mehdi ravanshadnia

The purpose of this research is to evaluate the mechanical performance and durability of Roller Compacted Concrete (RCC) with fibers as an alternative to asphaltic pavements in industrial areas with heavy traffic loading. RCC is a hard and relatively dry mixture of aggregate (maximum nominal size 19 mm), cement and water which is spread by conventional asphalt pavement finishers and compacted by a vibrating roller. After completing the hydration reactions, the RCC has the same appearance as the concrete with zero slump. In this research the compressive and bending strength, durability and cycles of freezing and thawing were tested. The results showed that the performance of RCC containing fibers is better than RCC without fibers. Also, the resistance of RCC against fire is much higher than asphaltic mixture. The results showed that RCC pavement is suitable for roads with heavy vehicle traffic and low speed due to its engineering and mechanical characteristics. The main purpose of this research is to investigate the engineering and mechanical properties of RCC as an alternative to asphaltic pavement in industrial areas with heavy traffic loading. Also, by conducting a test, the fire resistance of RCC and asphaltic pavements was evaluated.

This study addresses the critical issue of building element defect management, focusing on prevalent concerns like cracks, dampness, and surface degradation. Recognizing the limitations introduced by human subjectivity in defect classification, the research proposes a novel, data-driven approach to automate the process. The methodology leverages extensive field data collection, encompassing 500 painted walls from 24 geographically dispersed buildings, to develop a robust fuzzy logic-based building element condition assessment model. The model categorizes element conditions (C1-C5) and classifies damage severity into five groups: no damage, slight damage, moderate damage, extensive damage, and complete damage, with nuanced precision. The efficacy of the fuzzy C-Means clustering is rigorously validated through the application of silhouette index and Davis-Bouldin index, ensuring optimal cluster formation and enhanced model accuracy. A real-world case study involving an office building exemplifies the model's practical application, showcasing its effectiveness in minimizing human error during defect identification and classification. This research contributes a sophisticated defect management framework informed by extensive field data and validated fuzzy logic, ultimately leading to demonstrably improved building quality and reduced operational costs within the construction industry.

By considering financial resource constraints, this article, stems from applied-developmental research, conducted to develop a suitable decision-making model for prioritizing the country's unfinished freeway projects. The main question of the research is: given the existing system documents and the specific internal and external conditions, what criteria and models can effectively guide decisions on prioritizing the country's incomplete freeway projects? The research employs an analytical-quantitative approach, with data gathered through both library research and field studies. Initially, relevant criteria for prioritization are identified by reviewing existing documents and previous studies, and these criteria, along with their sub-criteria, are compiled into a matrix. Expert interviews using the Delphi method are then conducted to assign weights to each criterion, resulting in a weighted criteria matrix. Finally, by applying network analysis (ANP) with Super Decision software and multi-criteria decision-making models (MCDM), a supermatrix of prioritized freeway projects is generated and prepared for implementation. This matrix enables the determination of project priorities using either single or multiple criteria. Additionally, the research identifies the potential to create a megamatrix that prioritizes all construction projects across the country.

Research in building information modeling and sustainability studies has been increasing recently. However, few studies have been conducted to examine the integration of building information modeling technologies to strengthen the implementation of sustainability methods in the construction industry. Building information modeling technology is one of these methods because it creates vital databases for the building and its components instead of generating and displaying rich information IDs. As a result, executive management's time and costs are significantly reduced because of the ability to make optimal decisions regarding the implementation of projects at each stage. It has provided the construction. Building information modeling technology as a powerful manager tool improves project success criteria. This study aims to identify the dimensions and components affecting the sustainable development of the construction industry based on building information modeling. The method used in this research is Grounded Theory based on the study's exploratory nature. The primary basis of data collection is in-depth interviews with experts, professors, and construction project specialists of Tehran Municipality, District 3. A total of 15 interviews were conducted. After collecting the information, the codes related to the written interviews were analyzed. After performing three steps of open coding, axial coding, and selective coding, the final research model was presented. The codes obtained from the interviews were categorized into 55 concepts and 14 main categories. According to the results of this study, building information modeling and optimal building design are influenced by a range of environmental and causal factors. An integral part of the sustainable development of the construction industry is the integration of contractual models and sustainability development. The use of natural resources, the product, and the training of organizational and macro management and technology are included.

Sports projects are one of the important projects that play an important role in the cultural, social and health development of the community. Building sports projects, like many other types of projects, has different challenges. Assessing the success of the method of providing this type of projects using Islamic treasury documents and providing corrective solutions in this research has been considered by the researcher. The case study of this research is the company for the development and maintenance of sports venues in the country. success rate and identification of effective factors, it can be considered as an innovation of this research. The statistical sample size of this research is 385 people and the interviewees have been identified using the snowball method. The statistical questionnaire is organized in three sections: general questions, primary market and secondary market. The reliability of the questionnaire based on Cronbach's alpha formula is 0.763. The results show that contractors are not very receptive to Islamic Treasury documents and market fluctuations, inflation and market stagnation affect the performance of these documents. In the primary market of these documents, weakness in the awareness of managers, weakness in the variety of tools and documents of the Islamic treasury are among the problems. There are also obvious problems in the secondary market, such as the lack of full receipt of receivables, the discount rate is not commensurate with the tax received from contractors. The main criteria are managerial, contractual, legal and legislative, and upstream measures.

After the process of holding tenders and concluding contracts and agreements and forming a project management team, the obligations, responsibilities and authorities of each of the effective factors or project stakeholders will be identified and separated thematically. Of course, it should be noted that the considerable amount of these obligations, responsibilities and authorities in each project is similar and the same. The uncertain and complex situation of claims in construction projects that will lead to financial issues and prolongation of work, requires all project stakeholders to have a clear approach in order to manage potential claims. In this study, after identifying the claims and rooting out the concepts related to the claim as well as how to manage it in contracts, the proposed model identifies and evaluates the project stakeholders and their ability to measure the claim using stakeholder social network analysis. On the other hand, by calculating the stakeholder centrality measure in each claim and summarizing them, the most important stakeholders and the relationship between them were identified that can be the basis of planning and management. Therefore, using social network analysis between project stakeholders and common claims, it is possible to identify the effective stakeholders and take the necessary actions to manage the claims.

Today, surface treatments have become extensively popular for pavement maintenance and repair around the globe. A major environmental problem of the present age is the ever-increasing generation of construction wastes (CWs). Application of recycled CW in pavements can contribute to preservation of non-renewable materials while reducing the environmental problems. The present research seeks to investigate possible usage of recycled waste travertine stone powder (RWTSP) as an alternative to mineral filler (MF) in thin-layer surface treatment mixtures (slurry sill). For this purpose, wet cohesion test, wet abrasion test, loaded wheel – displacement test, and loaded wheel – sand cohesion test were performed on mixtures in which the MF was replaced by the RWTSP at 0, 25, 75, and 100 wt.% (by total weight of filler). Then, FESEM-EDS, XRF, and FTIR analyses were performed to check for the particle geometry and surface analysis, chemical composition, identification of organic compounds and their structures, chemical bonds, and recognition of functional groups and their molecular structure. Results showed that the mixture containing RWTSP at 100 wt.% with a residual bitumen content of 9% provided for improved wet cohesion, abrasion, and vertical and lateral displacements by about 27.2, 24, 28, and 20%, respectively. Indeed, thanks to irregular particle geometry with uneven and rough surfaces coupled with higher contents of CaO and SiO2, the RWTSP filler replacement enhances the performance of the thin-layer surface treatment.

The swift expansion of intricate projects in the global construction industry has prompted numerous investigations in the last twenty years, highlighting the significance of comprehending project intricacy for the triumph of construction project management. Identifying, assessing, and ranking procedures in response to risk is a crucial yet currently difficult aspect of project management to handle intricate projects at every phase of their existence effectively. Project managers have consistently focused on complexity and its linked hazards since it is a significant factor in project cost and time delays. This study explores the correlation between project complexity and modeling its outcomes' risks.
The study employed a deductive, positivistic methodology. The literature review examined the history and definition of complex projects. The risk factors were identified based on the underlying causes of the project's complexity. To achieve the best possible outcome in financial terms, a comprehensive model was proposed that considered the type of project contract with different risk response activities. The model was then tested by analyzing the risks associated with a sample project, and cost-response index graphs were generated for each risk individually and aggregated.
This research aimed to examine the current state and developments in project complexity research and to provide valuable insights for scholars and practitioners. The study's findings indicated that risks do not impact all projects equally. It was found that the actual effects of a risk event depend not only on the event itself but also on the management actions taken to address the contingency and their timing. These factors can influence the severity of the problems caused by the event and its ripple effects throughout the project organization.
According to the results of this field study, risks do not uniformly affect all projects. The actual impact of a risk event is contingent not only on the nature of the event itself but also on the managerial response to the contingency and its timing. These factors can influence the severity of problems caused by the event and the cascading effects within the project organization. While no single set of guidelines can guarantee project success, it is essential to recognize that the process is not random. A better understanding of the organizational dynamics that affect project performance and the factors contributing to risks in complex projects is a crucial precondition for creating a cross-functional solid team capable of managing risks before they negatively impact project outcomes. Therefore, this study can represent the first attempt to investigate the relationship between project complexity, risk consequences, and financial goals in complex construction projects. Among the various criteria contributing to complexity, the project's content, organization, and external environment were identified as the most significant risk generators in complex construction projects.

The Iran civil code is based mainly on the Egyptian Civil Law (ECL), which is itself derived from two principal sources like French civil law and Islamic law. On the other hand the general conditions of contracts published by the Fédération Internationale des Ingénieurs-Conseils or International Federation of Consulting Engineers (FIDIC), which based on common law principles and this standard form of contract, have been applied in large construction projects in Iran. Due to the Iran legal system is rooted in civil law, FIDIC forms of contract may face serious challenges. This research, through a comparative method, has analyzed the Egypt Civil Code (ECC) and Iran (as two members of the Islamic legal system) for better decisions in FIDIC-based contracts. Our study offers some strategies for modification of the FIDIC 1999 Red Book [FIDIC (CONS)] and also Iran Civil Code for construction contracts, which are associated with the termination for convenience clause. Therefore, with a better understanding of the termination for convenience by the employer clause, which has referred to in many contractual claims in arbitration centers and courts, can be prevented disputes. Moreover, this study is useful for other Middle East countries because most of them follow the civil law jurisdictions.

Today, the construction industry has a significant share of the economy and is considered as a leading and employment-generating industry. Due to various and sometimes risky activities during construction, there is a possibility of risks and personal and financial injuries, the control of which can be very effective in the success of the project. In the present study, a model for evaluating the safety risks of construction projects has been presented and new powerful tools such as fuzzy expert system improved with genetic algorithm have been used. Therefore, at first, the main factors influencing the safety of construction projects were identified by studying the literature and consulting with experts. Then, a questionnaire was provided to the experts to obtain their views and assess the severity of the risk effect and the probability of the occurrence of each risk. Then, based on the experts’ views, an expert system was obtained to assess the risks, which instead of using zero and one logic, governing expert systems, fuzzy logic was used. In the proposed model, to improve the performance of the fuzzy expert system, the genetic algorithm was employed as an optimizer. The research results indicated the optimal performance of the proposed model in assessing the safety risks of construction projects, so that the error rate of the model was acceptable. The model can also provide an effective tool for project managers in assessing and refining the safety situation in the construction site.

The importance of human resources is an inescapable issue that lack of proper management will reduce productivity in project-based organizations. human resources assessment is one of the complex processes in organizations that require explicit analysis by strategic, key, and operational jobs in order to periodically monitor, recruit and hire it according to the organizational position of employees. In recent years, various models for measuring human resources in project-based organizations have been proposed, but the important issue is to provide an expert system that can provide results with high reliability. To this end, the fuzzy inference system is felt like a response to this need. Due to the identified study gap, the present study seeks to design an expert system consistent with Mamdani fuzzy inference to measure manpower in a project-based organization in Iran. This system shows the final status of human resource assessment in the Iranian project-oriented organization and the status of each of its main dimensions. In order to show the potential and practical benefits of this system was implemented in a case study. Finally, by analyzing the system outputs, the optimal performance of the designed system is analyzed and finalized with the relevant information of the organization.

Considering the growth of industrialization for construction works, the role of on-site equipment and machinery in enhancing productivity and efficiency as well as improving working standards of construction. Hence, selecting the proper construction equipment is a challenging task owing to a wide range of available types as well as a host of criteria to be considered during decision making. However, the selection may result in incorrect decision-making or neglection of factors that are as important as cost or technical features. For this reason, nowadays the decision makers use multi-criteria decision making (MCDM) methods to make the most suitable or beneficial decision on machine and equipment selection. One of the most widely used construction equipment is wheel loader. This machine is widely used in all fields of construction. Therefore, proper selection based on the real needs of the project seems necessary. Hence, in this study, the selection of a suitable wheel loader was studied using MCDM methods. In this regard, an integrated approach using AHP and TOPSIS method for evaluating wheel loader selection were used. In this regard, the Analytic Hierarchy Process (AHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), are used in the evaluation procedure. More precisely, AHP is applied to determine the relative weights of evaluation criteria and TOPSIS is applied to rank the wheel loader alternatives. The proposed approach also provides a relatively simple and very well suited decision making tool for this type of decision making problems.

Most construction workers, including operators and engineers, suffer respiratory injuries due to exposure to hazardous materials and particulate matter (PM). This review article presents a brief overview of previous research on respiratory diseases in construction sites and links it to the COVID-19 epidemic, trying to explain other possible routes of coronavirus spread. The purpose of this review study is to find other methods of coronavirus transmission in construction sites. To achieve this goal, on the one hand, the literature on the spread of COVID-19 disease was reviewed. On the other hand, by reviewing the literature related to the health of construction department workers, we find that people who work in this occupational class suffer from respiratory diseases after a while. Therefore, they are at high risk for coronavirus. The next step is to review the literature on the effects of COVID-19 on the bodies of people with a history of respiratory disease. It is found that these people are at risk of death. It seems that transmission is not limited to known methods such as sneezing and coughing. In addition, the virus can be spread by dust and airborne particles. Due to the special conditions at the construction site, there is a higher probability that the coronavirus will be transmitted between individuals and employees. Obviously, the infection of individuals can cause irreparable harm and economically affect the construction industry.

Many studies have been conducted on the fields of Building Information Modelling, Lean construction and Sustainability not only individually but also pairwise. Despite that, there are currently no researches that integrate these concepts collectively. In order to fill this gap, a systematic literature review was conducted. The input data of this research are 95 valid international articles that are mostly focused on pairwise interaction of these concepts. Using Grounded Theory, which is a method based on line-by-line review of articles and coding of sections related to the purpose of the article and with the help of Atlas.ti software, we found triple codes that represent the integrated fields of all three concepts. The triple codes were placed in 6 main categories: Stakeholder management, cost management, material waste management, resource management, project productivity and energy management. Then, by comparing each code with other codes, 6 main theories were created. To analyse these theories and prioritize them, an interview was presented in the form of a 6-question questionnaire, in which 10 experts and professors expressed their opinions. Then, the questionnaire was analyzed using statistical methods and SPSS software. To that end, Friedmann's non-parametric test was used to prioritize theories after the variables were found to be abnormal by the Kolmogorov-Smirnov test. as a result, combining the three concepts could be more effective on waste material management than other categories.

Today, with the increasing urban development, construction waste is a major problem for urban life. The city of Qazvin is no exception to this, and researching an optimum landfill site is an important necessity. The purpose of this research is to optimum site selection areas for landfill of Construction wastes using the geographic information system (GIS) in a boundary area of Qazvin county which taking into account the terms and conditions of organizations such as the Municipality, Waste Management and Environmental Protection Organization. In this study, 16 layers of information including geology, soil type and permeability, Landuse, climate, river distance, distance from protected areas, aspect, etc. in the boundary of Qazvin county were used. After producing the preliminary maps, the sub-criteria of each information layer are classified and evaluated and the values are converted to fuzzy values between zero and one. Then, Fuzzy Hierarchical Process (FAHP) method have been used to determine the absolute weight of each information layer and by integrating and overlapping weighted layers, to the landfill suitability map of construction landfill for Qazvin city is produced. According to the suitability map, sites for landfill were identified in five distinct zones and high-lying areas of the fifth zone (with value 9) were suggested as the best landfill site for a 40-year period. The results showed that northwest of Qazvin due to good soil type, suitable land use, distance from rivers, faults and access to communication road and dry climate could be the most suitable site for landfill.

Portland cement as the main constituent of conventional concrete is the most widely used cementitious material in the construction industry. But Portland cement production has major environmental disadvantages, including high energy consumption and carbon dioxide (CO2) emissions. So that production of Portland cement is accounted for 7 to 10% of global CO2 emissions. Considering the amount of Portland cement production and CO2 emissions in Iran, it can be concluded that Iran is facing environmental problems caused by cement production. Hence, various CO2 emissions mitigation strategies of Iranian cement industry have been evaluated in this study. This research work applied Analytical Hierarchy Process (AHP) method to evaluate and prioritize mitigation strategies. The obtained results showed that among the 16 strategies studied, clinker substitution (blended cement) and production of low carbon cements such as geopolymer cement were recognized as the most important strategies to reduce CO2 emissions in the Iranian cement industry.

In this thesis, we tried to study the patterns of rail transportation development in European and Asian countries, taking into account the development criteria of the rail network in our country and no matter of political, ethnic and taste orientations, taking into account the potential of provincial development and increasing the transit of international goods based on upstream documents regarding the prioritization of the planning and executive projects of the Deputy Director of Construction and Development of the country's railways and transparent horizons For development of rail transportation network according to the restrictions of the lead Financial particularly drawn to be placed on the agenda.It is hoped that by considering the scientific research conducted in the field of prioritization of construction projects, we will see a reduction in the duration of projects at the appropriate time considered in the studies Due to the lack of funds and financial resources, as well as the appropriate time of productivity and operation of projects under construction, they must be prioritized..

One of the hallmarks of any country's economic development is the completion of development plans optimally at the lowest cost and most profit.The goal of success in residential projects is to reduce costs and time, increase quality and customer satisfaction. The method of data collection was library-based. Then, by reviewing the research background and interviewing the contractors, the factors affecting the success of Mehr Housing Projects were investigated. Residents were also considered important factors in their view. This set of data was analyzed to determine the factors affecting the success of these projects and then the importance of each of these indicators and their correlation was shown in the success of these projects in order to develop a proposal for future housing projects such as Present a national action plan to achieve their success. Outputs from the statistical analysis of this study show that from the contractors' point of view, indicators such as project financing guidelines, labor supply, materials and machinery, senior management support, and project team members qualifications. , The presence of responsible, experienced and expert people Employer idleness is more important in issuing approvals and approvals and enforcing contractual obligations. Also, from the point of view of residents, features such as timely delivery, consideration of project site conditions in natural disasters (floods, storms, etc.) provide Making the necessary divisions, adapting the infrastructure to the family population, and ease of access are more important.