710CONCRETE PAVEMENT

7-11 (E) Compressive Strength

Determine the compressive strength of concrete using one set of two 6 inch x 12 inch cylinders at 28 calendar days. Test samples will be made by the Engineer fr om the concrete as it comes from the mixer. The samples will be made and cured in accordance with AASHTO R 100. Test specimens will be tested by the Engineer in accordance with AASHTO T 22. Furnish curing facilities for the test samples in accordance wi th Section 725.

700-16 Measurement and Payment

Remove and repair defects and damage to underlying asphalt course, Portland cement concrete and joints at no cost to the Department.

710-1 Description

Perform the work covered by this section, including, but not limited to , designing the concrete mix; furnishing and placing concrete; furnishing of all admixtures and additives; constructing all joints and furnishing joint materials; marking the pavement; curing the pavement and furnishing all curing materials; furnishing conc rete necessary for making test beams and cylinders ; performing maturity testing; coring and patching the pavement; calibrating and checking the operation of batching equipment; taking actions necessary to prevent or to repair cracking; sawing and sealing j oints ; verifying dowel bar alignment ; removing and replacing of defective pavement; and constructing Portland cement concrete pavement in accordance with these Standard Specifications and with the lines, grades and dimensions shown on the plans.

7-12 710-2 Materials

Refer to Division 10. Item Section Curing Material s 1026 Dowels and Tie Bars 1070 -6 Joint Filler 1028 -1 Low Modulus Silicone Sealant 1028 -3 Portland Cement Concrete 1000 Water 1024 -4

710-3 Composition of Concrete

Design the concrete mix in accordance with Section 1000. Before placement, produce a trial batch through the plant. The Engineer will make compressive and flexural samples from the trial batch for testing at 1, 3, 7, 14 and 28 days of age. Until the trial batch meets 650 psi flexural strength and 4,500 psi compressive strength, the En gineer will make acceptance samples for flexural and compressive tests for mix placed. If the trial batch test results meet strength requirements, flexural samples representing placed concrete will be discarded, and compressive samples will be used for acceptance. If the trial batch does not meet strength requirements, flexural samples will be used for acceptance until plant produced mix meets strength requirements. If any major change as defined in Article 1000- 1 is made to the mix design, this process s hall be initiated again.

710-4 Acceptance of Concrete

The Department will test the concrete pavement for acceptance with respect to compressive strength and thickness on a lot by lot basis in accordance with Article 700 -15 and the requirements herein. For all concrete pavement, including mainline, shoulders, ramps, tapers, intersections, entrances, crossovers and irregular areas not otherwise defined, produce a lot consisting of 1,333.3 sy or fraction thereof placed within 28 calendar days. From each lot, the Engineer will make at least one set of two 6 inch x 12 inch cylinders from a randomly selected batch of concrete. The average compression strength of the 2 cylinders is considered one test. If Department personnel make and test additional sets of cylinders for a lot, all sets will be averaged with the original set to determine the strength. In the case of low strength, the Engineer will perform an investigation.

710-5 Construction Methods

Construct concrete pavement in accordance with Section 700. Place concrete in 2 lane minimu m widths in a single operation except as follows:

710-6 Finishing

Screed and float finish the concrete to the required cross section that minimizes or eliminates hand finishing. Additional water for finishing will not be allowe d. Hand finishing will not be permitted except under the following conditions:

7-13 (B) If a breakdown of mechanical equipment occurs , hand methods may be used to finish

only that concrete deposited on the base before the breakdown.

710-7 Final Surface Testing

Use an Inertial Profiler to measure the longitudinal pavement profile for construction quality control and smoothness acceptance. Use a profiler with line laser technology as single -point

7-14 laser technology will not be allowed. Produce International Roughness Index (IRI) and Mean

Roughness Index (MRI) values for measuring smoothness. Use testing and recording software to produce electronic inertial road profiles in a format compatible with the latest version of FHWA’s ProVAL ( Profil e Viewing and Analysis) software. The Inertial Profiler shall be calibrated and verified in accordance wit h the most current version of AASHTO M 328. Provide certification documentation that the profiler meets AASHTO M 328 to the Engineer before the first day the Inertial Profiler is used on the project. Configure the profiler to record the actual elevation o f the pavement surface. Do not use the profiler’s internal IRI calculation mode. The profile data shall be filtered with a 300 feet Butterworth high- pass filter . The interval at which relative profile elevations are reported shall be a maximum of 1 inch. Provide IRI data in accordance with most current version of ASTM E1926. Use personnel trained to record and evaluate IRI data. Provide a n Inertial Profiler Operator that has been cert ified by the Department ’s Profiler and Operat or Certification Program as administered by the Materials and Tests Unit . Provide the user selected Inertial Profiler settings to the Engineer for the project records. In the presence of the Engineer, at the beginning of each day’s data collection, perform a block test to verify the Inertial Profiler’s ability to accurately collect elevation data is met and perform bounce test to verify that the Inertial Profiler’s accelerometers are performing correctly. Remo ve all objects and foreign material on the pavement surface prior to longitudinal pavement profile testing. In the presence of th e Engineer, operate the profiler at any speed as per the manufacturer’s recommendations, however, the speed must be constant to within ± 3 mph of the intended speed and any required acceleration should be as gradual as possible. For example, if the intended speed were 30 mph, the acceptable range of speed for testing would be 27 to 33 mph . Operate the Inertial Profiler in the direction of the final traffic pattern. Collect IRI data from both wheel paths during the same run. It is permissible to collect data one wheel path a t a time if each wheel path is tested and evaluated separately. Define a “wheel path ” as the 3 f eet from the edge of the travel lane. MRI values are the average of the IRI values from both wheel paths. When using an inertial profiler that collects a single trace per pass, take care to ensure that the measurements from each trace in a travel lane start and stop at the same longitudinal l ocations. Unless otherwise specified, multiple runs are not necessary for data collection. Operate the automatic triggering method at all times unless impractical. A tape stripe or traffic cone wrapped with reflective material may be used to alert the pr ofiler’s automatic triggering sensor to begin data collection. The profiler shall reach the intended operating speed before entering the test section. The runup and runout distances should be sufficient to obtain the intended operating speed and to slow down after testing is completed. Divide the pavement surface for the project into sections which represent a continuous placement (i.e. the start of the project to bridge, intersection to intersection). Terminate a section 50 f eet before a bridge approach, railroad track, or similar interruption. (Separate into 0.10- mile sections). The evaluation of the profiles will be performed on a section basis. A section is 0.10 mile of a single pavement lane. For any section, which is less than 0.10 mile in length, the applicable pay adjustment incentive will be prorated on the basis of the actual length.

7-15 Mark the limits of structures and other special areas to be excluded from testing using the

profiler’s event identifier such that the exact locations can be extra cted from the profile data file during processing. Unless otherwise authorized by the Engineer, perform all smoothness testing in the presence of the Engineer. Perform smoothness tests on the finished surface of the completed project or at the completion of a major stage of construction as approved by the Engineer. Coordinate with and receive authorization from the Engineer before starting smoothness testing. Perform smoothness tests within 7 days after receiving authorization . Any testing performed with out the Engineer’s presence, unless otherwise authorized, may be ordered retested at the Contractor’s expense. After testing, transfer the profile data from the profiler portable computer’s hard drive to a write once storage media ( USB flash drive, externa l hard drive or electronic media method approved by the Engineer ). Label the disk or electronic media with the Project number , Route, file number, date, and termini of the profile data. Submit the electronic data on the approved media to the Engineer imm ediately after testing and this media will not be returned to the C ontractor. Submit documentation and electronic data of the evaluation for each section to the Engineer within 10 days after completion of the smoothness testing. Submit the electronic file s compatible with ProVAL and the evaluation in tabular form with each 0.10- mile segment occupying a row. Include each row with the beginning and ending station for the section, the length of the section, the original IRI values from each wheel path, and the MRI value for the section. Each continuous run for a section will occupy a separate table and each table will have a header that includes the following: the project contract number, county, the roadway number or designation, a lane designation, the dat es of the smoothness runs, and the beginning and ending station of the continuous run. Summarize each table at the bottom. Traffic control and all associated activities included in the pavement smoothness testing of the pavement surface will be the respon sibility of the Contractor.

7-16 Table 710-1

MRI PRICE ADJUSTMENT PER 0.10 -MILE SECTION MRI after Completion (Inches Per Mile) Price Adjustment Per Lane (0.10 -Mile Section) 45.0 and Under $200.00 45.1-55.0 PA = 600 – (10 * MRI) 55.1-70.0 Acceptable (No Pay Adjustment) 70.1-90.0 PA = 650 – (10 * MRI) Over 90.1 Corrective Action Required This price adjustment will apply to each 0.10 -mile section based on the Mean Roughness Index (MRI), the average IRI values from both wheel paths. When corrections to the pavement surface are required, the Engineer shall approve the Contractor’s method of correction. Methods of correction sh all be diamond grinding, remove and replace , or other methods approved by the Engineer . To produce a uniform cross section, the Engineer may require correction to the adjoining traffic lanes or shoulders. Corrections to the pavement surface, the adjoining traffic lanes and shoulders will be at no cost to the Department. Where corrections are made after the initial smoothness testing, the pavement will be retested by the Contractor to verify that corrections have produced the acceptable ride surface. No i ncentives will be provided for sections on which corrective ac tions have been required. The C ontractor will have one opportunity to perform corrective action(s).

710-8 Marking for Station Numbers and Drainage Outlets

Mark the pavement at locations as shown on the plans with station numbers. Mark the pavement by pressing beveled- face metal dies between 4 inches and 6 inches high into the plastic concrete.

7-17 At locations where shoulder drain outlets are placed, mark the edge of pavement nearest the

outlet with the letters “ OL”. Use the same marking procedure as for s tation numbers.

710-9 Thickness Tolerances

A lot for thickness acceptance testing is defined in Article 710 -4. To establish an adjusted unit price, if appropriate, for mainline pavement, take one 4 inch diameter core from each lot at a random location as directed by the Engineer . Other areas such as intersections, entrances, crossovers and ramps will each be considered as one lot and the thickness of each of these lots will be determined separately. Small irregular areas may be included as part of another lot. Take one core for each 1,333.3 sy of pavement or fraction thereof in the lot. When the measurement of any core, original core or additional cores taken to calculate the average, is less than the plan thickness by more than 1.0 inch, the extent of the removal area due to thickness deficiency will be determined by taking additional e xploratory cores at approximately 10 f oot intervals parallel to the center line in each direction from the deficient core until an exploratory core is found in each direction which is within 1.0 inch of the plan thickness. The pavement between these explo ratory cores will be removed full lane width wide and replaced with concrete of the thickness shown on the plans. Exploratory cores for deficient thickness will not be used in averages for adjusted unit price. When the measurement of the core from a lot i s deficient by 0.2 inch or less from the plan thickness, no pay reduction will be made for thickness . When such measurement is deficient by more than 0.2 inch from the plan thickness, take 2 additional cores at random locations within the lot and calculate the average thickness of the lot from the 3 cores. In determining the average thickness of the pavement lot, the Engineer will use all 3 core measurements. Individual core measurements which are greater than the plan thickness + 0.2 inch will be conside red as the plan thickness + 0.2 inch. Individual cores which are less than the plan thickness - 1.0 inch will be considered as the plan thickness - 1.0 inch. If the average measurement of the 3 cores is within 0.2 inch from the plan thickness, full payme nt will be made. If the average measurement of the 3 cores is deficient by more than 0.2 inch from the plan thickness, an adjusted unit price in accordance with Subarticle 710 -10(B) will be paid for the lot represented. Areas found deficient in thickness by more than 1.0 inch shall be removed and replaced with concrete of the thickness shown on the plans. Any full lane or full shoulder width repairs to the concrete pavement shall be performed in accordance with the North Carolina Department of Transportation Partial and Full Depth R epair Manual and not be less than 1/2 of the slab length. Patch all core holes within 72 hours of taking the core, using a Department approved nonshrink grout compatible with the pavement concrete.

710-10 Measurement and Payment

7-18 Cement Concrete Pavement, Miscellaneous, (without dowels) , or if applicable, at such

contract unit prices adjusted in accordance with the requirements shown below. No unit price adjustments on lots will be made until a final determination of the lot strength and depth is made. Pa vement will be classified as through lane, ramp or miscellaneous pavement in accordance with the classification shown on the plans. Payment for all work of surface testing will be incidental to the contract unit price for Portland Cement Concrete Pavement, Through Lanes, (with dowels) for Surface Testing Concrete Pavement .

Article 710 — 10, will be paid at an adjusted contract unit price per square yard for

__" Portland Cement Concrete Pavement, Through Lanes, (with dowels), __" Portland Cement Concrete Pavement, Ramps, (with dowels) or __" Portland Cement C oncrete Pavement, Miscellaneous, (without dowels) completed in place and accepted. The adjusted contract unit price is determined by the following formula, except no pay over 100% will be allowed: Pay Factor (%) = ( ) [ ] Thickness Core Average Thickness Plan − × −50 110 Exploratory cores for deficient thickness will not be used in averages for adjusted unit price. Where pavement deficient by more than 1.0 inch is removed and replaced, the replacement pavement will be paid at the contract unit price per square yard for __" Portland Cement Concrete Pavement, Through Lanes, (with dowels), __" Portland Cement Concrete Pavement, Ramps, (with dowels) or __" Portland Cement Concrete Pavement, Miscellaneous, (without dowels) which price and payment will be full compensation for a ll work of placement, removal, restoration of subgrade and base and replacement.