SECTION 421 – MICRO SURFACING AND SLURRY SEAL
421.01 Description
This section describes the requirements for micropaving joints, micro surfacing, and slurry seal.
421.02 Materials
421.02.01 Materials
Provide materials as specified: Tack Coat: Emulsified Asphalt, Grade RS-1, RS-1h, CRS-1, or CRS-1h ................................ ................................ ... 902.01.02 Micro Surfacing ................................ ................................ ................................ ................................ ........... 902.09 Slurry Seal ................................ ................................ ................................ ................................ ................... 902.10
421.02.02 Equipment
Provide equipment as specified: Pneumatic-Tired Compactor ................................ ................................ ................................ ........................ 1002.01 Bituminous Material Distributor ................................ ................................ ................................ .................. 1003.07 Mechanical Sweeper ................................ ................................ ................................ ................................ ... 1008.03 Micro Surfacing and Slurry Seal Paver ................................ ................................ ................................ ........ 1012.01 Provide hand squeegees, shovels, and other equipment necessary to perform the work. Provide cleaning equipment such as power brooms, air compressors, water flushing equipment, and hand brooms adequate for surface preparation.
421.03 Construction
421.03.01 Micro Surfacing Aggregate, Type III Rut Filling
Fill ruts in the wheel paths and restore the designed profile of the pavement cross section as shown on the Plans and as directed by the RE. Fill ruts which are 1/2 inch or less with a single full lane micro surfacing operation. Fill ruts which are greater than 1/2 inch depth with a separate rut filling operation. Fill ruts which are greater than 1 1/2 inch depth with multiple applications utilizing a rut filling equipment. Do not over fill rut areas. Cure rut filling and level-up material for at least 24 hours before additional material is placed.
421.03.02 Micropaving Joints
Clean the joint, removing unsound patches and loose material. Use micro surfacing Type II as specified in 902.09 and rut filling equipment or slurry seal paver equipment modified to provide a 2 feet to 5 feet wide application of material to fill in open longitudinal joints and rumble strips in one pass as shown on the Plans and as directed by the RE. For joint filling greater than 2 inches deep and less than 6 inches wide, perform multiple applications to even out settlement of the material after curing. For joints greater than 2 inches deep and greater than 6 inches wide, perform HMA pavement repair as specified in 401.03.03. Avoid excess crowning and over filling of joints and rumble strips. Cure each pass of material under traffic for at least 24 hours before additional material is placed.
421.03.03 Micro Surfacing Aggregate and Micro Surfacing Emulsion
A.Micro Surfacing Plan. At least 20 days before beginning placement of material, submit a detailed plan of operation to the RE for approval that includes the following:
1.Paving contractor’s superintendent qualifications with a list of at least 5 successful projects, including project owner contact information.
2.Size and description of crew.
3.Number, type, model of equipment and material control/metering devices along with the current cali bration documentation.
4.Lighting plan for night operations as specified in 108.06 for milling and paving.
5.Method of locating, protecting and maintaining manholes, inlets, other utilities and RPM’s.
6.Paving procedures for maintaining continuous operation as specified.
7.Paving sequence. Indicate that the surface is to be constructed for the full lane width as a single paving operation.
8.Schedule, hours of operation, and production rates for the Project.
9.Plant and stockpile locations for aggregate, emulsion, mineral filler and additives.
10.Method of maintaining modified emulsion temperature during transportation.
11.Method of constructing joints.
12.Quality control plan outlining the material testing, number and frequency planned in order to ensure compliance.
13.Mix design of the mixture, the AASHTO accredited laboratory used, and the test results of the mixture. Do not begin paving until the RE approves this plan. Submit an adjusted plan before making adjustments to the paving operation.
B.Weather Limitations. Do not place material if the surface temperature of the underlying pavement is below 50 °F or if the National Weather Service is forecasting temperatures below 50 °F during installation or within 3 hours after installation. Do not place material if the existing surface is wet. Do not place material if it is precipitating and when precipitation is imminent. If within the 3 hours of placement, the National Weather Service locally forecasts a 50 percent chance, or greater, of precipitation during the scheduled placement, then postpone the placement of material. The Contractor may resume operations when the chance of precipitation is less than 50 percent, and the surface is dry.
C.Test Strip. Construct a test strip of at least 500 feet in length on the roadway before initial placement commences. Ensure that the mixing uni t has been calibrated according to the International Slurry Surfacing Association Inspector’s Manual or as recommended by the manufacturer. Ensure that the tack coat has been placed as specified in 401.03.05. Ensure the test strip is performed during weather and sunlight conditions which represent project production placement of the material. While constructing the test strip, record the following information and submit to the RE:
1.Ambient Temperature. Measure the ambient temperature at the beginning and end of each day’s operation.
2.Base Temperature. Measure the surface temperature of the existing pavement at the beginning and end of each day’s operation.
3.Weather Conditions. Document the wind speed, weather conditions, time of day, and humidity at the time of placement.
4.Tack Coat . Measure to verify the proper application rate, coverage , and temperature of tack coat for compliance.
5.Material Quantities. Measure to verify the prop er proportions of emulsion, cement, aggregate, additives (if any), and temperature of the mixture during placement. Measure to verify the proper application rate of the mixture for compliance.
6.Roller Pattern. Provide details on the number of rollers, type, and number of passes used on the test strip.
7.Initial Set Time. Record the initial time of placement. Verify that the mixture has achieved initial set within 30 minutes of placement.
8.Performance Under Traffic. Verify that the surface shows no visual signs of distress when exposed to traffic after curing for 1 hour.
9.Calibration. Measure to verify that the gate opening is what was determined during calibration. Submit test strip results to the RE. The RE will analyze the test strip results in conjunction with the approved mix design to approve the test strip. Do not proceed with production placement until receiving written permission from the RE. If the test st rip does not meet requirements, make adjustments and construct a second test strip. If the second test strip does not meet requirements, suspend operations until written approval to proceed is received from the RE. Before making adjustments to the operations, notify the RE in writing. The RE may require a new test strip to verify the performance of the adjusted operations.
D.Surface Preparation. Ensure repairs are completed prior to beginning installation. Ensure rut filling and micropave joints have cured for at least 24 hours prior to applying material. Ensure that manholes, inlets, utilities, curbs, RPMs, structures, rumble strips, traffic striping and traffic markings to remain are protected by methods app roved by the RE. Do not proceed with placement until the RE approves the prepared surface. Clean the surface of the pavement to remove all dust, debris, oil, and any other materials that may prevent bonding of the treatment to the existing surface. Ensure that the surface is clean and dry. Apply tack coat prior to application of the treatment as specified in 401.03.05.
E.Micro Surfacing Application. Apply the mixture over the full lane width as specified in Table 421.03.03-1. Table 421.03.03-1 Job Mix Types and Application Aggregate Type (See Table 902.09.03-1) Location Application Rate (lbs./yd2) Type II Surface Course 16 – 22 Intermediate Course 10 – 20 Type III Rut filling 20 – 40 (See ISSA1 A 143)
1.International Slurry Surfacing Association (ISSA) Operate equipment to prevent the loss of the mixture on super-elevated curves. Spread the mixture to fill cracks and minor surface irregularities and leave a uniform high -skid resistant application of aggregate and asphalt on the surface. Operate spreader box so a uniform consistency is achieved without causing skips, lumps , or tears in the finished surface. Carry a sufficient amount of material, at all times, in all parts of the spreader box, so complete coverage is obtained. Water may be sprayed into spreader box to facilitate spreading without harming the mix. No lumping, balling , or unmixed aggregate is permitted in the finished surface. Adjustments to the additive may be required for slow setting where hand spreading is needed. Use squeegees and lutes to spread the mixture in areas inaccessible to the spreader box and areas requiring hand spreading. When hand spreading, pour the mixture in a small windrow along one edge of the surface to be covered and then spread uniformly by a hand squeegee or lute. Make a neat appearing seam where two passes join. Ensure transverse joints of micro surfacing are made straight, clean, and perpendicular to the direction of travel. The maximum overlap of longitudinal lane line joints is 3 inches. Ensure micro surfacing longitudinal joints are parallel to , and not offset by more than 3 inches maximum from the final traffic striping. Immediately remove excess material from ends of each run. Do not leave streaks in the finished surface. If streaking develops, stop the operation and submit a corrective action plan to the RE. Do not resume operations until the RE approves the plan.
F.Compaction. Do not roll until the material has cured sufficiently to av oid damage by the roller. Use a pneumatic-tired compactor as specified in 1002.01, except ensure the roller is equipped with a water -spray system. Roll the material with a minimum of at least 2 passes of the pneumatic-tired compactor. The RE may direct additional passes to eliminate roller marks or facilitate compaction of rut filled areas.
G.Opening to Traffic. Allow the material sufficient curing t ime before opening to traffic. Remove loose material from the traveled way before opening to traffic. If the material becomes damaged replace the damaged area.
H.Applying Striping and Traffic Markings. Allow material to cure for at least 14 days before applying permanent traffic striping and traffic markings. Use temporary traffic striping and markings as directed by the RE until the material has cured.
I.Surface Quality Requirements. Ensure that there is no excess buildup , uncovered areas , or rough areas on the pavement surface including the longitudinal and transverse joints. The RE will visually inspect the pavement for approval. The RE may reject areas of pavement that are unsatisfactory based on visual inspection. Correct areas of the pavement that the RE rejects. Visual inspection by the RE is considered sufficient grounds for such rejection. The RE may use a 10 foot straightedge to verify transverse profiles of finished surfaces. Correct areas that have more than 1/4 inch deviation between any 2 contact points of the straightedge in a manner approved by the RE. Following correction, retest the area to verify conformance with this requirement.
J.Ride Quality Requirements. The Department will evaluate the ride quality of the final riding surface of all constructed pavement on the project using the International Roughness Index (IRI) according to ASTM E 1926. The final riding surface is defined as the last lift of the pavement structure where traffic will be allowed. The pavement will be evaluated using the target IRI (T) determined from Table 421.03.03-3. For projects paving on mainline travel lanes equal to or greater than 2,500 feet length and any lane within the project of at least 1,000 feet length, the Department will evaluate the ride quality of the final riding surface of the mainline travel lanes using IRI. The Department will use the measured IRI to calculate the pay adjustment (PA) using pay adjustment equation (PAE) type PA1 as specified in Table 421.03.03-2. PA will be based on lots of 0.01 mile length. The PA will be positive for superior quality work or negative for inferior quality work. For projects paving on mainline travel lanes of less than 2,500 feet length, the RE will visually inspect the final riding surface. Based on visual inspection, if the RE determines that the work may not conform to the ride quality requirements, then the Department will evaluate the ride quality of the final riding surface using IRI. Visual inspection by the RE is considered sufficient grounds for such evaluation. The Department will use the measured IRI to calculate the PA using pay adjustment equation (PAE) type PA1 as specified Table 421.03.03-2. For paving on ramps and shoulders, the RE will visually inspect the final riding surface. Based on visual inspection, if the RE determines that the work may not conform to the ride quality requirements, then the Department will evaluate the ride quality of the final riding surface using IRI. Visual inspection by the RE is considered sufficient grounds for such evaluation. The Department will use the measured IRI to calculate the pay adjustment using pay equation type PA2 as specified in Table 421.03.03-2.
1.Smoothness Measurement. The Department will test the longitudinal profile of the final riding surface for ride quality with a Class 1 Inertial Profiling System according to NJDOT R-1. If project conditions preclude the use of the Class 1 Inertial Profiling System, the Department will use a Class 1 Walking Pr ofiler or Lightweight Profiler.
2.Quality Control Testing. Perform quality control testing during lift placement to ensure compliance with the ride quality requirements specified in Table 421.03.03-3.
3.Preparation for IRI Testing. Notify the RE when all paving is complete and the RE will request IRI testing by Pavement & Drainage Management & Technology (PDMT) unit . Provide traffic control when the Department performs IRI testing. Perform mechanical sweeping of the surface before IRI testing. To facilitate auto triggering on laser profilers, place a single line of temporary pavement marking tape perpendicular to the roadway baseline at the beginning and end of each lane, shoulder, and ramp to be tested or at the direction of the Department. Submit the actual stationing for each temporary pavement marking tape location to the RE.
4.Quality Acceptance. The Department will determine acceptance and provide PA based on the following:
a.Pay Adjustment . The acceptable IRI for the roadway pav ement will be the target IRI (T) from Table 421.03.03-3 for which full payment will be made and will be determined using the latest available existing current average IRI (C) data of the right most travel lane specified in 102.04 or from PDMT. The number of lots for final pay adjustment will be reduced by the number of lots excluded for each segment shown in Table 421.03.03-2. Lots excluded from final PA will be those with the highest recor ded IRI numbers for respective roadway and bridge deck segments. A single average IRI value and the corresponding PA for each 0.01 mile lot will be reported. IRI units are in inches per mile. Table 421.03.03-2 Pay Equations for Ride Quality Pay Equation Type Excluded Lots Pay Equation(s) PA1 As shown in the Special Provisions Table 421.03.03-2A IRI < (T – 25) PA1 = $10 (T – 25) ≤ IRI < (T – 5) PA1 = $(T – IRI – 5) x 0.5 (T – 5) ≤ IRI ≤ (T + 5) PA1 = 0 (T + 5) < IRI ≤ (T + 75) PA1 = –$(IRI – T – 5) x 1.4286 IRI > (T + 75) PA = –$100 PA2 Will include, if tested IRI ≤ 120 PA2 = $0 120 < IRI ≤ 170 PA2 = (IRI − 120) x (−$10.00) IRI > 170 Maximum Negative Pay or Corrective Action Table 421.03.03-3 Target IRI for Micro Surfacing or Slurry Seal (T)1 Roadway Type Excluded Lots Current average IRI (C) Target IRI (T) Freeways or Limited Access Highways As shown in the Special Provisions Table 421.03.03-2A ≤ 50 50 >50 C1 Other than Freeways or Limited Access Highways with speed limit > 35 MPH ≤ 60 60 >60 C1 Other than Freeways or Limited Access Highways with speed limit ≤ 35 MPH ≤ 70 70 >70 C1
1.Current average IRI (C) is the average of the latest available preconstruction network level IRI data of right most travel lane from PDMT.
b.Corrective Action. If the average IRI is greater than T+75 inches per mile after testing is performed, the Department may require corrective action or assess the maximum negative pay adjustment as computed in Table 421.03.03-2. If the Department requires corrective action, submit a plan for corrective action. If the plan for corrective action is approved and the lot is corrected, the Department will retest and evaluate the corrected area as a new lot that must meet the same requirements as the initial work. If the plan fo r corrective action is not approved, the Department may require removal and replacement. The replacement work is subject to the same requirements as the initial work.
421.03.04 Slurry Seal Aggregate and Slurry Seal Emulsion
A.Slurry Seal Plan. At least 20 days before beginning placement of slurry seal mixture, submit a detailed plan of operation to the RE for approval as specified in 421.03.03.A.
B.Weather Limitations. Place slurry seal mixture in weather as specified in 421.03.03.B.
C.Test Strip. Construct a test strip as specified in 421.03.03.C.
D.Surface Preparation. Prior to placing slurry seal mixture, prepare the existing surface as specified in 421.03.03.D.
E.Slurry Seal Application. Apply the slurry seal mixture as specified in 421.03.03.E, except that application rate should be as specified in Table 421.03.04-1. Table 421.03.04-1 Job Mix Types and Application Aggregate Type (See Table 902.10.03-1) Location Application Rate (lbs./yd2) Type I Surface Course Intermediate Course 10 – 14 Type II Surface Course Intermediate Course 16 – 20
1.International Slurry Surfacing Association (ISSA)
F.Compaction. Roll slurry seal as specified in 421.03.03.F.
G.Opening to Traffic. Open to traffic as specified in 421.03.03.G.
H.Applying Striping and Traffic Markings. Apply traffic striping and traffic markings as specified in 421.03.03.H.
I.Surface Quality Requirements. The Department will evaluate the surface quality of slurry seal as specified in
421.03.03 I.
J.Ride Quality Requirements. The Department will evaluate the ride quality of the final riding surface of all constructed pavement on the project as specified in 421.03.03.J.
421.04 Measurement and Payment
The Department will measure and make payment for Items as follows: Item Pay Unit MICRO SURFACING AGGREGATE, TYPE III RUT-FILLING TON MICROPAVING JOINTS LINEAR FOOT MICRO SURFACING AGGREGATE, TYPE II TON MICRO SURFACING AGGREGATE, TYPE III TON MICRO SURFACING EMULSION GALLON SLURRY SEAL AGGREGATE, TYPE I TON SLURRY SEAL AGGREGATE, TYPE II TON SLURRY SEAL EMULSION GALLON The Department will make payment for TACK COAT as specified in 401.04. The Department will not include payment for removal of traffic stripes, removal of traffic makings, epoxy traffic stripes, epoxy traffic marking, lines, epoxy traffic markings, symbols, and epoxy traffic markings, route symbols in the various Items of this Section. The Department will pay for removal of traffic stripes, removal of traffic makings, epoxy traffic stripes, epoxy traffic marking, lines, epoxy traff ic markings, symbols, and epoxy traffic markings, route symbols under REMOVAL OF TRAFFIC STRIPES, REMOVAL OF TRAFFIC MARKINGS, TRAFFIC STRIPES EPOXY, TRAFFIC MARKINGS LINES, EPOXY, TRAFFIC MARKINGS SYMBOLS, EPOXY , and TRAFFIC MARKINGS ROUTE SYMBOLS, EPOXY as specified in 610.04 respectively. The Department will not include payment for latex traffic stripes, latex traffic markings lines , and latex traffic markings symbols in the various Items of this Section. The Department will pay for latex traffic stripes, latex traffic markings lines, and latex traffic markings symbols under TRAFFIC STRIPES, LATEX, TRAFFIC MARKINGS LINES, LATEX , and TRAFFIC MARKINGS SYMBOLS, LATEX as specified in 159.04 respectively. The Department will measure MICRO SURFACING EMULSION and SLURRY SEAL EMULSION by the gallon on the certified weigh tickets, excluding unused material, with the exception that micro surfacing emulsion required for micropaving joints is included in the price per linear foot of MICROPAVING JOINTS. The Department will measure MICRO SURFACING AGGREGATE TYPE II, MICRO SURFACING AGGREGATE TYPE III, MICRO SURFACING AGGREGATE TYPE III RUT-FILLING, SLURRY SEAL AGGREGATE TYPE I, and SLURRY SEAL AGGREGATE TYPE II by the ton as indicated on the certified weigh tickets, excluding unused material.
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Source: Standard Specifications for Road and Bridge Construction, 2019 (rev. 2022-12-21) Edition. Pages 225–230 of 651. View official source ↗