455.05 Basis of 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 t he 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. 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 It em No .: 455-A Grinding Concrete Pavement - per square yard {square meter} 455-C Smoothness Testing, Certified Inertial Profiler - per each 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 f urnished 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: Proper ties of Crack Sealer Property Requirement* Test Method Viscosity poises, max. 7 ASTM D 2556 Tensile Strength, min. psi. 2500 AASHTO M 235 Elongation, % min. 30 AASHTO M 235 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
490.03 Construction Requirements.
***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 th e aggregate shall meet the requirements in Table 490-3. 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 sout heastern 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 completel y 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 composi tion (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.) • Appli cation 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 inc lude, but not be limited to, construction procedures, anticipated schedule for traffic control, patching and crack
490.03 Construction Requirements.
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).
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 mix ing, 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 c onstant 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 shal l 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 fo r 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 c oncrete 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 Con tractor 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 satisfactor y 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 whi ch 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 pl acement 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 Cont ractor’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 t han 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
490.05 Basis of Payment.
1 Not less than 2.5 Not less than 10.0 2 Not less than 5.0 Not less than 14.0 The Contractor shall plan and execute the work in a manner to provide at least eight hours of curing or the minimum cure time recommended by the manufacturer prior to opening the section to traffic. Prior to opening the section to traffic, the Contractor shall perform at least one pull off test per every 200 linear feet of each lane of bridge deck. The Engineer will randomly select the test locations. Pull off tests shall be performed in accordance to the requirements of ASTM C 1583. The Contractor shall provide all testing equipment. Each individual test shall have a minimum adhesive strength of 175 psi when the bond failure is located at the interface of the concrete and the overlay as described in ASTM C 1583. Unacceptable test results will require removal and replacement of the overlay at the Contractors expense. The thickness of the overlay shall be verified by using the cores obtained from the pull off tests. Areas found to be less than ¼ inch thick shall be re -coated and re- tested at no cost to the Department. The overlay manufacturer shall have a representative present at the job site at all times during placement of the polymer overlay. The manufacturer’s representative shall advice the engineer o f any procedure and/or material not meeting specifications. The Engineer will suspend placement of the overlay system based on the advice of the manufacturer’s representative or his/her own observations. Work shall not resume until the Engineer is satisfi ed that appropriate remedial action has been taken by the Contractor. Polymer overlays shall not be placed when the ambient temperature is below 55°F or above 90°F and when the surface temperature is below 60°F. Placement of overlays will not be permitted when rain is forecast within 24 hours of application.
f.Performance Guarantee . The polymer overlay manufacturer shall provide ALDOT with a ten year performance warranty after the application of the overlay is complete. The warranty shall be submitted t o the Engineer for review. The overlay will not be accepted, and final payment made until the Contractor is notified in writing by the Engineer that the warranty is acceptable. The warranty shall include the requirement that the Manufacturer will be fully responsible for all corrective work required due to performance related issues and to restore the overlay to a serviceable condition. The warranty shall state that the overlay shall be restored to a serviceable condition by the manufacturer within sixty d ays of notification by ALDOT that corrective work is required.
490.04 Method of Measurement.
a.Shot Blast Cleaning . The area of the deck acceptably shot blast cleaned prior to placing the overlay will be measured in square yards computed from surface measurements taken to the nearest 0.1 of a foot {0.1 m}. The shot blast cleaning of any longitudinal and transverse construction joints and vertical surfaces and bridge deck spall repairs will not be measured for payment.
b.Bridge Deck Spall Repair . Bridge deck spall repairs will be measured in square feet computed from surface measurements taken to the nearest 0.1 of a foot {0.1 m}.
c.Polymer Overlay. The area of the deck acceptably overlaid will be measured in square yards computed from surface measure ments taken to the nearest 0.1 of a foot {0.1 m}.
490.05 Basis of Payment.
a.Unit Price Coverage .
1.Shot Blast Cleaning . Payment for the measured areas at the contract unit price per square yard of “Shot Blast Cleaning” will be considered full payment for all expenses associated with the blast cleaning operation.
501.01 Description.
2.Bridge Deck Spall Repair. The accepted quantity will be paid for at the contract unit price per square foot of “Bridge Deck Spall Repair". This price shall include all materials, equ ipment, tools, labor, and incidentals required to complete the work.
3.Polymer Overlay. The accepted quantity will be paid for at the contract unit price per square yard of “Polymer Overlay". Layers will not be paid for individually. This price shall incl ude all materials, procurement, handling, hauling and processing, coring for pull of testing, guarantee, and includes all equipment, tools, labor, and incidentals required to complete the work.
b.Payment will be made under Item No.: 490-A Blast Clea ning – per square yard 490-B Bridge Deck Overlay – per square yard 490-D Bridge Deck Spall Repair – per square foot
Division 500
STRUCTURES SECTION 501 STRUCTURAL PORTLAND CEMENT CONCRETE
501.01 Description.
The work under this Section shall cover the furnishing of portland cement concrete to be used in constructing concrete structures. Structures shall include but are not limited to bridges of all types, box culverts, headwalls, retaining walls, and other mis cellaneous structures.
501.02 Materials.
a.General . Handling, storage, and control of materials shall comply with appropriate portions of Section 106. All materials shall conform to the requirements set forth in Division 800, M aterials. Specific reference is made to applicable portions of the following Sections: Section 801 - Coarse Aggregate Section 802 - Fine Aggregates Section 806 - Mineral Admixtures Section 807 - Water Section 808 - Air Entraining Admixtures for Concrete Section 809 - Chemical Admixtures for Concrete Section 815 - Cement Section 830 - Concrete Curing Material Section 832 - Concrete Joint Fillers, Sealers and Waterstop Material Section 835 - Steel Reinforcement
b.Special Requirements . Aggregates from different sources, which are to be used for concrete Class A and Class C as specified in Item 501.02(c)2, may be stockpiled together provided material from each source meets the requirements of Section 801 and the specific gravity of the ag gregates from each source does not vary more than plus or minus 0.05. In the event the coarse aggregate shows a tendency to segregate in the stockpile, the Engineer may order the coarse aggregate be furnished and batched in two fractions from two separate stockpiles. The Contractor may be required to adjust the size of coarse aggregate for the concrete used around steel reinforcement of heavily reinforced members.
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 283–286 of 934.