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A WSB 701 Xenia Avenue South I Suite 300 I Minneapolis, MN 55416 I (763) 541-4800 December 27, 2016 Mr. Bruce Westby P.E. City Engineer 7550 Sunwood Drive NW. Ramsey, MN 55303 Re: Pavement Evaluations and Recommendations for City of Ramsey Improvement Project #17-01 2017 Alpine Drive Reconstruction Observation: On December 20, 2016 WSB & Associates cored Alpine Drive from Variolite Street to Armstrong Blvd in the City of Ramsey, MN. This pavement was constructed in the early 1990s and suffers from severe cracking and tenting during cold weather. A geotechnical report had been completed earlier and did not clearly define the cause of the cracking and tenting. The goal of the additional coring was to try to determine why the pavement cracked and tents so severely and to make recommendations on what to do to reconstruct the pavement. As we cut thru the hot mix asphalt (HMA) at the first core site we observed a white to cream color slurry coming out of the core hole. Once the core was removed we observed in the bottom of the core hole what appeared to be concrete material. We were able to core another 4 inches deeper and remove an intact core out of the base aggregate material. This material seemed like a lean concrete material. Photos of the cores are provided in Appendix B of this report. Base on the finding of the first core location we move to an area that the City personnel stated tented the worst and cut another core. We observed similar results to the first core location. We then cored two more locations evenly spaced to make sure that similar materials were used the length of the project. All the cores taken had similar base materials observed under the HMA. It appears that when the pavement was originally constructed the contractor used crushed recycled concrete for the Class 5 base materials. Based on observations, it appears that not enough sand was blended into the recycled concrete to keep it from rehydrating and forming a weak concrete pavement. This type of material can be prone to swelling when permeated with water causing abnormal cracking and a very rough driving surface when below freezing. All of the Hot Mix Asphalt (HMA) cored were approximately 4 inches in thickness. Recommendations: Based on the information above, our recommendation would be to do full depth reclamation (FDR) of all the HMA pavement into the Class 5 recycled concrete material to lean out the existing recycled concrete materials to make it less prone to cracking and swelling. Once the FDR has been completed then 4 or 5 inches of the newly reclaimed materials would be removed and hauled off to make room to repave the HMA over newly compacted recycled aggregate base materials. Based on the traffic levels we would recommend paving it with 4 to 5 inches of SPWEA340C Super Pave. We would recommend priming the reclaimed materials with penetration emulsion prime to help reduce water infiltration into HMA. Please let me know if you have any other questions of comments regarding this report. Sincerely, WS & Associates, inc. Thomas J. Wood Project Manager Building a legacy — your legacy. Equal Opportunity Employer I wsbeng.com W.1aly of remseyVkpiine Drive recommendation 12.27.16 (mai.docx