Art. 402.12 Micro-Surfacing and Slurry Sealing
402.12 Method of Measurement. Aggregate used for aggregate surface
course will be measured for payment in tons (metric tons), cubic yards (cubic meters), or square yards (square meters) of the thickness specified, according to the requirements of Article 311.08. The cost of excavation for the transition at the bridge, railroad crossing, or existing pavement will not be measured for payment.
402.13 Basis of Payment. This work will be paid for at the contract unit price
per ton (metric ton) for AGGREGATE SURFACE COURSE, TYPE A, or AGGREGATE SURFACE COURSE, TYPE B; or at the contract unit price per cubic yard (cubic meter) for AGGREGATE SURFACE COURSE, TYPE A; or AGGREGATE SURFACE COURSE, TYPE B; or at the contract unit price per square yard (square meter) for AGGREGATE SURFACE COURSE, TYPE A; of the thickness specified. Aggregate for temporary access will be paid for at the contract unit price per ton (metric ton) for AGGREGATE FOR TEMPORARY ACCESS. BITUMINOUS SURFACES AND HOT-MIX ASPHALT PAVEMENTS SECTION 403. RESERVED SECTION 404. MICRO-SURFACING AND SLURRY SEALING
404.01 Description. This work shall consist of micro-surfacing or slurry
sealing existing hot-mix asphalt (HMA) surfaces.
404.02 Materials. Materials shall be according to the following.
Item Article/Section
a.Cement (Note 1) ..................................................................................... 1001
b.Water ...................................................................................................... 1002
c.Fine Aggregate .................................................................................. 1003.08
d.Bituminous Material (Tack Coat) ........................................................ 1032.06
e.Emulsified Asphalts (Note 2) (Note 3) ................................................ 1032.06
f.Fiber Modified Joint Sealer ................................................................ 1050.05
g.Additives (Note 4) Note 1. The cement shall be Type 1 portland cement. Note 2. When used for slurry seal, the emulsified asphalt shall be CQS-1h according to Article 1032.06(b). Note 3. When used for micro-surfacing, the emulsified asphalt shall be CQS-1hP according to Article 1032.06(e). Micro-Surfacing and Slurry Sealing Art. 404.06 Note 4. Additives may be added to the emulsion mix or any of the component materials to provide the control of the quick-traffic properties. They shall be included as part of the mix design and be compatible with the other components of the mix.
404.03 Equipment. Equipment shall be according to the following.
Item Article/Section
a.Slurry Systems Mixing Machine .......................................................... 1102.08
b.Slurry Systems Spreader .................................................................... 1102.09
c.Slurry Systems Proportioning Devices ................................................ 1102.10
d.Air Compressor ................................................................................... 1101.19
e.Oil Kettle ............................................................................................. 1101.20 CONSTRUCTION REQUIREMENTS
404.04 General. Slurry systems shall be according to the following.
a.Micro-Surfacing. The paving mixture shall be capable of filling up to 1 1/2 in. (38 mm) wheel ruts in one pass, be capable of field regulation of the setting time, and be suitable for nighttime placement. The compatibility of all ingredients of the mix, including the mix set additive, shall be certified by the emulsified asphalt manufacturer.
b.Slurry Seal. The slurry seal shall be capable of field regulation of the setting time. The compatibility of all ingredients of the mix, including the mix set additive, shall be certified by the emulsified asphalt manufacturer.
404.05 Weather Limitations. Placement of the slurry system shall be done
between May 1 and October 15, and when the air temperature in the shade is at least 50 ºF (10 ºC) and rising and the forecast for the next 24 hours is above 40 °F (5 °C).
404.06 Mix Design. Prior to beginning work, the Contractor shall submit
designs for each required mixture to the Department for verification and approval. The mixture design shall be performed at a laboratory accredited for pavement preservation testing by AASHTO re:source in addition to the following.
a.Micro-Surfacing. The micro-surfacing mix design shall be according to the Bureau of Research’s (BR) PT001 “Micro-Surfacing Job Mix Formula Form”. Materials for the mix design shall be within the following limits. Art. 404.06 Micro-Surfacing and Slurry Sealing Material Limits Mineral Aggregate, lb/sq yd (kg/sq m) dry weight (mass) 15 - 50 (8 - 30) Latex Emulsified Asphalt Residue, % by weight (mass) of aggregate 7.0 - 10.5 Latex Base Modifier, % by weight (mass) of binder 3.0 min. Mix Set Additive Per laboratory requirements Cement, % by weight (mass) of aggregate 1/ 0.25 - 3 depending on weather conditions 1/ Cement shall be considered as part of the aggregate gradation. The Department will verify the micro-surfacing sample according to the following acceptable limits. Illinois Modified AASHTO T 164 Requirements Parameter Acceptable Range Asphalt Binder (AB) Content ± 1.0 % Moisture Content ± 1.5 %
b.Slurry Seal. The slurry seal mix design shall be according to the BR PT002 “Slurry Seal Job Mix Formula Form”. Materials for the mix design shall be within the following limits. Material Limits Mineral Aggregate, lb/sq yd (kg/sq m) dry weight (mass) 15 - 25 (8 - 15) Emulsified Asphalt Residue, % by weight (mass) of aggregate 7.5 - 13.5 Mix Set Additive Per laboratory requirements Cement, % by weight (mass) of aggregate 1/ 0.0 - 3.0 depending on weather conditions 1/ Cement shall be considered as part of the aggregate gradation. After the mix design is approved, no substitutions will be permitted unless approved by the Engineer.
404.07 Test Strip. For each contract, an 1,800 sq yd (1,505 sq m) test strip
shall be required with a quantity of 70,000 sq yd (58,500 sq m) or more of micro- surfacing. At least one day prior to starting the project the Contractor shall designate a mutually agreeable location and apply a test strip using the approved mix design. The Engineer will evaluate the application rate and cure time. If more than one mix design is used, a test strip shall be performed for each mix design.
404.08 Surface Preparation. Pavement markings shall be removed
according to Article 783.03(a). Only very small particles of tightly adhering existing markings may remain in place. Micro-Surfacing and Slurry Sealing Art. 404.09 Raised reflective pavement markers shall be removed according to
Article 783 — 03(b) and holes filled with HMA, rut filling mix, or other material approved
by the Engineer. Bumps greater than or equal to 1/2 in. (13 mm) shall be removed by grinding. The Contractor shall determine bump grinding locations in the presence of the Engineer by using a 16-ft (5-m) straightedge with the scratcher bolts set to 1/2 in. (13 mm). All locations marked by the scratcher bolts shall be ground using either a grinding machine consisting of multiple saws or a cold-milling machine with a double- or triple-wrap milling head. Joints and cracks 3/16 in. (5 mm) or wider shall be cleaned of vegetation, loose and unsound material and filled. The sealant shall be applied only when the joints and cracks are clean and dry, and the ambient temperature is 40-85 °F (4-29 °C). The sealant shall be applied using a pressurized wand delivery system with such devices as necessary to fill the cracks/joints and form a nominal 0.125 in. (3 mm) thick by 3 in. (75 mm) wide overseal band centered so the center of the 3 in. (75 mm) wide band is within 1 in. (25 mm) of the crack. The sealant shall be allowed to cure before opening to traffic. When approved by the Engineer, the sealant may be dusted with fine sand, Portland cement, or mineral filler to prevent tracking.
404.09 Micro-Surfacing. The micro-surfacing shall be applied as shown on
the plans and the following.
a.Preparation. Prior to applying the micro-surfacing, the pavement surface shall be cleaned. A tack coat shall be applied uniformly at a rate that will provide a residual rate of 0.025 lb/sq ft (0.122 kg/sq m) for HMA surfaces and/or 0.05 lb/sq ft (0.244 kg/sq m) for concrete surfaces according to
Article 406 — 05(c). Manholes, valve boxes, drop inlets, and other service
entrances shall be protected from the micro-surfacing by a suitable method. The surface preparation shall be approved by the Engineer prior to the application of the micro-surfacing. No dry aggregate either spilled from the lay-down machine or existing on the road will be permitted.
b.Application. The Contractor shall apply the micro-surfacing according to the following methods.
1.Micro-Surfacing Rut-Filling. This method shall consist of filling each of the two wheelpath ruts in a lane using the specially designed rutbox and the rutfill mix. It shall be the Contractor's responsibility to determine and estimate the quantities of rutfill mix required for rut-filling. This work is then followed by the micro-surfacing type shown in the plans and as described below.
2.Micro-Surfacing, Single Pass. This method shall consist of applying the surface mix over the entire width of each lane in one pass at an application rate of not less than 20 lb/sq yd (11 kg/sq m).
3.Micro-Surfacing, 2 Passes. This method shall consist of applying the surface mix over the entire width of each lane in two passes to provide Art. 404.09 Micro-Surfacing and Slurry Sealing a total rate of application of not less than 32 lb/sq yd (17 kg/sq m). The rate of application per pass shall be 16 ± 3 lb/sq yd (9 ± 1.6 kg/sq m). Unless otherwise directed by the Engineer, all hand work shall be completed during the first pass. The second pass shall be placed not less than 18 hours after placing the first pass and the first pass is free of surface moisture. Determinations of application rates shall be from daily readings taken from the material control devices during the progress of the work. The moisture of the aggregate shall be measured and recorded at a minimum of once daily. Additional moisture testing may be required if conditions change or at the discretion of the Engineer. The Contractor shall maintain continuous control of the latex-modified emulsified asphalt to dry aggregate proportioning to conform to the approved mix design within a tolerance of ± 2 gal/ton (± 8 L/metric ton). The pavement surface shall be prewetted by water fogging ahead of the spreader box when road conditions require, as determined by the Engineer. The rate of fogging shall be adjusted during the day based on pavement temperature, surface texture, and dryness. The paving mixture shall be spread to fill minor cracks and shallow potholes and leave a uniform surface. Care shall be taken when rut-filling to restore the designed profile of the pavement cross section. Excess crowning (over- filling) of rut areas shall be avoided. A sufficient amount of material shall be carried at all times in all parts of the spreader box to ensure complete coverage. Overloading of the spreader shall be avoided. No lumps or uncoated aggregate will be permitted in the finished surface. Adjustments to the mix design may be required during construction, based on field conditions. The cement in the mix design may be increased or decreased by less than 0.5 percent when the micro-surfacing is being placed if it is found to be necessary for better consistency or set times. The Engineer will give final approval for all adjustments.
c.Mix Consistency. The finished product shall be uniform in color and composition. No streaks, such as those caused by oversized aggregate, shall be left in the finished surface. If excess streaking develops, the job shall be stopped until the Contractor proves to the Engineer that the situation has been corrected. Excessive streaking is defined as more than four drag marks greater than 1/2 in. (13 mm) wide and 4 in. (100 mm) long, or 1 in. (25 mm) wide and 3 in. (75 mm) long, in any 30 sq yd (25 sq m) area. No transverse ripples or longitudinal streaks of 0.25 in. (6 mm) in depth will be permitted, when measured by placing a 10 ft (3 m) straightedge over the surface.
d.Mix Stability. The micro-surfacing shall possess sufficient stability so that premature breaking of the material in the spreader box does not occur. The mixture shall be homogeneous during and following mixing and spreading. Micro-Surfacing and Slurry Sealing Art. 404.10 It shall be free of excess water or emulsified asphalt and free of segregation of the emulsified asphalt and aggregate fines from the coarser aggregate. Under no circumstances shall water be sprayed directly into the lay-down box while placing micro-surfacing material.
e.Joints and Edges. The Contractor shall devise a joint plan according to ISSA A143 and submit to the Engineer for approval. When practical, the surface course joint shall be at least 10 in. (255 mm) away from the nearest edge of any subsequent permanent pavement markings. Micro-surfacing edges shall be parallel with the existing pavement edges. If the existing pavement edge cannot be used to give a straight edge, a stringline or other guide will be required. Edge lines shall not vary by more than ± 2 in. (50 mm) horizontally in any 100 ft (30 m) of length. A smooth, neat seam shall be provided where two passes meet. Excess material shall be immediately removed from the ends of each run. Any damage to, or irregularities in, the micro-surfacing shall be repaired, as directed by the Engineer. All repairs shall be made with a paver box, except areas designated as hand work areas.
f.Hand Work. Those areas inaccessible to the spreader box and approved by the Engineer shall be designated as hand work areas. Adjustments to the additive will be permitted to provide a slower setting time when hand spreading is needed. If hand spreading is necessary, the mixture shall be poured in a small windrow along one edge of the surface to be covered and then spread uniformly by a hand squeegee or lute. Hand work areas shall have an appearance consistent with that being placed with a spreader box.
404.10 Slurry Sealing. The slurry seal shall be applied as follows.
a.Preparation. Prior to applying the slurry seal, the pavement surface shall be cleaned. A tack coat shall be applied uniformly at a rate that will provide a residual rate of 0.025 lb/sq ft (0.122 kg/sq m) according to Article 406.05(c). Manholes, valve boxes, drop inlets, and other service entrances shall be protected from the slurry seal by a suitable method. The surface preparation shall be approved by the Engineer prior to application of the slurry seal. No dry aggregate either spilled from the lay-down machine or existing on the road, will be permitted.
b.Application. The slurry seal shall be applied over the entire width of each lane in a single pass at a rate of 20 lb/sq yd (11 kg/sq m). The application rate shall be verified from daily readings taken from the proportioning devices during the progress of the work. The pavement surface shall be prewetted by water fogging ahead of the spreader box when road conditions require, as determined by the Engineer. The rate of fogging shall be adjusted during the day based on pavement temperature, surface texture, and dryness. Art. 404.10 Micro-Surfacing and Slurry Sealing The paving mixture shall be spread to fill minor cracks and shallow potholes and leave a uniform surface. A sufficient amount of material shall be carried at all times in all parts of the spreader box to ensure complete coverage. Overloading of the spreader shall be avoided. No lumps or uncoated aggregate will be permitted in the finished surface. Adjustments to the mix design may be required during construction, based on field conditions. The cement in the mix design may be increased or decreased by less than 0.5 percent when the slurry seal is being placed if it is found to be necessary for better consistency or set times. The Engineer will give final approval for all adjustments.
c.Mix Consistency. The finished product shall be uniform in color and composition. No streaks, such as those caused by oversized aggregate, shall be left in the finished surface. If excess streaking develops, the job shall be stopped until the Contractor proves to the Engineer that the situation has been corrected. Excessive streaking is defined as more than four drag marks greater than 1/2 in. (13 mm) wide and 4 in. (100 mm) long, or 1 in. (25 mm) wide and 3 in. (75 mm) long, in any 30 sq yd (25 sq m) area. No transverse ripples or longitudinal streaks of 0.25 in. (6 mm) in depth will be permitted, when measured by placing a 10 ft (3 m) straightedge over the surface.
d.Mix Stability. The slurry seal shall possess sufficient stability so that premature breaking of the material in the spreader box does not occur. The mixture shall be homogeneous during and following mixing and spreading. It shall be free of excess water or emulsified asphalt and free of segregation of the emulsified asphalt and aggregate fines from the coarser aggregate. Under no circumstances shall water be sprayed directly into the lay-down box while placing slurry seal material.
e.Joints and Edges. The Contractor shall devise a joint plan according to ISSA A105 and submit it to the Engineer for approval. When practical, the surface course joint shall be at least 10 in. (255 mm) away from the nearest edge of any subsequent permanent pavement markings. Slurry seal edges shall be parallel with the existing pavement edges. If the existing pavement edge cannot be used to give a straight edge, a stringline or other guide will be required. Edge lines shall not vary by more than ± 2 in. (50 mm) horizontally in any 100 ft (30 m) of length. A smooth, neat seam shall be provided where two passes meet. Excess material shall be immediately removed from the ends of each run. Any damage to, or irregularities in, the slurry seal shall be repaired, as directed by the Engineer. All repairs shall be made with a paver box, except areas designated as hand work areas.
f.Hand Work. Those areas inaccessible to the spreader box and approved by the Engineer shall be designated as hand work areas. Adjustments to the additive will be permitted to provide a slower setting time when hand spreading is needed. If hand spreading is necessary, the mixture shall be poured in a small windrow along one edge of the surface to be covered and Micro-Surfacing and Slurry Sealing Art. 404.15 then spread uniformly by a hand squeegee or lute. Hand work areas shall have an appearance consistent with that being placed with a spreader box.
404.11 Clean-Up. All areas, such as manholes, gutters, and intersections,
shall have the slurry system removed as specified by the Engineer. The Contractor shall, on a daily basis, remove any debris associated with the performance of the work.
404.12 Sampling and Testing. The Contractor shall check yield of the
application after the first 1000 ft (300 m), and throughout each day’s paving, with a minimum of three tests per day. Yield check results shall be furnished to the Engineer daily. The Contractor shall submit a daily “run sheet” for each day’s work as soon as all the data is available. The run sheet shall provide a breakdown of the actual meter numbers and quantities of all materials actually used each day, as well as the respective locations. The Contractor shall provide a copy of the paver calibration to the Engineer for verification and approval. The calibration shall be performed a minimum of once per job mix formula (JMF), per contract. The Contractor shall collect a minimum of one sample per JMF in the presence of the Engineer. Material for the sample shall be collected from the loading shoot of the pug mill prior to being deposited into the drag box. The sample shall be placed in a 1 gal (3.8 L) sealed plastic bag. Enough material shall be collected, evenly distributed in the plastic bag, and laid flat to form approximately 1/2 in. (13 mm) of material. The bag shall be squeezed to remove excess air, sealed, and placed on a hard, flat surface. After allowing the bag to sit flat for 15 minutes, it shall be picked up and evaluated. The material should have turned black and show positive signs of setting up (stiffening). The results at 15 minutes shall be documented and the sealed bag placed into a 1 gal (3.8 L) friction top container and sent to the Department for AB content testing.
404.13 Opening to Traffic.
a.Micro-Surfacing. The micro-surfacing shall be opened to traffic within one hour of its application.
b.Slurry Seal. The slurry seal shall be opened to traffic within two hours of its application.
404.14 Curing. The slurry system shall cure for a minimum of 7 days before
placement of the permanent pavement markings.
404.15 Method of Measurement. This work will be measured for payment as
follows.
a.Contract Quantities. The requirements for the use of contract quantities shall conform to Article 202.07(a). Art. 404.15 Micro-Surfacing and Slurry Sealing
b.Measured Quantities. Crack/Joint sealing will be measured for payment in feet (meters), measured along the crack. Pavement marking removal will be measured for payment according to
Article 783 — 05.
The micro-surfacing will be measured according to the following for the method of application provided on the plans.
1.Micro-Surfacing Rut-Filling. Micro-surfacing rut-filling will be measured for payment in place in feet (meters) along the wheel path or filled rut.
2.Micro-Surfacing, Single Pass. Micro-surfacing, single pass will be measured for payment in place and the area computed in square yards (square meters). The width for measurement will be the width of the top surface as shown on the plans or as directed by the Engineer.
3.Micro-Surfacing, 2 Passes. Micro-surfacing, 2 passes will be measured for payment in place and the area computed in square yards (square meters). The width for measurement will be the width of the top surface as shown on the plans or as directed by the Engineer. The slurry seal will be measured for payment in place and the area computed in square yards (square meters). The width for measurement will be the width of the top surface as shown on the plans or as directed by the Engineer. Tack coat, when required, will be measured for payment according to
Article 406 — 13(b).
404.16 Basis of Payment. Crack/joint sealing will be paid for at the contract
unit price per foot (meter) of FIBER-MODIFIED ASPHALT CRACK SEALING. Bump removal will be paid for at the contract unit price per each for BUMP REMOVAL. Pavement marking removal and pavement marker removal will be paid for according to Article 783.06. Rut-filling will be paid for at the contract unit price per foot (meter) for MICRO- SURFACING RUT-FILLING. Micro-surfacing, single pass will be paid for at the contract unit price per square yard (square meter) for MICRO-SURFACING, SINGLE PASS. Micro-surfacing, 2 passes will be paid for at the contract unit price per square yard (square meter) for MICRO-SURFACING, 2 PASSES. Slurry seal will be paid for at the contract unit price per square yard (square meter) for ASPHALTIC EMULSION SLURRY SEAL. Tack coat, when required, will be paid for according to Article 406.14. Cape Seal Art. 405.02 SECTION 405. CAPE SEAL
405.01 Description. This work shall consist of constructing a single
bituminous surface treatment (A-1) and a micro-surfacing on existing hot-mix asphalt (HMA) surfaces.
405.02 Materials. Materials shall be according to the following.
a.A-1 Surface Treatment. Materials for A-1 surface treatment shall be according to the following. Item Article/Section
1.Seal Coat Aggregate (Note 1) ............................................... 1003, 1004
2.Bituminous Materials (Note 2) ......................................................... 1032 Note 1. The seal coat aggregate shall be either fine or coarse aggregate. When fine aggregate is used, it shall be stone sand, wet bottom boiler slag, slag sand, or steel slag sand. The aggregate quality shall be Class C. The aggregate gradation shall be FA 1 (Special), FA 4 (Special), or FA 22 as specified on the plans and shall meet the following. FINE AGGREGATE GRADATIONS Grad. No. Sieve Size and Percent Passing 3/8 in. (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 16 (1.18 mm) No. 40 (425 um) No. 200 (75 um) FA 1 (Special) 100 90 ± 10 62.5 ± 17.5 32.5 ± 7.5 7.5 ± 7.5 1.5 ± 1 FA 4 (Special) 100 -- -- 2 ± 2 -- 1.5 ± 1 FA 22 100 1/ 1/ 8 ± 8 -- 2 ± 2 1/ For the fine aggregate gradation FA 22, the aggregate producer shall set the midpoint percent passing, and the Department will apply a range of ± 10 percent. The midpoint shall not be changed without Department approval. When coarse aggregate is used, it shall be crushed gravel, crushed stone, wet bottom boiler slag, crushed slag, crushed sandstone, or crushed steel slag. The aggregate quality shall be Class C and the total chert count shall be no more than 25.0 percent by weight (mass) as determined by the Illinois Test Procedure 203. The aggregate gradation shall be CA 15, CA 16, or CA 20 as specified on the plans. Note 2. The bituminous material shall be either a CRS-2P or HFRS-2P according to Article 1032.06(e).
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Source: Illinois Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 199–208 of 1,217. View official source ↗