- 422 - SECTION 605 -- CONCRET E PAVEMENT REPAIR
605.01 Description
1.This work shall consist of repairing Portland cement concrete pavement at the locations shown in t he contract or as designated by the Engineer. The work shall include removing deteriorated concrete, disposing of the old concrete, preparation of the repair area, and furnishing, placing, finishing, and curing the concrete.
2.Concrete pavement repairs are grouped into 3 types based on the surface area of the patch (see Table 605.01). If a concrete repair extends across more than one lane, the repairs in each lane will be counted as a separate repair. Table 605.01 PCC Pavement Repair Groups Type Size Square Yards or m² A Less than 5 B 5 to 15 C More than 15
3.Full width concrete pavement repairs shall be a minimum of 4 feet (1.2 m) in length.
4.Removal of concrete for partial depth pavement repair shall be to the depth necessary to reach sound concrete. The minimum depth of removal shall be 3 inches (75 mm), or as shown in the contract.
5.Full depth pavement repair s hall be constructed on a prepared subgrade or foundation course as describ ed in the contract. The thickness of the new concrete pavement will be as shown in the contract, or 2 inches thicker than the adjacent pavement, if not shown in the contract.
6.a. When performing concre te pavement repairs on 2-lane roadways, the Contractor shall have a ll lanes open to traffic before sunset and at times when the Contractor is not working. Where the pavement has been removed and the Contractor is unable to complete the required patching in time for the concrete to obtain the full curing time required prior to opening the section of the road to tra ffic, the excavation shall be filled with a commercially available cold-mix bitu minous mixture, or other suitable temporary patch material with a durable surface. The Contractor will be required to maintain traffic flow across these patches while they are in service. When it is necessary to us e a temporary patch, the patch shall be removed, and the required permanent patch placed, within 48 hours unless otherwise directed by the Engineer. The temporary patches will be at no cost to the Department.
b.When performing concrete pavement repairs on multi-lane highways, the Contractor may have one lane closed while performing the repair work. Repairs shall not be left open overnight. Where the pavement has been removed, and the Contractor is unable to complete the required patch before sunset, the Contractor sha ll fill the excavated area with either:
1.the appropriate patching concrete material for curing overnight, or (2) a suitable material with a durable surfac e. The material, installation, removal and disposal of these temporary patches will not be measured and paid for Concrete Pavement Repair 605.04 - 423 - directly, but shall be considered subsidiary to the concrete joint and pavement repair work being performed.
605.02 Material Requirements
1.a. Repairs shall be made with Class PR1-3500 (PR1-25 MPa) or Class PR3-3500 (PR3-25 MPa) concrete.
b.Repairs shall be made with Class 47B-3500 (47B-25 MPa) or Class 47B-HE-3500 (47B-HE-25 MPa), if the contract allows for lane closures or detours to accommodate the extended curing period.
2.All materials shall be furnished by the Contractor and shall conform to the requirements in Table 605.02. Table 605.02 Material Requirements Applicable Materials Section Portland Cement Concrete ..................................... 1002 Aggregates ............................................................. 1033 Fly Ash .................................................................... 1008 Curing Compounds (Without Asphalt Overlay) ....... 1012 Curing Compounds (With Asphalt Overlay) ............ 1013 Joint Sealing Filler .................................................. 1014 Admixtures .............................................................. 1007 Water ...................................................................... 1005 Epoxy Compounds & Adhesiv es............................. 1018
605.03 Equipment
1.A mobile mixer conforming to the requirements of Section 1002 may be used.
2.Adequate hand tools shall be provided, including an internal vibrator.
3.Screeds, either mechanical or hand operated, shall be used to finish the concrete except for small patches and curb repair. The screeds shall be either a vibrating or roller type screed specifically designed for striking off concrete.
4.Internal vibrators shall meet the requirements of Section 601.
5.Drills for dowels or tie bars, shall be capable of drilling the appropriate sized hole parallel to the surface of the concrete and the longitudinal centerline within 1/8 inch.
605.04 Construction Methods
1.Removals General Requirements
a.The Contractor shall re move the concrete pavement and curbs, if applicable without damaging the adjacent concrete pavement and curbs.
b.The Contractor shall remove and dispose of all old pavement, reinforcing steel, and all other materials.
1.The repair section shall be removed with minimum disturbance of the underlying foundation course. Any loosened foundation course material shall be removed and replaced with concrete.
605.04 Concrete Pavement Repair
- 424 - c. If reinforcing fabric is encountered, it shall not be replaced.
d.The Contractor shall cut around the perimeter of the repair area as shown in the contract.
1.All repairs shall be cut so the edges are parallel or perpendicular to the traveled way.
2.Curb repairs shall be cut a minimum of 2 inches (50 mm) in depth with a diamond saw and breaking back the remaining thickness to form vertical edges on the existing concrete.
3.Saw over-cuts shall be kept to a minimum.
e.The Contractor shall use care to prevent damage to the concrete to remain in place. Repair of unnecessary damage will be at no cost to the Department.
f.When tie bars in longitudinal joints are damaged during concrete removal, they shall be replac ed by the Contractor at no additional cost to the Department with reinforci ng bars [No. 5 (16 mm in diameter) bars that are 18 inches (450 mm) in length ]. The new tie bars shall be installed into holes drilled in the existing concrete and secured in place with a non- shrink grout or epoxy on the Department’s Approved Products List.
2.Preparation
a.General
1.The repair sections shall be removed to the lines designated by the Engineer, including rein forcement that interferes with the operations.
2.The wheel-type cutter shall be operated to produce minimum disturbance of the foundation course material, with no encroachment of the cut into the concrete of the adjoining lane.
3.“Foundation Course Replacement” consists of removing and disposing of foundation course (i .e., bituminous, cement treated, crushed concrete, granular) or subgrade below the concrete pavement, which excludes the additional 2 inch (50 mm) of removal, as shown in the contract.
i.When the Engineer determines that the foundation course and/or subgrade needs replacing, the Contractor shall remove and dispose of the foundation course a nd/or subgrade, prepare the subgrade, and replace the materials with the same type of material.
4.The Contractor shall co mpact the subgrade or foundation course under full depth patches to the maximum density achievable.
5.A bond breaker shall be used as shown in the contract. (6) The subgrade or foundation course shall be uniformly wetted before placing the concrete. Ponding or puddling shall be prohibited.
7.Where the repair area is not bordered by existing concrete pavement, a form shall be used as the pavement edge to provide the same surface elevation and edge alignment as the existing pavement. The form shall be supported or braced in posi tion to prevent movement during the placement and finishing of the concrete. Forms for concrete pavement repair shall conform to the requir ements of Subsection 603.03. Concrete Pavement Repair 605.04 - 425 - b. Preparation full depth with dowels or tie bars
1.Removal shall extend across the existing joint a minimum of 2 feet (600 mm) into the adjacent panel in doweled concrete.
2.Dowel bars or tie bars shall be anchored into the faces of the existing concrete as designated in the contract.
3.The dowel bar holes shall be drilled at the same plane ± 1/8 inch and at the spac ing shown in the contract.
4.The tie bar holes may be drilled independently. (5) The drilled holes shall be thoroughly cleaned with compressed air to remove all dust, di rt, loose material and moisture.
6.After cleaning and prior to dowel or tie bar insertion, an application of grout or Type IV, Grade 3 epoxy shall be made at the back of the hole. The grout or epoxy shall be from the Approved Products List. Twist the dowel or tie bar one full turn during insertion to completely surround it with the grout or epoxy. Retention di sks shall be placed on the bars as designated in the contract. The furnishing and installation of dowel and tie bars will not be paid for directly but shall be considered subsidiary to the concrete pavement or joint repair work being performed.
7.When matching transverse joints on repairs that span existing joints, the dowel baskets shall be placed parallel to the joint, and the dowel bars shall be parallel to centerline.
c.Preparation partial depth
1.For partial depth repairs, the Contractor shall cut and chip the pavement edges with a 15 pound (6.8 kg) maximum chipping hammer to form reasonably neat vertical surfaces.
2.All surfaces, including the bottom, of the partial depth concrete repairs shall be free from loose concrete, sand, and other debris and shall be maintained in a dry and clean condition.
3.A bonding agent shall be applied to all cleaned and dried surfaces.
i.The bonding agent shall be a Type IV, Grade 2 Epoxy Adhesive on the Approved Products List. (ii) The bonding agent shall be applied to all surfaces, including the bottom. The vertical faces of the transverse joints, longitudinal joints, or cracks exposed in the repair shall not be coated with the bonding agent.
3.Placing and Finishing a. The Contractor shall fu rnish and place the concrete. The concrete shall be handled and consolidated so there will be no separation of the aggregate and the mortar.
b.An internal vibrator shall be used to consolidate the concrete. c. A vibrating screed shall be used on a full depth concrete repair that is 5 feet or wider, to finish the concrete to the final elevation.
d.The concrete shall be floated with a magnesium bull float and then given a drag finish with wet burlap, carpet, or canvas in a direction
605.04 Concrete Pavement Repair
- 426 - parallel to the traffic flow. If the surface is not to receive an overlay or smoothness grinding, it shall be ti ned to match the existing surface.
4.Joints
a.The Contractor shall create jo ints in full depth repairs as shown in the contract.
b.When pavement and joint repairs will not be overlaid, all sawcuts, transverse joints, and longitudinal joints shall be thoroughly cleaned with compressed air to remove all dust, dirt, loose material and moisture, and sealed with hot pour joint sealant.
c.Random cracks which develop in the new concrete repair that will not be overlaid with asphaltic concrete shall be removed or repaired as directed by the Engineer.
d.Joints shall not be sealed until after any corrective work or Diamond Grinding and Texturing Concrete Pavement is completed. Formed joint wells that are destroyed shall be re-constructed, and joints of insufficient depth shall be deepened prior to sealing.
5.Curing a. The Contractor shall apply curing compound to all concrete pavement repairs. The cure compound shall be applied immediately after each patch is completed.
1.When pavement and joint repairs are overlaid with asphaltic concrete, the curing method shall be with tack coat. An approved asphalt emulsion or bituminous based compound may be used with approval of the Engineer.
2.White pigmented curing compound shall be used when the repair will be the wearing surface. The application rate shall be 1 Gal/150 SF (0.4 L/m²).
b.Class PR1-3500 (PR1-25) or PR3-3500 (PR3-25) concrete pavement repairs shall be covered with polyethylene film and then insulation board or insulated blankets immediatel y after the curing compound has been applied.
1.The insulation board and insulated blankets shall have an R-value (thermal resistance) equal to or greater than 5 ft²-hr-°F/BTU [1.0 m²(°C/W)].
2.Insulation and polyethylene film shall be maintained until concrete reaches opening strength.
c.Class PR1-3500 (PR1-25 MPa) or PR3-3500 (PR3-25 MPa) concrete pavement repairs shall not be opened to traffic until the compressive strength reaches 3500 psi (25 MPa). This will be determined by use of Maturity Method or cylinders, at the discretion of the Engineer. Table 605.03 is a guide to the minimum time the PR-3500 concrete will reach a compressive strength of 3,500 psi. Concrete Pavement Repair 605.04 - 427 - Table 605.03 (Class PR1-3500 [25 Mpa] and PR3-3500 [25 Mpa]) Minimum Ambient Air Temperature [°F (°C)] (Hours) Below 41 (5 C) 12 41 – 60 (5 -16C) 8 Above 60 (16 C) 4
1.Concrete shall not be placed when ambient air temperatures are expected to drop below 40 °F (4° C) during the cure period.
2.Class PR3 Concrete shall be used for all concrete repairs if the repaired areas must be opened to traffic within 24 hours, except that Class PR1 Concrete may be used provided the minimum required strength can be attained within the allotted time.
3.Strength measurements for the opening and the 24-hour pay strengths of the PR 1 and PR3 Concrete may be performed using the Maturity Method or cylinders, at the discretion of the Engineer.
d.Class 47B-3500 (47B-25 MPa) or Class 47B-HE-3500 (47B-HE-25 MPa) concrete pavement repairs shall not be opened to traffic until the compressive strength reaches 3, 500 psi (25 MPa) as determined by the Maturity Method or cylinders, at the discretion of the Engineer. Table 605.04 is a guide to the minimu m time the 47B-3500 concrete will reach a compressive strength of 3,500 psi.
1.Concrete shall not be placed when ambient air temperature is expected to drop below 40°F (4 C) during the cure period. Table 605.04 (Class 47B-3500 25 MPa) Minimum Ambient Air Temperature [°F (°C)] (Hours) Below 41 (5 C) 120 41 – 60 (5 -16C) 72 Above 60 (16 C) 48
6.Smoothness
a.The pavement elevation of repair areas shall be corrected in a manner that eliminates dips or bumps. Dips and bumps are defined as having a 1/8 inch or greater deviation using an approved 10 foot straightedge. If the repair will be the we aring surface, the correction shall be diamond grinding or replacement. If the repair will be overlaid, the correction shall be milling, diamond grinding or replacement. The condition of the adjacent pavement shall be considered when evaluating the 1/8 inch deviation requirement.
605.04 Concrete Pavement Repair
- 428 - 7. a. Disturbed or damaged areas in the existing surfaced shoulder resulting from the repair operation sha ll be repaired by the Contractor at no additional cost to the Department.
b.The perimeter of the damaged areas of the surfaced shoulders shall be sawed prior to removing.
c.The shoulder shall be repaired with the same material as the existing shoulder or as directed by the Engineer.
605.05 Method of Measurement
1.a. The quantity of each type of concrete pavement repair and joint repair are measured in cubic yards (meters) of pavement replaced in each separate lane.
b.Concrete pavement repairs that adjoin full depth repair areas of varying widths in the same traffic lane which are situated such that the removals of the areas may be accomplished concurrently, shall be considered as a single repair. The total area of the adjoining areas shall be combined to determine the repair type as shown in Table 605.01.
c.Joint repairs in excess of 9 feet in length will be paid for as the appropriate pavement repair item.
d.The quantity of curb repair is measured in linear feet.
2.“Foundation Course Replacement” will be measured by the cubic yard of foundation course replaced.
605.06 Basis of Payment
1.P a y I t e m P a y U n i t Concrete Curb Repair Linear Feet (LF) [Meter (m)] Concrete Pavement, ____ Joint Repair Cubic Yard (CY) [ C u b i c M e t e r ( m 3)] Concrete Pavement Repair, Type A, Cubic Yard (CY) F u l l D e p t h [ C u b i c M e t e r ( m3)] Concrete Pavement Repair, Type B, Cubic Yard (CY) F u l l D e p t h [ C u b i c M e t e r ( m3)] Concrete Pavement Repair, Type C, Cubic Yard (CY) F u l l D e p t h [ C u b i c M e t e r ( m3)] Concrete Pavement Repair, Type A, Cubic Yard (CY) P a r t i a l D e p t h [ C u b i c M e t e r ( m3)] Concrete Pavement Repair, Type B, Cubic Yard (CY) P a r t i a l D e p t h [ C u b i c M e t e r ( m3)] Concrete Pavement Repair, Type C, Cubic Yard (CY) P a r t i a l D e p t h [ C u b i c M e t e r ( m3)] Foundation Course Replacement Cubic Yard (CY) [ C u b i c M e t e r ( m 3 ) ] Concrete Pavement Repair 605.06 - 429 - 2. When the Engineer directs that partial depth concrete pavement repairs be constructed with a thickness greater than what is shown in the contract, an adjustment will be made to provide compensation for the work. The adjustment will be as follows: Adjusted Unit Price = Bid Price x (Actual Thickness Placed) (Thickness shown in the contract)
3.a. The 24-hour compressive st rength shall be used to determine pay factor deductions for all PR type concrete in accordance with Table 603.03.
b.The 28-day compressive strength of each day's production will be determined from cylinder strengt h tests for all 47B type concrete.
1.Payment shall be reduced by the amount described in Table 603.03.
2.For 47B concrete, if the 28 day strength fails, the Contractor has the option to take 3 core samples at no additional cost to the Department. The average compressive strength of these cores will be used to determine the actual 28-day co mpressive strength of each day's production.
i.Cores must be taken within 45 days from the date the concrete was poured. (ii) The Engineer shall select the site where the cores will be taken.
4.“Foundation Course Replacement” will be paid for at the contract unit price per cubic yard for the item "Foundation Course Replacement". This price shall be full compensation for removing and disposing of the old foundation course, preparation of t he subgrade, furnishing and placing the replacement concrete, and for all labor, equipment, tools and incidentals necessary to comp lete the work.
5.The sealing of all random cracks or joints will not be measured and paid for directly but shall be considered subsidiary to the joint or pavement repair work being performed.
6.Payment is full compensation for all work described in this Section. - 430 - SECTION 606 -- CONCRETE CURB AND CONCRETE GUTTER
606.01 Description
1.The Contractor shall furnish all materials and construct concrete curb, combination concrete curb and gutter, and concrete gutter as described in the contract. This Section sh all not include integral curb that is covered under Section 603.
606.02 Material Requirements
1.The concrete Class shall be specified in the contract.
2.All materials shall be furnished by the Contractor and shall conform to the requirements in Table 606.01. Table 606.01 Material Requirements Applicable Materials Section Portland Cement Concrete ...................... 1002 Joint Sealing Filler ................................... 1014 Preformed Join t Filler .............................. 1015 Reinforcing St eel ..................................... 1020, 1021, 1024 Deformed Metal Join t Material ................. 1027 Curing Materi als ...................................... 1010, 1011, 1012, 1013 Aggregates .............................................. 1033 Admixtures .............................................. 1007 Water ....................................................... 1005
606.03 Construction Methods
1.a. The Contractor shall prepar e the curb and gutter subgrades by excavating or filling with suitable material to the required depth below the finished surface in accordance with the dimensions shown in the contract.
b.All soft and yielding or other unsuitable material shall be removed and replaced with suitable material.
c.The material shall be compacted thoroughly by tamping or rolling and finished to a firm, smooth surface.
d.If necessary, water shall be added by sprinkling to facilitate compaction.
e.Concrete shall be deposited upon a thoroughly moistened subgrade. Ponding or puddling shall be prohibited.
2.a. Forms shall be metal, straight, free from warp, and of sufficient strength to resist the pressure of the concrete and vibration.
b.Wood forms or curved metal forms shall be used for curves having a radius of less than 100 feet (30 m).
c.Forms shall be used for both the inside and outside faces of the curb and gutter.
d.All forms shall be thoroughly cleaned and oiled before concrete is placed against them. Forms that have become worn, bent, or broken shall not be used.
e.The forms shall be neatly and tightly joined and then securely pinned and staked to line and grade.
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 456–463 of 1,048.