Around 2009, Mackay Regional Council implemented a robust heavy grading technique that included ripping the road to create a windrow height close to the hip (road pavement depth at about 100mm+). This approach, combined with adding adequate moisture mixing and compaction using both multi-tyre and steel rollers, resulted in the best compaction and observed superior road performance compared to past techniques.

With a number of new grading staff and increased budget pressures, it was timely for Mackay to review its practices and consider alternative grading techniques. One such alternative is heavy cutting the road over ripping, reducing the windrow height to the knee (road pavement depth at about 70mm+). This method is suitable for roads with fewer defects and less traffic, increasing production by 30-40%, while maintaining effective compaction with a pavement depth of two times the average stone height (roughly 35mm).

Trials were competed at four separate sites to review both techniques, which also doubled as training for staff. The techniques were videoed and discussed during an in-office review day to cap off the week.

Additionally, a budget model was developed to display the resources required and distances graded for different assigned techniques across various road classes and crew zones.

Check out the video snippet highlighting the key differences between the techniques.