GJN4579 Pavement Srvcs Contract #2009-00237

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` Matt Rodrigues December 11, 2008 Page 4 dynamic cone penetrometer (PDCP), which is a manually operated device far measuring penetration resistance of soil. The following laboratory tests will be conducted on bulk soil samples from W 13'" and W 18'" [o evaluate their plasticity, compaction characteristics and compacted resilient modulus: • Atterberg Limits determinations (up to 4 soil samples) • Standard Proctor moisture-density relationship (compaction curve) of subgrade soil (2 sample curves) • Laboratory resilient modulus of subgrade soil samples compacted to 95% of standard Proctor maximum density (2 sample tests) Laboratory testing will be conducted on recovered samples of AC and AB from borings in W 18`" [o determine the appropriate cement content for in-place cement stabilization. The testing work will consist of one laboratory compaction test and duplicate compressive strength test specimens of cement- treated mixtures at 4 cement contents for determination of 7-day compressive strength. Pavement Visual Survey We will visually survey the pavement [o identify locations such as areas of medium to high severity alligator cracking distress and/or rutting distress where pavement repair may be necessary in preparation for the recommended rehabilitation work. The results of the visual survey will be graphically mapped and the areas where preparatory pavement repair work is required will be tabulated in the destgn report. Pavement Analysis & Report Truck and bus traffic data provided by the Ciry will be analyzed to develop estimates of the cumulative Equivalent 18,000-pound Single Axle Load (ESAL) repetitions during the design period. Backcalculation analysis of the FWD test data will be accomplished in general accordance with the guidelines of ASTM D5858 using our PAYBACK software. Pavement design analysis will be accomplished in accordance with the procedures of the 1993 AASHTO Guide for Design of Pavement Structures (AASHTO Guide) and the December 2007 ODOT Pavement Design Guide (ODOT Guide). Overlay thickness and/or inlay depth will be analyzed for each FWD test point using our PAVCALC software. The results of the point by point overlay/inlay analysis will be used to delineate boundaries of segments (work units) having significantly different structural conditions. Design recommendations will be developed for inlay, deep milling, partial depth reconstruction on existing base or reconstruction as appropriate for the project conditions. Alternative reconstruction designs will be developed for W 13'" and W 18`" utilizing in-place recycling of existing AC and AB with portland cement stabilization (W 18'" only since W 13'" has PCC base), conventional AC on AB, full depth AC, "perpetual" or "long life" AC, aggregate `cut and cover" stabilization of subgrade in lieu of compaction and PCC pavement. We will prepare technical memorandum reports for each project to present .our findings and recommendations. These reports will include design documentation, distress maps, core logs and photos of the core samples. The effective structural number of the existing pavement and the overlay and/or inlay requirements (based on the traffic loading) for each test location will be plotted versus the street stationing and included in the design reports. Field Review Meeting We have assumed one meeting with City staff for field review of the projects. Project Schedule We can begin work within 1 week of your notice to proceed. Based on receipt of traffic data by February 2009, drafts of the technical memorandum reports for each project will be submitted during March 2009 in the order of priority indicated in Table 1 as they are completed. Our final report incorporating review comments on the draft technical memorandums will be submitted by April 30, 2009.