نشریه عمران و پروژه
سال سوم شماره 10 (پیاپی 32، دی 1400)

Public-Private Partnership is a mechanism in which the public sector uses the capacity of the private sector to provide infrastructure services. Due to the economic and political conditions of governments, moving towards using the capacities of the private sector has become more necessary than ever. In this regard, examining the main obstacles to success in private and government partnership projects has been one of the main management issues in recent years. The purpose of this study is to investigate the main barriers to success in private and public sector participatory projects and a case study of Zanjan Provincial Deputy for Civil Engineering projects. In this research, which is an applied research, an attempt has been made to determine the main barriers to success in collaborative projects using quantitative methods and questionnaires. For this purpose, based on the four components of PEST analysis (political, economic, cultural and technical), the identified factors were classified and a questionnaire was formed. Demetel technique was used to analyze the collected questionnaires and the questionnaire was distributed using Cochran's formula among the statistical population. The results of the analysis of the questionnaires show the impact of all four main political, economic, cultural and technical components on the participation process. Among these, the criterion of political components with a normal weight of 0.180 is in the first priority. Economic criteria with normal weight of 0.162, technical criteria with normal weight of 0.087 and social criteria with normal weight of 0.066 have the following priorities, respectively.

One of the new types of concrete that helps to solve problems such as cracking, grooving in concrete, and is known as one of the most popular concretes in the civil engineering community, is roller concrete (RCC) which is made in construction. Types of road pavements and structural uses can be used. In recent years Due to the high cost of pavement construction and environmental considerations, various waste and recycled materials have been used in concrete mixes and roller concrete. In this research, a relatively comprehensive review of the composition of waste and recycled materials on the mechanical properties of roller concrete is presented. The mechanical properties of roller concrete by replacing coarse and fine-grained materials in concrete with recycled materials including rubber chips and steel slag have been investigated in a leading study. In the researches, compressive strength, indirect tensile and three-point bending tests have been performed on 7 and 28 day samples.3-point bending test is used to obtain flexural strength and toughness and energy absorption.

Annually, a part of the budget of different countries is spent on repairing and repairing the damages caused to the pavements. In our country, where most of the pavements are asphalt and the low resistance of pavements to dynamic loads and their short service life are among the most important problems in the field of road protection and maintenance, which cause various breakdowns on the road. Instrumentation begins. Nanotechnology is used in pavement engineering due to its unique properties in improving the properties of asphalt mixtures. In the present study, a review of new ideas for the use of nano-clay, nano-iron oxide, carbon nanoparticles with different percentages as a modifying additive in asphalt bitumen has been done. Then, the mechanical properties and behavior and temperature sensitivity properties of the modified asphalt mixture with nanomaterials that have the ability to improve the performance of the flexible asphalt surface are investigated. And the effect of using nanoparticles with lower percentages and better performance for a way resistant to environmental factors with a longer useful life on the asphalt mixture has been obtained. Research shows that the addition of optimal amounts of nanomaterials to modify asphalt bitumen increases the strength, durability, flexibility, fatigue resistance, slip resistance, impermeability and ease of application of asphalt mixtures. Therefore, improving the mentioned properties increases the service life of flexible pavement.

This study evaluates the effective factors in the development of creative tourism in Chalous county. It is applied-developmental research and The study method is documentary and field research. A questionnaire was used to collect information and were used SPSS to analyze the data. The statistical population of the study was calculated using the Cochran's formula of 384 people that to increase 400 people for more reliability and validity. The results show that the 5 factors of research, play an effective role in the development of creative tourism and Pearson coefficient (0/459) has a direct effect on travel motivation and this coefficient has a direct and positive effect on Variety of attractions (0/372), cultural diversity (0/431) Facilities (0/312)and Quality of place and region(0/488). Considering that the level of significance in the 5 studied variable is less than 0.05, there is a relationship between these 5 variables and creative tourism development. According to the study, all variables in explaining the development of creative tourism are not the same direction. As the standardized coefficient shows, the travel motivation factor with the impact factor (0/532) has the first rank and the facilities with the impact factor (0/276) have the least effect on the development of creative tourism. The results of the research show that if we want to develop creative tourism in Chalous, we must study the 5 variables studied and their components with a coherent and integrated planning so that we can improve the tourism and Consequently the environment of citizens, which requires serious attention of experts, And specialist in tourism, cultural heritage and handicrafts.

 One of the most important challenges for municipalities is to provide the financial resources needed to carry out the development projects required by cities. But for various reasons, projects are not implemented on an acceptable schedule and speed. One of the most important reasons is the lack of funding. The purpose of this study is to investigate the methods of financing new projects in Yazd Municipality. The data collection tool in this research is a library and a questionnaire. The statistical population of this research is Yazd Municipality employees related to the financial sector to 50 people in 2021 that the sample size using Cochran's formula was 44 people. Delphi method was used to analyze the information. The results indicate that the factors of capital participation, profit sharing, artisan, credit lines, etc. in order to reduce project operating costs are the most important methods of financing municipalities. Also, the dependence of Yazd Municipality budget on unsustainable revenue sources is one of the most important obstacles to provide new methods of financing projects.