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City of Arden Hills <br /> Project BL-12-05201 <br /> September 28, 2012 <br /> Page 4 <br /> ■ Following pavement removal, we recommend removing the remaining materials to a total depth <br /> of approximately 10 inches below final grade and fine grading the site to accommodate the <br /> recommended pavement section. <br /> ■ Some conditioning (wetting or drying)of the subgrade soils may be necessary to facilitate <br /> compaction. We recommend compacting the subgrade to 100 percent of the standard Proctor <br /> density. <br /> ■ Following compaction,we recommend proofrolling the subgrade with a loaded tandem-axle <br /> dump truck under the direction of a geotechnical engineer. The proofroll will help reveal areas <br /> that are soft or weak and require additional compaction and/or removal and replacement. For <br /> areas showing excessive surface deflection,we recommend that the subgrade be subcut an <br /> additional one foot and backfilled with MnDOT select granular borrow(MnDOT Specification <br /> 3149.2B2)and compacted to 100 percent of the standard Proctor density. A final proofroll <br /> should follow the correction. <br /> ■ For the new pavement section, we recommend that 6 inches of aggregate base be installed on <br /> the subgrade and that the aggregate base material meet the requirements for Class 5 Aggregate <br /> Base per MnDOT Specification 3138. We recommend that the bituminous paving be done in <br /> two lifts; 11/2 inches of non-wear course and 2 inches of wear course. Compaction of the <br /> bituminous should follow MnDOT specifications 2360. <br /> Pavement Reclamation <br /> Pavement reclamation options include full-depth reclamation (FDR)or cold-in-place recycling(CIR). For <br /> full-depth reclamation, a sufficient depth of both asphalt and aggregate base material are typically <br /> needed. Based on the boring results, only two of the six boring locations noted the presence of <br /> aggregate base material. In our opinion, additional borings or hand augers would be warranted to <br /> determine the feasibility of FDR. <br /> Remarks <br /> Our evaluation,analyses and recommendations were based on the information provided to us by the <br /> City and Element Materials Technology. Samples were not collected or reviewed by Braun Intertec. <br /> This report is for the exclusive use of the parties to which it has been addressed. Without written <br /> approval,we assume no responsibility to other parties regarding this report. Our evaluation,analyses <br /> and recommendations may not be appropriate for other parties or projects. <br /> BRAUN <br /> INTERTE : <br />