Paper Title
Materials Selection in the Construction Projects: Challenges, Criteria and Patterns

Abstract
The choice of materials for engineering purposes in the construction industry is a time consuming and costly process. Almost always, more than one material is suitable for engineering applications in the building industry, and the choice of final materials is a compromise option that can have some benefits and some disadvantages. A large number of materials, along with the complex relationships between the various selection parameters, often make the selection of materials in the construction industry a complex and difficult issue, which is associated with uncertainties in the decision making process. In other words, selecting materials in a construction project is a multidisciplinary effort and often requires a variety of research fields such as materials science and engineering, mechanical engineering, industrial engineering, and other utilities and utilities. From the other hand, in recent decades, according to the proof of the need to observe the principles of sustainability across all industries and societies around the world, sustainable materials also attracted important role in the stability of many construction play. The selection of sustainable materials in construction projects, despite a wide variety, is characterized by a variety of specifications that determining these indicators can have positive outcomes in advancing the construction industry's goals; Determining these indicators is an interactive process that requires the coordination of various information from different sources of the project and overlooks the various factors involved in the projects at all stages of the project implementation and the decision-making process in the design process. According to the above, in this research, the research will attempt to evaluate the main criteria for selecting materials from the first stage, considering the life cycle of materials and sustainable development in construction projects, in the form of a key model. The results show that sustainability criteria can be selected in the main five technical, economic, social, managerial and environmental categories, and in each section, could be determined the sub-criteria and based on them and before the starting of the project, the selection of materials be Managed with the objectives of sustainability. Keywords - Sustainability Criteria, Material Management, Material Selection, Challenges and Pattern.