Special Provision No. 399S43 July This Special Provision deletes and replaces the following specifications:

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1 FAST TRACK FULL DEPTH CONCRETE REPAIR Item No. FULL DEPTH CONCRETE REPAIR Item No. PARTIAL DEPTH CONCRETE REPAIR Item No. FAST TRACK PARTIAL DEPTH CONCRETE REPAIR Item No. Special Provision No. 399S43 July 2007 Repairs to Concrete Pavement and Concrete Base This Special Provision deletes and replaces the following specifications: OPSS Construction Specification for Full Depth Repair of Concrete Pavement or Concrete Base (March 1995), OPSS Construction Specification for Fast Track Full Depth Repairs To Concrete Pavement (March 1998) OPSS Construction Specification for Partial Depth Repairs in Concrete Pavement (September 1996) 1.0 SCOPE This Special Provision covers the requirements for partial depth, full depth and fast track repairs to concrete pavement and concrete base. 2.0 REFERENCES This Special Provision refers to the following standards, specifications or publications: Ontario Provincial Standard Specifications, Construction: OPSS Management of Excess Material OPSS Concrete Pavement and Concrete Base OPSS Sealing or Resealing of Joints and Cracks in Concrete Pavement OPSS Concrete Structures OPSS Steel Reinforcement for Concrete OPSS Abrasive Blast Cleaning - Concrete Construction Ontario Provincial Standard Specifications, Materials: OPSS Aggregates Concrete OPSS Cementing Materials OPSS Water OPSS Joint Filler (Concrete) OPSS White Pigmented Curing Compounds for Concrete OPSS Concrete (Materials and Production) OPSS Load Transfer Assemblies OPSS Epoxy Coated Steel Reinforcement for Concrete July 2007 Pg. of 1 16 SSP 399S43

2 American Association of State Highway and Transportation Officials AASHTO M Standard Specification for Burlap Cloth made from Jute or Kenaf American Society for Testing and Materials Standards: ASTM C Sheet Materials for Curing Concrete Canadian Standards Association Standard: CSA A23.1/A CSA A23.2-3C CSA A23.2-9C Concrete Materials and Methods of Concrete Construction/ Methods of Test for Concrete Making and Curing Concrete Compression and Flexural Test Specimens Strength of Cylindrical Concrete Specimens Ministry of Transportation Publications: MTO Laboratory Testing Manual LS Procedures for Calculating Percent Within Limits LS-407 Method of Test for Compressive Strength of Moulded Cylinders LS Method of Test for Linear Shrinkage of Concrete 3.0 DEFINITIONS For the purpose of this Special Provision the following definitions apply: Autogenous Cylinders: are used for estimating compressive strength of concrete in fast track repair areas. These cylinders are stored in insulated curing containers in which the elevated curing temperature is obtained from heat of hydration of the cement. Cold Weather: means those conditions when the air temperature is at or below 5 o C. It is also considered to exist when the air temperature is at or is likely to fall below 5 o C within 96 hours after concrete placement. Temperature refers to shade temperature. Diamond Grinding: means altering the profile and texture of a concrete surface by utilising grinding equipment that employs diamond tip blades. Fast Track Repair: is a process in which a section of concrete pavement or concrete base is closed to traffic, repairs are completed and the section re-opened to traffic within a specified time period of 24 hours or less. Hot Weather: means those conditions when the air temperature is at or above 28 o C. It is also considered to exist when the air temperature is at or is likely to rise above 28 o C within 24 hours after concrete placement. Temperature refers to shade temperature. Maturity Method: is a technique for estimating concrete strength that is based on the assumption that samples of a given concrete mixture attain equal strengths if they attain equal values of the maturity index. Partial Depth Repairs: are repair areas in the concrete pavement or concrete base which have a minimum depth of 50 mm to a maximum depth of one-third the thickness of the existing concrete slab. July 2007 Pg. of 2 16 SSP 399S43

3 Staged Repair: means a repair area which can not be repaired in one complete operation due to traffic or construction sequence requirements and must be completed in separate stages. Each stage shall be a minimum of one lane in width and 2 m in length. Working Cracks: are full depth cracks which are subject to horizontal or vertical movement. 4.0 DESIGN AND SUBMISSION REQUIREMENTS 4.01 Concrete Mix Design The Contractor shall submit the concrete mix design(s) to the Contract Administrator according to OPSS 1350 with the following addition: a. The Contractor shall submit within 40 days of the mix design submission, for information purposes only, test data for linear shrinkage tested according to LS-435. All supporting test data shall not be more than 12 months old at the time the concrete mix design is submitted to the Contract Administrator Fast Track Repairs General The Contractor shall use both the Autogenous Cylinder Method and the Maturity Method for all fast track repairs. The minimum length of time for the development of the charts for both methods shall be the length of lane closure specified elsewhere in the Contract Documents Autogenous Cylinder Method The Contractor shall submit to the Contract Administrator the following information at the time of submission of the mix design: a. Calibration chart indicating compressive strength versus temperature. b. Calibration chart indicating temperature versus time. c. Ambient air temperature during trial. The above data shall be accompanied by a covering letter signed and sealed by a Professional Engineer detailing the following information: a. Curing method. b. Test method. c. Development of calibration chart. In the event that field performance or conditions are no longer representative of the conditions under which the submitted calibration charts were developed, a new mix design and charts shall be resubmitted prior to proceeding with concrete repairs Maturity Method At the time of submission of the mix design, the Contractor shall submit to the Contract Administrator a plan with details of all equipment and procedures to be used for estimating the in-place compressive strength of fast-track repairs by the maturity method. July 2007 Pg. of 3 16 SSP 399S43

4 The plan shall bear the seal and signature of a Professional Engineer and shall include but not limited to the following: a. Laboratory calibration procedure and equipment for developing the equivalent age vs. strength relationship. b. Calibration chart indicating temperature-time factor vs. time. c. Calibration chart indicating temperature vs. time of the concrete and ambient air temperatures. d. Field procedure and equipment to be used for maintaining, monitoring and recording the internal temperature of the in-place concrete with respect to time Method of Removal of Existing Concrete The Contractor shall submit to the Contract Administrator, a description of the method to be used to remove the existing concrete at least two weeks prior to the start of any work, including the sawcutting and removal process, equipment and disposal Chipping Hammers One week prior to the commencement of the partial depth removal operation, the Contractor shall submit to the Contract Administrator the manufacturer s published specifications on the chipping hammers Cold Weather Protection One week prior to the commencement of concrete production in cold weather, a description of the methods to be used to control the concrete temperature shall be submitted to the Contract Administrator, except for fast track repairs. The submission shall be accompanied by samples of insulation, if requested by the Contract Administrator and shall contain the following information: a. Weather conditions for which the description applies. b. Type of insulation, metric R value and number of layers to be used. c. The method by which the in-place minimum concrete temperatures are to be maintained. d. Method of ensuring cold weather protection measures are maintained when work requiring adjustment to the protective measure is being performed. e. Method of withdrawal of protection to avoid sudden temperature change in the concrete Hot Weather Concreting One week prior to the commencement of concrete production in hot weather, a description of the method used to control the concrete temperature shall be submitted to the Contract Administrator. 5.0 MATERIALS 5.01 Bond Breaker for Dowel Bars and Load Transfer Devices Dowel bars and load transfer devices shall be shop coated with RC-250, Tectyl 506 or an approved equivalent. July 2007 Pg. of 4 16 SSP 399S43

5 5.02 Bonding Agent The bonding agent shall consist of Portland cement and sand mixed with sufficient water to form a stiff mixture. The Portland cement shall be according to OPSS The fine aggregate (sand) shall be according to OPSS The consistency of the mixture shall be such that it can be applied with a stiff brush to the concrete surface in a thin even coating that will not run or puddle Burlap Burlap shall be according to AASHTO M182 Class 4 and shall be free from substances which are deleterious to concrete. The burlap shall have no tears or holes Concrete The minimum compressive strength of concrete at 28-days shall be 30 MPa. Concrete shall meet the requirements of OPSS 1350 with the following exceptions: a. The nominal maximum size of coarse aggregate shall be as specified in Table 1. TABLE 1 Nominal Maximum Size of Coarse Aggregate Repairs Partial Depth Full Depth or Fast Track Nominal Maximum Size of Coarse Aggregate 19.0 mm 19.0 mm, 37.5 mm or combined gradation of nominal maximum aggregate size of 37.5 and 19.0 mm b. The compressive strength of the concrete in the repair area shall be a minimum of 20 MPa prior to opening to traffic. c. For fast track repairs, Type HE (Type 30) Portland cement shall be used. The use of superplasticizer and calcium chloride based accelerators shall be permitted. d. For partial depth concrete repairs, the Contractor may submit a proposal to the Contract Administrator for approval to use a proprietary patching material, in areas where the greatest dimension of the width or length of the patch is less than 300 mm. e. For fast track partial depth repairs, the Contractor shall use a proprietary patching material. The fast track concrete mix design shall not be used for partial depth repairs. f. The requirements for hardened air void system parameters, rapid chloride permeability and compressive strength do not apply Curing Compound White pigmented curing compounds for concrete shall be according to OPSS Epoxy Adhesives Epoxy adhesives shall be of the type approved for horizontal dowel application and mixed in nozzle (cartridge). July 2007 Pg. of 5 16 SSP 399S43

6 5.07 Joint Materials Expansion joint filler shall be according to OPSS The joint sealant material shall be according to OPSS Moisture Vapour Barrier The moisture vapour barrier shall be a white opaque polyethylene film according to ASTM C171 and shall not be less than 100 μm thick Proprietary Patching Materials Proprietary patching materials shall be from the Ministry s list of Concrete Patching Materials. The list of proprietary patching material shall be obtained from the Contract Administrator Tie Bars, Dowel Bars and Load Transfer Devices Tie bars and dowel bars shall be according to OPSS Dowel bars and load transfer devices shall be according to OPSS Water Water used for production, curing, pre-soaking of burlap and bonding agent shall be according to OPSS EQUIPMENT 6.01 Chipping Hammer Chipping hammers shall be hand held and meet the following requirements: a. Chipping hammers shall have a maximum weight of 9.0 kg prior to any handle modification, where applicable, and a maximum piston stroke of 102 mm. b. All hammers shall have the manufacturer s name and parts or model number engraved on them by the manufacturer. All information must be clearly legible. c. The manufacturer s published specifications shall be the sole basis for determining air hammer weight and piston stroke Compressor - Air Blasting The compressor for air blasting shall have a minimum capacity of 3.5 m 3 /min. The compressed air shall be free from oil and other contaminants Diamond Grinder When a diamond grinder is used, it shall be power-driven, self-propelled equipment specifically designed to grind and texture concrete surfaces. It shall be equipped with a grinding head with at least 50 diamond blades per 300 mm of shaft. The grinding head shall be at least 0.9 m wide. The grinder shall be equipped with the capability to adjust the depth, slope and cross-fall to ensure that concrete is removed to the desired dimensions and uniformly feathered and textured across the width and length of the required area. The equipment shall also include a slurry pick-up system. July 2007 Pg. of 6 16 SSP 399S43

7 6.04 Gang Drill The gang drill shall consist of not less than three independently powered pneumatic drills. Drilling equipment shall be used in a manner to ensure adjacent concrete is not damaged Hand Finishing Equipment Only magnesium or wood floats shall be used to finish concrete, except that, bull floats shall be magnesium Maturity Instruments The Contractor shall use a commercial multi-channel maturity meter that meets the following requirements: a. Capable of measuring the ambient and concrete temperature simultaneously as a function of time. b. Calculates maturity at least every 30 minutes. c. Internal memory with sufficient capacity to store all relevant information. d. Able to transfer data to an external device. d. Digital display. e. Battery operated. f. Built-in 24 hour clock running on local time Placing and Finishing Equipment Equipment used for placing, consolidating and finishing concrete for full depth and fast track repairs shall be a vibratory steel screed or steel cylinder screed with integral internal vibration including automatic shut-off and shall operate on fixed forms. For any repair areas less than 3 m in length, the concrete may be placed and consolidated using hand held vibrators and finished with a straightedge. 7.0 CONSTRUCTION 7.01 Operational Constraints General The Contract Administrator shall be notified in writing of the intent to repair the concrete pavement or concrete base one week prior to the commencement of the concreting operation. Concrete shall not be placed when the air temperature or existing surface temperature is below 5 o C, or is above 30 o C. Traffic, other than foot traffic and rubber-tired sawing equipment, shall not be permitted on the concrete until it has attained a compressive strength of 20 MPa. The concrete pavement or concrete base shall be protected from damage to the surface at all times when steel-tracked equipment is used Fast Track Repairs Fast track repairs shall not be placed between October 1 and May 1. The Contractor shall complete each repair location within the time frames defined in the Contract Documents. If the repair is not progressing at a rate that will permit the restoration of traffic within the specified time July 2007 Pg. of 7 16 SSP 399S43

8 period, the Contractor shall undertake appropriate temporary measures acceptable to the Contract Administrator to allow opening of the road to traffic. These measures shall be at the Contractor's expense. A full depth fast track concrete repair shall replace the above temporary work during the next scheduled closure Protection of Tie Bars and Dowel Bars Protection of dowel bars and tie bars shall be according to OPSS 905. Bars with coating damage greater than 1% of the surface area of the bar shall not be used. Bars with coating damage less than 1% of the surface area of the bar shall be repaired according to OPSS Staged Repair Where the operation requires a staged repair, a construction joint shall be placed between stages. Partial lane width repairs are not permitted Concrete Removal Full Depth and Fast Track Full Depth Repairs The Contract Administrator will delineate the limits of the areas to be repaired unless otherwise shown in the Contract Drawings. Repairs shall extend the full width of the lane. Partial lane width repairs shall not be permitted. The outer limits of the concrete removal area shall be sawcut full depth and not extend into existing adjacent concrete that is to remain in place. Sawcutting shall not be carried out more than one week in advance of the expected date of repair. Concrete removal shall be by a lift-out method rather than breaking in place. The Contractor shall ensure that the adjoining concrete and underlying base remains undisturbed. Heavy breaking equipment such as hoe rams shall not be used in the removal operation. If the existing base is disturbed, the loosened material shall be removed, the surface compacted and replaced with an additional depth of concrete at the Contractor's expense. If during the removal process the adjacent concrete in the lane is damaged or cracked due to the Contractor s removal procedure, the damaged area shall be cut back full depth to sound concrete and replaced at the Contractor s expense. The full area shall be repaired as one continuous placement. If the damage is in the adjacent lane, the repair shall be carried out as directed by the Contract Administrator and at the Contractor s expense Partial Depth The Contract Administrator will delineate the limits of the areas to be repaired. The perimeter of the repair area shall be sawcut vertically to a depth of 25 mm. The concrete within the sawcut area shall be removed using a chipping hammer to a minimum depth of 50 mm, and to a maximum depth of one-third the thickness of the existing concrete slab using equipment that will not damage the underlying sound concrete. Any wire mesh in the concrete shall be removed within the repair area. In the event that the partial depth concrete removal operation reveals deterioration extending to a depth greater than one-third the thickness of the existing concrete slab, the repair shall be treated as a full depth repair or fast track full depth repair and concrete shall be removed according to clause of this Special July 2007 Pg. of 8 16 SSP 399S43

9 Provision. However, additional work shall not proceed without prior approval from the Contract Administrator Preparation Work Full Depth and Fast Track Full Depth Repairs The preparation work shall be according to OPSS Partial Depth Repairs All concrete surfaces to receive new concrete shall be abrasive blast cleaned according to OPSS 929. Immediately prior to wetting the concrete surface, all dust and loose material shall be removed from the prepared surface of the repair area by using compressed air. The surface of the patch to receive new concrete shall be maintained in a wet condition for a period of one hour prior to placing any new concrete. Prior to placing concrete, excess water shall be removed from the surface using compressed air. Immediately prior to filling the repair area with concrete, a thin even coat of bonding agent shall be brushed onto all vertical and horizontal prepared surfaces against which concrete will be placed. After application of the bonding agent, any fine aggregate separated from the mixture or any excess bonding agent shall be removed from the surface of the concrete. The bonding agent shall be applied within 30 minutes after mixing and shall not be permitted to dry prior to placing any concrete on it. In the event that the bonding agent has dried, it shall be removed and reapplied prior to concrete placement. Any bonding agent or concrete deposited in areas other than the intended point of discharge shall be removed immediately Joints Full Depth and Fast Track Full Depth Repairs General Joints for concrete pavement and concrete base shall be according to OPSS 350. Where the operation requires a staged repair, a construction joint shall be placed between stages Dowel Bar and Tie Bar Gang drills shall be used to drill holes in the existing concrete for insertion of the dowel bars. The diameter of the drill hole shall be no more than 5 mm larger then the diameter of the dowels or tie bars. Prior to filling the drill holes, the inside surfaces of each drill hole shall be wire brushed and then cleaned using compressed air. The dowel bars and tie bars shall be secured into the existing concrete with epoxy adhesive. The epoxy adhesive shall be injected into the back of the cleaned drill hole and the dowel or tie bar, with grout retention disks attached, shall be inserted to ensure the bars are completely encased with epoxy adhesive for the full depth of the hole. July 2007 Pg. of 9 16 SSP 399S43

10 Tie bars and dowel bars shall be installed at locations specified in the Contract Documents. Where reinforcement is present, dowel bars may be adjusted 25 mm horizontally and raised or lowered 10 mm, to avoid drilling reinforcement. The dowel bars shall be placed mid-depth of the specified slab thickness and parallel to the longitudinal axis and the horizontal plane of the pavement with the following tolerances: a. Vertical Alignment ± 15 mm along the length of the dowel bar. b. Horizontal Alignment ± 15 mm along the length of the dowel bar. c. Side Shift - The centre of the dowel bar shall lie within ± 40 mm from the transverse joint. The tie bars shall be installed within a tolerance of ± 15 mm from the specified depth Transverse Joints Transverse contraction joints shall be cut or formed as detailed in the Contract Documents and skewed if required. Joints shall have a minimum spacing of 2 m and a maximum spacing of 4 m. Expansion joints shall be placed where specified in the Contract Documents and when replacing existing expansion joints Mid-Lane Longitudinal Joints For Fast Track Full Depth Repairs For repairs not longer than 3 m in length, the Contractor shall create a longitudinal joint in the middle of the lane and for the full length of the repair. Tie bars shall be placed at mid-depth of the slab along the full length of the longitudinal joint. The tie bars shall be 25M epoxy coated deformed bars and shall be 760 mm in length. These bars shall be spaced every 400 mm and shall not be placed within 400 mm of a transverse joint. Tie bars shall be installed and secured in a manner that will ensure they remain in the proper position and orientation during the concreting operation Sawcutting Sawcutting of joints shall be carried out before uncontrolled cracking occurs and prior to opening to traffic. Sawcutting operations shall not result in ravelling or other damage to the concrete. The cut shall extend onethird the depth of the concrete slab. For fast track full depth repairs, the Contractor shall use equipment specifically designed for dry-cut joint sawing and the sawing shall be carried out within 2 hours of final finishing. In lieu of sawcutting, the Contractor may form the joint to a minimum depth of 50 mm, when the concrete is in the plastic state Partial Depth Where the partial depth repair area includes an existing pavement joint or working crack, a joint shall be formed in the repair area to match the existing pavement joint or working crack. The joint shall be formed by placing a compressible joint material along the cut line in such a manner that prevents the plastic concrete from entering the existing joint or crack. The width of compressible material shall match the existing joint or working crack. Prior to placement of compressible material, joints or working cracks shall be blown clean with compressed air. July 2007 Pg. 10 of 16 SSP 399S43

11 7.07 Concreting Before placing concrete, the Contractor shall demonstrate to the Contract Administrator that the equipment to be used, provides for proper adjustment of screeds, floats, propulsion and control equipment. The method of transporting and placing the concrete in the repair areas shall be according to OPSS 350 with the following exceptions and/or additions: a. Concrete shall be placed in such a way as to avoid disturbing or displacing tie bars, dowel bars or load transfer devices. b. When an interruption of more than 45 minutes occurs during placing of full depth concrete or 5 minutes for fast track concrete, a transverse construction joint shall be formed. Not withstanding the time limits, there shall be no delays which will result in a cold joint. Concrete placed in the areas between the newly formed joint and the previous joint is subject to removal and replacement at the Contractor s expense if the Contract Administrators deems it necessary. c. The temperature of the fast track concrete at the time of placing shall be less than or equal to 35 o C. The use of insulation to retain heat in the concrete is permitted Consolidating Consolidation of concrete in the repair areas shall be according to OPSS Finishing No water or other chemical agents shall be applied to the concrete surface to aid in the finishing. For concrete pavements where fixed forms are being used or where concrete is being placed against an existing pavement and before surface texturing, the edge of the pavement shall be finished with an edging tool having a radius of not more than 6 mm. The finished pavement edge shall be left smooth, true to line and grade Texturing of Surface Texturing of the concrete surface shall be according to OPSS 350, except that manual devices may be used to provide the required tined texture. Texturing is not required on concrete base or when the Contract Documents specify that the concrete surface is to be diamond ground Surface Tolerance The surface of the concrete repair shall join flush with the existing concrete pavement or concrete base. The surface of the concrete shall be such that when tested with a 3 m long straightedge placed in any location and direction, including the edge of pavement and joints, except across the crown or drainage gutters, there shall not be a gap greater than 3 mm between the bottom of the straightedge and the surface of the concrete pavement. For concrete bases, the tolerance over a 3 m straightedge shall be 6 mm. Diamond grinding will be required to ensure the concrete surface meets these requirements. July 2007 Pg. 11 of 16 SSP 399S43

12 7.12 Curing Curing shall be according to OPSS 350. If curing compound is used in areas greater than 10 m in length, for concrete base, the curing compound shall be completely removed from the concrete surface prior to applying the tack coat and overlaying with asphalt pavement. The method of removal shall be by shotblasting and not result in any damage to the concrete surface. It shall also meet all environmental constraints as stated elsewhere in the Contract Documents Cold Weather Protection Full Depth and Partial Depth Repairs General The Contractor shall protect the concrete during cold weather, except for fast track repairs. The cold weather protection system shall be designed for the worst conditions that can be reasonably anticipated from local weather records, forecasts, site conditions and past experience for the time period during which the protection is required Control of Temperature During cold weather, the Contractor shall for a minimum period of seven days following concrete placement, monitor and control the temperature of the concrete to ensure that the concrete temperature does not fall below 15 o C for the first three days of protection and 10 o C for the subsequent four days. The minimum cold weather protection measures shall be according to Table 3 of OPSS 904. The Contractor shall take measures to ensure that the concrete temperature remains within the acceptable limits. The Contractor shall supply thermocouple wires and digital temperature indicators with an accuracy of ±0.5 o C to monitor the ambient air temperature and concrete temperature. The digital temperature indicators shall be left in place or one provided to the Contract Administrator to facilitate additional readings for verification purposes. Thermocouple wires shall be embedded near the concrete surface in a minimum of four locations, equally spaced throughout each day of concrete placement, as directed by the Contract Administrator Temperature Records The Contractor shall record the ambient air temperature and concrete temperature at a minimum frequency of once every four hours for the first 24 hours after concrete placement and then once every eight hours for the remainder of the protection period and during the removal of the cold weather protection. Temperature records shall be forwarded to the Contract Administrator at the end of every day. At the end of the cold weather protection period, the Contractor shall submit a complete temperature record consisting of a summary of the recorded temperatures and a graphical plot of temperature vs. time to the Contract Administrator. The Contract Administrator shall be provided the necessary access to the location and equipment to verify temperature readings. July 2007 Pg. 12 of 16 SSP 399S43

13 7.14 Joint Sealing Joint sealing shall be according to OPSS Sampling and Testing Slump, Air Content and Temperature The Contractor shall be responsible for sampling and testing the plastic concrete for slump, air content and temperature according to OPSS 1350 and the results of these tests recorded. The minimum frequency of testing shall be one test from each load of concrete Compressive Strength The Contractor shall cast, cure, handle and deliver concrete test cylinders for 28-day compressive strength testing according to CAN/CSA C and deliver them to the Regional Quality Assurance Laboratory specified elsewhere in the Contract Documents. Testing shall be carried out according to LS 407. The frequency of testing shall be as follows: a. Normal Concrete - one set of two cylinders shall be taken for each 15 m3 of concrete but not less than one set of cylinders per day. b. Fast Track Concrete - one set of two cylinders for each load of concrete Special Requirements of Fast Track Full Depth Repairs Trial Area The Contractor shall demonstrate a typical fast track full depth repair at a location designated in the Contract Documents a minimum of one week prior to any concreting operation. If a repair location is not designated in the Contract Documents, the Contractor shall select a location which is acceptable to the Contract Administrator to demonstrate a repair. This repair area shall be a minimum of 2 m (Length) x 3.75m (Width) x m (Depth). The Contractor shall demonstrate the ability to fully complete the trial repair area within the time frame of the closure as defined in the Contract Documents. The trial repair shall simulate the Contract site conditions as if it were the last repair of the closure including sampling and testing as detailed above. The trial area shall not be overlaid and must remain exposed for at least seven days to permit inspection for deficiencies, such as, poor surface finish or cracks. The Contractor shall verify the calibration chart for the mix design strength versus temperature and the calibration chart for the mix design temperature versus time using the autogenous cylinder method. Readings shall also be taken using the maturity method for information purposes. Permission to proceed with repairs on the Contract will only be given when the Contract Administrator is satisfied that all of the above conditions have been met Early Strength Determination General The Contractor shall use the autogenous cylinder method to determine compressive strength for purposes of opening to traffic. The maturity method shall be used in parallel for information purposes. July 2007 Pg. 13 of 16 SSP 399S43

14 Autogenous Cylinder Method The Contractor shall make a minimum of three sets of two autogenous test cylinders for the final repair area of each closure according to CSA A23.2-3C. Testing of autogenous cylinders shall be carried out by the Contractor at a CSA certified laboratory according to CSA A23.2-9C to verify if the concrete in the repair area has attained a minimum compressive strength of 20 MPa. The concrete compressive strength specimen shall be tested to complete failure. These test results shall be communicated immediately to the Contract Administrator, prior to opening to traffic. The Contractor is responsible for the timing, frequency of testing of the autogenous cylinders and shall determine when the concrete pavement or concrete base has attained a minimum compressive strength of 20 MPa. The compressive strength of the concrete in the repair area shall be based on the following procedure: a. Install thermocouple wires as per clause of this Special Provision. b. Monitor and record the temperature of the repair slab and autogenous cylinders a minimum of once every 30 minutes. c. Pairs of autogenous cylinders shall be tested for compressive strength at time intervals decided by the Contractor until a compressive strength of 20 MPa or greater is obtained. The slab shall not be open to traffic until the slab temperature has reached at least the same temperature as the cylinders which attained a compressive strength of 20 MPa or greater Maturity Method The Contractor shall not proceed with any fast track concrete repair work until the plan described in subsection 4.02 of this Special Provision is reviewed by the Contract Administrator. The maturity meter shall be activated and readings continuously taken immediately after concrete placement until just prior to opening to traffic. The Contractor shall submit to the Contract Administrator, within 24 hours of the last concrete placement for the closure, the following information: a. A summary of the time-temperature readings, maturity index, corresponding compressive strength and patch identification for each closure. b. Calibration procedure and equipment for developing the equivalent age vs. strength relationship. c. Calibration chart indicating temp-time factor vs. time. d. Calibration chart indicating temperature vs. time of the concrete and ambient air temperatures Thermocouple Wires The Contractor shall supply and install thermocouple wires at a minimum of two test locations in the final full depth repair area for each closure. At both locations, thermocouple wires shall be installed for each method of early strength determination. The thermocouple wires shall be embedded near the concrete surface and at the edge of the repair area. The Contractor shall also embed thermocouple wires in each of the autogenous cylinders Removal of Unacceptable Concrete Concrete found to be unacceptable shall be removed and replaced with new concrete meeting the Contract requirements at the Contractor's expense. July 2007 Pg. 14 of 16 SSP 399S43

15 The area to be removed shall extend to the nearest contraction joint and longitudinal joint or edge outside the deficient area so that there are no additional joints. Concrete which does not meet the surface tolerance may be corrected by diamond grinding instead of removing and replacing at the Contractor s expense Management of Excess Material Management of excess material shall be according to OPSS QUALITY ASSURANCE 8.01 Inspection The Contract Administrator will inspect the work to determine if the completed work contains: a. Concrete which is cracked the full depth of the repair. b. Partial depth, full depth and fast track repairs with honeycombing or other deficiencies detected visually. c. Partial depth repairs with debonding as identified by sounding. d. Concrete which does not meet the surface tolerance requirements of this Special Provision Acceptance or Rejection The Contract Administrator will reject all or a portion of the lot based on the presence of one or more of the defects identified in subsection 8.01 or one or more of the following conditions: a. Compressive strength not meeting the minimum strength requirements prior to opening to traffic. b. Compressive strength less than 30 MPa at 28-days. c. A lot with a Percent Within Limit (PWL) less than 50%. d. Any work that does not conform to the requirements of this Special Provision Acceptance Criteria for 28-Day Compressive Strength Acceptance of concrete strength for each lot shall be based on the mean and standard deviation of the compressive strength results of all sublots contained in the lot. The compressive strength result of a sublot will be the average strength of the two cylinders made for the sublot, rounded to one decimal place. The Percent Within Limits (PWL) shall be calculated according to MTO LS-101 using 30 MPa as the lower limit. If the lot PWL is greater than 95%, the lot will be accepted with a bonus. If the lot PWL is less than or equal to 95% and greater than or equal to 90%, the lot is accepted with no price adjustment. If the lot PWL is less than 90% and greater than or equal to 50%, the lot is accepted with a price adjustment. If the lot PWL is less than 50%, the lot is rejected and shall be removed and replaced. Notwithstanding the overall PWL, if any individual 28-day compressive strength result is less than 25 MPa, the Contractor shall remove and replace the sublot. July 2007 Pg. 15 of 16 SSP 399S43

16 8.04 Lot Size A lot shall consist of the total quantity of partial depth and full depth repairs to concrete pavement or concrete base. Fast track concrete repairs shall be treated as a separate lot. Each lot will be divided into sublots. The quantity of concrete represented by each set of cylinders, as defined in clause of this Special Provision shall be considered a sublot. 9.0 MEASUREMENT FOR PAYMENT 9.01 Actual Measurement Fast Track Full Depth Concrete Repair Partial Depth Concrete Repair Fast Track Partial Depth Concrete Repair Measurement will be of the surface area of the concrete repair placed in square metres. The total area will be calculated to the nearest 0.1 m Plan Quantity Measurement Full Depth Concrete Repair Measurement shall be by Plan Quantity as may be adjusted by Adjusted Plan Quantity of the surface area of the concrete repair placed in square metres calculated to the nearest 0.1 m BASIS OF PAYMENT Fast Track Full Depth Concrete Repair - Item Full Depth Concrete Repair - Item Partial Depth Concrete Repair - Item Fast Track Partial Depth Concrete Repair - Item Payment at the Contract price for the above tender items shall be full compensation for all labour, equipment and material required to do the Work. Where Work does not conform to the quality requirements for compressive strength, a payment adjustment will be made according to the following equation: Pa = Quantity x Tender Unit Price x (PF 1.0) The pay factor (PF) for the lot shall be determined according to Table 2. July 2007 Pg. 16 of 16 SSP 399S43

17 TABLE 2 Pay Factor Percent Within Limits (PWL) Pay Factor (PF) PWL > 95 PF = [0.002(PWL - 95)] (Bonus) 90 < PWL < 95 PF = 1.0 (No Price Adjustment) 50 < PWL < 90 PF = 0.005PWL (Penalty) PWL < 50 Remove and Replace July 2007 Pg. 17 of 16 SSP 399S43