Observations/Finding

At the request of the client’s representative, our AS ENGINEERING AND CONSULTING, LLC (ASEC) representative, Amin Azimi, visited the job site to observe the contractor’s work activities from a quality assurance standpoint. The purpose of the visit was to verify compliance with project drawings, specifications, applicable codes, approved material submittals, and to conduct QC testing in accordance with project requirements.

Observations for This Shift:

Compaction Testing: Compaction testing was performed on the Taxiway between STA 79+00 to 86+00 using a Troxler nuclear density gauge, supplemented by general probing with a 3/8″ diameter probe rod. The density test results indicated that most of the compacted materials did not meet the project requirement of achieving a minimum of 100% of the maximum dry density, in accordance with ASTM D1557 (Modified Proctor).

Proof Rolling Observation and Performance: A second proof-roll was performed on Section 1A between STA 1020+00 to 1028+00 on Runway 3R-21L using a fully loaded tandem axle truck. This section had previously been treated with lime, mixed into the soil to a depth of approximately 10 inches. Multiple passes were made across the subgrade. During the proof roll, some yielding and deflection were observed in approximately 18 feet of the center portion of Section 1A, where movement was noted, indicating that the subgrade soils in this area still showed poor stability.

Recommended Corrective Action: It was recommended to undercut 12 inches of the soft, unstable area and replace it with graded aggregate base (GAB) to achieve the required stability.

Additional Personnel Present: The proof-roll was jointly performed and observed by the undersigned (Amin Azimi), James/Nova (QA Representative), and Brad (CWM Representative).

We appreciate the opportunity to be of service on this project. Should you have any questions regarding this report, please do not hesitate to contact us. We would be pleased to discuss our findings further.