b.Payment will be made under Item No.: 454-A Cleaning and Sealing Concrete Pavement, Type * ** - per linear foot {meter} * Specify I or II ** Specify Joints or Cracks GRINDING CONCRETE PAVEMENT SURFACES
455.01 Description.
This Section shall cover the work of grinding Portland Cement Concrete pavement at locations shown on the plans or directed by the Engineer. The primary locations will be the right-hand lane, or truck lane, of each roadway, but may include other locations. Said grinding is intended to substantially correct joint faulting, surface drainage, skid resistance, riding characteristics and/or removal of excessive surface material.
455.02 Materials.
N/A
455.03 Construction Requirements.
a.General. It is intended that areas of the pavement surface designated by the plans or Engineer to be processed shall be ground to eliminate joint or crack faults and to provide a constant pavement cross slope within the designated grinding limits in each lane. Adjacent sides of longitudinal joints or crack shall be in the same plane. Adjacent sides of transverse joints or cracks in excess of 1/16 of an inch {2 mm} shall be reground until flush. If a progress schedule for the grinding operation is not shown on the plans, the Contractor may select his own grinding operation schedule. The grinding operation shall be expeditiously performed in a continuous operation on a traffic lane before grinding begins on a succeeding lane. The residue created by the grinding operation shall be satisfactorily removed as the grinding operation proceeds.
b.Equipment. Grinding equipment shall be a self-propelled unit specifically designed to grind Portland Cement concrete pavement using diamond grinding blades capable of grinding the designated surfaces without causing spalls at cracks or joints or at other locations. The equipment shall be of a size, shape and dimension capable of working within the designated work limits without restricting the movement of traffic outside of the work limits. The Contractor shall provide positive means for the removal of the grinding residue before such residue is blown by traffic action or wind. Residue shall not be permitted to flow across lanes designated for traffic use or into gutters or other drainage structures.
c.Operational Requirements.
1.General. It is the intent that the work of grinding of the pavement surface be performed under traffic. Traffic may be shifted to one lane on a 4-lane facility; but no consideration will be given to transferring traffic to one travel way during this operation. The area of pavement surfaces to be ground will be designated on the plans, unless directed otherwise by the Engineer. The construction operations shall be scheduled and prosecuted in such a manner that a uniform surface finish which eliminates the joint or crack faults while maintaining positive lateral drainage by maintaining a constant cross slope is obtained.
2.Main Roadway. All preliminary work of stabilizing and repair on the main roadway shall be completed prior to commencing grinding operations. This preliminary work includes the stabilization of designated pavement slabs and removal and replacement of certain slab sections as noted by plan details or as directed by the Engineer. The entire area of the travel way designated to be ground shall be ground until the adjacent sides of joints and cracks are in the same plane, the cross slope complies with typical section shown by plan details and the surface requirements of Subarticle 455.03(d). It is the intent of this specification that the faulting at joints and cracks be eliminated, the overall roughness be within the specified limits and that the pavement surface of the lane designated for treatment be textured.
d.Final Surface Finish. The grinding process shall produce a pavement surface that is true to grade and uniform in appearance with a longitudinal line type texture. Said line type texture shall consist of parallel longitudinal corrugations of approximately 60 evenly spaced grooves per foot {300 mm} with the ridges approximately 1/32 of an inch {1 mm} higher than the bottom of the grooves. Joints and cracks shall be visually inspected to ensure that adjacent surfaces are in the same plane. Misalignment of the surface planes of adjacent sides of joints or cracks which is in excess of 1/16 of an inch {2 mm} shall be ground until the surfaces are flush. The transverse slope of the ground pavement shall be uniform to a degree that no depressions or misalignment of slope greater than 1/4 of an inch {6 mm} in 12 feet {3.5 m} are present when tested with a 12 foot {3.5 m} straightedge placed perpendicular to the pavement centerline. Straightedge requirements do not apply outside of the ground areas.
e.Smoothness Requirements.
1.Application of Smoothness Requirements. Smoothness requirements shall be applicable to the grinding of the concrete pavement surfaces if Pay Item 455-C Smoothness Testing, Certified Inertial Profiler is included in the contract.
2.Smoothness Testing Procedure. The smoothness testing procedure shall be ALDOT-448, Evaluating Pavement Profiles . This procedure is posted on the ALDOT Internet site in the pages of the Materials and Tests Bureau. The Mean Roughness Index shall be measured after the grinding of the concrete pavement surface. The results of the smoothness tests will be evaluated by the Engineer.
3.Contract Price Adjustment based on Mean Roughness Index. Payment for the grinding will be made in accordance with the contract price adjustments given in the following table. Mean Roughness Index Inches/Mile/Section {meters/kilometer/section) Contract Price Adjustment, Percent of "Grinding Concrete Pavement" Unit Contract Price Under 40.0 {Under 0.6} 105 40.0 to less than 65.0 {0.6 to less than 1.0} 105 – [(Mean Roughness Index-40)/5)] {105 – [(Mean Roughness Index- 0.6)/0.08]} 65.0 to less than 95.0 {1.0 to less than 1.5} 100 95 through 145 {1.5 through 2.3} 100 – [(Mean Roughness Index – 95.0)/2.5] {100 – [(Mean Roughness Index – 1.5)/0.04]} Over 145.0 {Over 2.3} Unacceptable
455.04 Method of Measurement.
The grinding of pavement ordered and accepted will be measured in square yards {square meters} computed from surface measurements taken to the nearest 0.1 of a foot {0.1 m} on the processed pavement. Those areas of pavement requiring corrective action due to inappropriate or unacceptable work or negligence on the part of the Contractor will be excluded from measurement for payment.
455.05 Basis of Payment.
a.Unit Price Coverage. The grinding of pavement ordered and accepted, measured as noted above, will be paid for at the contract unit price bid which shall be full compensation for the grinding of the pavement, the removal of grinding residue and the satisfactory disposal thereof, the cleaning of the pavement and for all materials, equipment, tools, labor and incidentals necessary to complete the work. SECTION 490 BRIDGE DECK THIN POLYMER OVERLAY Payment for the grinding will be adjusted in accordance with the requirements for smoothness if Pay Item 455-C, Smoothness Testing, Certified Inertial Profiler is included in the contract.
b.Payment will be made under Item No.: 455-A Grinding Concrete Pavement - per square yard {square meter} 455-C Smoothness Testing, Certified Inertial Profiler - per each SECTION 490 BRIDGE DECK THIN POLYMER OVERLAY
490.01 Description.
This Section shall cover the work of applying Thin Polymer Overlays (TPO) and crack sealing to waterproof and provide a skid resistant riding surface.
490.02 Materials.
a.General. Materials furnished for use shall conform to the appropriate requirements of Division 800, Materials, and the requirements noted in this Section.
b.Crack Sealer Material. The crack sealer material, if needed, shall be specified as shown in plans. The crack sealing material shall be a solvent less Type I Grade 1 epoxy as specified in AASHTO M 235. The crack sealer material shall be used to repair bridge deck cracks by gravity feeding. The crack sealer shall meet the properties in TABLE 490-1. TABLE 490-1: Properties of Crack Sealer Property Requirement* Test Method Viscosity poises, max. 7 ASTM D 2556 Tensile Strength, mix. Psi. 2500 AASHTO M235 Elongation, % min. 30 AASHTO M235 Water Absorption, % by wt. max. 1.0 AASHTO M235 * Based on samples cured and tested at 75°F
c.Overlay Material. The overlay material shall be a completely non-porous polymer bridge deck overlay system designed for low temperature applications. The overlay system shall consist of polymer epoxy binder and aggregate. The overlay system shall not contain any fillers or volatile solvents. The overlay system shall meet the properties in TABLE 490-2. TABLE 490-2: Properties of Overlay System Property Requirement* Test Method Viscosity poises 7 - 30 ASTM D 2556 Tensile Strength, min. psi. 2500 AASHTO M 235 Elongation, % min. 30 AASHTO M 235 Adhesive Strength, min. psi. @ 24 hours** 250*** ASTM C 1583 Compressive Strength, min. psi. @ 3 hours*** 1000 ASTM C 579 Method B Compressive Strength, min. psi. @ 7 days*** 5,000 ASTM C 579 Method B Water Absorption, % by wt. max. 1.0 AASHTO M 235 Chloride Permeability, max. Coulombs @ 28 days 100 AASHTO T 277 *Based on samples cured and tested at 75°F **Or the manufacturers minimum cure time ***Or 100% substrate failure
d.Aggregate. All aggregates used shall be 100 percent fractured, non-polishing, and non-friable. Aggregates shall be calcined bauxite. The physical and chemical properties of the aggregate shall meet the requirements in Table 490-3. SECTION 490 BRIDGE DECK THIN POLYMER OVERLAY Table 490-3: Aggregate Physical and Chemical Requirements Property Requirement Test Method Polish Stone Value 38 min. AASHTO T 279 Resistance to Degradation 20% max AASHTO T 96 Moisture Content 0.2% max AASHTO T 255 Aluminum Oxide 87% min. ASTM C 25 Aggregate Gradation % Passing by Weight AASHTO T 27 Sieve Size No. 4 (4.75 mm) 100 min. No. 6 (3.35 mm) 95 min. No. 16 (1.18 mm) 5 max
e.Storage and Handling. The polymer overlay materials shall be transported and handled in accordance with the manufacturer’s recommendations. Polymer overlay materials shall be stored at the job site in their original containers, protected from moisture, and maintained at a temperature between 60 to 90°F for a minimum of 24 hours prior to use. All aggregates shall be stored in a dry environment protected from rain, moisture, and contaminants.
f.Other Requirements. All requirements listed in this Subarticle shall be submitted to ALDOT no less than 30 days prior to placement of the polymer overlay. The Contractor shall submit a copy of a certified test report with actual test results from an independent laboratory verifying that the materials meet all the requirements specified in Article 490.02 including Tables 490-1, 490-2, and 490-3. The Contractor shall submit a verification test report for each material lot number to be used on ALDOT projects. The Contractor shall provide the Materials and Tests Engineer with ten years of performance history data from a minimum of three projects where the proposed (TPO) has been used. The performance history shall be from projects located in Alabama. If no ten-year performance history data is available from Alabama, then data from any southeastern states with similar climate conditions, such as temperature and humidity as Alabama may be accepted.
490.03 Construction Requirements.
a.Submittals. The Contractor shall submit to the Engineer three sets of copies of product data that completely identifies the physical components, and performance characteristics of the overlay system. The submittal shall also include safety data sheets for all materials to be used. The overlay materials shall not be ordered until the product data has been accepted by the Engineer as providing an adequate description of the overlay system. The following items shall be included as a part of the product data submittal: Material composition (type of polymer, curing agents, coloring additives, etc.) Surface preparation (special cleaning requirements, required extent of cleaning, etc.) Curing requirements (acceptable ambient temperature range, acceptable level of humidity, etc.) Application requirements and application equipment requirements, etc. No less than 30 days prior to construction of the polymer overlay, the Contractor shall submit to the Engineer for approval a work plan for constructing the overlay. The work plan shall include, but not be limited to, construction procedures, anticipated schedule for traffic control, patching and crack repair procedures, overlay placement procedure, and proposed shot blasting procedure. The work plan shall also include all test reports and samples required as per Subarticle 490.02 (f). SECTION 490 BRIDGE DECK THIN POLYMER OVERLAY
b.Equipment. The equipment for cleaning the concrete bridge decks shall be recommended by the manufacturer of the overlay system. The polymer overlay shall be placed using mechanical equipment capable of mixing, metering, and distributing all components of the overlay system in a continuous application as per the polymer overlay manufacturer’s specifications. The equipment shall be capable of heating and maintaining the components of the epoxy binder at a constant temperature. The equipment shall be capable of mixing the components of the epoxy binder at a constant ratio and shall be capable of consistent application rates of both the epoxy and the aggregate and have the capability to display and record the application rates of both materials. The use of agricultural type spreaders for the distribution of the aggregates will not be allowed when mechanical continuous application is required.
c.Surface Preparation. The entire area of the deck surface shall be cleaned by shot blasting to provide a surface free from curing compound, laitance, dust, dirt, oil, grease, bituminous material, paint, and all foreign matter. The contractor shall use the test method described in ASTM C 1583 “Standard Test Method for Tensile Strength of Concrete Surfaces and the Bond Strength or Tensile Strength of Concrete Repair and Overlay Materials by Direct Tension (Pull-off Method)” to determine the shot blasting procedure. The shot blasting procedure shall consist of size of shot, flow of shot, forward speed, and number of passes of the shot blasting machine necessary to expose the coarse aggregate and provide tensile adhesion strength equal to or greater than 250 psi or a failure area, at a depth of 0.25 in. or more into the concrete deck. A test section of not less than 300 sq. ft. of bridge deck will be used to establish the shot blasting procedure. Three random test sites will be selected within the test section by the Engineer and tested according to ASTM C 1583. The Contractor shall provide all test equipment and perform the tests. If the adhesion strength or failure depth criteria are not met, the Contractor shall adjust the shot blasting procedure and the test section will be re-blasted and re-tested until satisfactory test results are attained. Once an acceptable shot blasting procedure is established it shall be continued for the remainder of the bridge. The Contractor may, with the permission of the Engineer, change the shot blasting procedure or equipment, in which case an additional test section and testing will be required. Shot blast cleaning shall include the preparation of all bridge deck spall repair areas. The shot blast cleaning of an area of the deck shall be performed within a 24-hour period preceding placement of the overlay. The shot blast cleaned areas shall be protected against contamination prior to placement of the overlay. Contaminated areas and areas exposed more than 24 hours shall be shot blast cleaned again as direct by the Engineer at the Contractor’s expense. In areas that the shot blasting equipment cannot reach (i.e., along curbs and median walls), sandblasting will be permitted to an extent satisfactory to the Engineer. This shall be performed prior to the shot blasting whenever applicable and practical. Immediately before applying the overlay system, all prepared surfaces shall be cleaned with compressed air (or vacuumed) to remove dust and debris. All surfaces to be overlaid shall be dry.
d.Repair of Spalls. The Contractor shall be responsible to repair any spalled areas prior to the placement of the overlay system. The Contractor shall submit a repair procedure to the Engineer for acceptance prior to performing any repair.
e.Application of Overlay. Overlay applications consisting of more than 1,000 square yards shall be placed using mechanical equipment capable of continuous application. Manual application will be allowed only when the overlay application consists of less than 1,000 square yards. The polymer overlay shall be placed in two layers of epoxy and aggregate. Both layers shall consist of a layer of epoxy followed with a layer of aggregate. The layer of aggregate shall completely cover the epoxy. The total thickness of the polymer overlay (both layers) shall not be less than ¼ inch nor greater than ½ inch. The application rates of the polymer overlay shall comply with TABLE 490-4. TABLE 490-4 Application Rates Layer Polymer Gallons/100 Square Feet Aggregate Pounds/Square Yard 1 Not less than 2.5 Not less than 10.0 2 Not less than 5.0 Not less than 14.0
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Source: 2026 Standard Specifications for Highway Construction, 2026 Edition. Pages 286–290 of 826. View official source ↗