SOW TDVG202693 Repair Taxiway H (1).pdf

S T A T E M E N T O F W O R K

For

TDVG202693

Repair Taxiway H

Alpena CRTC, Michigan

Prepared by:

James McCraven

24 August 2020

STATEMENT OF WORK

FOR

TDVG202693

Repair Taxiway H

Alpena CRTC, Michigan

The contractor shall provide all materials and labor required to Repair Taxiway H at the Alpena CRTC, Alpena, MI 49707. This shall include but is not limited to the repair of pavement in two areas of Taxiway H as follows: Demolition, removal and replacement of two areas consisting of a 12’x18’ and a 12’x30’ panel repair, each approximately 14” in depth. Taxiway H was constructed with a 5” bituminous pavement overlay of 9” of concrete pavement on virgin sand. It is unknown if reinforcing steel exists in the existing pavement sections to be repaired. This work shall also include demolition, saw cutting, selective removal and replacement of one monolithic 14” lift of concrete, including reinforcing steel and joint sealants. All work performed shall be in accordance with the Unified Facilities Criteria (UFC) 3-270-01 Asphalt and Concrete Pavement Maintenance and Repair. Contractor is responsible to provide an acceptable final product that meets the requirements of this Statement of Work (SOW). All work performed under this SOW shall be conducted in accordance with UFC 3-270-01, all applicable state and federal laws, regulations, and codes, ANG policies and regulations, and the SOW as outlined below:

1. The tasks of this SOW includes but is not limited to:

a. Repair Taxiway H pavement in kind and/or as approved by COR.

b. The repair will consist of saw cutting, selective removal of panels, disposal off site, compaction of soils, installation of reinforcing steel, placement of 5000 psi concrete w/air, finishing, curing and joint sealants. Soil and material testing will be provided by the contractor.

c. Removal of existing concrete sections will be performed by the lift-out method, jack hammering is not permitted.

d. The contractor shall complete a mandatory site visit prior to bid opening. Contractor shall investigate current conditions to verify material types and quantities needed to properly complete this project before the bid opening and construction work can begin.

e. Implement waste management plan as approved by the Contracting Officer’s Representative. Provide handling, containers, storage, signage, transportation, and other items as required to implement waste management plan during the entire duration of the Contract. See Section 017419 - Construction Waste Management.

f. Provide a Superintendent to oversee the Contractor’s workforce.

g. The wage schedule shall be based on Alpena County.

2. General guidelines include, but are not limited to the following specifications and regulations:

a. UFC 3-270-01 Asphalt and Concrete Pavement Maintenance and Repair

3. There will be a site visit, prior to award to allow for site investigation. Any site visits post award shall be coordinated with the Government.

4. Warranty: Contractor shall provide a one year warranty on workmanship of the entire project in addition to any manufacturer’s warranty on materials installed. The contractor will provide any commercial warranty on materials or equipment included in the construction that exceeds this one-year, all-inclusive warranty. The commercial warranty will be issued to the Government.

5. Record drawings and utility maps may be provided to the contractor as a courtesy at the discretion of the Government, but their accuracy is not guaranteed. The contractor shall do his own field investigations of the utilities and other items in the area and base his work accordingly. The Government assumes no responsibility for any conclusions or interpretations made by the Contractor based on the information made available by the Government. Nor does the Government assume responsibility for any understanding reached or representation made concerning conditions which can affect the work by any of its officers or agents before the execution of this contract, unless that understanding or representation is expressly stated in this contract. These record drawings bear no such representation or understanding.

6. Contractor shall conduct an intensive field survey of all existing conditions. The contractor should survey existing conditions and correlate their work requirements accordingly. Contractor shall verify all dimensions, calculations and code requirements for all elements of work. The contractor is ultimately responsible for constructability and providing a complete and usable product at the completion of the project.

7. The disturbance of Asbestos-Containing Building Material (ACBM) is not anticipated during this project. However, if suspected ACBM is encountered, work in the immediate vicinity must stop and notify the Government. After consultation with base personnel, the PM will direct further action to be taken. Work should proceed uninterrupted in unaffected areas of the project.

8. The presence of lead on painted surfaces is not expected.

9. The disturbance of communication lines and/or equipment is not anticipated during this project. However, if communication lines or equipment are encountered, work in the immediate vicinity must stop and notify the COR. After consultation with base communication personnel, the COR will direct further action to be taken. Work should proceed uninterrupted in unaffected areas of the project.

10. Period of Performance shall be 120 calendar days from notice to proceed.

11. The contractor shall submit to the Program Manager a coordinated schedule indicating the sequence of operations for review prior to commencement of the work. Currently hours of construction are limited to Monday thru Friday 0730-1630. Any work outside these hours and on Federal Holidays must be requested at least 72 business hours in advance and then approved by the Program Manager. The federal holidays are listed below:

a. January 1st – New Year’s Day

b. Third Monday in January – Martin Luther King Jr. Day

c. Third Monday in February – Washington’s Birthday

d. Last Monday in May – Memorial Day

e. July 4th – Independence Day

f. First Monday In September – Labor Day

g. Second Monday in October – Columbus Day

h. November 11th – Veterans Day

i. Last Thursday in November – Thanksgiving Day

j. December 25th – Christmas Day

12. The Contractor shall fully cooperate with the other contractors and with Government employees and shall carefully adapt scheduling and performing the work under this contract to accommodate the additional work (of others), heeding any direction that may be provided by the Government.

The Contractor shall not commit or permit any act that will interfere with the performance of work by any other contractor or by Government employees. This is within close proximity to an active airfield. Work is far enough away that airfield operations will not be disturbed. Scrap materials must be closely monitored to prevent any Foreign Object Debris from blowing towards any aircraft.

13. Taxiway H is currently inactive and is under NOTAM (Notice to Airmen) closed to airfield activity.

However, this repair is within the boundaries of an active airfield and the Contractor will be responsible to coordinate all activities with Airfield Management and maintain radio contact with the Air Traffic Control tower. Radios can be obtained from Airfield Management.

14. Temporary utilities (power, HVAC, lighting, etc.) is not expected to be needed on this project.

15. Egress: Do not close or obstruct walkways, corridors, or other occupied facilities without written permission from the Government.

16. Life Safety

a. When demolition occurs in or near an occupied space, measures must be taken to protect the indoor air quality, reduce noise, limit vibration from cutting or chopping, reduce odors emanating from demolition debris, and mitigate dust infiltration from airborne particles and foot traffic.

b. Use water mist, temporary enclosures, and other suitable methods to limit dust and dirt rising and scattering in the air. Do not use water when it may damage existing construction or create hazardous or objectionable conditions such as ice, flooding, and pollution. Remove decayed, vermin-infested, moldy or otherwise dangerous or unsuitable materials, and promptly dispose of them off-site. Maintain adequate ventilation when using cutting torches.

c. Avoid unsightly conditions by cleaning adjacent structures and architectural finishes.

Eliminate tractable dirt by wet-mopping floors and wiping down walls and doors of the demolition enclosure. Provide walk-off mats from the area of work to prevent dust from being tracked onto adjacent floor finishes. Do not use public corridors, lobbies, or hallways as staging areas. Damage to adjacent construction during demolition must be repaired and restored within 48 hours by the contractor.

17. Locate, identify, disconnect, and seal or cap off any utilities as necessitated by the project. Do not interrupt existing utilities serving occupied or operating facilities unless authorized in writing by the Government. Arrange to shut off indicated utilities with respective providers. Provide at least 72 hours’ notice to the government if a shutdown of service is required during the changeover. Maintain services to remain and protect them against damage during the project.

Prior to any digging, an AF Form 103 (Dig Permit) is required to coordinate with the Base and to locate utilities. The Contractor must allow 10 business days to process this form.

18. ANTITERRORISM & OPERATIONS SECURITY: The Alpena-CRTC is a closed facility, with controlled access. The contractor shall comply with all applicable installation/facility access and local security policies and procedures, which may be obtained from the Government. The contractor shall also provide all information required for background checks to meet installation access requirements to be accomplished by the local installation’s Security Forces. The contractor shall ensure compliance with all personal identity verification requirements as directed by DoD, HAF and/or local policy. Should the Force Protection Condition (FPCON) change, the Government may require changes in contractor security matters or processes.

Contractor and all associated sub-contractors employees shall comply with adjudication standards and procedures using the National Crime Information Center Interstate Identification Index (NCIC-III) and Terrorist Screening Database (TSDB) (AFI 31-101 and AFI 10-245), applicable installation, facility and area commander installation/facility access and local security policies and procedures (provided by government representative), or, at OCONUS locations, in accordance with status of forces agreements and other theater regulations.

The contractor will submit Contractor EAL’s for all contractor employees and subcontractor employees. All contractor employees, to include subcontractor employees, requiring access to Government Installations, Facilities and Controlled Access areas shall complete AT Level I awareness training. AT Level I Awareness Training will be conducted when personnel report to Pass and ID to receive their base access credentials. Personnel will sign the awareness and a copy will be maintained with the Contractor EAL. The contractor is responsible for contacting and coordinating Contractor EAL’s directly with Pass and ID. Please contact Shirley Hart at (989) 354- 6370 or e-mail shirley.hart.ctr@us.af.mil or Loretta Smith at (989) 354-6245 or e-mail loretta.smith.6.ctr@us.af.mil

Attachments:

1 – UFC 3-270-01 Asphalt and Concrete Pavement Maintenance and Repair mailto:shirley.hart.ctr@us.af.mil mailto:loretta.smith.6.ctr@us.af.mil

UFC 3-270-01

21 February 2018

UNIFIED FACILITIES CRITERIA (UFC)

O&M MANUAL:

ASPHALT AND CONCRETE

PAVEMENT MAINTENANCE AND

REPAIR

APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED

UNIFIED FACILITIES CRITERIA (UFC)

O&M MANUAL: ASPHALT AND CONCRETE PAVEMENT REPAIR

Any copyrighted material included in this UFC is identified at its point of use.

Use of the copyrighted material apart from this UFC must have the permission of the copyright holder.

U.S. ARMY CORPS OF ENGINEERS (Preparing Activity)

NAVAL FACILITIES ENGINEERING COMMAND

AIR FORCE CIVIL ENGINEER CENTER

Record of Changes (changes are indicated by \1\ ... /1/)

Change No. Date Location

This UFC supersedes UFC 3-270-01, dated 15 March 2001; UFC 3-270-02, dated 15 March 2001; UFC 3-270-03, dated 15 March 2001; UFC 3-270-04, dated 15 March 2001; UFC 3-250-06, dated 16 Jan 2004; Air Force ETL 96-4, dated 9 July 1996; Air Force ETL 97-2, dated 28 July 1997; Air Force ETL 02-7, dated 7 August 2002; Air Force ETL 02-8, dated 5 September 2002; Air Force ETL 11-26, dated 21 December 2011; and Air Force ETL 14-2, dated 21 November 2014.

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CHAPTER 14 FULL-DEPTH REPAIR OF CONCRETE PAVEMENTS

14-1 INTRODUCTION.

When normal maintenance procedures can no longer correct the deteriorated concrete pavements, full-depth repair may become necessary to restore damaged areas to their original condition and extend the service life of the pavement. Full-depth repairs are generally necessary when slabs have been shattered (Figure 14-1) or have deteriorated to such an extent that the safe support of the required load is no longer possible. Full-depth repairs are an effective means of restoring the rideability and structural integrity of deteriorated concrete pavements and, therefore, extending their service life.

14-2 NEED FOR FULL-DEPTH REPAIR.

There are several types of distress that occur at or near transverse joints that may require full-depth repair when classified as medium- or high-severity level distress.

Comprehensive distress manuals (ASTM D6433, Standard Practice for Roads and Parking Lots Pavement Condition Index Surveys, and ASTM D5340, Standard Test Method for Airport Pavement Condition Index Surveys) are available that define distress types and severity levels.

14-2.1 Rigid Pavement Distress Types.

Types of distress that occur in rigid pavements that may justify full-depth repair when classified as medium- or high-severity distresses include:

• Blowup

• Corner break

• Durability (“D”) cracking

• Patch deterioration

• Shattered slab (a slab broken into four or five pieces with some or all cracks of high severity or a slab broken into six or more pieces with over 15 percent of the cracks of medium or high severity) (Figure 14-1)

• Spalling (if spalling extends to greater than one-third the slab thickness)

• Punchout

• Railroad crossing distress

Figure 14-1 Shattered Slabs

14-2.2 Other Rigid Pavement Concerns.

Concrete pavements may also exhibit spalling and faulting at intermediate cracks. This deterioration may be caused by repeated heavy traffic loads, failure of doweled joints to function properly, and/or the intrusion of incompressible materials in the open cracks. If the spalling extends to greater than one-third the slab thickness or if the faulting is in excess of 0.5 inch (12 millimeters), full-depth repair at the crack locations may be considered.

14-2.3 Full-Depth Repair Key Steps.

The key steps in performing a full-depth repair include the following:

1. Selection of repair boundaries

2. Sawing of repair boundaries

3. Removal of existing concrete

4. Restoring the repair area support (subgrade and base preparation)

5. Dowel bar and tie-bar placement

6. Replacing reinforcement, if any

7. Restoring expansion joints, if any

8. Use of filler material at joints

9. Dowel bar placement

10. Concrete placement

11. Concrete finishing and texturing

12. Curing

13. Joint sealing

14. Opening to traffic.

Caution: Successful performance of full-depth repairs requires proper restoration of the base and subgrade and provision of effective load transfer across trafficked joints, other than thickened edge slip joints. Also, full-depth repairs are not effective over the long-term if the existing pavement exhibits materials-related distress, such as D-cracking or ASR.

14-2.4 Selection of Repair Boundaries.

First, conduct a detailed survey to accurately identify the required repair areas so all significant underlying distresses are identified and corrected. Quite often, and particularly in freeze-thaw climates, the deterioration near joints and cracks is greater at the bottom of the slab than is apparent from the top of the slab.

In both plain jointed and reinforced jointed concrete pavement, partial-slab replacement is acceptable where the distresses are within one-half of the slab length.

Full-width slab patching is required if the original slab width is less than 20 feet (6 meters) or full-depth cracks are located within the interior area of the slab. A minimum slab length is required to avoid rocking and pumping of the repair. General experience indicates that 10 feet (3 meters) is a minimum length for airfield applications. For roadways with 11- to 14-foot (3.4- to 4.3-meter) -wide lanes, the repair area needs to be full lane width with a minimum length of 6 feet (1.8 meters). If the repair extends over half the length of the panel, consider full panel replacement.

14-2.4.1 Saw Cut.

Saw cut will be a minimum of 3 feet (900 millimeters) from a joint and the minimum patch length will be 6 feet (1.8 meters). Saw cut in lines forming rectangles parallel with or perpendicular to the jointing pattern.

14-2.4.2 Patch Boundary.

Extend the patch boundary to the joint(s) if the length of the patch is greater than half the length of the panel.

14-2.4.3 Utility Cut.

If the patch is a utility cut, make cut about 12 inches (300 millimeters) beyond limits of the excavation and any sloughing of the trench. This saw cut limit of the excavation area allows the repair concrete to extend beyond the excavation. (Figure 14-2)

14-2.4.4 Continuously Reinforced Concrete.

For continuously reinforced concrete, position the patch area so the distressed portion is in the middle of the patch area. Patch at least 6 feet (1.8 meters) in length if reinforcing steel is to be tied, and at least 4 feet (1.2 meters) long if welded or if mechanical splices are used to connect reinforcing steel.

Figure 14-2 Utility Cut

14-2.5 Sawing Cutting Repair Boundaries.

The repair boundaries of mesh-reinforced, plain doweled, and plain undoweled jointed concrete pavement are typically cut full-depth using diamond blade sawing (Figure 14- 3). Sawing is the recommended method.

14-2.5.1 Hammer Use.

Do not use hammers to outline the area. The rough joint formed by hammers typically spalls in service and it is difficult to lift out the concrete within the repair boundaries or break it up with large pavement breakers.

14-2.5.2 Partial-Depth Cuts.

The use of the partial-depth saw cut is not recommended. The partial-depth saw cut does provide some aggregate interlock due to a rough face but micro-cracking will develop at the bottom of the repair area and the bottom of the slab may spall when using a large pavement breaker to shatter the concrete within the repair boundaries.

14-2.5.3 Full-Depth Cuts.

Full-depth saw cuts will completely separate the concrete that is to be removed, leaving undamaged vertical faces, and eliminate damage at the bottom of the remaining slab.

14-2.5.4 Warm Weather.

On warm days, a double saw cut method may be necessary to prevent binding of the sawing blade.

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Figure 14-3 Diamond Blade Sawing

14-2.5.5 Continuously Reinforced Concrete (CRC).

The repair boundaries of CRC pavement are provided by sawing full depth at the repair boundaries. Partial-depth saw cuts above the reinforcing steel are then provided at a distance (typically about 20 inches [500 millimeters]) required by the lap length of the reinforcement) from the repair boundaries (Figure 14-4). Locate the partial-depth saw cuts at least 18 inches (450 millimeters) from the nearest tight crack and do not saw across an existing crack. If any of the reinforcing steel is cut during partial-sawing, extend the repair area by the required lap length of the reinforcement.

Figure 14-4 CRC Pavement Full-depth Repair Layout

14-2.5.6 Matching Joints.

Matching joints in adjacent lanes (typically for roadways) is not necessary as long as a debonding material (e.g., fiberboard) has been placed along the longitudinal joint to separate the lanes. However, if the distressed areas in both lanes are similar and both lanes are to be repaired at the same time, it is a good practice to align repair boundaries to avoid small offsets and maintain continuity.

14-2.6 Removal of Existing Concrete.

Do not use procedures for removal that spall or crack adjacent concrete or significantly disturb the base or subgrade. There are two basic methods to remove concrete pavement, as discussed below.

14-2.6.1 Breakup and Cleanout Method.

Concrete breakup is accomplished using a pavement breaker with removal by a backhoe (Figure 14-5). This method disturbs the base and requires base replacement or filling with concrete. It also has the potential to damage the adjacent slab if proper sawing procedures are not followed. This is not a preferred method for concrete removal.

After the repair is isolated by full-depth saw cuts, additional saw cuts using a wheel saw with at least 1.5-inch (38-millimeter) kerf, are made within the repair area, parallel and approximately 1.5 feet (450 millimeters) from each perimeter saw cut or joint (Figure 14-6). Begin breakup in the center of the removal area within the inner saw cuts. After breakup of the inner area, a backhoe can be used to gently pull the outer region free of the adjacent slab, or this strip can be broken up with light hand-held jackhammers.

Figure 14-5 Concrete Removal Using Backhoe

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Figure 14-6 Additional Saw Cuts (Breakup Method)

14-2.6.2 Lift-out Method.

This is a recommended practice as it results in little damage to the base and the subgrade. This procedure is accomplished using a crane or front-end loader to lift the deteriorated concrete from its in-place position (Figure 14-7). Closely control lift-out operations to prevent accidents. After the repair area is isolated by full-depth saw cuts, holes are drilled through the slab and fitted with lift pins and the slab is then lifted in one or more pieces. If it is necessary to decrease the load, the slab may be saw cut into smaller pieces.

Figure 14-7 Lift-out Method

During hot weather, the sawing equipment may bind during initial transverse sawing procedures. It may be necessary to perform sawing at night when the temperatures are lower and the slabs are contracting. Another solution is to use a carbide-tipped wheel saw to provide a pressure relief cut within the patch area prior to the perimeter sawing (Figure 14-8). It is strongly recommended that the carbide-tipped wheel saw cut be made no closer than 6 to 8 inches (150 to 200 millimeters) from the proposed patch boundary due to the possibility of damage and micro-cracking in adjacent concrete. The same procedures may be used for the removal of CRC.

Carefully remove concrete in the two reinforcing lap areas by jackhammering so as not to damage the reinforcing.

For CRC pavements, after the concrete between the two full-depth saw cuts is removed, remove the concrete between the full-depth saw cuts and the partial-depth saw cuts by jack-hammering to expose the steel reinforcement.

Figure 14-8 Pressure Relief Cuts for Lift-out Method

14-2.7 Subgrade and Base Preparation.

After the deteriorated and loose concrete has been removed, examine the base course.

Remove all excess disturbed material. Compact the patch area using a plate compactor (Figure 14-9). If excessive moisture exists in the repair area, remove it or dry the repair area before re-grading and compacting the base. It is difficult to adequately compact granular material along the perimeter and the corner areas of the patch, which may result in settlement of the patch under future traffic loading. Replacing some or all disturbed base material with lean concrete or flowable fill is a very good alternative for critical operational areas.

Figure 14-9 Patch Area Compaction

14-2.8 Dowel and Tie-Bar Placement.

In full-depth repair of jointed concrete pavements, good load transfer across the transverse repair joints is a critical factor affecting the performance of the full-depth repairs. Load transfer is best achieved by properly installed dowel bars of sufficient size and number. For dowel bar size and spacing, follow the recommendations provided in Table 18-1.

Deformed tie-bars along longitudinal joints in new construction are used to restrict movement at these joints. These bars are typically #5 or #6 in size and spaced at about 30 inches (750 millimeters). For roadway full-depth repairs, tie-bars along interior joints (e.g., centerline joint) are necessary for repair lengths exceeding 40 feet (12 meters) to prevent drifting of the full-depth patch.

For full-depth repair of airfield pavements, incorporate dowel bars along longitudinal joints within the patch and dowel all edges to the existing pavement (longitudinal and transverse).

14-2.8.1 Smooth Dowel Bars.

Use of smooth dowel bars at the joints provide load transfer across these joints while allowing the joint to open and close as the surrounding pavement expands and contracts in response to temperature and moisture changes.

18-4 CORRECTION OF DEFICIENCIES.

Before load transfer devices are installed, it is necessary to determine the cause of the joint or crack distress. Attempt to correct the cause(s) of these deficiencies prior to LTR.

Slabs exhibiting extensive distress along a joint may require portions of or the entire slab to be replaced. Also, successful installation of load transfer devices requires sound concrete adjacent to the joint or crack. If the concrete near the joint or crack is significantly deteriorated, perform full-depth repair (with provisions for load transfer) in lieu of LTR. Perform the following additional work if required prior to LTR. Subsealing (essential if loss of support exists) to fill voids in the pavement structure and to restore support to the pavement slabs, and full-depth and spall repairs to replace highly distressed joints and slabs with corner breaks, “D” cracking, etc.

18-5 DOWEL LOAD TRANSFER RESTORATION (LTR) PROCESS.

Installing round dowel bars is the primary method of restoring load transfer at existing joints or cracks. In the past, use of proprietary devices was attempted but has fallen out of favor because of cost and uneven performance in the field. Field experience indicates that round dowel bars can effectively transfer loads across joints and cracks.

18-5.1 Dowel Size Requirement.

Specify different size dowels for different thicknesses of pavements. Dowel size and spacing for construction, contraction, and expansion joints are shown in Table 18-1.

Table 18-1 Dowel Size Requirements

Pavement Thickness, inches (millimeters)

Dowel Length, inches

(millimeters)

Dowel Spacing, inches

(millimeters)

Dowel Bar Diameter, inches (millimeters)

8 to 11.5 (200 - 290) 16 (400) 12 (300) 1 (25) 12 to 15.5 (300 -395) 18 (450) 15 (380) 1.25 (32) 16 to 20.5 (400 - 520) 20 (500) 18 (450) 1.5 (38) 21 to 21.5 (530 - 550) 24 (600) 18 (450) 2 (50)

>26 (660) 30 (762) 18 (450) 3 (75)

For roadway pavements, four dowel bars are typically used for each wheel path.

The bars are typically spaced at 12 inches (300 millimeters).

18-5.2 Cutting Slots for Dowel Installation.

Slots for installing dowels are cut using diamond-blade saws. Gang-mounted multiple blade saws are recommended to speed operations (Figure 18-2). Cut the slots so the

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14-2.8.2 Deformed Dowel Bars.

In contrast to smooth dowel bars, deformed dowel bars are used along certain repair joints to provide both load transfer and prevent movement at the specific joints. Since in repair both smooth and deformed dowel bars have a load transfer role, select their dimensions and spacing based on the design loading for that facility.

14-2.9 Drilling Dowel and Tie-Bar Holes.

Installation of smooth or deformed dowel bars and deformed tie-bars requires drilling holes at specified locations into the exposed (saw cut) face of the existing slab. Gang drills are available to drill multiple holes simultaneously (Figure 14-10). The gang drill maintains the drills in a rigid frame to prevent the drill bits from wandering and holds them in a horizontal position at the correct height (typically, one-half the slab thickness).

Make the depth of the holes approximately one-half the length of the dowel or tie-bar.

Do not use hand-held drills to drill holes for dowel bars as the required dowel alignment cannot be easily achieved.

Figure 14-10 Drilling Multiple Holes at Mid-depth for Dowel Bars

Hole diameters exceeding the bar diameter by 0.125 inch (3 millimeters) or less are recommended when using epoxy materials. Clean the drilled holes using air blasting before injecting the epoxy grout into the hole. Take care during the drilling to ensure that spalling around the drilled hole at the joint face is kept to a minimum. Ensure spalling does not exceed the diameter of the retainer ring used to keep the epoxy from flowing out of the drilled hole. In case of such minor spalling, the epoxy is used to patch the spalls. For larger spalls around the drilled holes, the spalled area needs to be repaired before installing the dowel bars.

14-2.10 Dowel and Tie-Bar Installation.

Use dowels, tie-bars, or reinforcement that are clean and free of flaking rust. Specify appropriate sizes of dowels (at least matching the size of dowel bars used in the existing pavement) for different thicknesses of pavements (refer to UFC 3-260-02, 1148069308C Highlight

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Pavement Design for Airfields, for required sizes). Exercise care in epoxy grouting dowels or tie-bars to ensure complete coverage and support of the bars. Use grout retention devices that fit tightly over the dowel or tie-bar and seal the hole to prevent loss of epoxy. The steps for correctly installing dowel bars after air-blasting the holes are illustrated in Figure 14-11.

The proper installation of the smooth dowel bars is very important. Misaligned dowels can lead to early joint failure (spalling around the dowel bars) or cracking in the slab panel adjacent to the joint. The smooth dowels allow movement of the adjoining slabs. Oil or treat with a debonding material the portion of the bars that extend into the repair when using dowels to prevent bonding of the bars with the repair concrete. Cap one end of dowels used at expansion joints, in addition to oiling or treating with a debonding material, to permit further penetration of the dowels into the concrete when these joints close during warm weather.

Deformed tie-bars with surface ridges provide a locking anchorage with surrounding concrete. These tie-bars are placed in joints that are not intended to have movement.

Figure 14-11 Dowel Bar Installation

A. Injecting the epoxy into the back of the hole in sufficient amount to ensure full coverage around the inserted dowel bars

B. Inserting dowel bars into the hole with a slight twisting motion C. Using a retainer ring to stop the epoxy from flowing out of the hole

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14-2.11 Continuous Reinforced Concrete (CRC) Pavement Repair.

Successful performance of CRC pavements requires good load transfer across all transverse cracks and repair joints. Failure to provide adequate load transfer will cause the repair and the surrounding pavement to fail due to excessive deflection at the joints.

For conventional full-depth repair of CRC pavements, the longitudinal reinforcing is generally carried through the repairs by carefully removing the old concrete to allow the appropriate length of steel (lap length) from the existing pavement to extend into the repair area. This steel is then tied, welded, or mechanically connected to new reinforcing steel that extends through the repair area. When replacing reinforcing steel in the patch area, match the original rebar in size (diameter), grade, and number. Place the new bars on bar supports to ensure proper position and cover. Do not extend bars closer than 2 inches (51 millimeters) to the patch/slab interface.

14-2.11.1 Tied Splices.

Lap tied splices the proper length that provides full bar strength. The recommended lap length for tying longitudinal steel is a minimum of 25 times the diameter of the steel bars.

14-2.11.2 Welded Splices.

Use the proper length for the welding procedure chosen when using welded splices.

Lap bars at the center of the repair area to avoid the potential buckling of bars on hot days.

14-2.11.3 Mechanical Splices.

Use mechanical splices in accordance with the supplier’s instructions.

14-2.12 Expansion Joints.

Expansion joints are placed in concrete pavements to provide relief for expansion of the concrete pavement due to temperature changes. Generally, expansion joints are installed at all intersections of pavements with structures or when a pavement ends near a structure but are rarely required within pavement features.

Expansion joints may be required if longer-length full-depth repairs are made during cool weather when adjacent concrete is in a contracted state or crushing and spalling of concrete at the joints may occur during subsequent hot weather when the concrete expands. Keep expansion joints in pavements to the minimum necessary to minimize future maintenance issues. The types of expansion joints commonly used by the military are the thickened-edge expansion joint (Figure 14-12) and the doweled type expansion joint (Figure 14-13).

Figure 14-12 Thickened-edge Expansion Joint

Figure 14-13 Doweled Expansion Joint

14-2.12.1 Thickened-edge Longitudinal Expansion Joint (Without Dowels).

The thickened-edge type is suggested for longitudinal expansion joints (slip joints) within airfield pavements. Dowels are not used in thickened edge longitudinal expansion joints because differential expansion and contraction parallel with the joints may develop undesirable localized stresses and possibly failure of the existing concrete or the full-depth patch, especially near the corners of existing slabs at transverse joints.

14-2.12.2 Thickened-edge Isolation Joint (Without Dowels).

The thickened-edge isolation joint (without dowels) is the expansion joint best suited to surround or separate any structure that projects through, into, or against the pavement (approaches to buildings, drainage inlets, roadway bridges, and hydrant refueling outlets).

14-2.12.3 Doweled Transverse Expansion Joints.

Use doweled transverse expansion joints within roadway pavements. However, at the angular intersection of pavements, it might be desirable to allow some slippage in the transverse joint to prevent the expansion of one pavement from distorting the other. In such instances, design the transverse expansion joint as a thickened-edge expansion joint.

14-2.13 Filler Material.

Use non-extruding type material for filler material for the thickened-edge and doweled-type expansion joint. The type and thickness of the filler material will depend upon the particular project. Usually, a preformed material of 0.75-inch (20-millimeter) thickness will be adequate, but in some instances a greater thickness may be required, depending on the geometric design of the facility and temperature at the time of full-depth repair.

Use a heavy coating of bituminous material not less than 0.25 inch (6 millimeters) in thickness or a standard non-extruding type material not less than 0.25 inch (6 millimeters) in thickness for filler material for thickened-edge slip joints.

Filler material at expansion joints where dowels are used require that the dowels be securely placed and properly aligned. Drill or punch the non-extruding filler material to the exact diameter at the location of the dowels. Furnish it in lengths equal to the width of the placement. When more than one length of the filler board is used along a joint, hold the abutting ends of the filler in alignment. Hold the filler boards firmly in place and extend downward completely to the bottom of the slab and hold the top edge about

0.5 inch (13 millimeters) below the surface of the pavement. Protect the top edge of the filler material while the concrete is being placed. Use a zip strip to accomplish this, where available.

14-2.14 Concrete Placement.

Conventional concrete is typically used for full-depth repairs. The concrete mixture selection depends on the curing time available to reach required strength before the repair area is opened to traffic. If it is acceptable for the concrete to cure for several days (similar to new construction), regular concrete mixtures using Type I or Type II cement can be used. If an earlier opening time (12 hours to 3 days) is needed, a high early-strength concrete, incorporating a higher volume of Type I or Type II cement or using Type III cement, can be used. However, carefully consider the use of a higher volume of cement in areas subject to ASR in concrete. Follow standard concrete placement procedures, including concrete consolidation procedures.

Place the concrete when the ambient temperature is between 40 and 90 degrees F (4 and 32 degrees C).

14-2.14.1 Vibration Adjacent to Edge.

Give extra attention to ensure that the concrete is vibrated well around the edges and beneath the reinforcement.

14-2.14.2 Rapid-set Proprietary Cementitious Materials.

Rapid-set proprietary cementitious materials that attain sufficient strength for opening to traffic in as little as four hours are available. Use rapid-set proprietary materials in compliance with the manufacturer’s recommendations. These recommendations typically include mixture proportioning, placing, consolidation, curing, time required before opening to traffic, and allowable placement temperature ranges.

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14-2.15 Concrete Finishing and Texturing.

Follow standard procedures when finishing. For repairs less than 10 feet (3.048 meters) in length, strike off the surface of the concrete with the screed parallel to the centerline of the pavement. For repairs more than 10 feet (3 meters) in length, strike off the surface with the screed perpendicular to the centerline of the pavement. Give extra attention to ensure the concrete is not over-finished. Before the concrete becomes non-plastic, give the surface a burlap drag or broom finish to approximately match the surface finish of the existing adjacent concrete pavement unless a grinding operation is to follow the repair work. Typical finishing techniques are illustrated in Figure 14-14.

Figure 14-14 Typical Finishing Techniques for Full-depth Repairs

14-2.16 Curing.

There are many ways to cure concrete. Wet burlap (with or without sand) or white pigmented curing membranes are commonly used for full-depth repairs. Although ponding and constant spraying are the best curing methods, it is generally not practical to do so. Use of white pigmented curing membrane is better for indication of proper coverage and minimizes heating from solar radiation on warm, sunny days. Start curing as soon as the concrete has set sufficiently and the bleed water, if any, has evaporated, but typically no later than 45 minutes after concrete finishing. In hot weather conditions, curing may need to be initiated earlier to minimize the risk of plastic-shrinkage cracking.

Proper concrete curing is crucial to achieving a good repair.

14-2.17 Joint Sealing.

Seal any longitudinal or transverse joints around the perimeter of the repair area and any intermediate joints within the repair area. This reduces the entry of water, which may cause pumping and faulting, and reduces the incidence and severity of spalling along the joints. Saw, do not form, the transverse and longitudinal joint sealant reservoirs at the repair area.

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14-2.17.1 Inspection of Saw Cuts.

After joint sawing for sealing purposes, inspect the saw cuts for spalling. Repair spalls that extend more than 0.25 inch (6 millimeters) horizontally from the sidewall of the saw cuts. Patch void areas caused by honeycombing of the concrete to provide a solid joint sidewall for the sealant to bond.

14-2.17.2 Cleaning Joints.

Following the sawing operation, clean the joint by sandblasting to remove laitance, sawing dust, and other foreign debris from the joint sidewalls and from the pavement surface adjacent to the joint to a width of approximately 1 to 2 inches (25 to 50 millimeters). A multiple-pass technique has proven very successful in removing foreign debris. When using the multiple-pass technique, the nozzle is directed at one of the joint faces and that face is sandblasted the entire length of the slab. After one face has been completed, the nozzle is directed at the other joint face and it is sandblasted for the entire length of the slab. The pavement surface adjacent to the joint is then sandblasted to remove all surface debris. If water-blasting is used instead of sandblasting, employ a multiple-pass technique and dry the joints before starting the sealing operation.

Cleaning the joint is one of the most important steps in obtaining high-quality sealed joints. If the joints are not clean and dry before the sealant is installed, the sealant will usually prematurely fail.

After the joint has been cleaned by sandblasting, clean it again with compressed air to remove any remaining sand or dust. However, complete the final air cleaning of the joint immediately before sealing to prevent sand and dust from blowing back into the joint. A vacuum sweeper can be used to clean around the joints, which will help reduce the amount of debris that blows back into the joints.

14-2.17.3 Installing Backer Rod.

After the joint is cleaned, install the backer rod or separating material. Do not leave the backer materials in the joint for an extended period of time before sealing. These materials may work loose and move up or down in the joint or may even come completely out. Do not twist, stretch, or otherwise damage these materials when they are installed in the joint. Damaging the backer material can cause sealant failure or a poor-quality finished product. Inspect the backer rod or separating material after installation to ensure it has been placed at the proper depth and has not been damaged. After installation of the backer or separating material, the joint is ready for the sealant material. However, seal the joint only if all steps have been properly performed.

14-2.17.4 Sealant Specifications.

Special considerations for the sealant material are jet fuel and jet blast resistance. The full-depth repair may be located in an area where fuel or lubricating or hydraulic fluid spillage may occur or in an area subjected to high temperature from jet blast or exhaust from APUs. Provide and use sealant material that conforms to UFGS 32 01 19 or to ASTM specifications designated for joint and crack sealants for use in these areas.

14-3 PRECAUTIONS.

Comply with the following precautions when performing full-depth repairs:

• Avoid undercutting spalled areas at bottom of remaining existing slab; saw back into adjacent slab until sound concrete is encountered.

• Avoid damaging remaining concrete when lifting out damaged concrete pieces.

• Keep repair areas dry before concrete application.

• Ensure dowel bars are properly aligned.

Although not a common practice for roadway full-depth repairs, consider reinforcement (about 0.2 percent of the cross-sectional area) along the long direction of the full-depth patch at the mid-width location for airfield applications. The reinforcement will keep any crack that may develop tight.