ITEM 255 FULL DEPTH PAVEMENT REMOVAL AND RIGID REPLACEMENT
255.01
Description
255.02
Materials
255.03 Removal
of Existing Pavement
255.04
Correction of Disturbed Subgrade
255.05 Placing
Dowels and Tiebars
255.06
Placement of Portland Cement Concrete
255.07 Wearing
Course Replacement
255.08 Opening
to Traffic
255.09 Method
of Measurement
255.10 Basis of
Payment
255.01 Description. This work consists of full depth
removal of existing pavement; removing subbase where
specified; compacting the subgrade; furnishing and placing dowels, tiebars, and mesh where specified; placing, consolidating,
finishing, and curing new portland cement concrete to
the level of the existing portland cement concrete
pavement; and restoring affected shoulders.
255.02 Materials. Furnish materials conforming to:
Concrete, Class QC 1, QC
MS, QC FS....................... 499
Curing materials, Type
2.......................................... 705.07
Non-shrink non-metallic
grout................................. 705.20
Reinforcing steel ..................................................... 709.00
Preformed elastomeric
joint sealer........................... 705.11
Tiebar steel, epoxy
coated........................................ 709.00
Dowel bars and basket
assemblies.......... 705.01 or 709.13
Expansion shield anchors
Type A........................... 712.01
Use
epoxy coated Hook bolt, Wiggle bolt, and Coupling.
Select
and furnish grout from the Qualified Product List issued by the Laboratory that
firmly anchors the dowel or tiebar within 30 minutes.
A.
Rapid Repair Concrete Mix Materials. If the bid item requires RRCM (Rapid Repair Concrete Mix) do not use the Concrete
classes listed above. Develop a specialized mix design as follows:
Using
the following special Rapid Early Repair admixture Systems such as
1. 4 x 4 concrete
system
2. Rapid -1
3. Or other manufactured systems
acceptable to the Director
Develop a RRCM concrete mix design that will achieve a flexural
strength of 400 psi (2.8 MPa) in not less than 4
hours and not more than 6 hours using 6” x 6” (150 mm x 150 mm) beam samples
conforming to ASTM C293.
Use
cements conforming to 701.02, 701.04 or 701.05
Use
fine aggregate conforming to 703.02.A
Use
Coarse Aggregate(s) conforming to 703.02.B
and 703.13
During
the testing of the RRCM mix design develop the mix’s
maturity curve according to supplement 1098
using the actual materials that will be used on the project.
Document
and Submit to the Engineer the RRCM mix design
results showing flexural strength, time to strength, materials, sources of
materials, quantities of materials and batching requirements.
The
Engineer will have 10 days review the mix design and accept or reject.
255.03
Removal of Existing Pavement. The Engineer will locate and
mark all areas for repair before the start of diamond sawing. Provide the
Engineer with aerosol spray paint to outline those areas for repair.
Saw
cut the existing rigid pavement to the full depth at the limits of the area
designated by the Engineer using a diamond saw blade. Where there is an
existing asphalt concrete overlay on top of the concrete pavement to be
removed, the Contractor may make either a full depth saw cut through the
asphalt concrete overlay and the concrete pavement, or make an offset saw cut
through the asphalt concrete overlay. If making an offset saw cut through
the asphalt concrete overlay, remove the overlay as necessary to provide
clearance for the full depth saw cut through the concrete pavement. The
Contractor may elect to make additional cuts to facilitate the removal of the
pavement.
Remove
pavement in the repair area by the lift-out method without damaging or
undermining the remaining pavement. After the repair area is isolated by
full depth saw cuts, drill holes through the deteriorated slab, and install
lift pins. Vertically lift the pavement out of the repair area.
Remove loose debris left behind after lift-out using hand methods.
Dispose of removed pavement according to Item 202.
Do
not break the pavement and clean out the material using a backhoe unless the
Engineer determines that the lift-out method is not feasible due to
deteriorated pavement or existing asphalt concrete repairs, or deteriorated
concrete pavement.
If
the bottom face of the adjacent concrete pavement is deteriorated for a height
greater than one-fourth (1/4) the thickness of the rigid pavement, make
additional full depth saw cuts as directed by the Engineer along the full width
of the lane or lanes to remove the deteriorated areas. Repair pavement
damaged during the pavement sawing or pavement removal according to Item 255 or Item 256.
255.04 Correction of Subgrade. After
removing the existing pavement full depth and before installing dowels or tiebars, shape and recompact the
subgrade to the satisfaction of the Engineer. Replace any subgrade
material removed with the existing concrete pavement removal with concrete as
part of the rigid pavement replacement.
255.05 Placing Dowels and Tiebars. Drill
dowel and tiebar holes using hydraulic or electric
drills without spalling or damaging the existing
concrete. To drill for dowels, use a device capable of drilling a minimum
of three holes at a time. For patches 10 feet (3 m) or greater in length,
provide tie bars or wiggle bolts of the size and spaced as shown on the
standard construction drawings. Blow clean all drilled holes with oil-free
compressed air. Maintain holes dry and frost free before grouting the
dowels or tiebars. Pneumatically inject grout
into the rear portion of the drilled holes. Use a grout retention disc
with a radius slot as shown in the standard drawings to retain the grout within
the drilled holes. Inject grout to fill all voids behind the grout
retention disc and until grout extrudes through the radius slot. Insert
dowels and tiebars through the grout retention disc
while the disc is placed flush with the sawed edge of pavement and aligned with
the drilled hole. Insertion of the dowels and tiebars
shall force the grout out of the radius slot in the grout retention disc.
Hold dowel bars in proper alignment until the grout has hardened.
255.06 Placement of Portland Cement Concrete. Do not
place any portland cement
concrete for rigid pavement replacement until the grout around the dowel or tiebar has hardened. Coat dowel bars with bond breaking
material conforming to 451.08.B.
Place portland cement
concrete according to 451.06. Use
forms at the shoulder. Cast each patch in one continuous operation.
Consolidate the concrete around the perimeter of the patch and within the
limits of the patch area using an internal type vibrator. Use approved
internal type vibrators capable of visibly affecting the concrete for a
distance of 12 inches (0.3 m) from the vibrator head.
When
using RRCM concrete install
maturity sensors to measure the maturity of each day’s placement according to
supplement 1098.
If RRCM placement from one location to another is
delayed by more than 1 hour treat the delayed placement as a new day’s
placement and install additional maturity sensors according to 1098.
Ensure
that batch tickets of the delivered RRCM conform to
the accepted mix design. Assure the
1.
water/cementitious ratio is not exceeded
2.
Admixtures are the same brand, type and dosage as the approved design.
3.
Aggregates, cementitious materials
4.
Air content
Screed
repairs less than 12 feet (3.7 m) in length parallel to the centerline.
Screed repairs 12 feet (3.7 m) in length and longer perpendicular to the
centerline.
While
the concrete is still in a plastic state, test the surface for trueness and for
being flush with the edges of the adjacent slabs using a 10-foot (3 m)
straightedge. Place the straightedge parallel to the pavement centerline
with half of the straightedge resting on the existing pavement, and draw the
straightedge across the patch to test the patch edges. Check areas within
the patch length in a similar manner. Where the straightedge does not
remain in contact with the existing pavement while drawing it across the patch,
correct all high or low areas exceeding 1/8 inch in 10 feet (3 mm in 3
m). Recheck the concrete surface after making corrections to ensure
conformance to the above tolerance. Make additional checks and
corrections until patch is within tolerance.
Texture
the new concrete surface similar to that of the surrounding pavement.
Apply
the liquid membrane-forming compound conforming to 705.07, Type 2 for curing at a minimum rate
of 1 gallon (1 L) of material for each 150 square feet (3.7 m²).
255.07 Wearing Course Replacement. Replace the
removed asphalt concrete overlay with Item 301 or 448 Type 2
material as shown on the plans. Compact these mixtures as approved
by the Engineer using any of the roller types specified in 401.13. Apply Item 407 tack coat to the replacement surfaces.
Trim
the limits of the repair to form a vertical face 1.5 inches (38 mm) deep from
the surface before placing the final asphalt concrete layer adjacent to the
existing pavement.
Before
opening the rigid replacement to traffic, restore the shoulders to the original
line and grade. Use either aggregate or asphalt concrete as shown on the plans
or as the Engineer directs. Fill the low areas, and compact them flush
with the surrounding shoulder.
Seal
the perimeter surface of the repaired areas by applying a nominal 4 inch (100
mm) wide strip of approved 702.04 asphalt
material, RS-1, RS-2, CRS-1, or CRS-2 or 702.01 approved PG binder.
255.08 Opening to Traffic. Do not
open the rigid replacement to traffic until the concrete attains a modulus of
rupture of 400 pounds per square inch (2.8 MPa).
For
RCCM mixes do not open the rigid replacement to
traffic until the RCCM attains a modulus of rupture
of 400 pounds per square inch (2.8 MPa) based on
maturity testing.
If
maintaining traffic in adjacent lanes, schedule work in order to place the
concrete in the prepared repair area within 48 hours after removing the
existing pavement. If unable to complete placement of the concrete in the
exposed repair area by the end of the daily work shift, cover unfilled repair
areas 10 feet (3 m) or less in length with a steel plate. Do not leave
repair areas unfilled with concrete when work is suspended on weekends or
holidays. If unable to complete placement of the concrete in the exposed
repair area before suspending work for a weekend or holiday or within the time specified
above, fill the excavation with an asphalt concrete mixture or other suitable
temporary patch material with a durable surface as the Engineer directs.
Maintain the temporary patches while they are in service.
255.09 Method of Measurement. The
Department will measure the quantity of Full Depth Pavement Removal and Rigid
Replacement by the number of square yards (square meters) repaired in the
complete and accepted work.
The
Department will measure the quantity of Full Depth Pavement Sawing by the
number of feet (meters) of perimeter full depth saw cuts in the complete and
accepted work. The Department will not measure offset saw cuts. The
Department will not measure additional cuts made to facilitate the removal of
the pavement.
255.10 Basis of Payment. Payment
is full compensation for furnishing all materials, including paint; developing
and testing the concrete mix, removing pavement by any method; removing subbase for undercut replacement; compacting subbase and subgrade; placing rigid pavement, including
concrete necessary to replace removed subbase or
subgrade; furnishing and placing dowels, tiebars, and
mesh; performing maturity testing and acceptance; placing, maintaining,
removing, and disposing of temporary patches, and restoring the shoulders.
The
Department will not pay for additional concrete sawing and removal depths
within 1 inch (25 mm) greater than those shown on the plans.
The
Department will not pay for additional work to repair damage caused by pavement
sawing or pavement removal.
The
Department will include tack coat in the cost of the asphalt concrete.
The Department will pay for asphalt concrete according to Item 301 or Item 448.
The
Department will pay for accepted quantities at the contract prices as follows:
Item
Unit
Description
255
Square
Yard
Full Depth Pavement Removal
(Square
Meter)
and Rigid Replacement, Class ___
255
Foot
(Meter)
Full Depth Pavement Sawing