Revised September 10, 2018 August 29, Mr. Steve Johnson City of Frederick Parking Department Two South Court Street Frederick, MD 21701

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1 565 East Swedesford Road, Suite 300 Wayne, PA walkerconsultants.com Revised September 10, 2018 August 29, 2018 Mr. Steve Johnson City of Frederick Parking Department Two South Court Street Frederick, MD Re: Condition Appraisal Report for Church Street Parking Garage Two South Court Street, Frederick, MD Project Number Dear Mr. Johnson: Walker Consultants is pleased to submit for your review the Condition Appraisal Report for the above project. If you have any questions regarding this report, please feel free to contact me. Thank you for the opportunity to serve you. Sincerely, WALKER CONSULTANTS Jason C. Gross, P.E., LEED AP Project Manager

2 CONDITION APPRAISAL REPORT CHURCH STREET PARKING GARAGE Frederick, Maryland Revised September 10, 2018 August 29, 2018 CITY OF FREDERICK

3 CONDITION APPRAISAL REPORT TABLE OF CONTENTS EXECUTIVE SUMMARY ii 1 - INTRODUCTION 1 Objective 1 Facility Description 1 Background Information RECOMMENDATIONS 2 Immediate Repairs 3 Repair Options 3 Future Preventive Maintenance 5 Benefits of a Timely Remediation 6 Opinion of Probable Constriction Costs DISCUSSION 9 Topping Slab 10 Precast Haunch 11 Waterproofing System SUMMARY 13 Observations 14 Material Testing 15 Analyses LIMITATIONS 18 APPENDICES APPENDIX A - Opinion of Probable Repair Costs APPENDIX B Photographs APPENDIX C Chlorides/ Material Testing APPENDIX D Scope of Services WALKER CONSULTANTS i

4 CONDITION APPRAISAL REPORT EXECUTIVE SUMMARY Walker Consultants conducted a condition assessment of the Church Street Parking Garage to evaluate the existence and nature of distress in various elements of the structure and develop an overall plan for implementation of repairs. The evaluation team compiled the condition assessment information and developed two repair options outlining our recommendations for a 10 yr and 20 yr repair program. The Church Street Parking Garage is in fair condition overall. A restoration program was performed in 2010, which completed repairs to the concrete topping, columns, beams and other framing members. Waterproofing systems were also repaired. Since those repairs, deterioration has continued, and we found the following key concerns: 1. Cracked haunch 2. Deteriorated concrete framing members 3. Delaminated and debonded topping 4. Scaled concrete 5. Cracked/broken capstone 6. Expansion joint failure 7. Failed joint sealant and unsealed joints 8. Deteriorating CMU 9. Open and eroded masonry joints 10. Corroded metal stairs and door frames 11. Rusted drainage piping We have developed two repair options to address these concerns through either a medium and long-term program. The costs for the two repair programs are provided in Table 1. For a budgetary comparison, our opinion of the probable construction cost to demolish and replace the Church Street Parking Garage with one of similar construction and size is $9.7 million. A CIP concrete post tensioned structure typically costs 5% to 10% more than a precast garage. The cost increase is dependent on project location, economic factors, etc. A study could be provided to determine the life cycle costs of both a precast concrete and CIP concrete P/T structure. The expected lifespan of a new deck would be 40+ years. Please see the attached discussion for a detailed report of our investigation. TABLE 1 SUMMARY OF REPAIR OPTIONS OPTION LIFESPAN REPAIR COSTS REPAIR COST /SF REPAIR COST/ REPLACEMENT COST Option 1 10 yrs. $1,210,000 $ % Option 2 20 yrs. $3,782,000 $ % The budgeted costs are in 2018 dollars and do not include soft costs such as lost revenue and other financial costs. In Option 2 approximately $1.3M of repairs do not need to be completed in 2018 and can be deferred approximately 8 years. WALKER CONSULTANTS ii

5 CONDITION APPRAISAL REPORT Please see the attached discussion for a detailed report of our investigation. Jason C. Gross, P.E., LEED AP Project Manager August 29, 2018 Revised September 10, 2018 Date WALKER CONSULTANTS iii

6 Introduction 01 Section

7 CONDITION APPRAISAL REPORT INTRODUCTION Representatives of Walker Consultants visited the Church Street Garage in Fredrick, Maryland on June 7, The following identifies our findings and recommendations for this garage. OBJECTIVE This report is intended to provide a general professional opinion of the conditions at the Church Street Parking Garage and identify two repair programs based on a medium and long-term extension of service life. Details of our observations for the garage are summarized in the following sections. These findings were used to develop an opinion of probable cost to repair the garage and provide preventive maintenance for key elements. Detailed cost estimates are included in Appendix A. FACILITY DESCRIPTION Built in 1975, the Church Street Garage is a four and half level parking garage. Vehicle circulation within this garage is one-way utilizing a double helix design with crossovers at every level. Vehicles can enter from Church Street or via an alley off of North Market Street. All traffic exits onto Church Street. Stair towers for pedestrian circulation are provided at the adjacent to the two entries and at approximately the center of the east elevation. A single elevator is provided off of Church Street. The typical level of the Church Street Garage occupies approximately 31,000 square feet with a total supported area of approximately 102,000 square feet. The slab-on-grade is approximately 31,000 square feet for a total building square footage of 133,000. The structural system of the garage consists of precast double tee floor beams spanning between precast spandrel beams. Spandrel beams are supported by precast columns. The slab of the supported levels is comprised of a three-inch cast-in-place concrete topping over two-inch flange of precast concrete double tee beams. Stair and elevator towers are constructed of concrete block with a brick veneer that are structurally isolated from the garage. BACKGROUND INFORMATION Walker was provided with the following documents: Original construction documents prepared by Conrad Associates which consisted of: o Civil Drawing C-1, o Architectural Drawings A1 thru A-16, o Structural drawings S-1 thru S-12, o Plumbing drawings P1 thru P8, o Electrical drawings E1 thru E-7. Restoration Condition Appraisal prepared by Desman Associates dated February Restoration Documents Titled Limited Repairs and Preventative Maintenance Church Street Parking Garage Fredrick Maryland dated December 2001 by Desman Associates. Drawings R1 thru R15. WALKER CONSULTANTS 1

8 Recommendations 02 Section

9 CONDITION APPRAISAL REPORT RECOMMENDATIONS The Church Street Parking Garage underwent a restoration program in 2010 that included repairs to the concrete topping slab, beams, columns, and waterproofing systems. As part of that program the majority of the sealant underwent replacement and a penetrating sealer was applied to the supported levels to reduce the rate of moisture and chloride passage and, therefore, reduce the rate of concrete deterioration. However, as with any parking structure, the Church Street Parking Garage requires certain repairs and maintenance to ensure of satisfactory future performance and service life. Below we have provided two repair options as well as immediate repairs for the structure. These options were developed to provide either a medium or long term repair program. For cost comparison, we have also provided our opinion of the cost to replace the garage. With any of the options, periodic repairs and maintenance will be required to achieve the expected service life. IMMEDIATE REPAIRS Immediate repairs are those items identified in our evaluation that require attention for reasons of structural integrity or operational safety. Knock down loose overhead concrete. Paint stair curbs yellow. Lower drain at slab-on-grade. Upgrade vehicular barricade systems on the top level. Install and upgrade pedestrian guardrail along perimeter opening at Level 1. At the time of this evaluation, we noted a severely cracked column haunch on the fourth level soffit at column E7. This condition was reported to on-site personnel at the time of the survey. The area beneath this haunch, including lower levels, are currently shored and cordoned off until the haunch is repaired. REPAIR OPTIONS The repair program implemented in 2010 addressed a significant amount of the deterioration to floor and framing members and included waterproofing the top level and replacing joint sealants. The joint sealant and concrete sealer offered some protection. However, sealing all cracks is problematic as some cracks may not be visible during construction or may develop after construction, and the sealant has a useful life of 7-10 years. We observed isolated failures of the sealant over the majority of joints indicating an age-related loss of elasticity and adhesion. The ongoing passage of moisture has continued deterioration with large areas of topping deterioration and debondment along with deterioration of concrete framing members observed. In the development of our repair options, the following items served as the focus for the development of our repair options: Repair of structural framing Repair of the topping slab Install and replace waterproofing systems WALKER CONSULTANTS 3

10 CONDITION APPRAISAL REPORT Due to their critical nature both repair options include repairs to the structural framing members (i.e. columns, beams, walls) but differ in the approach and extent of repairs to the topping slab. Both the topping slab and waterproofing component of the repair options are based on the anticipated extension of service life. REPAIR OPTION 1 (LIFESPAN 10 YEARS) Repair Option 1 would limit structural floor repairs to spot patch existing areas of deterioration and delamination in the topping slab. This includes both full depth of the topping slab and full depth to the precast tee. Waterproofing repairs include sealing tee-tee joints, cracks, failed crack/joint sealant, vertical joints, and cove joints. New vehicular waterproofing membrane will be installed at Levels 2 and 3 as well as a recoat of the top level. Additionally, repairs to the masonry façade, building drainage and stair towers would be performed. Finally, painting of traffic markings, metal doors, frames and lintels to protect these elements while improving the overall aesthetics of the garage. This option is a medium-term solution to get a few more years out of the structure before another repair program or replacement project is implemented. As such a comprehensive waterproofing is provided. Slab joints and cracks would be routed and sealed to reduce moisture passage to reduce the rate of deterioration. REPAIR OPTION 2 (LIFESPAN 20 YEARS) Repair Option 2 provides a long-term repair solution to restore the deteriorated slabs. This option includes a list of repairs to be performed now and a list of repairs that could be deferred until 2026 or so. Option 2 uses the strip patch approach which includes the complete removal and replacement of the topping slab of the end bays and crossover bays at levels 2 and 3. Given the marginal bond, moderate deterioration and heavy scaling of the floor surface at levels 2 and 3 requires replacement to provide a long-term extension to its service life. To protect the repairs, a comprehensive traffic coating system will be applied immediately in areas not including end bays and crossovers at levels 2 and 3 as well as a recoat of the top level. A traffic coating membrane system can be applied to the end bays and crossover bays at a later date since the concrete topping has been replaced. New waterproofing installation such as joint and façade sealants, drainage, and painting from Repair Option 1 are also included. We recommend replacing the entire stair tread, riser, guardrail system now to extend the life 20 years. All roof membranes in the stair towers along with the elevator will need to be replaced but could be deferred a few years. To extend the service life of the structure for 20 years the lighting and drainage systems will need to be replaced. These repairs can also be deferred for a few years. This option is a long-term solution to get a longer life out of the structure before another repair program or replacement project is implemented. As such a comprehensive waterproofing is provided. Slab joints and cracks would be routed and sealed to reduce moisture passage to reduce the rate of deterioration. WALKER CONSULTANTS 4

11 CONDITION APPRAISAL REPORT REPLACEMENT OPTION (LIFESPAN 40+ YEARS) This option assumes the existing parking structure is demolished and a new structure of approximately the same size is constructed. We assumed a precast concrete garage since in the Mid-Atlantic region it offers good durability and function at a competitive cost. Typical precast construction today uses pretopped double tees, which eliminates the need for a topping slab and the potential problems associated with it. FUTURE PREVENTATIVE MAINTENANCE Maintenance performed on a regular basis will take full advantage of the repairs and waterproofing work. Without maintenance, the facility will not see the expected service life from the structure or the repairs and waterproofing. Typical maintenance includes routine sealing of joints, recoating of wall coatings and floor membranes along with periodic concrete repairs. Funds for maintenance of the garage should be accrued yearly considering the life expectancies of certain elements such as sealants, coatings, floor membranes, concrete repairs, etc. The life expectancies expressed vary depending on workmanship, quality of materials, use and exposure to elements. After all the work is completed, the supported levels should be washed down at least twice a year. We have recommended the installation of urethane traffic topping to protect the concrete topping slabs. These waterproofing membranes are flexible enough to bridge the many micro-cracks and stop water and de-icing salts from entering the slab. These traffic toppings are subject to wear from automobile tire traffic and typically require installation of a new wear coat - overcoating at regular intervals. Typical overcoating is in drive lanes ever 5-10 years and in the drive lanes of turning bays every 3-7 years. For this particular garage, we would recommend you anticipate overcoating on the turning lanes every 3 years, drive lanes every 6-9 years, and the parking stalls every 15 years. Overcoating is considerably less expensive than the original coating, often in the range of $2.25 to $2.75 / s.f. under normal conditions. For expansion joint glands we recommend you anticipate replacement every 10 years. WALKER CONSULTANTS 5

12 CONDITION APPRAISAL REPORT BENEFITS OF TIMELY REMEDIATION There are many benefits to providing the repair and preventive maintenance program at the earliest feasible time, in addition to the imminent needs of providing the Immediate Repairs listed previously. Long-term delay of repairs significantly increases cost. The cost to repair and maintain this facility will continue to increase at progressively faster rates when deterioration continues as modeled in the following graph. The main benefits from implementing the recommended repairs and waterproofing are: o o o o o o o Arrest the infiltration of water and chlorides (from deicing salts) Maintain the structural capacity and maintain the service life for the structure. Cost savings due to avoidance of structural repairs that are more expensive and facility shutdown. Higher levels of service to the users of the facility due to fewer days of downtime because of more extensive structural repairs. Provides for a greater degree of safety by inhibiting deterioration mechanisms before they have a chance to cause serious harm. Long term delay of repairs significantly increases future costs. Less noise and disruption both within the garages and the buildings above. In the graph below, we have qualitatively identified the relative state of deterioration of the garages. Poor Garages are between points B and C Fair and Good Garages are between points A and B Short-term repairs (3-5 years) only move curve slightly Repaired Fair and Good Garages are between points B 1 and C 1 Long-term repairs (12 to 20 years) move curve considerably WALKER CONSULTANTS 6

13 CONDITION APPRAISAL REPORT OPINION OF PROBABLE CONSTRUCTION COSTS Most costs are determined by defining approximate quantities of differing work items and multiplying those quantities by the average unit price for the same work item from recent competitively bid projects. Once total work item costs are calculated, a series of multiplication factors are added to account for general condition, mobilization, engineering, material testing during construction and project contingency. The actual repair quantities will vary. Actual cost will vary on the bidding climate, actual scope of structural repairs, the amount of area captured for repair, and schedule of work. To address these variations within the opinion of the probable construction cost, we use each of the following different terms: contingency, quantity allowance and allowance. Their meanings are further described below. The term allowance is used for those items that are extremely difficult to approximate costs because the final scope is still undefined even though the item is identified, the repair is unusual and therefore has limited past pricing history, costs are heavily affected by regulatory or other variable constraints or the quantities are very small and common unit pricing is not applicable. The term quantity allowance is used for those items that are known to continue to deteriorate between the time of survey and the time of repair a time period that is typically between 12 and 18 months as well as for those items that often require additional removal at the repair boundaries to obtain sound structural connections. This addresses the variation in actual physical work from surveyed quantities. The term contingency is used for those items affected by contractual and bidding terms such as payment requirements, the local construction activity level (how busy contractors are), the contractor s opinion as to the fairness of the contract/design professional/owner, the bid period length and the contractor s internal economic forecast of future costs for materials and labor over the length of the contract. Therefore, in the development of repair options, allowance and contingency funds should be anticipated and included in any budget for repairs to account for concealed, unknown, or unanticipated conditions which may be encountered. For this type of restoration work, we have identified and included these potential changes in the opinion of probable cost. For a detailed breakdown of each work item, contingency, and allowance please see the spreadsheet in Appendix A. The cost estimate is based on current year dollars and future year expenditures should be increased by the anticipated inflation factor as appropriate. The potential for cost savings exists in having in-house staff perform some of the repair work. In particular, washing down the decks each year via power washing does not require a specialty contractor. On occasion, owners are willing to undertake installation of waterproofing items such as traffic topping or relighting if the total volume of work is deemed manageable. Please consider the following statement from the American Concrete Institute Committee 362, Repairing an existing deteriorated structure involves many unknowns, uncertainties and risks. Especially with regard to repair of chloride caused corrosion damage, the process is considered an extension of the useful life of the deteriorated structure. It is not equivalent to building a new structure with current technology. WALKER CONSULTANTS 7

14 CONDITION APPRAISAL REPORT Projections of both costs and life extension are based on beginning repairs and maintenance shortly and continuing with these actions on a consistent, regular basis. Deterioration will continue if not addressed, and the rate of deterioration may change and often the change accelerates if repairs are not promptly started or if maintenance is deferred. Addressing the deterioration now reduces the risk of dramatic growth in costs except for the year repair. See the Discussion section of this report for further detail. UNION OR OPEN SHOP LABOR The costs provided are based on open shop labor typical to our experience within Metro Washington, DC construction climate. SITE SPECIFIC IMPACTS The costs provided are based on the normal construction constraints which include but are not limited to: reasonable ability to make noise for at least 1 shift per day, work during the normal work week of Sunday night through Friday night, security constraints no greater than working in a typical publicly accessible environment, areas of construction of at least 150 parking spaces, for hydro-demolition a construction area footprint of at least 75 parking spaces on each level of the garage, no hazardous waste, and access to public water, sewer, and debris disposal. ADDITIONAL FISCAL CONSIDERATION The probable costs have been presented without consideration of the cost of money, inflation, opportunity costs, etc. As such, the program costs and respective repair terms should be evaluated with additional technical and fiscal judgment. For example, losses of revenue or providing alternate parking solutions during construction have not been included but may have a relatively substantial impact to the Opinion of Probable Construction Costs. WALKER CONSULTANTS 8

15 Discussion 03 Section

16 CONDITION APPRAISAL REPORT DISCUSSION The following discussion section provides further explanation into the survey findings to aide in understanding the nature and causes attributing to observed deficiencies, deterioration mechanisms, maintenance problems, and damage which form the basis of our recommendations. Refer to Appendix B for a brief photographic inventory of site conditions. TOPPING SLAB The floor system of the Church Street Parking Garage is constructed using a precast-prestressed concrete double tee beams with a composite three-inch field cast concrete topping. The long span and high capacity of this system is derived from steel strands that are placed in the formed stems of the double tee and prestressed to very high forces prior to placing the concrete. Once the concrete has gained sufficient strength the stands are released exerting compressive forces on the stems of the double tees. The tees are delivered to the site and erected in a similar fashion to structural steel. At the edges of the double tee flanges, steel connector plates are welded together to connect framing members. A field cast composite topping is then cast over the tee beams. This topping is grooved over each precast tee joint and sealed to prevent moisture passage. In terms of durability, the advantage of this system is the primary reinforcement is in the stems of the double tees far removed from moisture and chlorides brought into the garage on vehicles and used as deicing agents. The disadvantages are the miles of joint sealant between double tees that have to be maintained and lower quality concrete mixes used for the topping concrete. Deterioration commonly occurs at the steel connectors along the precast joints and delamination or debondment of the field cast topping as a result of moisture and chlorides penetrating the concrete topping and joint sealants. Material testing shows that carbonation is high in the top 1 of the concrete topping. The presence of carbonation will accelerate the corrosion process as the concrete deteriorates. As part of our appraisal, a chain drag survey was performed over approximately 20% of the supported areas. This chain drag survey consists of dragging light handheld chains over the supported floor surfaces; the audible differences denote questionable conditions. Our survey found two types of deterioration: small areas of corrosion induced spalling and large areas of debonded topping. The corrosion induced deterioration was typically located around previous repairs. This is common as chlorides remain in the unrepaired concrete. The addition of a joint between the repair and existing concrete can offer a conduit for chloride laden moisture to reach the reinforcing continuing corrosion of the unrepaired reinforcing while introducing chlorides into the repair concrete. In addition, the sounding of levels 2 and 3 topping indicated localized debondment of the topping. Potentially larger areas of debonded topping were also identified in our chain drag survey. These areas ranged in size to several square feet of localized debondment. The three cores extracted from Levels 2 and 3 showed that the topping was debonded from the precast concrete. The debondment is likely due to moisture penetrating through cracks or embedded conduit to the bond line of the topping and freezing. The resulting expansion force from the moisture freezing causes the topping to de-bond adjacent to the cracks. Another deterioration mechanism related to the debondment of the topping is the deterioration of the embedded steel connections between precast members. Precast systems place many of the embedded steel WALKER CONSULTANTS 10

17 CONDITION APPRAISAL REPORT connections on this bond line to speed up construction by reducing overhead welding. These connections are covered by the topping slab. Since concrete is naturally porous, wetting and drying cycles allow chlorides to penetrate into the concrete. In a dense, low water/cement ratio concrete it can take years for the chloride to penetrate through the topping to start corrosion. At this garage, testing of the slab indicates the level of chlorides to be well above the threshold to start corrosion. Additionally, the cracks and joints have allowed moisture and chlorides direct access to the bond line between the precast tee flange and concrete topping to cause deterioration of the steel connections. The topping at the flat end bays on levels 2 and 3 is also show signs of scaling. Please refer to Appendix C for material testing results for chloride content and petrographic analysis. It should be noted, that since this topping is meant to act compositely with the precast tee below, debondment of the topping slab from the precast tee flange could cause an overstressed condition in the flange of the tee beams. However, it is our understanding that a structural analysis was performed in conjunction with a previous condition appraisal report, not by Walker Consultants, that indicates the precast tees could support the loads imparted to the structure with the topping debonded. PRECAST HAUNCH There is one haunch on the top level of the garage that had a large vertical crack on either side. The owner was notified of this condition during our site visit. The haunch has been shored by CPR contractors. Review of existing drawings show there are to be two steel beams embedded in the haunch. CPR was directed to partially demo the haunch to verify these steel beams exist along with their condition. It is our understanding that this work has not yet been completed. WATERPROOFING SYSTEM The occasional debondment and the presence of moisture under the topping slab indicates the overall waterproofing system of the garage is in fair to poor condition. As discussed above, maintaining the water tightness of the supported floors is key to the long-term durability of this structure. The waterproofing measures for this garage consist of flexible joint sealant installed in control joints grooved into the topping slab over every precast to precast joint during construction. In general, these seals are in fair condition, but they are showing signs of age-related deterioration in the form of crazing on the joint surface and isolated adhesion failures indicating they are at the end of their service life. Additionally, there are many cracks throughout the topping slab. The previous repair package included application of a traffic coating membrane on the top level and penetrating sealer (water repellent) on the covered levels to reduce moisture and chloride passage into the slab. The traffic membrane typically needs to be recoated every 7-10 years and the sealer typically reapplied every 3-5 years to maintain effectiveness. Since sealers do not span cracks, the unsealed cracks and failed joint sealants observed allow moisture passage into the slab. To extend the service life of this garage we recommend applying a traffic membrane system on levels 2 and 3 to protect the precast structure and topping from further water infiltration and corrosion. ARCHITECTURAL / MEP / MISCELLANEOUS Any low points in the garage can be susceptible to ponding. Ponding allows water to penetrate micro-cracks throughout the concrete slab which can then accelerate deterioration during freeze-thaw cycles. Additionally, WALKER CONSULTANTS 11

18 CONDITION APPRAISAL REPORT these ponds become a serious safety issue at freezing temperatures as these ponds can then become ice patches. Prompt action to abate the ice would be required by management. The lack of drains also requires the salt-laden slush brought in by automobiles to pond on the slab rather than quickly drain off into the sewer system. This requires the salts to percolate into the slab accelerating deterioration. Ponding was also observed at existing drains, specifically around the middle stair tower curbs. All drains need to be unclogged. The façade consists of brick at all stair towers and North and South elevations of the garage. There are many masonry joints that need to be tuckpointed. Concrete spandrel panels exist along the upper levels of the East and West elevations with a CMU wall along the lowest level of the West elevation. The bottom row of CMU is deteriorating and needs to be replaced. The north stair tower has bridges extending from the stair to the garage. The bridge is attached to the stair tower. On levels 2 and 3 there is little to no gap between the bridge and garage superstructure to allow for lateral movement on these levels. We recommend saw cutting the edge of the bridge slab and parapet walls to provide a gap and install a proper expansion joint, similar to the current condition on the top level. Along the east side of the garage, toward the north end, the exterior grade is greater than 30 above the SOG and requires a guardrail per code. A pedestrian guardrail exists only along the west side of the garage, adjacent to Brewer s Alley but does not meet current code requirements for a proper guardrail. This guardrail needs to be modified or replaced to meet current code requirements. The vehicular barricade on the top level of the garage consists of two highway barriers stacked on top of one another. This system does not meet current code requirements for pedestrian protection, gaps are greater than 4, nor for vehicular loading. Vehicular barricades need to be 2-9 high to resist impact loads per code. We recommend upgrading this system to meet proper code requirements. WALKER CONSULTANTS 12

19 Summary 04 Section

20 CONDITION APPRAISAL REPORT SUMMARY The following is a summary of key visual observations and compiled information from the site survey performed on the garage. Refer to Appendix B for a photographic inventory of representative conditions documented during the survey. OBSERVATIONS STRUCTURAL ITEMS: A representative chain drag identified numerous concrete slab delamination throughout the supported levels. Numerous floor spalls were observed throughout the garage. Slab repairs that were previously completed were also found to be delaminating (See Photo 1). Typical concrete scaling of field-cast slab at end bays of supported levels (See photo 2). Isolated spalling at conduit with minimal concrete cover of less than 1 ½ (See Photo 3). Typical spandrel panel spalling at roof level and occasional at lower levels (See Photo 4). Occasional column spalling at roof level (See Photo 6) Occasional soffit spalling and leaching at precast tee flange (See Photo 7). Concrete slab soffit deterioration and spalling is found at tee-tee joints, more typical at shear connections (See Photo 8). Typical concrete spalling and deterioration around floor drains with rusted elbows (See Photo 9). Occasional spalling and leaching at edge of slab on the partial fourth level soffit with minimal concrete cover (See Photo 10) Typical concrete wall and beam spalling throughout garage on most levels (See Photo 11). Occasional flexural cracking of spandrel beam below spandrel panel walls (See Photo 12). Occasional precast tee stem spalling by stair tower due to impact/damage (See Photo 13). Occasional cracking and deterioration of precast tee stem. Other localized tee flange spalling at previous patch repairs in between tee-tee joints (See Photo 14). Isolated column haunch failing at column E7 of the fourth level. The column haunch is currently shored at all levels to slab on grade until adequate repairs are made (See Photo 15). Occasional wall spalling along exterior façade along grade. Isolated hole along façade should be filled (See Photo 16). ARCHITECTURAL / MEP / MISCELLANEOUS ITEMS: Missing vertical expansion joint between brick façade of stair tower and spandrel wall of the garage on some levels (See Photo 17). Typical cracked CMU wall in stair towers and at slab on grade wall (See Photo 18). Typical metal stairs rusted/corroded and needs to be prepped and repainted or eventually replaced for long term repair option (See Photo 19). Typical door frame rusted/corroded and needs to be prepped and repainted (See Photo 20). Isolated door closer is broken at Level 1 front entrance and needs to be replaced. Typical door lintels are rusted/corroded (See Photo 21). Stair nosings should be painted yellow for better visibility to avoid potential trip hazards for pedestrians (See Photo 22). WALKER CONSULTANTS 14

21 CONDITION APPRAISAL REPORT Brick joints along exterior façade of garage and stair tower are open and eroded (See Photo 23). Typical cracked masonry joints at Level 1 slab on grade CMU wall (See Photo 24). Occasional CMU wall deterioration at Level 1 slab on grade CMU wall from flooding. Some CMU bricks need repainting (See Photo 25). Deteriorated CMU wall along façade along sidewalk (See Photo 26). Occasional cracked and broken capstone along perimeter wall need replacement. Typical failing capstone joint sealing at roof level also needs replacement (See Photos 27 & 28). Occasional failed traffic topping at roof level needs a recoat or replacement. Curbs at stair towers need to be repainted (See Photo 29). Typical expansion joint is dirty and/or failing (See Photo 30) Typical drain is raised and clogged with debris. Drains need to be lowered and unclogged for adequate drainage (See Photo 31). Occasional areas of ponding are located at the fourth and partial fourth levels that need supplementary drainage (See Photo 32). Vehicular and pedestrian guardrail not per ADA code for barrier spacing and height. Gaps are greater than the 4 requirement and the height is lower than the requirement (See Photos 33 & 34). Pedestrian guardrail is not provided as fall protection along the perimeter wall of the first level (See Photo 35). MATERIAL TESTING: During our site visit on June 7 th, three samples were taken in the garage and were used for chloride testing. The samples were taken on the second and third levels in varying locations on the supported concrete slabs as shown in Appendix C. The samples were sent to Universal Construction Testing (UCT) for chloride sampling. Copies of the complete testing results are found in Appendix C. During our site visit on July 20 th, two samples were taken in the garage and used for petrographic analysis. The samples were taken at end bays on both the second and third levels on the supported concrete slabs as shown in Appendix C. The core samples were sent to American Petrographic Services (APS) for petrographic analysis. Copies of the complete testing results are found in Appendix C. CHLORIDE ION TESTING Chloride ion content testing consists of extracting pulverized concrete dust samples from cores at one-inch increments. The samples are then tested for Water Soluble Chloride Content in accordance with ASTM Standard C1218. Chloride ion concentration testing provides information for determining whether a corrosive environment is present in the slab, especially at the depth of steel reinforcement. Chloride ions are a component of the salt used for de-icing roads, bridges, and parking structure surfaces. Chlorides are often deposited on the structural concrete from vehicles as they drive through and park in the structure and drop slush containing de-icing salts which then melts. The chlorides then diffuse into the concrete creating a corrosive environment. Concentrations of soluble chlorides between 280 ppm and 410 ppm are needed to initiate corrosion within the concrete. Higher chloride levels beyond 410 ppm increasing corrosion activity. WALKER CONSULTANTS 15

22 CONDITION APPRAISAL REPORT Sealant failures, concrete surface cracks, and the general porosity of concrete provide the avenue for chlorides to enter into the slab. The garage was found to have numerous cracks in the structural slab which is typical for a conventionally reinforced slab. The severity of cracking and lack of waterproofing sealants provides a direct path for soluble chlorides to reach reinforcement steel and eventually create the need for structural repairs. Although current chlorides within the concrete matrix cannot be removed, significantly limiting moisture infiltration will dramatically reduce necessary corrosion components (moisture and oxygen) to significantly reduce corrosion activity. Review of the chloride ion concentration test results indicates the chloride concentrations have reached corrosive levels. Chloride concentration levels from 2-3 concrete depth, past the depth of reinforcement, have reached corrosive levels in 2 of the 3 samples. Due to the high levels of chloride concentration we are recommending a traffic membrane system be applied to levels 2 & 3 to stop further water and chloride infiltration. Please refer to Appendix C for chloride ion content graphs showing the extent of deterioration by depth from the floor slab surface. Please refer to Appendix C for the exact locations of testing samples. PETROGRAPHIC ANALYSIS The core samples consist of 2 thick precast tee flanges with a 3 thick concrete field-topping. The field-topped slab and precast tee is debonded in both samples. Petrographic analysis is a microscopic evaluation of concrete to determine the quality and in situ conditions of the mix. The cores taken from the garage had a hardened concrete examination based on ASTM Standard C856 and an air void analysis based on ASTM Standard C457. The air content and void frequency in core samples were at the recommended limit of 5% to 7%. Cores 1 and 2 both had around 6% entrained air and had less than 1% entrapped air. Low air content in the garage is a concern when the concrete encounters significant freeze-thaw cycles. Being an open, above-grade garage, the garage structure experiences many freeze-thaw cycles. The water/cement ratio for the cores ranged from 0.53 to 0.58 for Core 1 and 0.55 and 0.60 for Core 2. Both samples had a relatively high water content with typical water/cement ratios ranging from 0.45 to 0.6 Carbonation was present in the top surface of both cores with depths ranging from about a 7/16 to 1-3/16. Carbonation was also present in the bottom surface of core 1 with depths up to 1/16. Some carbonation was also found between the topping concrete slab and precast concrete slab. This indicates water is reaching this bonded area, which can cause further deterioration within the slab. Surficial scaling will continue to be an issue in areas of carbonation since the concrete is exposed to moisture and freezing. To extend the service life of the concrete topping a waterproofing membrane needs to be applied, 10-year plan, or the concrete topping replaced altogether, 20-year plan. No other major issues were found in the cement paste or aggregates of the two cores examined. Please refer to Appendix C for complete petrographic testing descriptions. WALKER CONSULTANTS 16

23 CONDITION APPRAISAL REPORT ANALYSES The Church Street Parking Garage is considered to be in fair condition overall. The waterproofing components have reached the end of their service life and have allowed moisture passage through the topping slab. This moisture passage has continued to deteriorate the field cast topping slab and supporting precast double tee floor beams and other structural framing members. In order for this structure to remain serviceable for the long term, a comprehensive restoration program to restore watertight integrity, structural integrity, and protect this asset. Should the outlook for this site be replacement of this structure, short term repairs can be performed to maintain operations until the replacement project moves forward in the next 1-2 years. Our repair options are presented in the Recommendations section of this report. WALKER CONSULTANTS 17

24 CONDITION APPRAISAL REPORT LIMITATIONS This report contains the professional opinions of Walker Consultants based on the conditions observed as of the date of our site visit and documents made available to us by City of Frederick Parking Department (Client). This report is believed to be accurate within the limitations of the stated methods for obtaining information. We have provided our opinion of probable costs from visual observations, limited testing, and field survey work. The opinion of probable repair costs is based on available information at the time of our assessment and from our experience with similar projects. There is no warranty to the accuracy of such cost opinions as compared to bids or actual costs. This condition appraisal and the recommendations therein are to be used by Client with additional fiscal and technical judgment. It should be noted that our renovation recommendations are conceptual in nature and do not represent changes to the original design intent of the structure. As a result, this report does not provide specific repair details or methods, construction contract documents, material specifications, or details to develop the construction cost from a contractor. Based on the agreed scope of services, the assessment was based on certain assumptions made on the existing conditions. Some of these assumptions cannot be verified without expanding the scope of services or performing more invasive procedures on the structure. More detailed and invasive testing may be provided by Walker Consultants as an additional service upon written request from Client. The recommended repair concepts outlined represents current generally accepted technology. This report does not provide any kind of guarantee or warranty on our findings and recommendations. Our assessment was based on and limited to the agreed scope of work. We do not intend to suggest or imply that our observation has discovered or disclosed latent conditions or has considered all possible improvement or repair concepts. A review of the facility for Building Code compliance and compliance with the Americans with Disabilities Act (ADA) requirements was not part of the scope of this project. However, it should be noted that whenever significant repair, rehabilitation or restoration is undertaken in an existing structure, ADA design requirements may become applicable if there are currently unmet ADA requirements. Similarly, we have not reviewed or evaluated the presence of, or the subsequent mitigation of, hazardous materials including, but not limited to, asbestos and PCB. This report was created for the use of Client and may not be assigned without written consent from Walker Consultants. Use of this report by others is at their own risk. Failure to make repairs recommended in this report in a timely manner using appropriate measures for safety of workers and persons using the facility could increase the risks to users of the facility. Client assumes all liability for personal injury and property damage caused by current conditions in the facility or by construction, means, methods and safety measures implemented during facility repairs. Client shall indemnify or hold Walker Consultants harmless from liability and expense including reasonable attorney s fees, incurred by Walker Consultants as a result of Client s failure to implement repairs or to conduct repairs in a safe and prudent manner. WALKER CONSULTANTS 18

25 05 Appendices

26 A Opinion of Probable Repair Costs Appendix

27 CHURCH STREET GARAGE APPENDIX A: OPINION OF PROBABLE COST REPAIR PROGRAM 10-YEAR PLAN August 29, 2018 Project No DESCRIPTION ESTIMATED ITEM COST GENERAL REQUIREMENTS Project Mobilization $79, Engineering $95, Material Testing $7, Staging for Façade Work $10, CONCRETE FLOOR REPAIR Floor Repair - Partial Depth - Stair Towers $2, Floor Repair - Full Depth Topping + Precast Tee $12, Floor Repair - Full Depth Topping $48, Floor Repair - Curbs/Sidewalks $1, Floor Repair - Partial Depth - Slab on Grade $1, CONCRETE CEILING REPAIR Ceiling Repair - Partial Depth - Stair Towers $2, CONCRETE BEAM AND JOIST REPAIR Inverted Tee Beam Repair - Partial Depth $6, Spandrel Panel Repair $9, CONCRETE COLUMN REPAIR Column Repair - Partial Depth $8, Column Haunch Repair $1, CONCRETE WALL REPAIR Wall Repair - Partial Depth $9, PRECAST TEE REPAIR Tee Flange Repair - Partial Depth $5, Tee Stem Repair - Partial Depth $1, EXPANSION JOINT REPAIR AND REPLACEMENT Expansion Joint - Compression Gland $11, Sawcut Expansion $6, Expansion Joint - MSEAL Bridge $3, CRACK AND JOINT REPAIR Rout and Seal Cracks $2, Seal Tee-Tee Joints $77, Repair Failed Crack/Joint Sealant $56, Install Vertical Joint Sealant $9, Epoxy Injection Column Haunch Cracks $2, Cove Sealant $36, WATERPROOFING Install New Vehicular Traffic Topping - Levels $252, Recoat Top Level $67, MECHANICAL - DRAINAGE Lower Drain SOG $3, Clean/Unclog Drains $5, BRICK/MASONRY REPAIR Tuck-Pointing $25, Masonry Unit Repair/Replacement $3, Replace Capstone - Covered Levels $2, Rout and Seal Capstone - Top Level $7, Replace Masonry Control Joint Sealant $5,600.00

28 DOORS, FRAMES, WINDOWS, AND HARDWARE Door Replacement $15, Replace Frame $4, New Door Closer $ Replace Storefront Gasketing $16, CONNECTIONS/BEARINGS Re-weld Shear Connectors $5, METAL STAIRS Repair Metal Stairs $10, Replace Vehicular Guardrail $17, Upgrade Guardrail $4, Install Guardrail $6, PAINTING Paint Traffic Markings and Curbs $14, Paint Doors and Frames $6, Paint Stair Treads, Risers and Nosings $75, % Contingency = $157, TOTALS = $1,210, Assumptions: 1: Costs are based on historical records of similar work. Costs may vary due to local economy, time of year bid, or other factors. 2: Open Shop, Normal Work Week. 3: No Hazardous Waste, Landfill within 50 Miles. 4: Costs are in 2018 Dollars. 5: Costs do not include cost of alternate parking, if any, during repair.

29 August 29, 2018 CHURCH STREET GARAGE APPENDIX A: OPINION OF PROBABLE COST REPAIR PROGRAM 20-YEAR PLAN Project No DESCRIPTION ESTIMATED ITEM COST GENERAL REQUIREMENTS Project Mobilization $176, $89, Engineering $211, $107, Material Testing $17, $8, Staging for Façade Work $10, CONCRETE FLOOR REPAIR Floor Repair - Partial Depth - Stair Towers $2, Floor Repair - Full Depth Topping + Precast Tee $12, Floor Repair - Full Depth Topping $20, Floor Repair - Replace Topping End Bays + Crossover $738, Floor Repair - Curbs/Sidewalks $1, Floor Repair - Partial Depth - Slab on Grade $1, CONCRETE CEILING REPAIR Ceiling Repair - Partial Depth - Stair Towers $2, CONCRETE BEAM AND JOIST REPAIR Inverted Tee Beam Repair - Partial Depth $6, Spandrel Panel Repair $9, CONCRETE COLUMN REPAIR Column Repair - Partial Depth $8, Column Haunch Repair $1, CONCRETE WALL REPAIR Wall Repair - Partial Depth $9, PRECAST TEE REPAIR Tee Flange Repair - Partial Depth $5, Tee Stem Repair - Partial Depth $1, EXPANSION JOINT REPAIR AND REPLACEMENT Expansion Joint - Compression Gland $11, Sawcut Expansion $6, Expansion Joint - MSEAL Bridge $3, CRACK AND JOINT REPAIR Rout and Seal Cracks $2, Seal Tee-Tee Joints $77, Repair Failed Crack/Joint Sealant $56, Install Vertical Joint Sealant $9, Epoxy Injection Column Haunch Cracks $2, Cove Sealant $36, WATERPROOFING Install New Vehicular Traffic Topping - Levels 2 & 3 $169, Recoat Top Level $67, Install New Vehicular Traffic Topping - End Bays & Crossov $0.00 $252, Install Roof Membrane $0.00 $16, MECHANICAL - DRAINAGE Lower Drain SOG $3, Clean/Unclog Drains $5, Replace Drains and Pipes 0.00 $180,000.00

30 BRICK/MASONRY REPAIR Tuck-Pointing $25, Masonry Unit Repair/Replacement $3, Replace Capstone - Covered Levels $2, Rout and Seal Capstone - Top Level Replace Masonry Control Joint Sealant $5, DOORS, FRAMES, WINDOWS, AND HARDWARE Door Replacement $15, Replace Frame $4, New Door Closer $ Replace Storefront Gasketing $16, CONNECTIONS/BEARINGS Re-weld Shear Connectors $5, MISCELLANEOUS Extract Cores for Material Testing $0.00 $8, Replace Light Fixture $0.00 $315, Replace Elevator $0.00 $120, METAL STAIRS Replace Stair Stringers, treads, and risers $275, Replace Vehicular Guardrail $17, Upgrade Guardrail $4, Install Guardrail $6, PAINTING Paint Traffic Markings and Curbs $14, Paint Doors and Frames $6, Paint Stair Railings, Treads, Risers and Nosings $96, % Contingency = $327,200 $164, TOTALS = $2,509,000 $1,261,000 Assumptions: 1: Costs are based on historical records of similar work. Costs may vary due to local economy, time of year bid, or other factors. 2: Open Shop, Normal Work Week 3: No Hazardous Waste, Landfill within 50 Miles 4: Costs are in 2018 Dollars 5: Costs do not include cost of alternate parking, if any, during repair

31 B Photographs Appendix

32 PHOTO LOG WALKER # Photo 1 Typical Floor Spall Photo 2 Typical Scaling at End Bays B-1 PHOTOGRAPHS

33 PHOTO LOG WALKER # Photo 3 Isolated Spalling at Conduit Minimal concrete cover Photo 4 Typical Spandrel Panel Spalling B-2 PHOTOGRAPHS

34 PHOTO LOG WALKER # Photo 5 Occasional Unsealed Control Joint in Spandrel Panel Exposed Conduit Photo 6 Occasional Column Spalling B-3 PHOTOGRAPHS

35 PHOTO LOG WALKER # Photo 7 Occasional Tee Flange Spalling and Leaching Photo 8 Typical Spalling at Tee-Tee Joints Rusted shear connections B-4 PHOTOGRAPHS

36 PHOTO LOG Photo 9 Typical Spalling and Deterioration at Drains WALKER # Rusted elbow Photo 10 Occasional Spalling and Leaching at Slab Edge B-5 PHOTOGRAPHS

37 PHOTO LOG WALKER # Photo 11 Typical Wall and Beam Spalling Photo 12 Occasional Spandrel Beam Cracking B-6 PHOTOGRAPHS

38 PHOTO LOG WALKER # Photo 13 Occasional Tee Stem Spalling Photo 14 Occasional Tee Stem Cracking/Deterioration Cracking at previous patches B-7 PHOTOGRAPHS

39 Photo 15 Isolated Column Haunch Failing F PHOTO LOG WALKER # Photo 16 Occasional Concrete Wall Spalling Fill Hole B-8 PHOTOGRAPHS

40 PHOTO LOG WALKER # Photo 17 No Vertical Expansion Joint Photo 18 Typical Cracked CMU Wall B-9 PHOTOGRAPHS

41 PHOTO LOG WALKER # Photo 19 Typical Corroded Metal Stairs Photo 20 Typical Corroded Door Frame B-10 PHOTOGRAPHS

42 PHOTO LOG WALKER # Photo 21 Isolated Broken Door Closer Corroded Door Lintels Photo 22 Paint Stair Nosings B-11 PHOTOGRAPHS

43 PHOTO LOG WALKER # Photo 23 Typical Open and Eroded Brick Joints Photo 24 Typical Cracked Masonry Joints at CMU Wall B-12 PHOTOGRAPHS

44 PHOTO LOG WALKER # Photo 25 Occasional CMU Wall Deterioration Wall Needs Painting Photo 26 Deteriorated CMU Wall along Façade B-13 PHOTOGRAPHS

45 PHOTO LOG Photo 27 Occasional Broken Capstone WALKER # Photo 28 Typical Failing Capstone Joint Sealant B-14 PHOTOGRAPHS

46 PHOTO LOG WALKER # Photo 29 Occasional Failed Traffic Topping Paint curb Photo 30 Typical Failing Expansion Joint B-15 PHOTOGRAPHS

47 PHOTO LOG WALKER # Photo 31 Typical Raised Drain Drain clogged Photo 32 Occasional Ponding B-16 PHOTOGRAPHS

48 PHOTO LOG WALKER # Photo 33 Typical Vehicular Guardrail Not Per Code Guardrail height: 2-10 Gap is greater than 4 Photo 34 Guardrail Not Per Code Gap exceeded B-17 PHOTOGRAPHS

49 PHOTO LOG WALKER # Photo 35 No Fall Protection B-18 PHOTOGRAPHS

50 C Material Testing Appendix

51 Depth (Inches) Appendix C: Material Testing Church Street Garage 6/22/ Chloride Ion Content vs Depth Water Soluble Chloride (PPM) Approximate depth of reinforcing CL-1 CL-2 CL Chloride ion content range that will begin the corrosion process ( PPM) Appendix C: Page 1 of 1

52 CHICAGO 61 Garlisch Dr. Elk Grove Village, IL P F DALLAS / FT WORTH SAN ANTONIO / SO. TEXAS AUSTIN / WACO HOUSTON MIAMI Mr. Jason C. Gross Walker Consultants 565 East Swedesford Road, Suite 300 Wayne, PA PH: jgross@walkerconsultants.com Re: Laboratory Studies of Concrete Powder Samples Frederick, Maryland Walker Project No Dear Mr. Gross: Enclosed please find the results of the chloride content analyses for six (6) concrete powder samples that were reportedly extracted from the referenced location and delivered to our laboratories on June 11, The water-soluble chloride ion content was determined according to the applicable provisions of ASTM Standard C Standard Test Method for Water-Soluble Chloride in Mortar and Concrete and AASHTO T-260. The obtained test results are compiled below in Table 1. Based upon the present state of knowledge, 0.15% and 0.06% respectively, should be the maximum water-soluble chloride contents expressed by weight of cement as suggested by the American Concrete Institute in order to minimize the risk of chloride-induced corrosion in conventionally reinforced and post tensioned reinforced concretes. ******* We appreciate the opportunity to be of continued service to you. Sincerely yours, Universal Construction Testing, Ltd. Elena I. Emerson Operations Manager PROJECT NUMBER: PROJECT NAME: DATE: Frederick, Maryland - Chloride Content Analysis PAGE 1

53 CHICAGO 61 Garlisch Dr. Elk Grove Village, IL P F DALLAS / FT WORTH SAN ANTONIO / SO. TEXAS AUSTIN / WACO HOUSTON MIAMI Table 1 - Chloride Content of Concrete ASTM C1218 (Water Soluble) AASHTO T260 Sample Number Location in Structure Level tested, inch from top by weight of concrete (PPM)* Chloride ion (CL - ) Content by weight of concrete % by weight of cement* % Frederick, Maryland CL-1 L CL-2 L CL-3 L Remarks: *) Assumed cement content 600 lbs/cu.yd. and U.W. = 3800 pcy. PROJECT NUMBER: PROJECT NAME: DATE: Frederick, Maryland - Chloride Content Analysis PAGE 1

54 REPORT OF CONCRETE TESTING PROJECT: REPORTED TO: CHURCH STREET GARAGE WALKER CONSULTANTS FREDERICK, MD 565 E. SWEDESFORD RD, SUITE 300 WALKER PROJECT NO.: WAYNE, PA ATTN: JASON GROSS APS PROJECT NO: DATE: AUGUST 27, 2018 INTRODUCTION This report presents the results of laboratory work performed by our firm on two concrete core samples submitted to us by Mr. Jason Gross of Walker Consultants on July 24, We understand the concrete cores were obtained from an exterior precast concrete parking structure that is currently under evaluation. The scope of our work was limited to performing petrographic analysis testing of the topping concrete in both cores to document the overall quality of the topping concrete. CONCLUSIONS Based on our observations, test results, and past experience, our conclusions are as follows: 1. The overall quality of the topping concrete in both cores was fair to poor due primarily to placement with high water content. The cement paste was moderately soft and porous with carbonation at the surface up to 1-3/16. The crushed carbonate coarse aggregate was relatively hard, appeared sound and durable. The topping concrete was purposefully air entrained and was placed with high water content. 2. The topping concrete in both cores contained an air void system that is consistent with current technology for resistance to freeze-thaw deterioration when saturated. However, we expect surficial scaling to occur in the carbonated paste if the concrete is exposed to moisture and freezing conditions. SAMPLE IDENTIFICATION Sample Number: C1 Concrete Topping C2 Concrete Topping Sample Type: Original Sample Dimensions: 70 mm (2-3/4 ) diameter by 146 mm (5-3/4 ) long Hardened Concrete Core 70 mm (2-3/4 ) diameter by 133 mm (5-1/4 ) long 550 Cleveland Avenue North Saint Paul, MN Phone (651) (800) Fax (651) AA/EEO

55 APS Project No Page 2 of 3 TEST RESULTS Our complete petrographic analysis test results appear on the attached sheet entitled 24-LAB-001 "Petrographic Examination of Hardened Concrete, ASTM C856." A brief summary of the general concrete properties is as follows: 1. The coarse aggregate in the cores was comprised of 3/4" maximum sized crushed carbonate that was well graded with good overall distribution. 2. Pozzolanic admixtures were not observed in either concrete sample. 3. The paste color of the cores was light olive gray to pale orange with the slump estimated to be medium (5-8"). 4. The paste hardness of the cores was judged to be medium to soft with the paste/aggregate bond considered good. 5. The depth of carbonation in both cores ranged from 11 mm (7/16 ) up to 30 mm (1-3/16 ) at the top surface. 6. The water-to-cement ratio of the cores was estimated at between 0.53 and 0.60 with approximately 2 to 6% residual Portland cement clinker particles. Air Content Testing Sample Identification: C1 Concrete Topping C2 Concrete Topping Total Air Analysis - Air Void Content, % Spacing Factor, in Entrapped Air (%) Entrained Air (%) TEST PROCEDURES Laboratory testing was performed on July 24, 2018 and subsequent dates. Our procedures were as follows: Petrographic Analysis A petrographic analysis was performed in accordance with APS Standard Operating Procedure 24-LAB-001, "Petrographic Examination of Hardened Concrete," ASTM C856-latest revision. The petrographic analysis consisted of reviewing cement paste and aggregate qualities on a whole basis as well as on a cut/polished section. The depth of carbonation was documented using a phenolphthalein indicator solution applied on a freshly cut and polished surface of the concrete sample. The water/cement ratio of the concrete was estimated by viewing a thin section of the concrete under a Nikon E600 polarizing microscope at magnification up to 600x. Thin section analysis was performed in accordance with APS Standard Operating Procedure 24-LAB-

56 APS Project No Page 3 of 3 009, "Determining the Water/Cement of Portland Cement Concrete, APS Method." The sample is first highly polished then epoxied to a glass slide. The excess sample is cut from the glass and the slide is polished until the concrete reaches 25 microns or less in thickness. Air Content Testing Air content testing was performed using APS Standard Operating Procedure 24-LAB-003, "Microscopical Determination of Air Void Content and Parameters of the Air Void System in Hardened Concrete, C457-latest revision." The linear traverse method was used. The concrete cores were cut perpendicular with respect to the horizontal plane of the concrete as placed and then polished prior to testing. REMARKS The test samples will be retained for a period of at least thirty days from the date of this report. Unless further instructions are received by that time, the samples may be discarded. Test results relate only to the items tested. No warranty, express or implied, is made. Report Prepared by: American Petrographic Services, Inc. Scott F. Wolter, PG President MN License No Phone: swolter@amengtest.com

57 24-LAB-001 Petrographic Examination of Hardened Concrete ASTM C856 Project No Date: Date reviewed: Sample ID: C1 Performed by: S. Malecha Reviewed by: B. Lemcke I. General Observations 1. Sample Dimensions: Our analysis was performed on both sides of a 98 mm (3-7/8") thick concrete topping of a 146 mm (5-3/4") x 70 mm (2-3/4") x 22 mm (7/8") thick lapped profile section and a 76 mm (3") x 52 mm (2") thin section that were sawcut and prepared from the original 70 mm (2-3/4") diameter x 146 mm (5-3/4") long composite core. The core sample arrived at the laboratory in two pieces. 2. Surface Conditions: Top: Fairly rough, mortar eroded or scaled surface Bottom: Rough, irregular, formed surface; placed on precast concrete flange base concrete 3. Reinforcement: None observed within concrete topping. A 5 mm (3/16") diameter steel mesh strand was present within the precast base concrete at 13 mm (1/2") from its formed bottom surface. No corrosion observed. 4. General Physical Conditions: The concrete core sample consisted of a concrete topping, at least 98 mm (3-7/8") thick, placed on precast concrete, at least 44 mm (1-3/4") thick. The concrete topping was de-bonded from the precast concrete upon arrival at the laboratory. The petrographic analysis of the core sample was mostly limited to the concrete topping. The top surface of the concrete topping was rough and scaled or mortar eroded with a few exposed coarse aggregate surfaces and protruding fine aggregate particles. The top surface of the concrete topping was darker in coloration relative to its appearance on the lapped profile. A few fine sub-horizontal microcracks were observed within the top few millimeters of the concrete. Several sub-vertical microcracks proceeded from the top surface of the concrete topping, with the deepest proceeding to 19 mm (3/4") depth. Carbonation of the topping concrete ranged from 22 mm (7/8") up to 30 mm (1-3/16") depth measured from the top surface of the concrete. The concrete was air entrained and contained an air void system that was consistent with current American Concrete Institute (ACI) recommendations to resist frost damage. Some carbonation along the bottom surface of the concrete was observed up to 2 mm (1/16"). The concrete topping was placed on an approximately 45 mm (1-3/4") thick precast base concrete. The top surface of the precast concrete was roughly screed-finished and the two concretes were de-bonded upon sample receipt. Carbonation of the base concrete was negligible from its top surface and proceeded into the concrete from its formed bottom surface to 15 mm (9/16"). The base concrete appeared to contain some air entrainment and a crushed carbonate coarse aggregate. II. Aggregate* 1. Coarse: 19 mm (3/4") nominal sized quarried and crushed carbonate consisting of micritic to sparitic limestone and some coarsely crystalline calcite. The coarse aggregate was mostly sub-angular to angular. The coarse aggregate appeared well graded and exhibited good overall distribution. The coarse aggregate contained a few flat and elongate particles. 2. Fine: Natural quartz and lithic sand. The grains were mostly sub-rounded with many smaller sub-angular particles. The fine aggregate appeared fairly well graded and exhibited good overall uniform distribution. III. Cementitious Properties* 1. Air Content: 6.5% total 2. Depth of carbonation: Ranged from 22 mm (7/8") up to 30 mm (1-3/16") depth from the top surface of the topping and up to 2 mm (1/16") from its bottom surface. 3. Paste/aggregate bond: Good 4. Paste color: Similar to light olive gray (Munsell 5Y 6/1), slightly lighter within the carbonated paste 5. Paste hardness: Moderately soft (Mohs 2.5-3) 6. Microcracking: A few fine sub-horizontal microcracks were observed within the top few millimeters of the concrete. Several sub-vertical microcracks proceeded from the top surface of the concrete topping, with the deepest proceeding to 19 mm (3/4") depth. 7. Secondary deposits: None observed. 8. w/cm: Estimated at between 0.53 and 0.58 with approximately 4 to 6% residual portland cement clinker particles 9. Cement hydration: Alites: Mostly fully Belites: Well to fully *Observations refer to the concrete topping unless otherwise noted.

58 24-LAB-001 Petrographic Examination of Hardened Concrete ASTM C856 Project No Date: Date reviewed: Sample ID: C2 Performed by: S. Malecha Reviewed by: B. Lemcke I. General Observations 1. Sample Dimensions: Our analysis was performed on both sides of a 133 mm (5-1/4") x 70 mm (2-3/4") x 22 mm (7/8") thick lapped profile section and a 76 mm (3") x 52 mm (2") thin section that were sawcut and prepared from the original 70 mm (2-3/4") diameter x 133 mm (5-1/4") long composite core. The core sample arrived at the laboratory in two pieces. 2. Surface Conditions: Top: Fairly rough, mortar eroded or scaled surface Bottom: Rough, irregular, formed surface; placed on precast concrete flange base concrete 3. Reinforcement: 5 mm (3/16") diameter steel mesh was observed within the concrete topping at 65 mm (2-9/16") depth from its top surface and within the precast base concrete at 13 mm (1/2") from its formed bottom surface. No corrosion observed. 4. General Physical Conditions: The concrete core sample consisted of a concrete topping, at least 82 mm (3-1/4") thick, placed on precast concrete, at least 51 mm (2") thick. The concrete topping was de-bonded from the precast concrete upon arrival at the laboratory. The petrographic analysis of the core sample was mostly limited to the concrete topping. The top surface of the concrete topping was rough and scaled or mortar eroded with several exposed and protruding fine aggregate particles. The top surface of the concrete topping was darker in coloration relative to its appearance on the lapped profile. A few sub-vertical microcracks proceeded from the top surface of the concrete topping, with the deepest proceeding to 9 mm (3/8") depth. Carbonation of the topping concrete ranged from 11 mm (7/16") up to 17 mm (11/16") depth measured from the top surface of the concrete. The concrete was air entrained and contained an air void system that was consistent with current American Concrete Institute (ACI) recommendations to resist frost damage. The concrete topping was placed on an approximately 45 mm (1-3/4") thick precast base concrete. The top surface of the precast concrete was roughly screed-finished and the two concretes were de-bonded upon sample receipt. Carbonation of the base concrete from its top surface ranged from negligible up to 2 mm (1/16") depth and proceeded into the concrete from its formed bottom surface to 19 mm (3/4"). The base concrete appeared to contain some air entrainment and a crushed carbonate coarse aggregate. II. Aggregate 1. Coarse: 19 mm (3/4") nominal sized quarried and crushed carbonate consisting of micritic to sparitic limestone and some coarsely crystalline calcite. The coarse aggregate was mostly sub-angular to angular. The coarse aggregate appeared well graded and exhibited good overall distribution. The coarse aggregate contained a few flat and elongate particles. 2. Fine: Natural quartz and lithic sand. The grains were mostly sub-rounded with many smaller sub-angular particles. The fine aggregate appeared fairly well graded and exhibited good overall uniform distribution. III. Cementitious Properties 1. Air Content: 6.7% total 2. Depth of carbonation: Ranged from 11 mm (7/16") up to 17 mm (11/16") depth from the top surface of the topping 3. Paste/aggregate bond: Good 4. Paste color: Slightly darker than very pale orange (Munsell 10YR 8/2) 5. Paste hardness: Moderately soft (Mohs 2.5-3) 6. Microcracking: A few sub-vertical microcracks proceeded from the top surface of the concrete topping, with the deepest proceeding to 9 mm (3/8") depth. 7. Secondary deposits: None observed. 8. w/cm: Estimated at between 0.55 and 0.60 with approximately 2 to 4% residual portland cement clinker particles 9. Cement hydration: Alites: Mostly fully Belites: Well to fully

59 AIR VOID ANALYSIS PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: REPORTED TO: WALKER CONSULTANTS 565 E. SWEDESFORD RD, SUITE 300 WAYNE, PA ATTN: JASON GROSS APS PROJECT NO: DATE: AUGUST 23, 2018 Sample ID: Conformance: Sample Data Description: Dimensions: C1 Concrete Topping The concrete contains an air void system which is consistent with current American Concrete Institute (ACI) recommendations for freezethaw resistance. Hardened Concrete Core 70 mm (2-3/4") diameter by 146 mm (5-3/4") long # VOIDS CHORD LENGTH (1x ") Test Data: By ASTM C457, Procedure A Air Void Content % 6.5 Entrained, % < 0.040"(1mm) 5.8 Entrapped, %> 0.040"(1mm) 0.7 Air Voids/inch 15.8 Specific Surface, in 2 /in Spacing Factor, inches Paste Content, % estimated 22 Magnification 75x Traverse Length, inches 96 Test Date 8/23/2018 Test Performed By S. Malecha Magnification: 30x Description: Hardened air void system. 550 Cleveland Avenue North Saint Paul, MN Phone (651) (800) Fax (651) AA/EEO This document shall not be reproduced, except in full, without written approval from American Engineering Testing, Inc.

60 AIR VOID ANALYSIS PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: REPORTED TO: WALKER CONSULTANTS 565 E. SWEDESFORD RD, SUITE 300 WAYNE, PA ATTN: JASON GROSS APS PROJECT NO: DATE: AUGUST 23, 2018 Sample ID: Conformance: Sample Data Description: Dimensions: C2 concrete topping The concrete contains an air void system which is consistent with current American Concrete Institute (ACI) recommendations for freezethaw resistance. Hardened Concrete Core 70 mm (2-3/4") diameter by 133 mm (5-1/4") long # VOIDS CHORD LENGTH (1x ") Test Data: By ASTM C457, Procedure A Air Void Content % 6.7 Entrained, % < 0.040"(1mm) 6.2 Entrapped, %> 0.040"(1mm) 0.5 Air Voids/inch 17.7 Specific Surface, in 2 /in Spacing Factor, inches Paste Content, % estimated 25 Magnification 75x Traverse Length, inches 95 Test Date 8/23/2018 Test Performed By S. Malecha Magnification: 30x Description: Hardened air void system. 550 Cleveland Avenue North Saint Paul, MN Phone (651) (800) Fax (651) AA/EEO This document shall not be reproduced, except in full, without written approval from American Engineering Testing, Inc.

61 APS PROJECT NO: DATE: AUGUST 27, 2018 PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: PHOTO: 1 SAMPLE ID: C1 DESCRIPTION: Profile of composite core sample as received in the laboratory with the top surface to the left. Note the topping concrete was de-bonded from the thinner precast base concrete flange at the bottom of the core. PHOTO: 2 SAMPLE ID: C1 DESCRIPTION: Top surface of the core sample as received. Note exposed coarse aggregate surfaces and fine aggregate particles.

62 APS PROJECT NO: DATE: AUGUST 27, 2018 PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: PHOTO: 3 SAMPLE ID: C2 DESCRIPTION: Profile of composite core sample as received in the laboratory with the top surface to the left. Note the topping concrete was de-bonded from the thinner precast base concrete flange at the bottom of the core. PHOTO: 4 SAMPLE ID: C2 DESCRIPTION: Top surface of the core sample as received. Note exposed fine aggregate particles.

63 APS PROJECT NO: DATE: AUGUST 27, 2018 PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: PHOTO: 5 SAMPLE ID: C1 DESCRIPTION: Saw cut and lapped profile of core sample with the top surface oriented to the top of the photo showing carbonation (unstained) proceeding up to 30 mm (1-3/16") depth from the top surface of the topping concrete and into the base concrete to a maximum depth of 15 mm (9/16").

64 APS PROJECT NO: DATE: AUGUST 27, 2018 PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: PHOTO: 6 SAMPLE ID: C2 DESCRIPTION: Saw cut and lapped profile of core sample with the top surface oriented to the top of the photo showing carbonation (unstained) proceeding up to 17 mm (11/16") depth from the top surface of the topping concrete and into the base concrete to a maximum depth of 19 mm (3/4").

65 APS PROJECT NO: DATE: AUGUST 27, 2018 PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: PHOTO: 7 SAMPLE ID: C1 DESCRIPTION: Sub-vertical microcrack (red arrows) proceeding into the concrete topping from its top MAG: 5x surface. In saw cut and lapped core profile under low magnification. PHOTO: 8 SAMPLE ID: C1 DESCRIPTION: Sub-horizontal microcrack (red arrows) within the near-surface concrete in saw cut and MAG: 10x lapped core profile under low magnification.

66 APS PROJECT NO: DATE: AUGUST 27, 2018 PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: PHOTO: 9 SAMPLE ID: C2 DESCRIPTION: Mortar eroded or scaled top surface of topping concrete under low magnification MAG: 10x showing exposed sand particles. PHOTO: 10 SAMPLE ID: C2 DESCRIPTION: Sub-vertical drying-shrinkage microcrack mapped in red ink which proceeds into the MAG: 10x concrete from the top surface of the topping. In saw cut and lapped core profile under low magnification.

67 APS PROJECT NO: DATE: AUGUST 27, 2018 PROJECT: CHURCH STREET GARAGE FREDERICK, MD WALKER PROJECT NO.: PHOTO: 11 SAMPLE ID: C1 DESCRIPTION: Mostly fully hydrated alite portland cement clinker relics/particles (red arrows) and well MAG: 400x hydrated belite portland cement clinker particle in thin section of concrete topping under transmitted plane polarized light. PHOTO: 12 SAMPLE ID: C2 DESCRIPTION: Fully hydrated alite portland cement clinker relics (red arrows) in thin section of MAG: 400x concrete under transmitted plane polarized light.