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Executive Summary in the next several decades, a significant percentage of the country's transportation, communications, environmental, and power system infrastructures, as well as public buildings and facilities, will have to be renewed or replaced. Next-generation infrastructure will have to meet very high expectations in terms of durability, constructability, performance, and life-cycle cost. One way of meeting future expectations will be through improved, high-performance materials, but before new materials can be confidently deployed in the field, a thorough and comprehensive understanding must be developed of their long-term performance in a variety of applications and physical environments. The National Science Foundation (NSF) has launched an initiative to promote the development of innovative short-term laboratory or in-situ tests for making accurate, reliable predictions of the long-term performance of materials and requested that the National Research Council (NRC) conduct a workshop as a reconnaissance-level assessment of models and methods that are being used, or potentially could be used, to determine the Tong-term performance of infrastructure materials and components. The objectives ofthe workshop were to: define the objectives for infrastructure-based research that would use accelerated testing and computational simulations to determine life-cycle performance assess the state of the knowledge base to identify gaps and overlaps in research activities establish outcome-oriented metrics for setting research priorities identify promising lines of research and collaborations As a result of the discussions at the workshop and the committee's deliberations, the committee appointed by the NRC to conduct the workshop believes that NSF should develop mechanisms (~) to promote the materials-based issues associated with the life prediction and reliability of infrastructure in order to attract the interest of scientists at the forefront of the study of complexity in materials research and (2) to foster collaborations among scientists and engineers engaged in life prediction and accelerated testing to encourage the transfer of knowledge, methods, and techniques among various fields and applications. The workshop discussions revealed a general agreement that the "root cause" of the deterioration and failure of any system is related to materials and that fault trees, risk analysis, and other related methods should be used to identify the most important degradation mechanisms. Accelerated-testing methods could potentially be used to rank the performance of materials in a real-worId system but are not, at present, sufficiently reliable to make system-life predictions. The committee concluded that a reasonable objective for infrastructure- based research is to develop methodologies for predicting the total and remaining life of a structure and that NSF should support materials research directed toward
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2 RESEARCHAGENDA FOR TESTMETHODSAND MODELS understanding the combined effects of degradation mechanisms and applying that understanding to quantitative predictions of system life. Life-prediction models and accelerated-testing procedures have the potential to increase the deployment of new materials in infrastructure applications and to improve traditional materials. The government and professional organizations will play major roles in encouraging the acceptance of new materials.