Section 502 Section 502
502.04 Method of Measurement . Concrete bridge end pavement, complete in place and
accepted, will be measured as sp ecified in Subsection 501.04.
502.05 Basis of Payment . Concrete bridge end pavement will be paid for at the contract
unit price per square yard in accordance with the methods as provided in Subsection 501.05, which price shall be full compensation for completing the work. Payment will be made under: 502-A: Reinforced Cement Concrete Bridge End Pavement - per square yard SECTION 503 - REPLACEMEN T OF CONCRETE PAVEMENT
503.01 Description . This work consists of replacing continuously reinforced concrete
pavement (CRCP), jointed reinforced concrete pavement (JRCP), or plain jointed concrete pavement (JCP) and the removal and replacement of base materials at locations designated on the plans or as determined by the Engi neer, all in accordan ce with the plans and specifications.
503.02 Materials. Materials shall meet the requirements of Subsection 700.01 and the
following Subsections of Division 700, Materials and Tests. Cement ........................................................................................... 701.01 and 701.02 Fine Aggregate ............................................................................... 703.01 and 703.02 Coarse Aggregate ........................................................................... 703.01 and 703.03 Concrete Admixtures ........................................................................................ 713.02 Water ................................................................................................................ 714.01 Concrete Reinforcem ent Bars ........................................................................... 711.02 Longitudinal Joint Filler ................................................................................... 707.02 Curing Material s ............................................................................................... 713.01
503.03 Construction Requirements.
503.03.1 Equipment . Equipment shall meet the requirements set out in Section 501 for
hand placement and finishing concrete paveme nt. Batching and mi xing equipment shall meet the applicable requirements of Section 804. On-site mixers or truck mixers will be permitted.
503.03.2 Removal of Existing Pavement.
503.03.2 1--General. Existing pavement shall be removed in accordance with details
shown on the plans and as specifically set out herein. Removal will be measured for payment as set forth in Section 202. The Contractor shall dispose of the concrete in accordance with Section 201. Equipment and methods used in all of the work shall not damage any of the underlying base and materials that are to remain in pl ace. All materials which are removed from the roadway shall be disposed of daily. 503.03.2.2--Jointed Reinforced Concrete Pavement (JRCP) . The removal of existing reinforced concrete pavement shall be accomplished by sawing the full thickness of the pavement along the edge of the repaired areas as shown on the plans and/or as directed by the Engineer.
503.03.2 3--Continuously Reinforced Concrete Pavement (CRCP). The pavement
within the lap area shall not be disturbed, da maged, or removed until the continuity of the concrete and steel has been severed between th e failed area and the lap area. This shall be accomplished by sawing the full th ickness of the pavement along the edge of the lap area. Jack hammers used for cutting and removal of the concrete in the lap area shall not exceed 20 pounds. The concrete in the lap area shall be removed in such a manner to result in a near vertical face at the saw line of the repair area. A chipping type removal is required to prevent spalling the bottom of the pavement to remain. Any spalling in excess of one and one-half inches shall be corrected by enlarging the repair area at no additional cost to the State. All shattered and damaged concrete shall be removed and the exposed faces cleaned. The reinforcing steel in the lap area shall not be bent more than four inches in twenty inches from its original position. Where more than 10 percent of the steel is damaged in the lap area along any one edge of a removed area, the pa tch shall be enlarged at no additional cost to the State to provide the specified lap. Wher e less than 10 percent of the steel is damaged, the bars may be repaired by welding. The steel shall be inspected for excessive ru sting and evidence of distress during the removal process. The Engineer may enlarge the patch to remove deteriorated steel from the lap area. When the patch is enlarged by the Engineer, payment will be made for such removal.
503.03.2 4--Plain Jointed C ement Concrete Pavement (JCP). The removal of existing
plain concrete pavement shall be accomplis hed by sawing the full thickness of the pavement along the edge of the repaired areas as shown on the plans and/or as directed by the Engineer.
503.03.3 Removal of Base Material . Base material referred to herein and on the plans
shall be all types of material below the paveme nt that requires removal and backfill. The material shall be removed to the dimensions and depths designated by the Engineer. Removal of all undercut materials shall be in accordance with Section 202 and measured for payment by the square yard of base. The Contractor shall dispose of the material in accordance with Section 201.
503.03.4 Installation of Smooth Dowel Bars . Smooth dowel bars shall be installed in
accordance with details shown on the plan s and as specifically set out herein. The commercial grout system used shall be one of the systems specified in Subsection
714.11.7 Installation and acceptance pr ocedures are also included therein.
After the dowel bars are installed, the placeme nt of reinforcing steel and any other work that may disturb the setting of the grout will not be permitted.
503.03.5 Installation of Tie Bars . The tie bars, except when directed otherwise on the
plans, shall be No. 5 deformed bars, 30 inch es long, placed on 24-inch centers and grouted using a commercial grout. The drilled holes sh all be partially filled with an epoxy grout and the tie bars inserted to ensure that the holes are completely filled. The commercial grout system used shall be one of the systems specified in Subsection
714.11.7 Installation and acceptance pr ocedures are also included therein.
After the tie bars are installe d, the placement of reinforcing steel and any other work that may disturb the setting of the grout will not be permitted.
503.03.6 Base and Pavement Replacement. Repair of the base and pavement shall conform to the requirements set forth herein and details shown on the plans. The exposed
faces of the concrete pavement, the soil cement base and/or polyethylene covering the base repair shall be sprayed with water just prior to pouring the new slab. The applicable provisions of Section 501 shall be adhered to with the following exceptions:
a.Concrete. Structural concrete for pavement repair shall be made of cement or cement with additives and/or admixtures. The use of additives or admixtures shall be in accordance with the manufacturer’s instructions. The Contractor shall submit a proposed concrete mix design to the Mississippi Department of Transportation Materials Division for approv al at least two weeks prior to use on the project. This concrete shall also meet the requir ement for a compressiv e strength of 3500 psi within 72 hours. To meet these requ irements, a Type F or G high range water reducing admixture shall be used. If the ambient temperature is less than 50ºF, the addition of a Type C or E acceleration admixture shall be used. The usage of admixtures shall be in accordance with manufacturer’s instructions. Air Content ............................................................................................... 3 to 6% Slump ............................................................................................ 8” maximum* * No requirement for an initial slump before the addition of the high range water reducer. Field verification trial mix results must be provided to the Engineer prior to placement if there is no previ ous data to verify strength.
b.Forms. The forms may be metal or wood. Where at all possible, the forms shall be metal. Metal form shall meet the requirements of Subsection 501.03.6.2 and the wood forms shall be made of 2 x 8 lumber. Forms shall be graded to a specified elevation as dir ected by the Engineer.
c.Longitudinal Joints. Where a repair area is required to extend across a longitudinal joint, a preformed or sawed longitudinal joint shall be constructed and sealed as shown on the plans or as directed by the Engineer.
d.Consolidating and Finishing. All concrete shall be thoroughly consolidated by internal vibration. Finishing may be performed by either machine or hand methods. All patches less than 20 feet in length shall be screeded longitudinally unless otherwise permitted by the Engineer. The surface of the pavement shall be fi nished as designated elsewhere in the contract and in accordance with the ap plicable portions of Section 501. The screed shall be metal of a type used on bridges for finishing short patches and may be a mechanical or bridge type on long patches exceeding 20 feet. All replacement concrete shall be checked long itudinal with a 10-foot straightedge in accordance with Subsection 501.03.19 for concrete pavement other than main- line pavement.
e.Curing and Protection. Concrete cylinders used to represent the minimum compressive strength shall be field cured and cured by the same methods used on that portion of the roadway it represents. If the ambient temperature is less than 50ºF, the field cured cylinders sha ll be placed in an insulated box. The concrete repair area shall be cured up until the time of opening to traffic. All exposed surfaces, including vertical surf aces, shall be cured immediately after finishing operations have been completed. Curing and protection shall be in accordance with Subsection 501.03.20. White pigmented curing compound shall be used and the sprayer shall be equipped with a container having a capacity of not less than five gallons and maintain a constant pressure by mechanical means. Curing time shall be continued until the concrete has attained the required compressive strength as evidenced by test specimens.
f.Concrete Saw Cuts. The saw cut shall be at the locations and depth shown on the plans.
g.Contraction Joint Assembly. Contraction joint assemblies shall be installed as per the details shown in the plans.
h.Concrete Placement. Limitations on placing continuously reinforced concrete pavement are set forth in the following schedule: CONCRETE PAVING SCHEDULE DURING DAYTIME HOURS Predicted High Temperature Hours of Daytime Placement Below 70ºF Daylight hours 70º - 84ºF 12:00 Noon to Sundown 85º - 89ºF 1:30 PM to Sundown 90ºF & Above 3:00 PM to Sundown Note: The National Weather Service's pr edicted high temperature for the day shall govern. Unless lighting provisions have been made for nighttime work, sufficient time must be allowed for the finishing operation prior to sundown but no less than 30 minutes will be permitted. CONCRETE PAVING SCHEDULE DURING NIGHTTIME HOURS During nighttime operations, concrete pours may be made anytime between sundown and sunrise without regard to predicted high temperatures.
503.03.7 Opening to Traffic. The traffic lane shall be opened within 72 hours of concrete placement and may be opened earlier if a 2500 psi compressive strength is obtained and
verified by a cylinder break or maturity meter probe. The approval of the Engineer must be obtained prior to opening the lane. Side forms shall be removed and the shoulder repaired with asphalt pavement, and the ar ea cleared of equipment and waste materials prior to opening to traffic. The sampling and testing frequency for concrete test cylinders shall be at least two cylinders per day per section of lane for which an individual lane closure is effected and concrete pavement is replaced. The Contractor must make arrangements to have the concrete compressive cylinders tested by an acceptable commercial laboratory. Re sults from laboratory tests may be accepted verbally to expedite the opening of traffic to a section of closed roadway, but the Contractor must furnish the Engineer with certified test reports within three days. Any misrepresentation of test cylinders which allows traffic to be opened in areas that did not meet minimum requirements will result in the Contractor removing and replacing the repair(s) represented by the cylinder at no additional cost to the State. If the Contractor has previously developed the strength/maturity relationship for the mixture, an approved maturity meter probe may be used to determine concrete strengths. A maturity meter probe shall be inserted into the last concrete placed that represents the pavement area to be tested. The maximum amount of concrete which may be represented by a maturity meter probe is 50 cubic yards. The pavement may be opened to traffic when maturity meter reading indicates that the required in place streng th is obtained. Procedures for using the maturity meter and developing the strength/maturity relationship shall follow the requirements of AASHTO T325. Validation of the maturity curves shall be made at least once for every 500 cubic yards produced of each concrete mixture used. Validation of the maturity curve shall be considered acceptable when the results of compressive strength tests are within 10% of the predicted value determined by the maturity curve. If the 10% requirement is not met, the existing maturity curve shall no longer be used and a new maturity curve shall be developed prior to continuing to use the maturity method to estimate the in-place compressive strength. Technicians using the maturity meter or calculating strength/maturity graphs shall be required to have at least two hours of traini ng prior to using the maturity equipment. Training and maintaining a list of approved ma turity technicians shall be the responsibility of the Mississippi Concrete Industries Association.
503.04 Me thod of Measurement . Replacement of the concrete pavement will be
measured for payment by the square yard complete in place. Saw cuts will be measured for payment by the linear foot when a pay item is included in the contract proposal. Concrete for base repair will be measured by the cubic yard complete in place. Smooth dowel bars and tie bars will be measured per each complete in place. No separate measurement will be made for reinforcing steel, wire mesh, longitudinal joints, polyethylene sheeting and asphalt pavement for repair of shoulders and maintenance of traffic items required. The plans may also provide for welding of the reinforcing steel as an optional method available to the Contractor. This method reduces the width of the lap area from 20 inches to eight inches which will reduce the size of the repair areas. If the Contractor elects to use the optional method, the subsequent reduction in plan quantities will not be justification for adjustment of contract unit prices as provided in Subsection 104.02.
503.05 Basis of Payment. The accepted quantities of saw cuts, concrete for base repairs,
smooth dowel bars, tie bars, and concrete pavement will be paid for at the contract unit prices which shall be full compensation for completing the work, furnishing all labor, equipment, tools, materials, and bituminous plant mix required for shoulder repair. Removal and disposal of pavement and base materials shall be made under appropriate items under Section 202. The price for each item of work shall include the cost of continuous maintenance of traffic and protective services as required by the De partment's Traffic Control Plan. This shall include all required individual traffic control devices. Payment will be made under: 503-A: ___" and Variable Type Concrete Pavement, Type Finish - per square yard 503-B: Saw Cut, Longitudinal Joints - per linear foot 503-C: Saw Cut, ___" - per linear foot 503-D: Concrete for Base Repair - per cubic yard 503-E: Tie Bars, No. ___ Deformed, Drilled and Epoxied or Grouted - per each 503-F: ___" Smooth Dowel Bars, Drilled and Epoxied or Grouted - per each SECTION 508 - SILICONE SEALED JOINTS
508.01 Description. This work shall consist of clean ing and sealing joints in accordance
with the plans and these specifications.
508.02 Materials . The silicone sealant material used in this construction shall meet the
requirements of Subsection 707.02.1.4. The backer rod shall meet the requirements of Subsection 707.02.1.5.
508.03 Construction Requirements.
Source: Mississippi Standard Specifications for Road and Bridge Construction, 2017 Edition. Pages 377–381 of 1,113.