Finding the value of materials testing, a field study. David Alexander, Road Science


The civil construction industry in New Zealand is serviced by a large number of laboratories carrying out testing for materials used. The results these laboratories produce are often compared to a specification that gives site engineers the satisfaction they need to ensure that they will stand the test of time.
This presentation will examine how this laboratory based information can be matched up with measurements taken from the field, and used to determine the lifespan of materials as they degrade. The methodology discussed will expose the end of life failure mechanism for asphalt surfacing, and how this mechanism can be quantified in the field. Field trials took place in the upper North Island where sites were reviewed after ten years in service.
The findings from these trials allow for the calculation of surface course life with unprecedented accuracy. Development of a tool that predicts the amount of time a surface course is expected to deliver a specific level of service is currently under development.