the ideology of de-industrialization in the late 1980s, and this was compounded by struggles over the politics of memory. Salgótarján, as the seat of Nógrád County, is a city with county rights that has one of the worst social and economic indicators in the country, with dozens of slums, many of them on former industrial sites. The number of sites suitable for greenfield investment in the valley town is low, while the proportion of under-utilized brownfields is high. The real turning point in the development of the settlement was the opening of the mines and the mining boom in the second half of the 19th century. The opening of the mines was soon followed by the construction of larger industrial plants: the steel mill, the hollow-glass and later flat-glass factory, and the ironworks (stove factory). Initially, skilled workers were recruited from abroad, which laid the foundations for a unique society, as much of the population had no ties to the settlement, or even to Hungary—only to the work and their employer. The industrial society of Salgótarján formed a well-defined local community with a sense of identity. The management of the companies and factories, the network of workers' welfare institutions, the managed leisure programs and facilities, and of course the built environment of the colonies played a major role in all this. Under state socialism, the factories continued to operate with an artificially inflated workforce, and after the political regime change in 1989, the privatized plants closed down with dramatic abruptness, leading to social trauma and high unemployment in the settlement. The preservation and presentation of industrial heritage is also important for the city's identity while the built environment is undergoing a radical transformation, which is why buildings that are deemed worthy of preservation should be given a new function as soon as possible so that they may remain an integral part of the settlement.

Unlocking Public Engagement in Reused Industrial Heritage: Weighting Point Evaluation Method for Cultural Expression

Industrial heritage has attracted much attention because of its significant historical and cultural values. Nowadays, the functional transformation of industrial heritage buildings, such as museums, parks, and so on, into public-space-oriented buildings has been taking place all over the world. The public users of these public realms become the main audiences of industrial culture. Architects transmit the industrial culture therein to public users by using the design language. However, differences in the public’s understanding of design from different backgrounds may affect the attractiveness of the project. The tension between industrial culture and public acceptance becomes a key issue in industrial heritage renovation. The proposal of the “weighting point evaluation method” is the aim of this study, which demonstrates the usability of this mathematical and statistical method for the assessment of the cultural expression aspect in the renovation of industrial heritage. Such a quantitative assessment method is used to find the strengths and weaknesses that exist in the project, thus providing a reference point for optimizing future development. The methodology was applied at the Dalian Industrial Culture Exhibition Hall to demonstrate its validity. The results of the methodology in practice identified four aspects of the experience of public users concerned with the case and, at the same time, identified the strengths and weaknesses of the project in terms of cultural expression, providing an important reference point for further optimization in the future. Moreover, it also demonstrates flexibility and generalizability in responding to different expressions in different projects due to the variability of the weighting judgements of the methodology.

Performance prediction of ventilated building-integrated photovoltaic system with lightweight flexible crystalline silicon module based on experimental fitting method

The novel ventilated building-integrated photovoltaic system with lightweight flexible crystalline silicon modules (VL-BIPV) has a self-weight of only about 6 kg/m2, which helps to address weight-bearing challenges on low-capacity industrial building rooftops. However, the unique thermal dissipation features of the system pose challenges for the analysis of its photovoltaic performance and thermal processes. Therefore, a comparative experimental testing approach was employed, comparing the VL-BIPV system with a conventional rooftop photovoltaic system. Using the efficiency equations of the conventional photovoltaic system as a reference, the functional equations were fitted based on experimental results. Based on typical meteorological year data in Nanjing, annual power generation and PV cell temperature variations were evaluated, along with power generation and carbon reduction benefits over a 25-year lifetime. The results indicate that the VL-BIPV system achieves an annual power generation of 262.22 kWh/m2, a 6.52% increase compared to the conventional system. Additionally, the highest average and maximum cell temperatures in the VL-BIPV system during the year are 58.39 °C and 64.74 °C, respectively, both lower than the conventional system's peak at 68.34 °C. Over a 25-year lifespan, the VL-BIPV system reduces carbon emissions by 20.17 kgCO2/Wp, exceeding the conventional system's reduction by 1.25 kgCO2/Wp.

Characterization of health and safety hazards of deconstruction activities.

Manual deconstruction-an alternative to mechanical demolition-is a crucial technique in the building industry that facilitates a circular economy for the built environment and achieves sustainable development goals (SDGs). However, the current body of literature lacks a thorough grasp of the OHS (occupational health and safety) hazards related to the deconstruction process. The current work closes this scholarly gap by outlining the deconstruction process as phases and sets of activities and highlighting potential health and safety hazards throughout different activities and phases. The study uses numerous case studies and applies a descriptive case study technique to gather and analyze primary data from hundreds of photos and notes from over 40 field visits. The primary data are first used to prepare a comprehensive process map of deconstruction. Six construction safety experts and four industrial hygiene experts were then interviewed to identify and characterize health and safety hazards in images representative of the deconstruction activities. A taxonomy of OHS hazards for deconstruction was developed based on identifying 35 unique safety and 51 unique health hazards. Significant safety hazards in deconstruction activities include "struck-by," "trip, slip, and fall" hazards, and "lack of personal protective equipment." Major health hazards include ergonomic concerns, respiratory diseases, and eye strain. The study highlights the occupational health and safety issues faced by the deconstruction trade with a granularity rarely covered in existing literature. The assessments can be helpful for OHS practitioners to identify potential health and safety improvements across various deconstruction phases.

Test Procedures and Mechanical Properties of Three-Dimensional Printable Concrete Enclosing Different Mix Proportions: A Review and Bibliometric Analysis

Three-dimensional printable concrete (3DPC) has become increasingly popular in the building and architecture industries due to its low cost and fast design. Currently, there is great interest in the mix design methods and mechanical properties of 3DPC, particularly in relation to yield stress analysis. The ability to extrude and build 3D-printed objects can be significantly affected by factors such as the rate of extrusion, nozzle size, and type of pumps used. It has been observed that a yield stress lower than 1.5 to 2.5 kPa is not sufficient to maintain the shape stability of concrete, while a yield stress above this range can limit the material’s extrudability. Furthermore, the strength properties of 3DPC are influenced by factors such as changes in yield stress and superplasticiser dosages. To meet the high mechanical strength and durability requirements of 3DPC in the construction industry, it is essential to analyse the material’s early-age mechanical properties. However, the development of standardised test methods for 3DPC is still deficient. To address this issue, a bibliometric analysis was conducted to comprehensively review the diverse test methods and mechanical characteristics of 3DPC with different mix proportions. To produce high-performance concrete from various additives and waste materials, it is critical to have a basic understanding of the hydration processes of 3DPC. Moreover, a detailed analysis of the environmental impact and energy efficiency of 3DPC is necessary for its widespread implementation. This review article will highlight the recent trends, upcoming challenges, and benefits of using 3DPC. It serves as a taxonomy to navigate the field of 3DPC towards sustainable development.

Characterization of tornado-induced wind pressures on a multi-span light steel industrial building

This study presents the characteristics of external wind pressures of a multi-span light steel industrial building through wind pressure measurements conducted in a tornado simulator. The test model is designed as a three-span low-rise building with gable roofs according to the practical measured sizes and shapes of the light steel industrial building destroyed in the Shengze tornado, China (2021). The distance from the tornado-like vortex center to the building, building orientation, roof angle, and swirl ratio are considered as experimental parameters. The effects of the parameters on the most unfavorable peak and mean pressure coefficients of each surface are analyzed. The roof zoning specified in ASCE 7–16 was re-analyzed based on the characteristics of wind pressure coefficients, and the tornado design pressure coefficients were calculated. The results of the analysis illustrate that the wind-ward roof surface at a distance of around one vortex core radius from the center experience the most severe pressure coefficient under tornado, the most unfavorable zone of the pressure coefficients on the building roof changes with the building orientation, the model with a smaller roof angle has smoother pressure coefficient contours than that with a larger roof angle because of the cutting effect of the ridge, and the simulated tornado with the lower swirl ratio generate higher external pressure coefficients on the building model. Moreover, the roof zoning in ASCE 7–16 for the boundary layer wind is not precise for tornado, thus an updated roof zoning for the tornado design pressure coefficients is defined.

Rental Housing Supply and Build-to-Rent Conundrum in Australia

Traditionally, rental housing has been supplied by a large pool of individual investors who own a few units and invest their savings, with some leverage, to take advantage of the tax regime in Australia. The last five years have seen the emergence of build-to-rent (BTR) units, which are supplied by investors who own a large number of units. The state of Victoria in Australia has the largest share of these projects. In the current market and regulatory environment, the financial viability of BTR projects is low for investors and hinges on the ability of units to be leased at higher than market rents. This paper examines four groups of levers, including those already being pursued by the building industry, that can be used to improve the financial viability of BTRs. These include: (i) revenue maximization, (ii) cost reduction (iii) fiscal and (iv) planning incentives. An archetypical BTR project which mimics current practice is considered, assumed to be in Docklands, Victoria, where several BTR projects are planned. For the robustness check, a feasibility analysis is conducted for a site in North Melbourne, a neighbourhood in Victoria with several BTR projects. The results indicate that for revenue maximization, the mix of unit types in a BTR project should be location-specific, as market preferences (and the characteristics of renters) determine the rent for different types of units that can be achieved. In a conventional BTR project development, where land is bought upfront and the project is developed, the mixed-use BTR (residential in combination with commercial) does not provide significant financial benefits though including small retail (3–4% of the net lettable area) may provide complementary benefits. Incurring large capital costs upfront and having the revenue stream spread over long periods reduces financial viability. While construction costs are more difficult to reduce, ways to reduce land costs could be through zoning land for BTR use, through mechanisms such as joint ventures with landowners, and land leasing. Exemptions on income, land tax, and rates (like CHPs) can result in a higher return for investors. A full GST refund, an incentive that industry is lobbying for, results in a similar IRR as an exemption on income, land tax and rates would offer. These results will assist in determining priorities for policies that are aimed at BTR.

Seismic performance of an innovative self-centering and repairable connection with SMA bolts in modular steel construction

Modular steel construction (MSC) is widely noticed and adopted in the building industry for its benefits of short construction period, low carbon emission, and great flexibility. The performance of inter-module connections, including the strength, toughness and ductility, is the focus of maintaining the load transfer mechanism and overall stability of modular structures. The structure with favorably designed connections can dissipate expected energy under cyclic loading with reduced structural damage. A self-centering and repairable connection (SRC) is herein proposed, with the benefits of a distinct load transmission path and easy assembly. Four full-size specimens were fabricated and tested under low-cycle loading, and the tested specimens were subsequently repaired by replacing angle cleats. The failure mode and bearing capacity of both SRC and repaired SRC specimens were investigated. Several seismic performance indices of the specimens, including hysteresis curves, strength and stiffness degradation, energy dissipation capacity, self-centering and repairable ability, were obtained. Furthermore, the performance of the SRC was comprehensively assessed according to Eurocode 3 Part 1–8, Chinese code GB 50011-2010, and American code AISC 341-16. In addition, an accurate finite element model (FEM) of the SRC was created and verified using experimental results. The developed FEM was used to investigate the effects of critical parameters, including angle cleat thickness and grade, vertical bolt diameter, and SMA bolt number and diameter, on the seismic performance of SRCs. Both experimental and FEM results show that only the replaceable angle cleats experienced the noticed plastic deformation for SRC specimens under cyclic loading, and SMA bolts provided the required self-centering force. It can be hence concluded that the proposed SRC can achieve the expected self-centering and recovery function.

Assessing The Impact of Rising Cost of Materials On Construction Activities in Enugu, Enugu State, Nigeria

This study focused on assessing the impact of rising cost of building materials on construction activities in Enugu, Enugu state, Nigeria. The aim of this study is to assess the impact of rising cost of materials on construction activities in Enugu, Nigeria in order to proffer a solution to the rise in the cost of these materials used in everyday construction in Enugu state. With the following objectives; to identify the factors that lead to increasing cost of material in Enugu State, Nigeria; to assess the impact of rising cost of materials on construction activities in Enugu; to proffer solutions to the rise in the cost of building materials. The research design employed was primary and secondary which encompasses descriptions and quantitative analysis on a randomly selected sample of receipt of building materials from the suppliers over the years. The population of the study is 223 professionals in the field and sample size of 143 which was gotten using Taro Yamane formula. The findings of the study reveals that the factors that lead to increasing cost on the building construction activities in Enugu State are; fluctuations in material costs, design changes and scope creep, regulatory compliance and permitting, project delays, weather and environmental factors, technology and innovation costs, interest rates and financing costs, and others. Finally, the study recommends that there will be need for relevant authorities in the building industry to re-examine and educate the people on its existence and equally generate the possible ways of reducing the increasing cost of building materials so as to enhance the building construction industry in Nigeria.

Optimization of roofs with solar panels using Rao algorithms

Steel space truss roof (SSTR) systems are widely used in structures with large spans such as stadiums, sports halls, and shopping malls, as well as in industrial buildings such as factories, workshops, and production facilities. Solar panels are integrated into SSTR systems to enable these structures to generate energy and to increase the use of sustainable energy sources. With the installation of the solar panels, an additional load was placed on the roofs. However, this raises questions regarding whether existing roofs can withstand this additional weight without compromising their design. This study can be an important reference source for future truss roof designs by increasing sustainable energy use and functionally optimizing the SSTR. Another contribution of this study is that it directly contributes to real-world applications by ensuring that SSTR designs are more efficient and economical for engineering projects. For these purposes, this study presents the size optimization of the SSTR with and without solar panels using the Rao-1 and Rao-2 algorithms, which are metaheuristic algorithms known as the Rao algorithms. Thus, information can be provided regarding whether existing roofs can safely carry solar panels. To optimize the SSTR system, a computer code was created in MATLAB, which works effectively with Rao algorithms and SAP2000-s Open Applicable Programming Interface (OAPI) features and allows repetitive analysis. For size optimization of the SSTR, which consists of 1728 elements, the roof system was divided into three and six groups. Changes in the weight of the SSTR system in the different groups were investigated. The optimum design of both the three-group and six-group SSTR systems with and without solar panels was performed. Based on the results obtained from this study, it was concluded that the Rao-1 algorithm achieved more robust and stable results than the Rao-2 algorithm in both three and six-group SSTR. The SSTR system divided into six groups achieved the minimum weight compared with the SSTR system, which was divided into three groups. In this case, increasing the number of groups provided better results.

Effect of steam curing system on compressive strength of recycled aggregate concrete

Abstract Steam curing prefabrication is a feasible way to promote the application of recycled aggregate in the background of building industrialization. The combined use of slag and fly ash contributes to the comprehensive improvement of both the early and later-stage performance of recycled aggregate concrete (RAC). However, the steam curing regime for RAC composed of slag and fly ash remains unclear, including appropriate curing temperatures and time. In this study, the influences of curing temperatures (20, 40, 60, and 80°C), steam curing time (6, 9, and 12 h) and mineral admixtures (slag powder and fly ash) on the demoulding strength and strength development of RAC were investigated. Based on the Arrhenius formula, the hydration reaction rate was characterized by the development of compressive strength, the apparent activation energy related to the steam curing time was calculated, and the energy-based compressive strength model was proposed to realize the early strength prediction of the steam-cured RAC.