This procedure shall be used at the top of a pavement foundation to measure and provide limitations to deformation in the foundation under construction trafficking.
Apparatus Required
(i) Straight edge with a minimum length of 2 m;
(ii) Two identical blocks; and
(iii) Ruler.
Procedure
1. Place a straight edge transverse to the rut and raise it clear from the rut by two identical blocks. The blocks shall be placed on undisturbed material outside the wheel path.
2. Measure the amount of deformation as the difference between the foundation at (A) and the height of the blocks at (B).
Note
Ruts that develop under construction traffic shall nowhere exceed the following limits:
(i) All bound surfaces – 10 mm;
(ii) < 250 mm design thickness of granular material – 30 mm; and
(iii) ≥ 250 mm design thickness of granular material – 40 mm.
