Chapter 4: Construction Details, Section 40: Concrete Pavement

Nominal Maximum Aggregate Size (in)	Minimum Cross-Sectional Dimension (in)
≤ 1	4 x 4
Between 1 and 2	6 x 6

Slump (in)	Method of Consolidation
≥ 1	Rodding or vibration
< 1	Vibration

Consolidation Method	Number of Layers of Equal Depth
Rodding	2
Vibration	1

Curing of beams: Initial curing and field curing for traffic opening are described in the following paragraphs.

Initial Curing: Store standard-cured specimens for as long as 48 hours after molding, while maintaining the temperature and moisture conditions specified in ASTM C31, Section 10.1.2.1., and in Table 40.4., "Curing and Strength."

Temperature range varies according to the specified concrete strength, as summarized in ASTM C31, Section 10.1.2.1., and in Table 4-40.4., "Curing and Strength."

Table 4-40.4. Curing and Strength

A satisfactory temperature environment can be created during the initial curing of the specimens by one or more of the following procedures: (1) use of ventilation; (2) use of ice; (3) use of cooling devices; or (4) use of heating devices, such as electrical resistance heaters or light bulbs. Other suitable methods may be used if the temperature requirements are met.

A satisfactory moisture environment can be created during the initial curing of the specimens by one or more of the following procedures: (1) immerse molded specimens with plastic lids in water; (2) store specimens in a container or enclosure; (3) place specimens in damp sand pits; (4) cover specimens with plastic lids; (5) place specimens inside plastic bags; or (6) cover specimens with wet fabric. Immersion in water may be the easiest method to maintain required moisture and temperature conditions during initial curing.

Field Curing for Traffic Opening: As nearly as practical, cure beams in the same manner as the concrete in the pavement. To meet these conditions, specimens made for determining when the pavement may be open to traffic must be removed from the molds 44-52 hours after molding. Store specimens representing pavement by placing them on the ground as molded, with their top surfaces up. Bank the sides and ends of the specimens with earth or sand that must be kept damp, leaving the top surfaces exposed to the specified curing treatment. Store concrete pavement specimens as near as possible to the pavement they represent. Provide specimens with the same temperature protection and moisture environment as the concrete pavement they are representing. At the end of the curing period, leave the specimens in place, exposed to the weather in the same manner as the concrete pavement. Remove all beam specimens from field storage and store in water saturated with calcium hydroxide at 70-77 degrees Fahrenheit for 20-28 hours immediately before time of testing to assure uniform moisture condition.

Where air entraining admixtures are required by the project’s pavement climate region, in accordance with Section 40-1.02B(4), “Air Entrainment,” of the Standard Specifications, perform verification testing and use quality control testing for acceptance for air content of concrete pavement. Follow the contractual procedure specified in Section 40-1.01D(8)(b)(ii), “Air Content” of the Standard Specifications.

Monitor the contractor’s conformance with their quality control plan. Verify that control charts for required quality control tests are being updated on each day of paving and adhere to the quality control plan, including action and suspension limits. When deficiencies are observed, notify the contractor and document in the daily report. When deficiencies are not resolved or continue to occur, suspend the contractor’s pavement operations until the contractor provides satisfactory assurances and written documentation of their corrective plans. Where appreciable differences are encountered between the quality control tests and acceptance tests, investigate and resolve these concerns with aid of the district materials engineer as necessary.

Verify that the contractor performs coefficient of thermal expansion sampling and specimen fabrication and submits test results and specimens as specified.

For JPCP, check that dowel bar baskets, tie bar baskets, and the bars themselves are not being displaced during the concrete placement and paving operations. Check that the contractor is properly identifying and constructing contraction joints relative to pavement references and bar centroids in conformance with the contract requirements and the contractor’s quality control plan.

For JPCP, monitor the contractor’s timelines from concrete placement to curing application and contraction joint sawing in comparison to their planned schedule from their early age crack mitigation system. Notify the contractor promptly of any deviations and record this information in the daily report along with the location of the work.

When joints are to be formed rather than sawed, be sure joint material is placed as specified.

Verify that the contractor constructs a transverse construction joint if the time interval between two successive concrete loads is greater than the specification allowance. Check that such joints are constructed at permissible contraction joint locations.

Caution the contractor to construct the pavement so it will meet requirements for inertial profile, straightedge, and edge slump before final finishing to minimize corrective work. Inconsistent delivery and nonuniformity of concrete can affect paver performance and have negative effects on the paved surface. Where encountered, document these locations in the field and within the daily record.

Measure the pavement’s width at the beginning of and periodically after paving. While the required width applies to both upper and lower surfaces, the bottom width can be greater than specified to reduce edge slump.

Check that end anchors are constructed at all required locations and to the dimensions shown on the plans. Be sure transverse contact joints are constructed and tie bars and dowels are placed as shown on the plans. When required, check that pressure relief joints are constructed as specified and shown on the plans.

4-4003C Finishing Pavement

• Make sure that the contractor performs preliminary finishing according to specifications and in a way that imparts the desired surface characteristics.
• During concrete finishing observations, consider the following information:

1. Pavement can be durable with inadequate texture or be well textured and not have enough durability to retain the texture.
2. Mixing water with surface mortar during finishing reduces surface durability. This mixture may result from “bleed” water that had not evaporated, water that was added to the surface to make finishing easier, or water that was added to prevent hairline cracking and checking.
3. If any of the concrete visible during finishing is more dilute than the mortar of the freshly placed concrete, too much water is being mixed into the surface. Telltale signs of the unacceptable practice include the following:
   1. Soupy mortar during finishing.
   2. Excess laitance.
   3. Small scallops in the slab’s edge.
   4. Areas still soft and wet in the finished surface while the surrounding area has turned firm and lost its watery sheen.
4. Standing bleed water may appear on the surface under certain conditions shortly after pavement is placed. To avoid mixing bleed water with surface grout, complete preliminary finishing before bleeding progresses to this degree.
5. Water applied for the convenience of finishing, not otherwise needed to produce the specified product, is contrary to specifications regarding water use for retempering.

• Check that the contractor performs the final finishing as specified and in a way that results in a finished surface with the desired characteristics.
• When sufficient rain may fall to damage fresh pavement, stop pavement placement or verify that other steps, such as covering, are taken to prevent damage.
• Before texturing, check that the contractor rounds the pavement edges to specified radii. Observe texturing for compliance with requirements. Verify that the contractor performs initial texturing with a broom or burlap drag to produce striations parallel to the centerline.
• Check that burlap drags are used as specified and kept sufficiently clean to avoid irregularities in the texture. Brooms used must also be kept sufficiently clean to avoid significant irregularities. Final texturing must be done with spring-steel tines that produce grooves parallel to the centerline. Grooves not straight and parallel to the centerline are unacceptable. Grooves are to be constructed over the entire pavement width with the exception of within 3 inches of pavement edges and longitudinal joints. Make sure the cross section of the steel tines complies with specifications. Inspect the pavement surface to verify that grooves meet the specified depth.
• Before and after the application of curing seal, make sure that the contractor keeps the pavement surface moist as specified.
• Verify that the contractor uses either the waterproof membrane method or curing compound method specified in Section 90-1.03B, “Curing Concrete,” of the Standard Specifications. During observations, also note the following:

1. Waterproof membrane:
   1. Make sure the contractor sprays the concrete with a mist of water until the concrete has set before placing the membrane. Make sure water does not flow over or wash the concrete surface.
   2. Examine the waterproof membrane to see that it meets specifications. For assistance, consult the district materials engineer.
   3. Verify that membrane material is placed and secured and that any damaged sheeting is repaired as the specifications require.
   4. If polyethylene sheeting is used, monitor maximum concrete temperatures during curing, checking that the maximum allowable is not exceeded.
   5. Make sure that the contractor adheres to the specified curing period.
2. Curing compound:
   1. Check that the contractor applies the curing compound uniformly after tining. See that sawed cuts or other disturbed areas receive additional curing compound. Your inspection should verify the following attributes for the compound:
      1. It is not contaminated, diluted, or altered before application.
      2. It is mixed thoroughly before application.
      3. It is applied when concrete surfaces are still visibly moist.
      4. The curing film remains unbroken for the specified duration of curing.
   2. Perform measurements and calculations for the curing seal’s application rate. To determine the rate, you may use California Test 535, “Method of Test for the Application Rate of Concrete Curing Compound in the Field.” Record the measurements in the daily report.

• Verify that concrete pavement joints are constructed in conformance with Section 40‑1.03B, “Joints” of the Standard Specifications; the contractor's quality control plan; and the contractor's early age crack mitigation system for JPCP. Longitudinal and transverse contraction joints must be sawed before cracking occurs and after the concrete is hard enough to saw without spalling, raveling, or tearing. The contractor is responsible for determining the exact time of sawing. Check that concrete debris, water residue, and paste are immediately removed during saw cutting operations and that slurry from the sawing operation is immediately washed from the joint and removed. Where spalling, raveling, and tearing are observed, make sure the contractor performs repairs in conformance with Section 40-1.03N, “Spall and Ravel Repair,” of the Standard Specifications.
• Check that concrete pavement temperature is maintained above 40 degrees Fahrenheit during the initial 72 hours after placement.

4-4003D Post-Paving

• Identify where core locations are to be taken by the contractor. Obtain core submittals throughout pavement operations for determining pavement thickness and air entrainment, which is required when the contractor’s quality control air entrainment test results are not verified by Caltrans testing. For JPCP, obtain cores for evaluating dowel and tie bar placement and concrete consolidation in these areas. Verify that specified placement tolerances have not been exceeded relative to constructed contraction joints and orientation of pavement edges.
• For JPCP, examine concrete pavement surfaces once the cure period is complete. If necessary, order the contractor to obtain concrete cores for further evaluation. Pavement slabs with full depth cracks other than working cracks require the removal and replacement of slab or slab portions. Refer to Section 40-4.03B, "Correcting Noncompliant Pavement Work," and Section 40-4.03C, "Correcting Cracks," in the Standard Specifications for further information on replacing JPCP and correcting JPCP cracks. Spall or ravel areas larger than specified allowance in Section 40-1.03N, "Spall and Ravel Repair," must be repaired in accordance with Section 41-4, “Spall Repair,” of the Standard Specifications. Slabs with combined raveled areas greater than 5 percent of the slab area or with a single area of more than 4 square feet must be removed and replaced.
• For continuously reinforced concrete pavements (CRCP), examine pavement surfaces for cracking and raveling. Refer to Section 40-2.03D, "Correcting Noncompliant Pavement Work," for partial-depth and full-depth repairs. High molecular weight methacrylate is not to be applied to any cracks in CRCP.
• Verify that the contractor performs inertial profiling on specified areas. Refer to Section 36-3, “Pavement Smoothness,” of the Standard Specifications and Section 4-36, “Surfacing and Pavements—General,” of this manual for additional information. Areas requiring correction for smoothness may be ground under Section 42-3, “Grinding,” of the Standard Specifications, subject to meeting minimum pavement thickness requirements. Alternatively, these noncompliant areas may be removed and replaced.
• Caltrans verifies and accepts pavement smoothness based on the results of the contractor's inertial profiler testing under Section 36-3.

For grinding existing concrete pavement, measure profile: 

1. Before any work is performed to calculate existing mean roughness index (MRI)
2. After any pavement replacement work is performed, but before grinding to calculate baseline MRI
3. After grinding is complete to calculate final MRI

For all other concrete pavement project types, measure profile: 

1. After placing concrete but before performing any smoothness correction to calculate pavement MRI
2. After performing any smoothness correction to calculate final MRI

• Obtain contractor’s inertial profiler information and reports for each day of inertial profiling of concrete pavement. Refer to Section 36-3, “Pavement Smoothness,” of the Standard Specifications and Section 4-36, “Surfacing and Pavements—General,” of this manual for additional information.

• Arrange through the district for inertial profile verification testing for pavement smoothness. Pavement areas not subject to inertial profiling requirements must meet specified straightedge requirements.
• Pavement smoothness is measured in accordance with Section 36-3, “Pavement Smoothness,” of the Standard Specifications. The Tables 4-40.5., “Pavement Type Smoothness Selection,” 4-40.6., “Target 60 Smoothness,” 4-40.7., “Target 67.5 Smoothness,” 4-40.8., “Target 75 Smoothness,” and 4-40.9., “Percent Improvement,” show the pavement and project types along with the applicable smoothness. A partial section less than 0.05-miles will not receive proportional pay adjustment but must still meet area of localized roughness (ALR) thresholds. No ALR greater than 160 inches per  mile inches per mile is allowed, except when grinding existing pavement. There are no ALR requirements for grinding existing pavement.

Table 4-40.5. Pavement Type Smoothness Section

Pavement Type	Project Type	Smoothness Table
CRCP	New alignment	Target 60
CRCP	Widening or lane replacement	Target 67.5
JPCP	New alignment	Target 67.5
JPCP	Widening or lane replacement	Target 75
CRCP/JPCP	Grinding existing concrete pavement	Percent Improvement

 

Table 4-40.6. Target 60 Smoothness

0.1-mi MRI (in/mi)	Pay Adjustment/0.1 mi	Corrective Action (Note 1)
≤ 45.00	+ $1,500	None
45.01-55.0	+ [(55 - MRI) x $150]	None
55.01-65.00	0	None
65.01-80.00	- [(MRI - 65) x $150]	Optional (Note 2)
> 80.00	-	Mandatory (Note 3)

Note 1: corrective action must not reduce pavement thickness below minimums in section 40-1.01D(8)(c)(iv), "Thickness," of the Standard Specifications. Applicable to MRI only. 

 

Table 4-40.7. Target 67.5 Smoothness

0.1-mi MRI (in/mi)	Pay Adjustment/0.1 mi	Corrective Action (Note 1)
≤ 50.00	+ $1,500	None
50.01-60.00	+ [(60 - MRI) X $150]	None
60.01-75.00	0	None
75.01-90.00	- [(MRI - 75) x $150]	Optional (Note 2)
> 90.00	--	Mandatory (Note 3)

Note 1: Corrective action must not reduce pavement thickness below minimums in section 40-1.01D(8)(c)(iv). Applicable to MRI only. 

Note 2: Diamond grinding allowed. 

Note 3: Correction is diamond grinding. 

Table 4-40.8. Target 75 Smoothness

0.1-mi MRI (in/mi)	Pay Adjustment/0.1 mi	Corrective Action (Note 1)
≤ 50.00	+ $1,500	None
50.00-60.00	+ [(60 - MRI) X $150]	None
60.01-90.00	0	None
> 90.00	--	Mandatory (Note 2)

Note 1: Corrective action must not reduce pavement thickness below minimums in section 40-1.01D(8)(c)(iv). Applicable to MRI only.

Note 2: Mandatory correction is diamond grinding.

 

0.1-mi MRIexist (Note 1)(in/mi)	0.1-mi MRIfinal (Note 2) (in/mi)	Corrective Action
≤ 100	≤ 60	None
≤ 100	> 60	Mandatory (Note 3)
> 100	≤ 0.6 x MRIexist	None
> 100	> 0.6 x MRIexist	Mandatory (Note 3)

Note 1: Existing MRI. 

 

 

• Caltrans does not pay for mandatory smoothness corrections. Grinding to improve pay to positive pay adjustments is allowed if thickness is not deficient in accordance with Section 40-1.01D(8)(c)(iv), “Thickness,” of the Standard Specifications. Pavement smoothness pay adjustments are applied in addition to other pay adjustments.

• After any required corrective grinding, determine locations where coring for thickness will be performed by the contractor. Observe coring operations and obtain drilled corings in properly identified plastic bags from the contractor. Use cores to determine acceptance of concrete pavement thickness. Do not allow coring machines on fresh concrete while any danger exists of damaging the concrete. Wait at least 72 hours.
• Check that any required rumble strips are ground into the concrete pavement after the minimum specified time and strength have been obtained. Verify that the completed rumble strip conforms to the tolerances for alignment, spacing, depth, length, and width. Make sure equipment noise restrictions are met. Refer to Section 84-8, “Rumble Strips,” of the Standard Specifications for additional information.
• Obtain contractor’s plan if repair or replacement of noncompliant concrete pavement is required.
• Use the following procedure for determining pavement thickness and any applicable deductions:

4-4003E Measurement of Pavement Thickness

Use the following procedure for determining pavement thickness and any applicable deductions:

• Cores taken in each primary unit of pavement at the minimum specified rate and cores in primary unit areas taken at the contractor’s request are referred to as primary cores.
• Primary cores do not include cores taken for secondary thickness measurements. Cores taken to determine the limits of secondary units are referred to as secondary cores.
• Before coring begins in primary units, designate areas where coring is excluded. Limit excluded areas to the following:

• Dig-out spots in the subgrade.
• Thickened slabs at bridge approaches.
• End anchors.
• Local areas where authorized modifications to the planned pavement thickness have been permitted.

• Do not exclude portions of the primary unit where equipment had difficulty or where unauthorized deviations from planned pavement thickness occurred.

4-4003E (1) Location of Primary Cores

Do the following to locate primary cores:

• For each pavement thickness on each day's paving, determine the net area, in square yards, of pavement placed, excluding the area of structures and other areas on which pavement is not placed during that day. The resulting measurement is the area of the primary unit. Divide the area of the primary unit by 1,200 square yards and take the next highest whole number. The resulting number is the number of primary cores to be taken, unless the contractor requests additional ones.
• Divide the net length of the primary unit by the number of primary cores to be taken in that unit. The resulting distance is the primary coring interval.

Locate the first core in any primary unit by starting at either end of the unit preferably proceeding in the direction of increasing stations, and select a lane at random. Select any factor from the longitudinal factors shown in Table 4-40.10., “Calculation Factors to Locate Cores,” in this manual and multiply the factor by the primary coring interval. The result is the distance from the beginning of the primary unit to the first core. Any random method of selecting the longitudinal location of the first core is within the intent of the specification. Determine the lateral location of the first core by selecting a value from the lateral column shown in Table 4-40.10., and measuring that distance from the right-hand edge of the lane selected.

Table 4-40.10. Calculation Factors to Locate Cores

• In turn, locate the remaining primary cores in the lanes. Space them uniformly, from the first core in the unit, at longitudinal intervals equal in length to the primary coring interval for the unit. Then locate them laterally within each lane as used for the first core by applying successive values from the lateral factors in Table 4-40.10. All values in the table are to be used successively for each primary unit throughout the project after the value for the first core in the unit is selected at random. The location of each core should be spotted on the pavement within “pacing accuracy” longitudinally and within about 1 foot laterally.

4-4003E (2) Location of Secondary Cores

To determine the limits of secondary units, locate cores in approximately the center of each adjacent panel. Note that for continuously reinforced concrete pavements, panel lengths are defined as 15 feet for this purpose.

4-4003E (3) Thickness Variation

For all cores, determine the pavement thickness variation by subtracting the specified thickness of pavement from the core measurements determined by California Test 531, “Method of Test for Length of Drilled Concrete Cores.” Record excess thickness by using a plus sign and deficient thickness by using a minus sign.

4-4003F Calculation of Deductions in Payment to the Contractor for Deficient Thickness

Take these steps when calculating deductions based on deficient thickness:

4-4003F (1) When None of the Primary Cores are Deficient in Thickness by More Than 0.05 Foot

When no primary cores are deficient in thickness by more than 0.05 foot, make an adjustment as follows:

• To determine the average thickness deficiency, if any, for the primary unit, average the thickness variations of all primary cores. Record this value to the nearest 0.01 foot. If the average thickness deficiency is less than 0.01 foot, make no deficiency adjustment. If the average thickness deficiency is more than 0.01 foot, continue with the following steps.
• To obtain the deficiency adjustment in dollars per square yard, use the table in Section 40-1.01D(8)(c)(iv), “Thickness,” of the Standard Specifications. The average thickness value is to be rounded to the nearest hundredth of a foot for averages from 0.01 foot to 0.05 foot when using the pay adjustment table.
• To obtain the total amount of payment to deduct for the primary unit, multiply the deficiency adjustment by the total area of the primary unit in square yards.

4-4003F (2) When One or More of the Primary Cores are Deficient in Thickness by More Than 0.05 Foot

When one or more cores are deficient in thickness by more than 0.05 foot, determine the limits of the deficiency by taking a secondary core in adjacent panels. Continue taking a secondary core in adjacent panels, expanding as necessary, until the deficient area is bounded by panels with deficient thickness of 0.05 foot or less. The bounded area is referred to as a secondary unit. Reject the secondary unit area for noncompliance pursuant to Section 5-1.30, “Noncompliant and Unauthorized Work,” of the Standard Specifications. Exclude the secondary unit areas from payment and deduction calculations. In the calculation to determine average thickness of the primary unit, use the average thickness of all secondary cores outside the secondary unit to replace the thickness of the initial primary core within that secondary unit.

To determine the primary unit deduction, multiply the primary unit area, excluding any secondary unit areas, by the appropriate factor, if any, in the table titled “Deduction for Thickness Deficiency” within Section 40-1.01D(8)(c)(iv), “Thickness,” of the Standard Specifications.

To determine the total deduction, add the deductions for primary units and the cost of all secondary cores, including those taken outside secondary unit areas.

Following is an example illustrating the procedure for measuring the pavement for thickness and calculating deductions for thickness deficiencies. The procedures and the dollar figures used for deductions from payments to the contractor used in the example are based on Section 40-1.01D(8)(c)(iv).

Assume the following:

The contractor paved two lanes (1 and 4) from Station 10+00 to Station 46+10. An equipment crossing and a bridge within the limits of the day’s run caused “skips” in the length paved totaling 460 feet (from Station 21+20 to Station 25+80). The actual length paved was 6,300 feet (3,150 feet x 2 lanes). The total area paved on this date was 8,400 square yards.

The engineer calculated the number of cores required for thickness measurements in the primary unit (8,400/1,200 = 7) and the core interval (6,300/7 = 900). To determine the location of the first core, the engineer chose the outside lane, lane 4, at random and used the seventh set of numbers at random, from Table 4-40.10., “Calculation Factors to Locate Cores.” The first core was taken at a longitudinal distance of 360 feet from the beginning and at a lateral distance of 4 feet from the right edge of the lane. Subsequent cores were taken at a core interval of 900 feet, excluding skip areas, proceeding from lane 4 to lane 1. Figure 4-40.1., “Primary Cores,” illustrates the primary unit and the locations of all the primary cores.

Figure 4-40.1., "Primary Cores," illustrates core thickness variations for the respective numbered cores. 

Figure 4-40.1. Primary Cores

 

 

Core 3 is more than 0.02 foot greater than the specified thickness, so + 0.02 foot was used in the calculation to determine thickness deficiency in the primary unit in accordance with Section 40-1.01D(8)(c)(iv), “Thickness,” of the Standard Specifications.

Core 7 was deficient by more than 0.05 foot. Because of this deficiency, the next step was to determine the dimensions of the secondary unit from secondary thickness measurements.

To determine the limits of the secondary unit, the resident engineer ordered secondary thickness measurements in the panels adjacent to the panel where Core 7 was taken. Subsequent thickness measurements were in panels adjacent to panels with thickness deficiencies of more than 0.05 foot. This process continued until the secondary unit was bounded by panels in which the secondary measurements were deficient in thickness by 0.05 foot or less. Cores in each of these panels were taken in the center of the panel.

Figure 4-40.2., “Secondary Cores,” illustrates the thicknesses of the secondary cores taken.

Figure 4-40.2. Secondary Cores

 

The panels in the secondary unit area represented by cores 7, 7a-1, 7a-2 and 7b-1 were measured and found to be 54 feet in length and represent 72 square yards.

The engineer averaged thickness variations of the secondary thickness measurements outside the secondary unit area. The resulting value was used in the calculation instead of the thickness variation for Core 7 to determine the average thickness deficiency of the primary unit area. The core thickness variations in the panels surrounding the secondary unit are tabulated in the following table.

The average of the thickness variations in the preceding table is -0.045 feet. This average was rounded to -0.05 foot, and used for the thickness variation for Core 7 in the primary unit.

Using -0.05 foot for the Core 7 thickness deficiency, the engineer calculated the average thickness deficiency (cores 1 through 7) for the primary area to be -0.016 foot. This average was rounded to -0.02 foot and used for the thickness deficiency for the primary unit.

The remaining area of the primary unit, after the area of the secondary unit was subtracted, was as follows:

8,400 - 72 = 8,328 square yards.

The deduction from payment to the contractor for thickness deficiency in the primary area in accordance with Section 40-1.01D(8)(c)(iv), “Thickness,” of the Standard Specifications was calculated as follows:

8,328 square yards x $2.30 per square yard = $19,154.40

The secondary unit area was later removed, reworked, and replaced. A single core was then taken to determine thickness variation and found to be -0.01 foot. A deduction was then taken on the remedied secondary unit as follows:

72 square yards x $0.90 per square yard = $64.80

In addition to the deductions for pavement thickness deficiencies in the primary and secondary units, a deduction from payment to the contractor was made for the cost of all secondary thickness measurements. The cost of secondary thickness measurements was the cost of cores 7a-1 through 7a-3, 7b-1 through 7b-2, and 7c-1 (core taken after replacement of secondary unit).

4-4003F (3) Contractor’s Requests for Additional Thickness Measurements

If, after the primary coring is performed, the contractor requests additional thickness measurements in any primary unit, treat the request as a request for doubling the frequency of coring in the primary unit area. Locate the additional cores in a manner similar to that used for locating the primary cores. This approach will halve the interval distance between primary cores. To calculate the deficiency adjustment, do not separately consider additional cores that are deficient in thickness by no more than 0.05 foot. Instead, include these cores with the original primary cores. If additional cores are deficient in thickness by more than 0.05 foot, determine the limits of the secondary areas.

Do not grant permission to the contractor for selective coring. However, if the contractor requests additional thickness measurements before the performance of any of the primary coring, you may shorten the length of the coring interval for the primary unit accordingly. For example, the contractor may request a rate of one core for each 600 feet of traffic lane rather than one core for each 900 feet. The request will have the effect of increasing, not necessarily doubling the number of cores.

Deduct from the payment to the contractor the cost of additional thickness measurements that resulted from the contractor’s request.

If a contractor requests more than one round of additional cores, consult with the construction field coordinator before granting permission.

4-4003G Handling of Skips in the Original Day’s Pour and Secondary Areas to Be Removed and Replaced

Skips, (such as gaps left for traffic or equipment crossing, short distances between adjacent bridges, and secondary areas to be removed and replaced), are ultimately poured at a later date. The net area of such pavement placed in any one day technically becomes a primary unit area and, as such, is subject to the specifications regarding thickness measurements. Use judgment regarding which of these areas warrant thickness coring. In general, any area excluded from final coring should be small, and you must have other measurements to confirm that the thickness of the pavement is not deficient.

4-4003H Handling Deficient Areas Not Cored

When you have specific knowledge of areas deficient in thickness and you have records of the extent of such deficiency, exclude these areas from the random coring. Make the deficiency adjustment on the average thickness deficiency in the same manner as for areas that have been cored.

4-4003I Administration

Notify the contractor in writing of the date and place where coring will be performed. Follow up orally, if necessary, to be certain the contractor knows when and where coring will take place.

After measuring and recording pavement thickness, retain the cores until final agreement is reached on payment for the concrete pavement, usually after the contractor returns the proposed final estimate.

The personnel who measure core thickness prepare the coring records, which include information about core location, and measured thickness, and include sketches. The original records and 1 copy are given to the resident engineer, who retains the original and forwards the copy to the contractor. Personnel from the district materials laboratory will keep one copy; another copy goes to METS in Sacramento.

Separate reports should be prepared and identified for secondary area measurements. These reports will help determine the cost to the contractor for secondary coring and provide a clear record of secondary areas. Follow the same distribution of copies described in the previous paragraph for primary unit reports.

Coring for determining acceptance of dowel bars and tie bar placement is to be conducted in a similar manner as that of thickness, except for use of revised lot sizes based on the specified frequencies. If dowel or tie bars are placed outside the specified tolerances, or cores show air voids around the bars, obtain additional cores to determine the limits of unacceptable work. Determine the areas that will require removal as specified in Section 40-2.03D, “Correcting Noncompliant Pavement Work,” and Section 40-4.03B, “Correcting Noncompliant Pavement Work,” of the Standard Specifications.

4-4004 Level of Inspection

Suggested levels of field inspection for typical concrete pavement activities are:

• Benchmark inspection of subgrade for compaction and elevation requirements.
• Benchmark inspection of forms and paving equipment.
• Intermittent inspection of reinforcement, dowel bars, tie bars, dowel bar baskets, and tie bar baskets.
• Benchmark inspection of the contractor’s early age crack mitigation system for JPCP.
• Continuous inspection of concrete delivery, placement, finishing, curing, and contraction joint operations.
• Continuous acceptance sampling and testing of fresh concrete.
• Intermittent monitoring of the contractor’s adherence to their quality control plan.
• Benchmark evaluation of pavement for cracking, faulting, spalling, and raveling.
• Benchmark inspection of dowel and tie bar placement through coring.
• Benchmark inspection of finished surface texture, smoothness, and thickness.

4-4005 Quality Control

Guidance for quality control activities included in this section is summarized as follows:

• Review contractor’s quality control plan.
• Make sure the contractor submits a copy of the AASHTO accreditation for the laboratory performing the mix design.
• Review control charts, verify that results for quality characteristics are in compliance, and check that copies of control charts are posted at designated location.
• For JPCP, check that the contractor performs quality control methods to properly locate contraction joints, dowel bars, and tie bars.
• For JPCP, review the contractor’s early age crack mitigation analysis. As necessary, verify contractor’s analysis by performing an independent simulation using high performance concrete paving software.

4-4006 Payment

Using the dimensions shown on the plans, calculate the quantity of concrete pavement to be paid for. Use curve corrections to make sure that calculations account for curves in alignment.

Make deductions from contract payments for deficient pavement thickness.

Back to top