J.1_-_Repointing_Project_Specifications.pdf

PEVI - 201919 TOC-1

TABLE OF CONTENTS

DIVISION 01 - GENERAL REQUIREMENTS

01 11 00 Summary of Work .......................................................................................................... 6 pages Appendix: Repointing and Cleaning Trials, Revised Report, dated November 24, 2015 01 26 01 Contract Modification Procedures ................................................................................. 6 pages Appendix: Profit Calculator 01 27 00 Definition of Contract Line Items .................................................................................. 2 pages Appendix: Contract Price Schedule 01 31 00 Project Management & Coordination ............................................................................ 7 pages 01 32 16 Construction Schedule ................................................................................................... 9 pages 01 32 33 Photographic Documentation ........................................................................................ 2 pages 01 33 23 Submittal Procedures ..................................................................................................... 8 pages Appendix: Submittal List 01 35 23 Safety Requirements ...................................................................................................... 4 pages 01 35 91 Historic Preservation Treatment Procedures ................................................................. 6 pages 01 40 00 Quality Requirements .................................................................................................... 8 pages Appendix: Statement of Structural Tests and Special Inspections 01 42 00 References ...................................................................................................................... 5 pages 01 50 00 Temporary Facilities and Controls ................................................................................ 7 pages 01 57 23 Temporary Storm Water Pollution Prevention .............................................................. 6 pages 01 67 00 Product Requirements .................................................................................................... 6 pages Appendix: Affirmative Procurement Reporting Form 01 73 40 Execution ........................................................................................................................ 5 pages 01 74 19 Construction Waste Management and Disposal............................................................ 5 pages Appendix A: Project Waste Management Plan Worksheet Appendix B: Standard Solid Waste Conversions 01 77 00 Closeout Procedures ....................................................................................................... 4 pages Appendix: Closeout and Operation & Maintenance Requirements

DIVISIONS 02 and 03 - NOT USED

DIVISION 04 - MASONRY

04 01 27 Repointing with Cement-Lime Mortar ......................................................................... 9 pages 04 01 40 Efflorescence Removal ................................................................................................. 8 pages 04 05 01 Masonry Mortar and Grout ........................................................................................... 3 pages

DIVISIONS 05 and 06 - NOT USED

DIVISION 07 - THERMAL AND MOISTURE PROTECTION

07 92 00 Joint Sealants ................................................................................................................. 8 pages

DIVISIONS 08 and 09 - NOT USED

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SUPPLEMENTAL INFORMATION IN SEPARATE VOLUME

Product File Constructability Analysis Sustainability Analysis Class A Construction Cost Estimate Contract Price Schedule with Class A Costs Suggested Construction Schedule

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091015 SUMMARY OF WORK

SECTION 01 11 00 - SUMMARY OF WORK

PART 1 - GENERAL

1.1 SUMMARY

A. This Section includes the following:

1. Work covered by the Contract Documents.

2. Contractor use of premises.

3. Public use of site.

4. Occupancy requirements for buildings.

5. Work Restrictions.

6. Special Construction Requirements.

7. Additional Reports.

1.2 WORK COVERED BY CONTRACT DOCUMENTS

A. Project Location: Perry’s Victory and International Peace Memorial, Put-in-Bay, South Bass Island, Ohio.

1. Perry’s Victory and International Peace Memorial is a 350-foot tall memorial in the form of a Doric column, constructed in 1913–1915. The exterior granite of the memorial is set against a concrete structure. The column is surrounded by a raised Upper Plaza structure paved with brick and granite pavers.

B. The Work consists of the following:

1. The Work includes the following major tasks, to the extent shown on the Drawings:

a. Providing suspended scaffolding (swing stages) and other general items required to perform the Scope of Work.

b. Removal of efflorescence stains using a microabrasive process.

c. Removal of existing sealant, backer rod, backup mortar, and efflorescence from joints.

d. Mixing and installation of new pointing mortar.

e. Mixing, installing, and curing mortar, inspecting work, and re-working joints if necessary, to ensure that the completed joints are free of hairline cracks, cracks visible upon close-up inspection, and other deficiencies.

f. Implementing Contractor’s own inspection and quality control and providing access for independent party inspection and quality assurance.

g. Removal of deteriorated material at backup mortar joints, and mixing and installation of new backup mortar, beyond a depth of twice the joint width or 2 inches from the surface of the wall.

2. The following options may be included in the Work:

a. At the penthouse walls, removal of efflorescence using the process specified.

b. At the penthouse walls, removal of existing sealant, backer rod, and backup mortar.

c. At the penthouse walls, mixing and installation of new pointing mortar.

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d. Removal of existing sealant and installation of new sealant at designated cracks and small spalls, at isolated locations on the column shaft.

e. Removal of efflorescence using the process specified, at the remaining portions of the granite of the shaft, where not included in the base Scope of Work shown on the Drawings.

3. The memorial is a historic landmark and all work shall be performed in accordance with the Secretary of the Interior Standards for the Treatment of Historic Properties. The monument and landscape are a historic property listed in the National Register of Historic Places. The entire site is a historic property and all reasonable precautions shall be taken to prevent damage to historic materials during the work. If damage to historic materials occurs, repairs shall be made at no additional cost to the Government to the satisfaction of the Contracting Officer. Emphasis shall be placed preserving, repairing, and conserving historic materials and features.

C. Project will be constructed under a single prime contract.

1.3 CONTRACTOR USE OF SITE

A. General: Contractor shall have limited use of the site for construction operations. Limit construction operations to areas indicated on the Drawings and enclosed within the construction fence. Do not disturb portions of park beyond the areas indicated.

B. Storage of Materials: Confine storage of materials to areas indicated on the Drawings and enclosed within the construction fence. Materials may be stored outdoors at grade as indicated on the Drawings or may be stored within the basement level under the Upper Plaza (accessible directly from grade).

Storage of bulk materials in the memorial column or on the Upper and Lower Plazas is not permitted.

1. Contractor is responsible for security of all stored materials and equipment.

C. Preservation of Natural Features:

1. Prevent damage to natural surroundings. Restore damaged areas, repairing or replacing damaged trees and plants, at no additional expense to the Government.

2. Provide temporary barriers to protect existing trees and plants and root zones.

3. Do not remove, injure, or destroy trees or other plants without prior approval. Consult with

Contracting Officer and remove agreed-on roots and branches that interfere with construction.

4. Do not fasten ropes, cables, or guys to existing trees.

5. Carefully supervise excavating, grading, filling, and other construction operations near trees to prevent damage.

D. Driveways and Entrances: Keep driveways, Upper and Lower Plazas, and entrances serving premises clear and available to Government, Government’s employees, and emergency vehicles at all times.

Do not use these areas for parking or storage of materials.

1. Provide locked gate at entrance to construction area, at the location indicated on the Drawings.

2. Provide keys to park personnel and other authorized Government representatives.

3. Schedule deliveries to minimize use of driveways and entrances.

4. Schedule deliveries to minimize space and time requirements for storage of materials and equipment on-site.

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E. Construction Camp: Establishment of a camp within the park will not be permitted.

F. Hauling Restrictions: Comply with all legal load restrictions in the hauling of materials. Load restrictions on park roads are identical to the state load restrictions with such additional regulations as may be imposed by the Park Superintendent. Information regarding rules and regulations for vehicular traffic on park roads may be obtained from the Office of the Park Superintendent. A special permit will not relieve Contractor of liability for damage which may result from moving of equipment.

1.4 PUBLIC USE OF SITE

A. The memorial will be closed to the public during construction.

B. The remainder of the park (outside of the construction fence) will remain open to the public.

Contractor shall at all times conduct his operations (such as delivery of materials) to ensure the least inconvenience to the public use of the portions of the park outside of the construction area.

1.5 OCCUPANCY REQUIRMENTS FOR BUILIDINGS

A. Contractor shall maintain access for National Park Service administrative personnel or their representatives, and any other official business, throughout the construction phase. Provide access for NPS personnel to the basement during construction. Cooperate with Government during construction operations to minimize conflicts and facilitate Government usage. Perform the Work so as not to interfere with Government’s day-to-day operations. Maintain existing exits, unless otherwise indicated.

1. Maintain access to existing walkways, corridors, and other adjacent occupied or used facilities. Do not close or obstruct walkways, corridors, or other occupied or used facilities without written permission from the CO.

2. Maintain existing building in a weather tight condition throughout construction period.

Repair damage caused by construction operations. Protect building and its occupants during construction period.

1.6 CONDUCT OF OPERATIONS

A. At all times the contractor shall conduct his operations in conformance with the rules and regulations promulgated by the Secretary of the Interior for the National Park Service, and applicable park rules and regulations prescribed by the Park Superintendent.

B. Work on Saturdays, Sundays, Federal holidays, or at night may not be performed without prior consent from the Contracting Officer. Submit requests 48 hours in advance of the work to the Contracting Officer for approval.

C. No signs or advertisements (except those specified herein) shall be displayed on the construction site or within the park unless approved by the Contracting Officer.

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1.7 WORK RESTRICTIONS

A. On-Site Work Hours: Work shall be generally performed within daytime working hours of 6:00 a.m.

to 8:00 p.m., Monday through Friday.

1. Weekend Hours: Permitted with prior arrangement with park staff and Contracting Officer.

B. Existing Utilities

1. Contractor shall be responsible for locating and preventing damage to known utilities. If damage occurs, repair utility at no additional expense to the Government.

2. If damage occurs to an unknown utility, repair utility. An equitable adjustment will be made in accordance with the Changes clause of the contract.

3. Protect the Coast Guard lights on the Penthouse and maintain electrical service to the lights throughout the project. Any interruptions must be coordinated with the Coast Guard through the Contracting Officer.

C. Existing Utility Interruptions: Do not interrupt utilities serving facilities occupied by Government or others unless permitted under the following conditions and then only after arranging to provide temporary utility services according to requirements indicated:

1. Notify Contracting Officer not less than two days in advance of proposed utility interruptions.

2. Do not proceed with utility interruptions without Contracting Officer’s written permission.

D. Hauling Restrictions: Comply with all legal load restrictions in the hauling of materials. Load restrictions on park roads are identical to the state load restrictions with such additional regulations as may be imposed by the Park Superintendent. Information regarding rules and regulations for vehicular traffic on park roads may be obtained from the Office of the Park Superintendent. A special permit will not relieve Contractor of liability for damage which may result from moving of equipment.

E. Nonsmoking Building: Smoking is not permitted within the building or within 25 feet of entrances, operable windows, or outdoor air intakes.

1.8 SPECIAL CONSTRUCTION REQUIREMENTS

A. Project Website: A project website administered by the NPS will be used for purposes of managing communication and documents during the construction stage. See Section 01 31 00 “Project Management and Coordination” for requirements on using the Project Website.

B. The work of this contract will be performed at elevations up to approximately 350 feet above grade.

C. Contractor shall provide suspended scaffolding (swing stages) for access to the exterior of the memorial column.

D. Contractor shall provide a material hoist as needed to facilitate delivery and removal of material from grade up to the Upper Plaza level of the memorial.

E. Due to the existing deteriorated condition of the Upper Plaza structure, storage of bulk material and placement of heavy equipment on the Upper Plaza is not permitted. Contractor may, in coordination

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with Contracting Officer, arrange for placement of essential equipment on the Upper Plaza, with appropriate shoring in the basement level below, as needed.

F. Protect exterior and interior features of the memorial from damage throughout the work.

G. Protect the memorial and site from accumulation of dust and debris.

H. Provide temporary protection for the rotunda, stairs, lower elevator landing level, penthouse, elevator mechanical room, and observation deck during the work. Temporary protection shall be provided for the Upper Plaza and all interior spaces in the memorial to prevent damage due to construction activities.

I. Contractor shall be permitted to use the passenger elevator in the memorial for moving personnel, materials, and equipment to the observation deck level.

1. Do not load elevator with more than maximum permitted weight.

2. Protect elevator equipment, cab, and shaft from dust and debris throughout the work.

Protect environmental monitoring equipment within the shaft during the work. Temporary protection shall be provided for the elevator to prevent damage due to construction activities.

3. Maintenance and repair of the elevator during the work shall be the Contractor’s responsibility.

4. Elevator and equipment are unique historic elements. Contractor shall inspect the elevator and elevator equipment before and after the work and shall be responsible for repairs as needed to address damage to elevator components caused by contractor or subcontractor personnel, restoring elevator to its historic appearance and condition before the work.

5. Contractor shall engage an elevator repair consultant to evaluate the condition of the elevator prior to the start of work, provide repairs as needed during the work, and certify the condition of the elevator for use at the completion of work.

J. Contractor staging area is as shown on Drawings. Provide a 6 foot tall chain link fence around construction and staging area as shown on Drawings. Contractor access to or across Lower Plaza is not permitted.

K. Access to South Bass Island is available from ferry services including Miller Boat Lines. Note that ferry service is extremely limited and is available only approximately from end of March to November due to wintertime weather restrictions. Ferry schedule information is available at www.millerferry.com. Ferry transportation for large trucks and the like requires advance reservations.

1.9 ADDITIONAL REPORTS

A. The following reports have been prepared by Wiss, Janney, Elstner Associates, Inc., relative to repointing of the memorial column:

1. Perry’s Victory and International Peace Memorial: Exterior Condition Assessment, dated February 12, 2007.

2. Perry’s Victory and International Peace Memorial: Additional Investigation, dated October 7, 2011.

3. Perry’s Victory and International Peace Memorial: Shaft Repairs, dated August 2012.

4. Perry’s Victory and International Peace Memorial: Mock-up Testing and Evaluation of

Repointing Options for the Exterior Column, dated June 1, 2015.

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5. Perry’s Victory and International Peace Memorial: Repointing and Cleaning Trials, Revised Report, dated November 24, 2015, copy attached.

B. Copies of the reports are available to all plan holders with this package.

C. If conflicts occur between the report and drawings or specifications, the drawings and specifications govern.

PART 2 - PRODUCTS (Not Used)

PART 3 - EXECUTION (Not Used)

END OF SECTION 01 11 00

PERRY'S VICTORY AND INTERNATIONAL PEACE MEMORIAL

Task Order P15PD02753 Repointing and Cleaning Trials

Put-in-Bay, Ohio

Revised Report

November 24, 2015 WJE No. 2015.4110

PEVI 201919

Task Order No. P15PD02753

Prepared for:

National Park Service U.S. Department of the Interior Denver Service Center Design & Construction Division 12795 W. Alameda Parkway Lakewood, Colorado 80228

Prepared by:

Wiss, Janney, Elstner Associates, Inc.

330 Pfingsten Road Northbrook, Illinois 60062

847.272.7400 tel | 847.480.9534 fax

Task Order P15PD02753

Joshua Freedland Associate Principal

Kenneth Itle Associate Principal

Harry Hunderman Senior Principal

Revised Report

WJE No. 2015.4110

Task Order No. P15PD02753

Prepared for:

National Park Service U.S. Department of the Interior Denver Service Center Design & Construction Division 12795 W. Alameda Parkway Lakewood, Colorado 80228

Prepared by:

Wiss, Janney, Elstner Associates, Inc.

330 Pfingsten Road Northbrook, Illinois 60062

847.272.7400 tel | 847.480.9534 fax

TABLE OF CONTENTS

Introduction Background

Description of the Column Historical Chronology of Column Repairs Project Purpose

Trials, Observations, and Discussion Methodology Initial Trials, September 2015 Larger Scale Trials, October 2015 Efflorescence Removal Trials

Conclusions and recommendations Repointing Cleaning Sequence and Scope of Work Quality Control During Construction

Figures Appendix: Sand Submittals and Quintek System Data

Task Order P15PD02753, Repointing and Cleaning Trials

INTRODUCTION

At the request of the National Park Service (NPS), Wiss, Janney, Elstner Associates, Inc. (WJE) performed the initial portion of the Repointing Investigation of the granite cladding at Perry’s Victory and International Peace Memorial, PEVI 201919, in accordance with Task Order P15PD02753. The task order was completed through existing National Park Service IDIQ Contract P14PC00448 held by JMA, a CCRG Company. WJE is a sub-consultant to JMA on the IDIQ contract. This revised report supersedes our report dated November 6, 2015.

The task order includes the installation of small scale repointing trials on site to identify and provide an optimal mix/type for repointing mortar. The trials were performed near grade from pipe scaffolding.

Cleaning trials were also conducted to remove the white deposits (efflorescence) on the exterior granite cladding.

The purpose of this report is to document the work completed to date under this task order. The overall purpose of the project, as stated by the NPS, was to design a mortar pointing system that would limit or eliminate the hairline cracks that were observed during previous repointing tests installed in September 2014 and reported in the WJE report Mock-up Testing and Evaluation of Repointing Options for the Exterior Column dated June 1, 2015.

BACKGROUND

Description of the Column

The column is 45 feet in diameter at the base, and a total of 2,340 granite blocks weighing between 2 to 5 tons each were used in the construction of the memorial. There are approximately 25,000 linear feet of joints between the granite blocks of the column.

There are twenty flutes in the column which, for purposes of this report, have been numbered 1 through 20, starting with the flute on the north that is directly over the entrance door and working clockwise around the memorial column. The memorial column is seventy-seven stone courses in height from the Upper Plaza to the Echinus. There are four courses in the Echinus. The Echinus supports the Observation Deck, together forming the column capital. The Penthouse rests on the Observation Deck and is surmounted by the ornamental bronze Lantern.

Historical Chronology of Column Repairs

A detailed history of the design, construction, and repair of the memorial is contained in the WJE report entitled Perry’s Victory and International Peace Memorial: Exterior Condition Assessment dated February 12, 2007. The following is a brief summary of previous work on the granite joints of the column as described in the report.

Perry's Victory and International Peace Memorial

Historically, there have been problems with the performance of the stone cladding and mortar joints, specifically issues related to the management of water ingress and egress from the memorial’s concrete structure. The original joints between the granite units are assumed to have been bedded and pointed with a portland cement/lime/sand mortar. Because of the subsequent repointing work over the past 100 years, little evidence of the original pointing mortar remains, apart from possible small fragments bonded to granite surfaces within the joints.

In 1952, the column shaft was cleaned by dry abrasive blasting with flint shot silica sand at 120 to 140 psi;

carbonate deposits were removed by hand with “metal tools;” and joints were raked and repointed with a mix of 1 part cement, 1/2 part hydrated lime, and 3 parts sand. Select composite patching was executed with a mix of “1 part special patching cement” and 3 parts pulverized granite. All “undeveloped surface cracks” were “waterproofed” with DRYWAL, as manufactured by Glidden Company of Cleveland, Ohio.

In 1963–1964, the column was covered by scaffolding, as seen in archival photographs. The column shaft was cleaned with wet aggregate blasting at low pressure, and all joints and cracks were raked, repointed, and sealed with polysulfide sealant, as noted on the drawings. In addition, the shaft was “coated with Thoro 777 silicone waterproofing.” Reportedly, the sealant was installed because of rapid deterioration of the repointing mortar that had been installed only about ten years earlier. It is not known why the mortar deteriorated so rapidly.

In the early 1980s a major repair program was initiated. This work was completed by 1984. As part of this project, all of the joints and previously routed cracks were sealed with sealant. The joints were cut out to “sound mortar” and filled with mortar to within one inch of the outer surface, and then a backer rod and Dow 790 silicone sealant were installed. The silicone sealant was broadcast with sand to simulate a mortar joint. Other open cracks in the granite were filled with epoxy, and the granite was also cleaned. No other work on the joints of the column have been completed since the mid-1980s.

Related to the late 1970s and early 1980s work campaign, there are several reports that at least in part addressed the treatment of the joints as well as the efflorescence and discoloration of the granite. These reports include the following:

1. Historic Structures Report (HSR) completed by Dalton, Dalton, Little, Newport, dated 1976.

2. Report prepared by John Milner Associates and Brisk Waterproofing dated August 21, 1979, entitled

Testing of Masonry Cleaning, Caulking, and Repointing.

3. Report prepared by Frank Matero entitled Perry’s Victory and International Peace Memorial Report on Masonry Cleaning and Long-Term Testing dated August 1981. This report concludes that the memorial was originally pointed and bedded with a “portland cement mortar.”

The current campaign of work began after a large portion of a granite panel fell from the observation deck fascia on June 22, 2006. WJE has previously prepared several reports on the condition of components of the memorial including the granite cladding of the column. These reports include:

1. Perry’s Victory and International Peace Memorial: Exterior Condition Assessment, dated February 12, 2007.

2. Perry’s Victory and International Peace Memorial: Investigation, dated February 12, 2008.

3. Perry’s Victory and International Peace Memorial: Additional Investigation, dated October 7, 2011.

4. Perry’s Victory and International Peace Memorial: Shaft Repairs, dated August 2012.

Since 2006, a number of repair projects have been completed related to the memorial column. In 2010– 2011, major structural and waterproofing repairs were implemented at the observation deck and penthouse.

Subsequent to these repairs, the amount of moisture entering the wall construction of the column shaft from above has been reduced. In summer 2012, granite repairs at the column shaft were completed, including installation of anchors at cracked units, dutchman repair of spalls, and routing and sealing cracks.

Project Purpose

During September 2014 and April 2015, WJE completed tests to evaluate the joint treatments between the granite units. The report Perry’s Victory and International Peace Memorial: Mock-up Testing and Evaluation of Repointing Options for the Exterior Column, dated June 1, 2015, summarizes the scope and results of these tests.

Based on the test installations completed in 2014, this report concluded that repointing with mortar is the best long-term treatment for the memorial’s joints. During the test installations, hairline cracks often occurred within the repointing mortar and near the outer edges of the joint adjacent to granite substrates (Figure 1), raising concerns about the mortar installation consistently providing an effective joint weather seal. However, because the cracks were observed to be very narrow, the cracks were considered to be minor and unlikely to significantly reduce the effectiveness of the repointing mortar as a joint treatment, and did not result in diminished mortar bond.

WJE concluded that the hairline cracks which formed in the mortar joints were likely the result of shrinkage of the repointing mortar. Accordingly, additional limited in-situ mortar studies were recommended to identify an optimal mix/type for repointing mortar to minimize or eliminate the potential for the hairline cracking observed in the trials. The report recommended testing other mortar formulations such as Type O mortar and larger aggregate. Also, the 2015 trials were designed to reduce the shrinkage of the mortar during curing. Shrinkage may occur in repointing mortar as a result of several factors, including rapid drying of mortar in a plastic state, prewetting a low porosity stone (thereby increasing the water in contact with the fresh mortar), overwatering repointing mortar to improve workability, wide joints (joint widths observed within the area of the mockups ranged from 3/16 inch up to 1-5/16 inch), and insufficient pre-hydrating of mortar. These recommendations led to the trials being conducted as part of this task order.

TRIALS, OBSERVATIONS, AND DISCUSSION

Methodology

WJE performed two initial site visits related to the repointing and cleaning trials. Small scale repointing trials were performed from pipe scaffolding within the bottom 20 feet of the shaft on September 8 through 11, 2015. Cleveland Marble and Mosaic Company (Cleveland Marble) installed the repointing trials at the direction of WJE. During the September site visit, Quintek Corporation also performed a cleaning trial to remove efflorescence. A subsequent site visit was performed on October 5 through 8, 2015. During this site visit, Cleveland Marble installed three larger repointing trials of select systems at the direction of WJE.

Some initial visual observations were performed at the time of the site visits. Additional analysis will be performed in the spring of 2016, after a winter of environmental exposure and weathering.

Initial Trials, September 2015

To potentially limit shrinkage cracks, the following techniques were considered and included in the pointing mortar installed:

1. An increase in the percentage of lime to improve the workability of the mortar and so as to reduce the amount of water required to produce a workable mortar mix.

2. The use of coarser aggregate (concrete sand, ASTM C33) rather than finer aggregate (mason’s sand, ASTM C144) to accommodate the wider joints frequently found at the memorial.1

In addition, the following modifications to the installation and curing techniques were employed during the trials to evaluate the effectiveness for these techniques to minimize the shrinkage of the repointing mortar:

1. An increase in time between installation of the second mortar lift and installation of the final mortar lift. (The mortar is required to be installed in approximately three 1/4 inch “lifts” to improve bond to the adjacent masonry, as well as to improve compaction of the installed mortar.)

2. The application of low-permeability tape over newly pointed joints to reduce the rate of water evaporation from the mortar and its drying shrinkage rate.

These variables were tested in combination and in isolation to determine their relative success at limiting the formation of the hairline cracks.

The following sands from different suppliers were brought to the site by Cleveland Marble:

1. Beck Sand & Gravel, Inc., ASTM C33, Concrete Sand

2. Beck Sand & Gravel, Inc., ASTM C144, Mason’s Sand

3. Huron Cement/Olen Corp: Concrete Sand Wooster Plant

4. Fairmount Santrol Best Sand, Silica Sand: batch no. 620

5. Fairmount Santrol Best Sand, Silica Sand: batch no. 540

6. Fairmount Santrol Best Sand, Silica Sand: batch no. 565

7. Young’s Sand, C33 Concrete sand

8. Young’s Sand, C144 Mason’s sand

The sand submittals are provided in an appendix to this letter. After a review of the submittals and performing a sieve analysis on site with the actual sands used in the trials, each of the concrete sands (ASTM C33) from the three sources was similar in terms of color, mineralogy, and aggregate distribution. Likewise, the two sources of mason’s sand (ASTM C144) were similar in terms of color, mineralogy, and aggregate distribution (Figure 2). The sands are likely from the same regional geological source. Therefore, it was determined that varying the sand supplier was not likely to create a difference in performance. As a result, the Young’s concrete sand and mason’s sand, available from the aggregate supplier on the island, was used to facilitate sourcing of the sand at the time of the trials.

A summary of the trials are provided in Table 1. Locations of trials are shown in Figure 3. All joints were prepared and pointed using the same techniques used in the 2014 tests, with the following process:

1. The sealant and backer rod was removed using hand tools and a caulk cutter.

2. The bond surface of the granite was cleaned very carefully using a utility knife blade.

3. The mortar was removed to a depth of approximately 1 inch with a grinder using a diamond impregnated grinder blade.

4. The bond surface was cleaned using diamond impregnated grinder blade.

1 ASTM C33, Standard Specification for Concrete Aggregates, and ASTM C144, Standard Specification for Aggregate for Masonry Mortar.

5. The prepared joint was cleaned to remove sealant and mortar using a stainless steel brush wire wheel.

6. The prepared joint was inspected visually close-up and the granite surfaces were probed by WJE, and small residual amounts of sealant were removed mechanically with a utility knife.

7. All mortar was prehydrated prior to installation.

8. All mortar was installed in three lifts.

Table 1. Repointing Trials, September 2015 Trial Proportions* Aggregate Comments 1A Type N

1 part portland cement, 1 part lime, 6 part sand

C33 concrete sand 30 minute prehydrate.

Prewet granite.

Lifts installed in succession without waiting.

2A Type N 1 part portland cement, 1 part lime, 6 part sand

C144 mason’s sand 30 minute prehydrate.

Prewet granite.

Lifts installed in succession without waiting.

3A Type O 1 part portland cement, 2 part lime, 9 part sand

C33 concrete sand 30 minute prehydrate.

Prewet granite.

Lifts installed in succession without waiting.

4A Type O 1 part portland cement, 2 part lime, 9 part sand

C144 mason’s sand 30 minute prehydrate.

Prewet granite.

Lifts installed in succession without waiting.

5A Type N 1 part portland cement, 1 part lime, 6 part sand

C144 mason’s sand (50 percent) C33 concrete sand (50 percent)

30 minute prehydrate.

Prewet granite.

Lifts installed in succession without waiting.

6A Type O 1 part portland cement, 2 part lime, 9 part sand

C144 mason’s sand (50 percent) C33 concrete sand (50 percent)

30 minute prehydrate.

Prewet granite.

Lifts installed in succession without waiting.

7A Type N 1 part portland cement, 1 part lime, 6 part sand

C144 mason’s sand (50 percent) C33 concrete sand (50 percent)

30 minute prehydrate.

No prewetting of granite.

Lifts installed in succession without waiting.

8A Type N 1 part portland cement, 1 part lime, 6 part sand

C144 mason’s sand (50 percent) C33 concrete sand (50 percent)

30 minute prehdrate.

No prewetting of granite.

Delay of 60 minutes prior to installing final lift.

Half of joints taped after repointing.

9A Type N 1 part portland cement, 1 part lime, 6 part sand

C144 mason’s sand (50 percent) C33 concrete sand (50 percent)

30 minute prehydrate.

No prewetting of granite.

Delay of 60 minutes prior to installing final lift.

Joints taped after repointing.

10A Type N 1 part portland cement, 1 part lime, 6 part sand

C144 mason’s sand (50 percent) C33 concrete sand (50 percent)

30 minute prehydrate.

No prewetting of granite.

Lifts installed in succession without waiting.

Left half of bed joint and lower half of head joint taped after repointing.

11A Type N 1 part portland cement, 1 part lime, 6 part sand

C144 mason’s sand (50 percent) C33 concrete sand (50 percent)

30 minute prehydrate.

No prewetting of granite.

Lifts installed in succession without waiting.

Left half of bed joint and lower half of head joint taped after repointing.

* Mortar type by proportions are standard as defined in ASTM C270 Standard Specification for Mortar for Unit Masonry.

The following observations were made during and subsequent to the September 2015 trials:

1. Hairline cracks formed in some of the mortar joints (Figure 4).

2. Hairline cracks were noticeable one day after installing the mortar.

3. The hairline cracks were very narrow, generally less than 0.0015 inches. Based on industry research, cracks this narrow do not allow significant water infiltration.

4. The backup mortar behind the sealant at some joint locations was found to be damp when the sealant and backer rod was removed.

5. White efflorescence deposits were visible on the backup mortar and granite within the joint behind the sealant, at isolated locations.

6. Some small isolated areas of older, possibly original, pointing mortar not removed during the previous sealant installations was observed after removal of the sealant, and was bonded to the granite (Figure 5).

7. Even after careful removal of the sealant and joint preparation, isolated fragments of sealant were still noted in the joints during WJE’s examination (Figure 6). The isolated areas of observed sealant were removed during the examination.

8. The trials prepared using 100 percent ASTM C33 concrete sand had poor workability. A significantly greater quantity of water was required to produce a workable mix, as compared to the other mix designs.

9. When the prepared joint was lightly rinsed at low pressure only as necessary to remove loose dust, and the granite was allowed to dry for 30 to 60 minutes before installing mortar, reduced formation of hairline cracks was observed.

10. Installing the final lift 30 to 60 minutes after the second lift was associated with reduced formation of hairline cracks.

11. Applying plastic tape over the newly pointed joint to reduce the rate of evaporation was associated with reduced formation of hairline cracks (Figure 7).

The September trials were examined during the second (October) site visit, prior to selecting the composition and installation techniques for the larger samples. No additional hairline cracking in the September trials was observed in October. A summary of our observations of cracking in the first round of trials is provided in Table 2.

Table 2. Observations of September 2015 Trials Sample Observations 1A No cracks 2A Isolated cracks from poor compression, <1 percent 3A Approximately 20 percent cracks, primarily on vertical joints 4A Approximately 50 percent of joints with cracks 5A Approximately 25 percent of joints with cracks

6A Approximately 10 percent of joints with cracks 7A No cracks, slight white deposit 8A Isolated cracks from difficulty encountered when tooling the joints; some white deposits 9A No cracks 10A No cracks 11A No cracks

Larger Scale Trials, October 2015

A second site visit was made on October 5 through 8. Based on the lessons learned during the September trials, three larger scale repointing trials were performed by Cleveland Marble. For all of these trials, a prehydrated Type N mortar mix, consisting of 1 part portland cement, 1 part hydrated lime, 3 parts mason’s sand, and 3 parts concrete sand, was used. The prepared joints were lightly rinsed at low pressure only as necessary to remove loose dust, and the granite was allowed to dry for 30 to 60 minutes before installing the mortar. The trials are summarized in Table 3. Locations of trials are provided in Figure 8 and Figure 9.

Table 3. Repointing Trials, October 2015 Trial Proportions Aggregate Comments 1B Type N

1 part portland cement, 1 part lime, 6 part sand

C144, mason’s sand (50 percent) C33, concrete sand (50 percent)

Light rinse to remove dust.

30 minute prehdrate.

Allow 1 hour prior to installation of third lift.

Joints left exposed during cure.

2B Type N 1 part portland cement, 1 part lime, 6 part sand

C144, mason’s sand (50 percent) C33, concrete sand (50 percent)

Light rinse to remove dust.

30 minute prehdrate.

Lifts installed in succession without waiting.

Joints taped to reduce evaporation of water.

3B Type N 1 part portland cement, 1 part lime, 6 part sand

C144, mason’s sand (50 percent) C33, concrete sand (50 percent)

Light rinse to remove dust.

30 minute prehdrate.

Allow 1 hour prior to installation of third lift.

Joints taped to reduce evaporation of water.

The following are observations during and subsequent to the trials:

1. No cracks were observed in Trial 1B the day after mortar installation (Figure 14).

2. Trials 2B and 3B were installed at the end of the site visit and were not examined the day after installation. The trials will be evaluated in spring 2016.

Efflorescence Removal Trials

The exterior granite has been abrasively cleaned in the past, and the existing granite is microscopically damaged, causing an uneven appearance. Due to long term water infiltration into the concrete structure, white deposits, primarily calcium carbonate, have formed on the exposed granite surface, typically below joints with breaches in the elastomeric joint sealant. A visual comparison of existing deposits and the extent of deposits photographically documented by WJE in October 2006 indicated a significant increase in the surface deposits over the last nine years, especially in the bottom portion of the memorial column (Figure 10 through Figure 13). In our report dated October 7, 2011, WJE recommended a trial using a gentle abrasive system to remove the deposits. On September 10, 2015, a cleaning trial was performed by Quintek Corporation (Quintek). Quintek is a proprietary gentle abrasive (microabrasive system) which uses low pressure and a fine abrasive (typically crushed glass or dolomite) projected at the surface through a nozzle (refer to product data provided in the appendix). To test the deposit removal technique, the flute with the greatest amount of deposits near grade, Flute 12, was selected for a cleaning trial (Figure 15). In accordance with the Secretary of Interior’s Standards for the Treatment of Historic Buildings, cleaning trials were performed using the gentlest method. Initial trials were performed using 15 psi pressure, and the pressure was increased to 25 psi until the technique was effective at a controlled but reasonable production rate (Figure 16). The tip of the nozzle was held at 12 inches from the surface of the stone. A subsequent trial was conducted of select granite units at Flute 10 (Figure 17). The trials were evaluated using field microscopy to identify potential damage to the granite as a result of the cleaning trial.

The following observations were made during and subsequent to the trials:

1. A pressure of 25 psi was necessary to remove the thickest deposits (Figure 18).

2. Overall, the cleaning was effective at removing the vast majority of the deposits. Minor, infrequent pinhole-size deposits were observed in crevices on the surfaces under close inspection.

3. After removal of the joint sealant, small, localized deposits were observed on granite surfaces within the joint as well as on backup mortar, that had been concealed by the backer rod and sealant (Figure 19).

When the joint sealant was removed prior to cleaning tests, the microabrasive was somewhat effective at removing efflorescence from these surfaces within the joint.

4. No new damage to the stone was visible under field microscopy, beyond the preexisting damage from previous aggressive cleaning interventions.

5. The deposit removal did not remove the deeply embedded discoloration of the stone adjacent to the joints.

6. During cleaning at Flute 12, water beaded on the granite surface, indicating the likely presence of a previously applied clear water repellent.

7. The previous abrasive cleaning has left an uneven appearance to the granite, likely as a result of high pressures, aggressive abrasive, and uneven application by the operator.

CONCLUSIONS AND RECOMMENDATIONS

Repointing

Based upon the September–October 2015 trials, and our observations to date of those trial installations, a prehydrated repointing Type N mortar mix, using an equal parts blend of ASTM C33 concrete sand and ASTM C144 mason’s sand, can be installed in a manner that results in the pointed joints not exhibiting hairline cracks, as long as careful installation methods are followed.

The following materials and techniques were found to be successful during the trails at minimizing or eliminating the formation of hairline mortar cracks. Therefore, the specifications will be prepared to include the following requirements:

Use of a Type N mortar by proportions including 1 part portland cement, 1 part hydrated lime, 3 parts ASTM C33 concrete sand, 3 parts C144 mason’s sand.

Preparation of joints for pointing using a diamond impregnated blade and stainless steel wire brush.

Note that the joint preparation work for this project requires much more attention to detail and time than a typical pointing project. During the tests and trials, it was found that even a highly skilled mason, working on small areas without time or productivity pressures, did not succeed in fully removing all traces of sealant from the joint. Only under subsequent inspection and probing was all sealant residue identified and removed. Note that removal of all sealant residue from mortar bondline surfaces is a critical aspect of the joint preparation work. Sealant left within the joint forms a bond breaker that prevents adhesion of mortar to the granite and failure of the pointed joint.

Pre-hydration of the mortar for at least 30 minutes prior to installing the mortar.

Rinsing of the prepared joints at low pressure only as necessary to remove loose dust, and allowing the granite to dry prior to installing the mortar.

Installation of the mortar in three lifts.

The following techniques were found to be successful during the trails at minimizing or eliminating the formation of hairline mortar cracks. While all of these techniques helped to reduce or eliminate hairline cracking, they will likely require modification during installation depending on weather conditions including temperature, humidity, wind speed, sun exposure, etc. Consequently, these techniques cannot be precisely specified because they may have to be modified to address varying field conditions:

Installation of the final mortar lift 30 minutes or more after the second lift Application of an impermeable tape following the installation of the mortar for the initial curing period.

An overnight application was used during the trials.

The repointing and cleaning trials will be reevaluated in spring 2016. The observations made at that time will be used to revise the contract documents if needed.

Cleaning

Based upon the September 2015 trials, it was demonstrated that a microabrasive system will be effective at removing the vast majority of the efflorescence, very likely without further damage to the granite.

Accordingly, the project contract documents will be developed to indicate the use of a microabrasive system with a crushed glass abrasive at 25 psi with the nozzle held 12 inches from the stone surface to remove the isolated areas of efflorescence. Mechanical methods using hand tools will be included for removal of any remaining efflorescence from within the joints as part of preparation for repointing.

The trial cleaning processes did not reduce the uneven appearance of the granite caused by previous aggressive cleaning interventions. Consequently, attempting to clean the memorial to mitigate the uneven appearance and deeply embedded dark discoloration is unlikely to be successful. Therefore, since there are extensive areas of granite with little to no efflorescence, overall cleaning of all granite is not recommended.

Since the efflorescence is concentrated near the base and near the top of the column, the cleaning treatment should be applied to all granite surfaces in those areas. In the middle of the shaft, only localized areas of efflorescence will require spot treatment using the microabrasive system.

Sequence and Scope of Work

During the trials, efflorescence was observed on granite and backup mortar surfaces within the joints after removal of joint sealant and backer rod. In order to remove the efflorescence underneath the sealant using the microabrasive process, the sealant would require removal before cleaning. If all sealant was removed first, followed by cleaning, followed by repointing, the sequence would result in having the joints open for an extended period of time, which is not desirable and would significantly increase the potential for water infiltration into the memorial.

Therefore, the recommended sequence of work is for the cleaning to precede the sealant removal and joint repointing. For surfaces of granite and mortar within the joints, part of the preparation work by the mason for repointing will include mechanical removal of efflorescence from granite surfaces and removal of backup mortar where efflorescence is present. In some locations, small spots of efflorescence may remain on the granite surface where currently concealed by the sealant, but which are not removed by joint preparation work or covered by new repointing mortar. If desired by NPS, requirements for follow-up spot cleaning and/or isolated sealant removal prior to be cleaning can be included in the contract documents to address these small areas of efflorescence.

Accordingly, the recommended scope and sequence of work for the memorial will be as follows:

1. Remove the efflorescence from the granite.

2. Remove all sealant and backer rod from the granite joints.

3. Grind the joints to remove backup mortar, to remove efflorescence within the joint, and to remove all silicone sealant residue from granite surfaces at the joint.

4. Using hand tools, remove loose debris present in joints up to 4 inches back from the surface of the granite.

5. Rinse joints to remove dust, using minimal water.

6. Inspect all surfaces carefully to ensure removal of all efflorescence and deposits.

7. Inspect all surfaces carefully to ensure removal of all sealant residue.

8. Remove additional remaining efflorescence, deposits, and sealant.

9. Inspect prepared joints.

10. Deep point the joints to fill all voids in the joints.

11. Repoint the joints with a pre-hydrated cementitious mortar installed in 1/4-inch lifts.

12. Rinse the joints to remove dust.

13. Repoint mortar joints in three lifts.

14. Allow the newly installed mortar to cure.

15. Inspect mortar for cracks.

16. Remove and replace any mortar with cracks.

17. Inspect mortar as final review.

17. Remove mortar from adjacent granite without use of chemical cleaners. Rinse all granite masonry surfaces to remove loose dust and debris.

At each step in the scope above, careful attention to detail by the mason, and independent inspection of the work, will be required.

Quality Control During Construction

Success of the repointing during construction will be greatly dependent upon proper preparation of the joints.