Category:209 Subgrade Preparation
209.1 Construction Inspection Guidance for Sec 209
Description (Sec 209.1)
Construction Requirements (Sec 209.2)
A stable grade is essential and it can be secured only if adequate attention is given to surface drainage. Water pockets create soft or spongy spots in the subgrade and unfit for pavement. Inspect the rolling operation. If the subgrade is pumping, cracking or is showing other signs of failure, determine the magnitude of the failure and take corrective action to address the problem. Rutting produces areas of deficient thickness and results in a poorly draining base course and unsuitable foundation for a pavement. Unstable areas should be corrected by aeration, further compaction, or in extreme cases, by removal and replacement of unsatisfactory materials. Before beginning the work of preparing roadbed and/or subgrade for placement of base, the entire roadway should be carefully checked to see that earthwork conforms to the required cross section and grade within the specified +/- ½” tolerance. Perform the required density tests. The grading inspector should at all times be sure that minimum density requirements are being met and that compactive effort is uniform. All checks made and test results obtained should be properly documented.
Basis of Payment (Sec 209.3)
No direct payment will be made for subgrade preparation.