city of east lansing marriott parking structure

City of East Lansing Marriott Parking Structure

Condition Appraisal East Lansing, MI

Project No. R1‐2015‐053 July 31, 2015

5160 Lovers LaneSuite 200

Kalamazoo, MI 49002

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Engineering Condition Assessment City of East Lansing, Marriott Parking Structure East Lansing, Michigan

T A B L E O F C O N T E N T S I. STRUCTURE DESCRIPTION ........................................................................................ 3

II. DOCUMENTATION REVIEW ...................................................................................... 4

III. MATERIALS TESTING ................................................................................................. 6

IV. FIELD OBSERVATIONS ............................................................................................... 7

V. DISCUSSION ................................................................................................................ 10

VI. LIMITATIONS ................................................................................................................ 14

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I. STRUCTURE DESCRIPTION The Marriott Parking Structure was constructed in 1986 and is currently 29 years old. The structure is composed of 2 levels with 3 bays per level. The south and middle bays are flat, while the north bay is sloped. The overall dimensions of the structure are approximately 304 feet in the east-west direction and 180 feet in the north-south direction. The total parking area of the supported and slab-on-grade levels are 43,440 square feet and 51,800 square feet, respectively. Functionally, the structure provides angled parking utilizing one-way traffic on the south and middle bays and two-way traffic on the north bay. The entrance/exit is located in the northeast corner of the structure and services Mac Avenue via a 26-foot wide 2-way speed ramp traveling east-west. The facility provides approximately 250 parking spaces. Since we do not have accurate structural drawings at this time, we can only speculate on the type of structural system. The slab appears to be cast-in-place concrete with mild reinforcement spanning between concrete beams. Reinforcement in the slabs was visible due to the spalls. Since we did not see any tendons, we are speculating that the slab is only mild reinforced. The slab spans 25’-4” in the east-west direction between the beams. The beams span 30 feet and 45 feet in the north-south direction and appear to be cast-in-place concrete with mild reinforcement. The slab-on-grade is 6 inches thick with welded wire fabric as reinforcement. There are two stair towers that service the parking structure in the southwest and southeast corners. There are also two elevator towers in the middle of the structure on the north and south sides of the middle bay. Each elevator tower contains a glass lobby area with two elevators. These elevators service the Marriott Hotel as well. The stair towers are cast-place-concrete.

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II. DOCUMENTATION REVIEW The documents available for review were the architectural and structural drawings by Ramp Engineering Associates dated October 13, 1986 and reports prepared by Carl Walker, Inc. Original Design Drawings The original design drawings indicated a structural system consisting of steel beams and mild reinforced slabs. The as-built structural system is different based on our structural description above. The design was in accordance with the 1985 Uniform Building Code. 2001 Letter Report Carl Walker, Inc. provided a letter report dated February 8, 2001. In this report we outlined five (5) repair options consisting of: patch and seal, patch and deck coat, strip patch – concrete overlay and deck coat, concrete overlay with cathodic protection, and full slab replacement. Following is a summary of the report’s findings and conclusions.

Top of slab delaminations were estimated at 5,600 square feet, which is 13% of the supported slab area.

The underside of the slab delaminations were estimated at 1,650 square feet. Slab cracks that were leaking were estimated at 2,350 feet. The Upper Level had poor slope for drainage. Recommended to replace all joint sealants. Patch and Seal estimated cost = $360,000 Patch and Deck Coat estimated cost = $495,000 Strip Patch, Concrete Overlay, and Deck Coat estimated cost = $1,018,000 Overlay with Cathodic Protection estimated cost = $806,000 Full Slab Replacement and Deck Coat estimated cost = $1,537,000

It is our understanding that Structural Preservation Services performed repairs based on the patch and deck coat option, however no repairs to the underside of the supported slab were performed. 2009 Condition Appraisal Carl Walker, Inc. provided a condition appraisal dated September, 2009. In this report we provided the recommended repairs with in the patch and deck coat option. The other options from our 2001 report were also discussed: strip patch – concrete overlay and deck coat, concrete overlay with cathodic protection, and full slab replacement. Following is a summary of the report’s findings and conclusions.

Top of slab delaminations were estimated at 2,120 square feet, which is 4.9% of the supported slab area.

The underside of the slab delaminations were estimated at 4,620 square feet. Deck coating was in moderate condition, but showing significant wear in some areas, such

as the drive lanes. Recommended repairs estimated cost = $588,900

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One of the major repair options will most likely be required near Year 2020. Future maintenance cost will be greatly reduced with any of these options.

2012 Letter Report Carl Walker, Inc. provided a letter report dated December 17, 2012. In this report we outlined six (6) repair options. Refer to list below. Following is a summary of the report’s findings and conclusions.

Top of slab delaminations were estimated at 4,360 square feet, which is 10% of the supported slab area.

The underside of the slab delaminations were estimated at 7,220 square feet. Summary Table

Option Estimated Construction Cost

Estimated Service Life

Option 1 – Patch and Deck Coat $880,000 12 to 15 Years

Option 1a – Patch and Deck Coat plus Anode Pucks $1,000,000 20 to 23 Years

Option 2 – Strip Patch and Deck Coat $1,380,000 18 to 23 Years

Option 2a – Strip Patch and Deck Coat plus Anode Pucks $1,450,000 26 to 31 Years

Option 3 – Full Slab Replacement and Deck Coat $2,180,000 45 Years

Option 4 – Do Nothing - 5 to 8 Years

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III. MATERIAL TESTING Material testing was not included in this evaluation. Below are the results of testing completed during Carl Walker, Inc.’s previous evaluation in 2000-2001. On November 7, 2000 Carl Walker, Inc. extracted concrete dust samples for chloride ion testing from the Marriott Parking Structure. Sixteen concrete powder samples were taken at 6 locations from the structural slab and were tested for water soluble chloride ion concentration (salt contamination). The samples were collected at one-inch increments to a depth of 3 inches at 5 locations so that the chloride ion content could be established as a function of depth. This information helps to determine the potential for corrosion of the embedded steel reinforcement. Also, one concrete powder sample was taken to determine the baseline (control) chloride content of the concrete. Chloride ions are found in road salt used for de-icing operations on roads, bridges, sidewalks and parking structure floor slabs. As vehicles enter parking structures, they deposit snow, water, and chlorides throughout the parking structure. Chloride ions then penetrate the concrete slab. Chloride ions above a certain concentration, along with moisture and oxygen at the depth of the steel, will create an ideal environment for corrosion of steel embedded in concrete. Concentrations of soluble chloride ions ranging from 1.1 to 1.6 pounds per cubic yard of concrete (280 ppm to 410 ppm) or greater are needed to support corrosion of mild steel in concrete. Of particular importance are the chloride ion concentrations at the level of reinforcement. Chloride ion content testing consists of extracting pulverized concrete dust sample from the concrete at one-inch increments. Samples are tested for “Water Soluble Chloride Content” in accordance with AASHTO T-260. Review of the chloride ion test results indicates concentrations as follows: • Above the corrosion threshold in five test locations at a depth of 1", at four test locations at

a depth of 1" to 2", and at two test locations at a depth of 2" to 3" below the driving surface. • At the corrosion threshold in one test location at a depth of 1" to 2", and at one test location

at a depth of 2” to 3” below the driving surface. • Below the corrosion threshold at two test locations at a depth of 2” to 3” below the driving

surface. The chloride concentrations were high throughout the deck at the 0" to 1" depth as well as the 1” to 2” depth. Chloride concentrations were high in some areas at the 2” to 3” depth. The average depth of the top slab reinforcement was estimated at 1-1/2 inches, which falls in the 1” to 2” inch depth testing range. At this depth, 100% of all chloride concentrations were at or above the threshold level to cause corrosion of the reinforcement. To determine the original chloride content of the fresh concrete, a baseline chloride sample was removed from the slab in an area not likely exposed to surface applied deicing salts. The chloride ion content of the baseline sample was measured at 595 ppm. This indicates that chloride may have been added to the concrete mix design as an accelerator during construction.

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IV. FIELD OBSERVATIONS On June 11, 2015 Carl Walker, Inc. reviewed the Marriott Parking Structure. The structure is in fair condition; however, several areas of considerable deterioration have been noted. Repair of the deterioration will extend the service life of the structure, increase the safety of its patrons, and improve the overall aesthetics of the structure.

CONCRETE DETERIORATION The concrete structural slab is in need of repairs. Chlorides have contaminated the concrete and help corrode the embedded reinforcing steel, as described in the chloride test results. Delaminations totaling 7,000 square feet were estimated on the top of the slab, which is 16% of the supported slab area. Many of these delaminations were adjacent to existing patches. The underside of the slab has 8,000 square feet of delaminated concrete primarily located at leaking cracks and construction joints. It appears that the corrosion of the reinforcement has increased, causing isolated areas of section loss. Also, corrosion is occurring on the top of the bar in isolated areas causing bond lost with the concrete. A large amount of cracking was noted at the underside of the slab. Some cracks have been previously injected with an epoxy. There are also several areas of ponding water on the slab, due to poor drainage slopes. Standing water increases the chances of the water penetrating the deck coating and also creating a slip hazard. Isolated deterioration was noted on columns, walls, and beams throughout the structure. This deterioration is minor, but should be repaired to prevent future damage to the reinforcing steel. Cracking was noted in the masonry walls along the entry / exit area at the south end of the structure. The cracks follow the masonry jointing and are due to the deflection of the slab creating a load onto the nonbearing walls. These joints should be repaired to prevent moisture from entering the masonry cavity and causing future damage.

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WATERPROOFING DETERIORATION The existing waterproofing system is in good condition, but in need of some repair. The existing deck coating throughout the supported slab is in moderate condition, but is showing significant wear in some areas, such as the drive lanes. The deck coating was applied to the slab to reduce the intrusion of damaging chlorides and moisture. The concrete surfaces within the south-east and south-west stairs are beginning to show signs of deterioration due to chloride intrusion. We recommend applying a full deck coating system at these locations as well, to prevent future damage. A large amount of cracking was noted throughout the supported slab. Much of this cracking appears to be the full depth of the slab and has led to wide spread deterioration of the underside of the slab, as they provide a direct path to the reinforcing steel for water and chlorides. We recommend routing and sealing these cracks to prevent future damage. The trench drain at the bottom of the entrance ramp on the upper level is in need of repair. It appears to have been clogged for some time now and the drains steel framing has begun to deteriorate. The entire drain basin should be removed and replaced to provide proper drainage at this location. FINISHES Handrail and wall coatings are worn and/or peeling throughout the stairs. Exterior walls directly adjacent to the stairs are also peeling. These areas should be cleaned and repainted to enhance the aesthetics of the structure. Pavement markings throughout the structure are showing signs of wear. We recommend the installation of new pavement markings throughout the structure to enhance vehicular and pedestrian way finding.

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STAIR TOWER DETERIORATION The stairs are in moderate condition with a few items of deterioration that were noted. Concrete delaminations were noted on stair treads at isolated locations within the south-east and south-west stairs. These delaminations are a hazard to pedestrians and should be repaired to prevent injury. Cracking was also noted within the cast-in-place concrete walls of the stairs. The cracking appears to be due to restraint of the structure. These cracks should be epoxy injected to prevent further structural damage at these locations.

STEEL BEAM DETERIORATION The ceiling of the Upper Level consists of concrete slab on metal decking supported by structural steel beams. The metal decking and beams are sprayed with fireproofing. This is all hidden by a suspended ceiling with insulation. We looked at a few areas of the ceiling to review the condition of the beams. In the past, some of the beams were corroded enough that steel plates had to be installed. The corrosion occurs primarily along the perimeter of the parking structure. During this survey, we observed some corrosion on the beams, but does not appear to be significant. In these areas the fireproofing has flaked off due to the corrosion.

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V. DISCUSSION The structure is in relatively fair to poor condition with a lot of concrete repairs needed at this time. As is typical with mildly reinforced cast-in-place concrete parking structures, the observed deterioration at the top of slab is concentrated along column lines, joints, and cracks. The observed deterioration at the ceiling is concentrated at midspan, leaking joints, and leaking cracks. Due to the apparent chloride ion penetration and the large amount of slab delaminations, a comprehensive repair/protection program should be incorporated. This program should focus on repairing the concrete slab and provide waterproofing to protect the concrete slab. It is our understanding that the City chose the following repair options from our 2012 report: Option 4 - Do Nothing with the plan to perform Option 3 - Full Slab Replacement and Deck Coat after a few years. Existing Condition of Cast-in-Place Concrete Slabs Previous chloride ion testing confirms that the corrosion threshold concentration is at or has been exceeded within the 1" to 2" depth of the slab in 100% of the samples. The slab reinforcement likely consists of uncoated steel rebar. This uncoated reinforcement is therefore subject to corrosion deterioration due to the presence of chloride ions in the concrete. The high chloride ion concentration is one of the main reasons deck coating was installed on this deck in 2002. Deck coating effectively waterproofs the slab and reduces the availability of water, oxygen, and chlorides at the slab reinforcing steel. Thus, the rate of corrosion of embedded reinforcing steel is considerably reduced. Performance of a deck coating on chloride contaminated slabs is highly variable and can often be limited by corrosion and spalling of floor slabs rather than wear resistance of the membrane itself. Where coatings have been applied to existing slabs with high chloride contaminated concrete, surveys indicate continued corrosion similar to this deck. The application of a deck coating will generally reduce, but does not stop, corrosion of embedded reinforcement. Where coatings have been applied to new slabs, the slabs will most likely have a very long service life if the coatings are maintained. After our survey of the ceiling, we recommended to the City to remove the loose concrete delaminations from the ceiling because they were a safety hazard. Once this was completed we reviewed the ceiling again and noticed additional concerns with the exposed reinforcement. As mentioned in the observation section, the exposed reinforcement at the ceilings was observed to have some section loss and loss of bond to the concrete at isolated areas. If this becomes widespread, then the structural capacity would be affected. We do not believe this is occurring in the top of slab delaminations, because the delaminations do not appear to be “jacking up”. However we would expect this to occur in the next few years.

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The following table shows the history of the top of slab delaminations observed in this structure and when top of slab repairs were performed. As shown in the table below there has been ongoing deterioration of the floor slab and significant increases in delamination quantities.

Slab Delamination History

2001 2002 2009 2012 2015

Top of Slab Delaminations (s.f.) 5,600 Repaired 2,120 4,360 7,000

Ceiling Delaminations (s.f.) 1,650 - 4,620 7,220 8,000

Replacement of Cast-in-Place Concrete Slabs It is our understanding that the City plans to implement Option 3 - Full Slab Replacement and Deck Coat from our 2012 report. Complete slab removal and replacement consists of removing and replacing the slabs while saving the existing columns and beams. For demolition of the existing slabs there are two methods that would be likely candidates for this option. The first is the conventional method which involves hammering out the existing concrete. This method produces significant noise and dust. The second is saw-cutting out the existing slab in rectangular sections, lifting and transporting the slab sections away. This method minimizes noise and dust production and is the basis for preparing the estimate of probable cost for this option. Because some of the existing columns support the weight of the building above, they will likely need to be temporarily braced laterally during slab demolition, new slab placement, and curing of the new slab. The existing slab is currently providing lateral support for the columns. Removal of the existing slab without providing temporary bracing would effectively double the unbraced length of the existing columns, possibly allowing them to suddenly buckle under load. An engineering analysis would be required to determine the column resistance to buckling and the temporary lateral support requirements. A similar situation may exist at perimeter walls in that the slab may be laterally supporting the walls, and temporary wall bracing may be required to ensure wall stability during construction. With total slab replacement, some modifications to the drainage slopes of the slabs can be implemented, possibly reducing the number of floor drains from current conditions while improving drainage slopes. We would recommend a minimum drainage profile of 1/8 inch per foot (1/4 inch per foot preferred) to the new floor drains if headroom permits. While beams, columns, and stair towers would be saved and reused, extensive removal and replacement of mechanical, electrical, and plumbing would accompany this option. It is also planned to remove and replace the suspended ceiling and insulation at the Upper Level. During this time, most of the structural steel framing could be reviewed for deterioration. For the new slab, all new reinforcement and high quality concrete should be used meeting the requirements of ACI 362.1R-97: Guide for the Design of Durable Parking Structures. With

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conventionally reinforced concrete the formation of random shrinkage cracks in the new slabs should be expected. We would recommend these cracks be routed and sealed with a flexible sealant material to prevent leaking onto vehicles below. For this option we would also recommend providing a traffic bearing membrane (deck coating) on top of the new slab. The deck coating can span most of the smaller shrinkage cracks that can be expected to develop. It is also important to minimize the amount of water penetrating the new slabs to maximize the time to first repair and extend the overall service life of the new slab.

We anticipate that with continued maintenance, this option would provide a service life of approximately 50 years. Repair and maintenance of the supporting framework would also be required during that time. We would estimate that annual maintenance under this option may be approximately $0.08 per square foot. We agree with the City’s plan to implement the repair option – Full Slab Replacement and Deck Coat. The initial cost of the slab replacement option is higher than the other options, but it provides the best long-term durability, minimizes risk of exceeding estimated repair cost, minimizes long term maintenance and repair costs, minimizes disruption to facilities during future construction, and minimizes long term safety risks. If this option is not performed in 2016, we would recommend the structure be reviewed by an engineer on a yearly basis. We would also recommend continuing removal of loose concrete from the ceiling on a periodic basis. Following is our table with the updated probable construction cost for the Full Slab Replacement and Deck Coat option.

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Marriott Parking Structure

Full Slab Replacement and Deck Coat

WORK ITEM WORK ITEM DESCRIPTION UNITS FACTORED

QUANTITY UNIT COST COST

C1 TOP OF SLAB REPAIR - SLAB-ON-GRADE S.F 100 $40.00 $4,000C2 WALLS AND COLUMN BRACING ALLOW. 1 $200,000.00 $200,000C3 SUPPORTED SLAB DEMOLITION S.F 43,440 $7.00 $304,080C4 INSTALL NEW SUPPORTED SLAB S.F 43,440 $24.00 $1,042,560C5 COLUMN REPAIR S.F 20 $80.00 $1,600C6 WALL REPAIR S.F 200 $80.00 $16,000C7 BEAM REPAIR S.F 40 $80.00 $3,200C8 TUCKPOINTING L.F. 330 $12.00 $3,960

W1 DECK COATING - FULL SYSTEM (HEAVY DUTY) S.F. 43,880 $3.25 $142,610W2 DECK COATING - FULL SYSTEM (HEAVY DUTY) AT STAIRS S.F. 530 $5.00 $2,650W3 INSTALL COVE AND JOINT SEALANTS L.S. 43,440 $0.25 $10,860

F1 CLEAN & PAINT HANDRAILS L.S 1 $2,000.00 $2,000F2 PAINT WALLS AND COLUMNS S.F. 33,800 $1.20 $40,560F3 PAINT LOWER LEVEL CEILING S.F. 47,790 $1.20 $57,350F4 PAVEMENT MARKING L.S 1 $2,500.00 $2,500F5 SUSPENDED CEILING S.F. 47,790 $6.00 $286,740F6 INSULATION S.F. 47,790 $1.75 $83,640

M1 INSTALL NEW FLOOR DRAINS AND PIPING L.S. 43,440 $1.50 $65,160M2 INSTALL NEW SPRINKLER PIPING L.S. 86,880 $1.10 $95,570

E1 INSTALL NEW LIGHTING L.S. 86,880 $1.40 $121,640

ST1 STAIR TREAD REPAIR S.F 20 $50.00 $1,000

SB1 STEEL BEAM REPAIR ALLOW. 1 $15,000.00 $15,000

$325,350$2,828,030

$282,810$3,110,840

CONCRETE REPAIRS

WATERPROOFING REPAIRS

CONSTRUCTION MOBILIZATION & GENERAL REQUIREMENTS (13%)TOTAL CONSTUCTION COSTCONSTRUCTION CONTINGENCY (10%)TOTAL CONSTRUCTION BUDGET

FINISHES

MECHANICAL

ELECTRICAL

STAIR TOWERS

STEEL BEAMS

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VI. LIMITATIONS It has been found that reinforced concrete that becomes contaminated by chlorides experiences progressive corrosion induced deterioration. It must be recognized that it is not possible to remove the salt that has accumulated in the concrete. Restoration and protection of the structure can be performed and the rate of further deterioration reduced. However, we cannot guarantee that further deterioration will not take place with continued service related exposure. Effective ongoing maintenance can significantly reduce long-term maintenance costs. Monitoring of the facility can assist in scheduling future maintenance. Specific repair procedures are not part of this evaluation. This report defines items in need of repair and presents conceptual procedures. Construction Documents are required to address all aspects of materials selection and methods for repair of the parking structure. Repair cost projections are based on deterioration quantities identified during our one-day review. Quantities and costs are not intended to define a guaranteed maximum cost, and variations in final quantities should be anticipated. The evaluation and restoration of existing buildings require that certain assumptions be made regarding existing conditions since some of these assumptions may not be confirmed without expending additional sums of money and/or destroying otherwise adequate or serviceable portions of the building, Carl Walker, Inc. cannot be held responsible for latent deficiencies which may exist in the structure, but which have not been discovered within the scope of this evaluation. Carl Walker, Inc. did not review the garage for conformance with the Americans with Disabilities Act (ADA).