Based on conversations with WSP personnel, the following items require Paterson s review:

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1 consulting engineers memorandum to: RR Ltd - Mr. Jonah Bonn - jbonn@firstbay.ca to: WSP - Mr. James Johnston - james.johnston@wsp.com re: Parking Lot Rehabilitation Pavement Structure Recommendations Robertson Road - Ottawa date: August 3, 2017 file: from: PG4080-MEMO.01 Faisal I. Abou-Seido As requested, Paterson Group (Paterson) prepared the following memorandum to provide an updated pavement structure recommendations for the parking lot rehabilitation program provided in Paterson Report PG4080-LET.01 dated April 18, The present recommendations provided in this memo will supercede our previous pavement structure recommendations. Background Information Based on conversations with WSP personnel, the following items require Paterson s review: Item 1: Limiting the asphalt replacement to areas where the grade is changing and/or new curbs and islands are proposed. Item 2: Limiting the sub-excavation within the areas where a crushed stone layer with a sufficient thickness is present below the existing structure and use the material as a replacement to the proposed Base/Subbase layers. Item 3: Whether the existing pavement within the east side of the building is sufficient for the proposed heavy truck parking area. As part of this assessment, Paterson has also reviewed the available historical information of the subject site. Based on the aerial photos, the majority of the existing parking area has been in place between 30 to 40 years. Paterson has completed a site visit on August 2, 2017 to assess the existing pavement structure within the areas to be modified as part of the new construction. Based on observations, the majority of the parking area was noted to be in fair to good condition. The parking lot was observed to suffer from moderate transverse and longitudinal cracking throughout. It should be noted that signs of vegetation growth were observed along the pavement cracking within the proposed heavy truck loading areas and the proposed drive-thru lane northwest of the subject site. Patching work was also observed in scattered locations throughout the parking lot. No excessive rutting or ravelling was observed during our site visit. Photographs taken during our site visit are attached to the present report.

2 Mr. Jonah Bonn Page 2 PG4080-MEMO.01 Geotechnical Recommendations Based on our review of the available information along with the results of the borehole coverage and the pavement structure site assessment, the existing pavement structure can be left intact for car only parking areas where no excessive cracking was observed. It should be noted that where the pavement is showing indications of deterioration or cracking, it is recommended that the pavement structure be replaced at those locations. For heavy truck parking areas, drive-thru lane and access lanes, it is recommended that the pavement structure be replaced. Areas deemed in poor condition and subject to pavement structure replacement are indicated in the attached Drawing PG Test Hole Location Plan. For pavement replacement from a geotechnical perspective, the existing crushed stone in place below the existing asphalt surface can be used as a subbase layer only provided proof rolling of the material using a vibratory roller making several passes and inspected by Paterson personnel at the time of construction is successfully completed. However, the granular base layer and asphaltic concrete are recommended to be replaced as per the original recommendations in the above noted report. It should be noted that due to the age of the existing pavement structure, it is expected that fines have migrated through the existing crushed stone fill. Therefore, if the existing crushed stone is used as a subbase layer, the overall life cycle of the new pavement structure may be significantly reduced and signs of deterioration may appear in a shorter period of time than a new full pavement structure. Site Grading and Preparation Topsoil and deleterious fill, such as, those containing organic material should be stripped from under any paved areas or other settlement sensitive structures prior to placing fill. Fill used for grading beneath the pavement granulars should consist of clean imported granular fill, such as Ontario Provincial Standard Specifications (OPSS) Granular B Type I or II. These materials should be tested and approved prior to delivery to the site. The fill should be placed in lifts no greater than 300 mm in thickness and compacted using suitable compaction equipment for the lift thickness. Fill placed below the pavement subgrade level, beneath the paved areas, should be compacted to at least 98% of its standard Proctor maximum dry density (SPMDD).

3 Mr. Jonah Bonn Page 3 PG4080-MEMO.01 New Pavement Structure Where the proposed pavement structure meets the existing asphalt surface, the following recommendations should be followed: A 300 mm wide section of the existing asphalt roadway should be saw cut from the existing pavement edge to provide a sound surface to abut the proposed pavement structure. It is recommended to mill a 300 mm wide and 40 mm deep section of the existing asphalt at the saw cut edge. The proposed pavement structure subbase materials should be tapered no greater than 3H:1V to meet the existing subbase materials. Clean existing granular road subbase materials can be reused upon assessment by the geotechnical consultant at the time of excavation (construction) as to its suitability. Pavement Structure Drainage Satisfactory performance of the pavement structure is largely dependent on keeping the contact zone between the subgrade material and the base stone in a dry condition. Failure to provide adequate drainage under conditions of heavy wheel loading can result in the fine subgrade soil being pumped into the voids in the stone subbase, thereby reducing its load carrying capacity. The subgrade soil will consist predominantly of either silty sand to sandy silt or firm silty clay. In this regard, the pavement granulars should be extended full width and the subgrade shaped to promote drainage towards the side ditches or to subdrains installed at the catch basis as per City of Ottawa standards. Field Review It is recommended that Paterson inspect all compaction and bearing surface exposure to provide immediate recommendations during the construction phase of the subject parking area and drive-thru lanes. Any soft areas or poor performing areas should be sub-excavated and replaced with OPSS Granular B Type II and compacted to minimum of 98% of the material s SPMDD. Due to the absence of any borehole coverage within the west portion of the site, it is recommended that Paterson complete a site review at the time of excavation to assess the existing fill beneath the proposed drive-thru lanes and provide on-site recommendations.

4 Mr. Jonah Bonn Page 4 PG4080-MEMO.01 We trust that this information satisfies for your requirements. Best Regards, Paterson Group Inc. August 3, 2017 Faisal I. Abou-Seido, P.Eng. David J. Gilbert, P.Eng. Paterson Group Inc. Head Office and Laboratory Northern Office and Laboratory St. Lawrence Office 154 Colonnade Road South 63 Gibson Street 993 Princess Street - Suite 100 Ottawa - Ontario - K2E 7J5 North Bay - Ontario - P1B 8Z4 Kingston - Ontario - K7L 1H3 Tel: (613) Fax: (613) Tel: (705) Fax: (705) Tel: (613)

5 Photo 1: Slight to moderate longitudinal and transverse cracking with vegetation growth, moderate raveling and slight depression noted in north parking area. Photo taken facing west. Photo 2: Slight to moderate longitudinal and transverse cracking and moderate raveling noted in rear parking area. Photo taken facing east.

6 Photo 3: Slight to moderate longitudinal and transverse cracking noted in rear parking lot. Photo taken facing south. Photo 4: Slight raveling noted in rear parking area. Photo taken facing east.

7 Photo 5: Moderate raveling and slight to moderate longitudinal and transverse cracking (partially sealed) noted on truck access route. Photo taken facing southwest. Photo 6: Moderate longitudinal and transverse cracking with associated moderate alligator cracking, moderate raveling and slight depression noted on truck access route. Note also the sidewalk panels in poor condition. Photo taken facing south.

8 Photo 7: Slight transverse cracking noted in south parking area. Photo taken facing south. Photo 8: Moderate longitudinal and transverse cracking noted surrounding patching around catch basin. Photo taken facing north.

9 Photo 9: Slight to moderate longitudinal and transverse cracking noted surrounding sawcut in pavement. Photo taken facing southeast. Photo 10: Moderate to severe longitudinal and transverse cracking and slight raveling noted in south parking area. Photo taken facing north.

10 Photo 11: Moderate longitudinal and transverse cracking and slight depression noted in south parking area. Photo taken facing south. Photo 12: Slight to moderate longitudinal and transverse cracking and slight depressions noted in south parking area. Photo taken facing southeast.

11 Photo 13: Moderate to severe longitudinal and transverse cracking with associated moderate alligator cracking noted in south parking area. Photo taken facing south. Photo 14: Moderate to severe longitudinal and transverse cracking and slight depressions noted in south parking area. Photo taken facing northwest.

12 Photo 15: Severe raveling and moderate to severe transverse cracking noted in truck loading area. Photo taken facing west. Photo 16: Moderate raveling and moderate alligator cracking noted in truck loading area. Photo taken facing northeast.

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