oa Seismic Methods for Quality Control and Quality Assurance of Civil Engineering Materials: Opportunities and Challenges

Modulus is one of the primary parameters to qualify civil engineering materials and plays an important role in structural design of structures and pavements. for portland cement concrete structural members, concrete strength is another major parameter of concern. in-situ determination or estimation of these parameters has been an essential and challenging task for quality control/quality assurance during construction. Seismic nondestructive testing technology based on the use of stress waves has shown to be a useful and convenient tool to achieve this goal. This paper provides the fundamentals, capabilities and limitations of stress wave methods and testing devices, and represents the results obtained from their recent applications in a numbers of construction projects. these applications include: evaluation of hot-mixed asphalt layers, characterization of base courses and subgrade with different treatments and monitoring of early-age modulus/ strength development of concrete. This presentation presents a process that can be potentially used by agencies for a comprehensive quality of materials based on seismic technology. Seismic-based laboratory and field tests were briefly explained and the process of combining them to evaluate the appropriateness of compacted soil and asphalt layers, and concrete pavements is discussed. Issues in understanding the results from stress-wave tests and how to incorporate them to the existing specifications or common practices are also discussed. A site for each case is thoroughly discussed to demonstrate the effectiveness, reliability and weaknesses of the process.