The responsibilities of a construction materials tester include performing inspections in the field for construction projects. You do soil density testing to ensure all materials conform to construction plans, specifications, and guidelines set by the ASTM standards organization. You also conduct sampling, inspect concrete, asphalt, and other materials as needed, document the results, and then prepare a daily field report summarizing each observation and test calculation. There are also positions where you complete these tests in a laboratory. Your duties may require you to work nights and weekends on occasion.