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Microsurfacing (2010)

Chapter: Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists

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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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Suggested Citation:"Appendix C - Microsurfacing Example Contract Clauses, Specifications, and Checklists." National Academies of Sciences, Engineering, and Medicine. 2010. Microsurfacing. Washington, DC: The National Academies Press. doi: 10.17226/14464.
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105 This Appendix contains copies of all the specifications, warranty clauses, etc., that are noted in the body of the report. STATE OF OHIO DEPARTMENT OF TRANSPORTATION SUPPLEMENTAL SPECIFICATION 881 MICRO-SURFACING WITH WARRANTY July 13, 1999 881.01 General 881.02 Warranty Bond 881.03 Materials, Mixture, Equipment, and Quality Control 881.04 Surface Preparation 881.05 Test Strip 881.06 Single Course Construction 881.07 Multiple Course Construction 881.08 Finished Pavement 881.09 Warranty Items and Work 881.10 Appeal Process 881.11 Basis of Payment 881.01 General. This work shall consist of constructing a cold laid polymer modified emulsified asphalt pavement course to fill ruts or provide one or more courses for existing pavements in reasonably close conformity with the lines shown on the plans or established by the Engineer and warrant it for 3 years. 881.02 Warranty Bond. When the successful Bidder provides the Department with the performance and payment bonds specified in 103.05, the successful Bidder shall also furnish a maintenance bond for a 3 year period in an amount equal to 75 percent of the contract amount. The Surety that underwrites the maintenance bond is required to have an A.M. Best rating of “A -” or better. The cost of the maintenance bond shall be included in the pay item for the premium for the contract performance and payment bonds. The effective date of the maintenance bond is the date the Department’s Form C-85 is issued for the pavement. The issuance of Form C-85 for the pavement shall occur within 30 days after all of the pavement items, including all pavement markings, are completed and the pavement is open to traffic in its permanent pattern. After Form C-85 is issued, the Department will notify the Surety and will establish all final quantities for the project and the project will be finalized using standard procedures. The maintenance bond expires 3 years after the issuance of Form C-85. The Contractor shall maintain the liability insurance specified in 107.14, insuring against Contractor or Contractor authorized operations negligently performed during the warranty period. This insurance shall be in effect throughout the warranty period. A copy of the Certificate of Insurance shall be sent to the District each year. 881.03 Materials, Mixture, Equipment, and Quality Control. The material shall meet or exceed the requirements of 406.02. The mixture used shall meet or exceed the requirements of 406.03. The equipment used for micro-surfacing shall be self-contained, self-propelled, continuous loading units designed for this purpose. A minimum of two weeks before the start of production, the Contractor shall submit their material quality control plan and final mix design to the District Engineer of Tests and Laboratory. During production, any changes in the mix design shall also be submitted. These submittals are for verification of the above minimum requirements. 881.04 Surface Preparation. Surface preparation shall meet the requirements of 406.08 except as follows: The Contractor is responsible for all surface preparation including cleaning, removal of any paint or plastic markings, tack coat and any other work that may effect the performance of micro-surfacing. This surface preparation shall be included in the bid price of the 881. All visible joints and cracks longer than 2 feet (600 mm) in length shall be sealed in accordance with 825.04. This crack seal shall be included in the bid price for 881. 881.05 Test Strip. The Contractor shall construct a test strip to be evaluated by the Engineer. This test strip shall be 1000 feet (300 meters) long and consist of all of the application courses specified. The test strip shall be constructed at the same time of day or night the full production will be applied and may be constructed in 2 days or nights when multiple course applications are specified. The Engineer will evaluate the completed test strip after 24 hours of traffic to determine if the mix design is acceptable. Full production may begin after the Engineer accepts a test strip. If accepted, the cost of the test strip shall be paid for at the bid price for 881. The test strip requirements will be waived if the following conditions are met: 1. The micro-surfacing will not be applied after September 30 or before May 1; and 2. The Contractor has constructed a test strip in the same construction season that was accepted by the Department and utilized the same materials and mix design. APPENDIX C Microsurfacing Example Contract Clauses, Specifications, and Checklists

881.06 Single Course Construction. The Contractor shall apply one course of mi crosurfacing mixture. The single course shall be completed using Gradation A aggregate applied at a mini mu m rate of 18 pounds/square yard (9.8 kg/m²) of dr y aggregate or Gradation B aggregate applied at a mi nimu m rate of 20 pounds/square yard (11 kg/m²) of dry aggregate. 881.07 Multiple Course Construction. The Contractor shall apply at a mi nimu m, two courses of micro- surfacing mixture, each applied separately. The pavement cross section shall be restored by rut filling and or one or more l eveling courses. This cross section correction shall be applied to the driving lanes only, prior to the surface course, which shall be applied to the entire paving pass, which ma y include the shoulder as directed by the plans. The total co mbin ed mini mu m application rate of 30 pounds/square yard (16.3 kg/m²) of dry aggregate shall be applied. The Department ma y specify a single course micro-surfacing on the shoulders when directed by the plans. Pavement segments greater than 1000 feet (300 meter) in length, with an average rut depth that exceeds 0.5 inch (12 mm), shall be rut filled. The Contractor shall use a micro surfacing mix with Gradation B aggregate applied with an approved rut box for each designated wheel track. A clean overlap and straight edges shall be required between wheel tracks. Each rutted wheel track shall be over crowned to allow for proper consolidation by traffic. For each 1 inch (25 mm) of applied mi x, an additional 0.125 to 0.25 inches (3 to 5 mm) crown is required for traffic consolidation. If the Contractor applies leveling courses to profile the pavement, a mi cro- surfacing mix with Gradation A or B aggregate shall be used. The final surface course shall be completed using Gradation A aggregate, applied at a mi nimum application rate of 16 pounds/square yard (9 kg/m²) of dry aggregate or a Gradation B ma y be used with a mi nimum application rate of 20 pounds/square yard (11 kg/m²) of dry aggregate. 881.08 Finished Pavement. Traffic shall not be allowed on the mi xture until it has cured sufficiently to prevent pickup by vehicle tires. The new surface shall be capable of carrying nor ma l traffic within one hour after application without any damage occurring. Filled ruts shall be able to sustain traffic within 2 hours after placement. The Contractor shall protect the new surface fro m potential damage at intersections and driveways. Any da ma ge by traffic to the mi xture shall be repaired by and at the Contractor’s expense. The finished surface should be free fro m excessive scratch marks, tears, rippling, and other surface irregularities. The surface area shall not contain transverse ripples or longitudinal streaks of 0.2 inch (5 mm) or more in depth, as measured with a 10 foot (3 meter) straight edge. The surface area shall not exhibit tear mark s greater than 0.5 inch (13 mm) wide and or 4 inches (100 mm) long, or a tear mark greater than 1 inch (25 mm) wid e and 3 inches (75 mm ) long. The longitudinal construction joints a nd lane edges shall coincide with the proposed painted lane lines. Longitudinal joints shall be constructed with less than a 3 inch (75 mm) overlap on adjacent passes and no more than 0.5 inch (6.5 mm) overlap thickness as me asured with a 10 foot (3 meter) straight edge. If applicable, place overlapping passes on the uphill side to prevent any ponding of water. Construct neat and unifor m transverse joints with no mo re than a 0.2 inch (5 mm) difference in elevation across the joint as measured with a 10 foot (3 me ter) straight edge. The edge shall be neat and unifor m with no more than 2 inch es (50 mm ) of horizontal variance in any 100 feet (30 meters). The restored cross section of the pavement section between any edge line, lane line or center line as measured using a 10 foot (3 meter) straight edge transversely across the pavement shall not exceed 0.4 inches (10 mm), or 0.2 inches (5 mm) when measured with a 6 foot (1.8 m) straight edge. The preceding shall not apply to any pavement segment that is designed with a quarter crown cross slope or any area of the pavement within 1 foot (300 mm) of the edge line, lane line or center line. These cross section requirements do not apply to single course micro-surfacing. 881.09 Warranty Items and Work. The District Review Tea m (DRT) will review the pavement before June 1 each year during the warranty period to determine the perform ance of the mi cro-surfacing. Any areas of the pavement that do not me et the Threshold Levels specified in Table A, will have to be repaired by the Contractor. The District will notify the Contractor in writing of any required Wa rranty Wo rk. Meeting the mi ni mu m requirements and guidelines of this specification are not to be construed as a warranty, expressed or im plied, as to the material s properties and workmanship efforts required to m eet the perfor ma nce criteria specified. 106

107 The Contractor shall supply all material and labor to perform the Warranty Work at no additional cost to the Department. All Warranty Work shall be performed with material meeting the requirements of 881.03. The Contractor shall certify the component materials and designed mix meet or exceed the requirements of 881.03. All Warranty Work shall be performed by August 31 of the same year as the review. If an appeal process uses the arbitration method, the District may revise the date for the completion of the Remedial Action for the appealed item. Any 1000 foot (300 meter) lane segment that has repairs or defects greater than 5 percent of the area shall be completely resurfaced with a full lane width of micro-surfacing meeting the requirements of 881.06 or 881.07. Only micro-surfacing shall be used for permanent repair and resurfacing areas. If the Department determines that immediate repairs are necessary, due to a potential hazard to the traveling public, the Department will notify the Contractor and establish a date that all repairs have to be finished. Temporary repairs may be performed using material approved by the Engineer. All temporary repairs shall be replaced with a permanent repair as soon as weather allows. The Contractor’s construction traffic control for performing any work required or allowed by this specification during the warranty period shall be in accordance with current Department policy, the Ohio Manual of Uniform Traffic Control Devices for Streets and Highways, and subject to Department approval of the time the work will be performed. Any major change in Department construction traffic control policy will be considered a changed condition. 881.10 Appeal Process. The Contractor may appeal a finding of the DRT. Any appeal shall be submitted to the DCE, in writing, within 15 days after the written results of the DRT are given to the Contractor. The DCE will evaluate the Contractor’s appeal. This evaluation will include reviewing the disputed area in the field and consulting with the Construction Section of the Office of Highway Management. The evaluation may also include reviewing test data, obtaining samples, or interviewing Department (District or Central Office) or Contractor employees. The DCE’s determination will be issued in writing to the Contractor within 45 days after the DCE receives the appeal. If the Contractor disagrees with the DCE’s determination, the Contractor may appeal the determination using an arbitration method acceptable to the Department. The Department will agree, in all cases, to arbitration in the manner in which those methods are practiced by the Department. If the Contractor selects arbitration, written notice of this approach must be made to the DCE within 15 days of receipt of the DCE’s determination. After written notice has been provided, the parties shall agree in writing to the Arbitrator and agree to share equally the fees of the Arbitrator. After the Arbitrator is given notice to proceed, the Arbitrator shall conduct an investigation and issue a determination within 45 days. The Arbitrator’s determination will be limited to determining whether or not the pavement distress is or is not the fault of the Contractor. 881.11 Basis of Payment. The method of measurement shall be on an area basis [square yard (square meter)] in accordance with 406.12. The accepted quantities of microsurfacing will be paid for at the contract price for: Item Unit Description 881 Square yard (square meter) Micro-surfacing with warranty, single course 881 Square yard (square meter) Micro-surfacing with warranty, multiple course

Missouri DOT Method Specification SECTION 413.10 MICRO-SURFACING 413.10.1 Description. This work shall consist of producing and placing a mixture of cationic polymer-modified asphalt emulsions, mineral aggregate, mineral filler, water, and other additives as needed at locations shown on the plans or as directed by the engineer. 413.10.2 Material. All material shall be in accordance with Division 1000, Material Details, and specifically as follows: Item Section Emulsified Asphalt 1015 Aggregate 1002 413.10.2.1 Aggregate. 413.10.2.1.1 The mineral aggregate shall be flint chat from the Joplin area, an approved crushed porphyry or an approved crushed steel slag. Blast furnace slag may be used from sources with a documented history of satisfactory use and that have been previously approved by MoDOT for use in micro-surfacing. For non-traffic areas such as shoulders, the mineral aggregate may be crushed limestone or crushed gravel in accordance with Sec 1002.1. The aggregate shall be free of cemented or conglomerated material and shall not have any coating or detrimental material. 413.10.2.1.2 Blends of approved aggregate may be supplied provided: (a) The individual aggregates are reasonably uniform in gradation and other qualities. (b) The aggregates are uniformly blended with designated proportions into a separate stockpile prior to use. Aggregate may be blended directly into the supply truck provided the blending device has been calibrated, gate settings are unchanged, and belt samples indicate material gradation compliance. (c) The proportion is not changed from the job mix formula during the course of placement. 413.10.2.1.3 The final aggregate, or blend of aggregates, shall be in accordance with one of the following gradations. In addition, the aggregate shall be ± 5 percent of the designated job mix gradation for all plus No. 200 (75 µm) material and within ± 2 percent for the minus No. 200 (75 µm) material. 413.10.2.1.4 The final aggregate mixture shall have no oversize material when deposited at the stockpile site. If the stockpile area contains any particles exceeding the specified maximum sieve, all aggregate shall be screened again as the aggregate is loaded into the final placement machine. 413.10.2.2 Mineral Filler. Mineral filler shall be Type 1 Portland cement or hydrated lime, and shall be free of lumps or any other deleterious material. 413.10.2.3 Water. Water shall be potable and free of harmful soluble salts. 413.10.2.4 Additives. Any other material added to the mixture or to any of the component materials to provide the required properties shall be supplied by the emulsion manufacturer. 413.10.2.5. Material Acceptance. All aggregate shall be sampled, tested and approved by the engineer prior to use. Portland cement and hydrated lime may be accepted for use based on visual examination. 413.10.3 Job Mix Formula. The manufacturer of the emulsion shall develop the job mix formula and shall present certified test results for the engineer's approval. The job mix formula shall be designed in accordance with the International Slurry Surfacing Association (ISSA) recommended standards by an ISSA recognized laboratory. Mix acceptance will be subject to satisfactory field performance. The job mix formula, all material, the methods and the proportions shall be submitted for approval prior to use. Proportions to be used shall be within the limits provided in the table below. If more than one aggregate is used, the aggregates shall be blended in designated proportions as indicated in the job mix formula, and those proportions shall be maintained throughout the placement process. If aggregate proportions are changed, a new job mix formula shall be submitted for approval. 108

109 413.10.3.1 All Types. The minimum dry mass per unit area will be based on a bulk specific gravity (BSG) of 2.65. In the event that crushed steel slag aggregate is used as a part of the blended aggregate or as the entire aggregate, the BSG of the final aggregate blend shall be determined and shown as part of the job mix formula criteria. If the BSG is different from 2.65 by more than 0.05, the above minimum masses shall be adjusted by dividing the specified unit mass by 2.65 and multiplying by the new BSG. (For example, for a new BSG = 3.15, the new minimum would be 3.15(10.8/2.65) = 23.8 lbs./sy (12.8 kg/m2)). These adjusted values shall be designated on the job mix formula and will apply in the field. 413.10.3.1.1 Type II. For Type II, if a specified thickness will be required, the amount of mineral aggregate per square yard (m2) shall be increased as necessary to obtain the thickness. 413.10.3.1.2 Type III. When specified, Type III shall be applied in two passes of approximately equal quantities, the first of which shall be to fill depressions and level the surface for the final pass. 413.10.3.1.3 Type IIIR. For Type IIIR mixes, there will be no minimum or maximum unit quantities. The contractor shall make the determination as to the amount necessary, except all depressed areas shall be filled level as specified. Type IIIR may be applied in more than one pass at the contractor’s expense. Type IIIR shall not be added to Type II or Type III applications in the field, but shall be a separate application. 413.10.4 Equipment. 413.10.4.1 Mixing Equipment. The micro-surfacing mixture shall be mixed and laid by a self-propelled mixing machine. The mixing machine shall be able to accurately deliver and proportion the aggregate, mineral filler, water, additive and emulsion to a revolving multiblade dual mixer and to discharge the thoroughly mixed product. The machine shall have sufficient storage capacity for all components to maintain an adequate supply to the proportioning controls. 413.10.4.1.1 Individual volume or weight (mass) controls for proportioning each item to be added to the mix shall be provided. Each material control device shall be calibrated and properly marked. The calibration shall be approved by the engineer prior to proportion. Each device shall be accessible for ready calibration and placed such that the engineer may determine the amount of each material used at the time. 413.10.4.1.2 The mixing machine shall be equipped with a water pressure system and nozzletype spray bar to provide a water spray to dampen the surface when required immediately ahead of and outside the spreader box as required. No free flowing water shall be present. 413.10.4.2 Spreading Equipment. The micro-surfacing mixture shall be spread uniformly by means of a mechanical-type spreader box attached to the mixer. The spreader box shall be equipped with paddles or augers to agitate and spread the material uniformly throughout the box. The paddles or augers shall be designed and operated so all the fresh mix will be agitated to prevent the mixture from setting up in the box, causing side buildup and lumps. 413.10.4.2.1 The spreader box used for surface course construction shall be equipped with flexible seals in contact with the road to prevent loss of mixture from the box. The box shall be equipped with devices to adjust the thickness or grade of the surface and shall have a squeegee strike-off rear plate. 413.10.4.2.2 A secondary strike-off shall be provided to improve surface texture. The secondary strike-off shall have the same adjustments as the spreader box. 413.10.4.2.3 The spreader box used for rut-filling shall have two metal strike-offs, angled from each side toward the center at approximately 45 degrees. Interrupted flight augers shall be used ahead of the first strike-off plate to spread the mix and maintain laminar flow. The second strike-off plate shall be adjusted to produce the desired grade and depth. The first strike-off and augers shall be adjustable up and down in order to maintain a fairly uniform flow or roll of material in front of the second strike-off. A rubber squeegee shall be attached to the adjustable metal plate at the rear of the spreader box, behind the second strike-off, to texture the surface. The adjustable metal plate shall have sufficient clearance not to affect the grade established by the second strike-off. 413.10.5 Construction Requirements. 413.10.5.1 Test Strip. A test strip 500 feet (150 m) long and the width of one lane shall be provided. The test strip will be evaluated for 24 hours after placement and will be subject to approval from the engineer before any further production. If unsatisfactory, the test strip shall be removed and another strip placed for evaluation at the contractor’s expense. 413.10.5.2 Surface Preparation. The surface shall be thoroughly cleaned of all vegetation, loose material, dirt, mud, and other objectionable material and shall be pre-wetted as required immediately prior to application of the micro-surfacing. All pavement marking shall be removed, maintained, and compensated for in accordance to Sec 620. 413.10.5.3 Application. The micro-surfacing mixture shall be spread to fill cracks and minor surface irregularities, and shall leave a uniform surface. No lumping, balling or unmixed aggregate will be permitted. Longitudinal joints shall be

placed on lane lines. Excessive overlap will not be perm itted. The finished mi cro-surfacing shall have a uniform texture free of scratches, tears and other surface irregularities. The contractor shall repair the surface if any of the following conditions exist: (a) More than one surface irregularity that is 1/4 inch (6 mm) or wider and 10 feet (3 m) or longer in any 100-foot (30 m) section of the micro-surfacing. (b) More than three surface irregularities that are 1/2 inch (12 mm ) or wider and more than 6 inches (150 mm) long in any 100-foot (30 m) section of the micro-surfacing. (c) Any surface irregularity that is one inch (25 mm) or wider and mo re than 4 inches (100 mm) long. The finished longitudinal and transverse joints in the mi cro-surfacing shall be complete and unifor m. 413.10.5.3.1 The contractor shall repair joints if any of these conditions exist: (a) Build-up of micro-surfacing ma terial at the joints. (b) Uncovered areas at the joints. (c) Longitudinal joints with more than 1/2 inch (12 mm ) vertical space between the surface and a 4-foot (1.2 m) straightedge placed perpendicular to the joint. (d) Transverse joints with more than 1/4 inch (6 mm) vertical space between the surface and a 4-foot (1.2 m) straightedge placed perpendicular to the joint. 413.10.5.3.2 The edges of the mi cro-surfacing shall follow the centerline, lane lines, shoulder lines and curb lines. The edges shall be repaired if the edges vary mo re than 3 inches (75 mm ) from a 100-foot (30 m) straight line or fro m a 100- foot (30 m) arc on a curved section. The repaired surface shall be dense with a uniform texture. 413.10.5.3.3 Any successive passes shall be separated such that each layer placed undergoes approxi matel y 12 hours of traffic for co mp action and curing. 413.10.5.3.4 Type IIIR applications to raise shoulders or fill ruts shall be applied with the rut spreader box, and the contractor shall place a strip as designated in the contract docu ments to raise an area to ma tch the surroundings. Rutting or traffic-bearing applications, excluding shoulders, shall be crowned 1/8 to 1/4 inch per inch (3 to 7 mm per 25 mm ) of depth, to allow for compaction. Shoulder applications shall drain and slope unifor ml y downward to the shoulder point. A Type II or Type III application may follow as a su rface course if specified in the contract documents. 413.10.5.3.5 Micro-surfacing shall not be placed over steel expansion plates. 413.10.5.3.6 When micro-surfacing is placed on concrete, a tack coat shall be applied first in accordance with Sec 407 and shall be given adequate time to break. 413.10.5.3.7 The mi cro-surfacing shall perm it traffic operations on a 1/2 inch (12 mm) thick surface within one hour after placement at 75°F (25°C) and 50 percent humidity. 413.10.5.4 Weather Limitations. Micro-surfacing shall not be placed when either the air temperature or the temperature of the surface on which the mi xture is to be placed is below 50°F (10° C), when it is raining, or when there is a chance of temperatures below 32° F (0° C) within 24 hours after placement. Te mp eratures shall be obtained in accordance with MoDOT Test Method TM 20. 413.10.5.5 Repair of Damaged Areas. Any traffic-da ma ged, ma rred areas or deficiencies as defined in Sec 413.10.5.3 shall be repaired by the contractor at the contractor’s expense. 413.10.5.6 Incidental Construction. Areas that cannot be reached with the mixi ng machine shall be surfaced using hand squeegees to provide complete and unifor m coverage. Utilities shall be protected from coverage by a suitable metho d. Wo rk at intersections shall be done in stages, or blotter ma terial shall be used to allow crossing or turning m ove ment s. Regardless of the me thod, no marred sections will be perm itted. 413.10.6 Method of Measurement. Final measurement of completed Type II and Type III surface will not be ma de except for authorized changes during construction, or where appreciable errors are found in the contract quantity. Wh ere required, me asurem ent of Type II, Type III and Type IIIR mi cro-surfacing, com plete in place, will be made to the nearest square yard (square me ter). Final me asur em ent of Type IIIR surface may be ma de as necessary to determine the actual areas placed. Field me asurement will be based on the esti ma ted width and length dimensions necessary to bring a designated area to a level plane, and not necessarily for the full rutted area. The revision or correction will be computed and added to or deducted fro m the contract quantity. 413.10.7 Basis of Payment. The accepted quantities of mi cro-surfacing will be paid for at the contract unit price for each of the pay items included in the contract. No additional pay me nt will be ma de for removing and replacing test strips. 110

111 Checklists: Suggested Field Considerations for Microsurfacing The following is an extract from Chapter 8: Micro-Surfacing of the NHI 2007 Pavement Preservation Treatment Construction Guide. The following tables are guides to the important aspects of performing a micro-surfacing project. The tables list items that should be considered to promote a successful job. Thorough answers to these questions should be determined, as required, before, during, and after construction. The appropriate staff to do this will vary by job type and size. Some topics may need attention from several staff members. The field supervisor should understand its contents. The tables are not intended to be a report but to draw attention to important aspects and components of the micro-surfacing project process. Some information may be product-specific and should be contained in the agency’s relevant standard specifications, special standard provisions, or special provisions. Preliminary Responsibilities Project Review Is the project a good candidate for micro- surfacing? Should a micro-surfacing seal be used? What is the depth and extent of any rutting? How much and what type of cracking exists? Is crack sealing needed? How much bleeding or flushing exists? Is the pavement raveling? What is the traffic level? Is the base sound and well drained? Have the project bid/plan quantities been reviewed? Document Review Bid specifications. Mix design information. Special provisions. Construction manual. Traffic control plan (TCP). Material safety data sheet Materials Checks Has a full mix design and compatibility test been completed? Is the binder from an approved source (if required)? Has the binder been sampled and submitted for testing? Does the aggregate meet all specifications? Is the aggregate clean and free of deleterious materials? Is the aggregate dry? Is the emulsion temperature within application temperature specifications? Pre-Seal Inspection Responsibilities Surface Preparation Is the surface clean and dry? Have all pavement distresses been repaired? Has the existing surface been inspected for drainage problems?

Equipment Inspection Considerations Broom Are the bristles the proper length ? Can the broom be adjusted vertically to avoid excess pressure ? Roller s (if used) Do the roller tire pressures comply with the ma nufacturer’s specification? W hat type roller will be used on the project (pneumatic-tired roller recommended)? Do the roller tire size, rating, and pressures comply with manufacturer’s recommendations? Is the pressure in all tires the same ? Do all tires have a smooth surface? Calibration of Equipment Has each machine been calibrated with the project’s aggregate and emulsion? W ho carried out calibration and what documentation has been provided? Stockpile Is the stockpile site well drained and clean? Does the Contractor have all of the equipment required at the stockpile site (loaders, tankers, and so on)? Micro- surfacing Machine Is the ma chine fully functional? Has the machine been calibrated for this project’s aggregate and certified. Is the spreader rubber clean and not worn? Is the texture rubber clean and set at the right angle? Are all paddles in the pug mi ll intact? Is the spreader box clean and is it a micro- surfacing type box? Equipment for continuous run operations Is all equipment free of leaks ? Are Flow boys or other nurse units clean and functional? Are there enough units to allow continuous running with mini ma l stops for cleaning box rubbers? Site Considerations W eather Requirements Have air and surface te mp eratures been checked at the coolest location on the project ? Do air and surface temperatures meet agency requirements ? Are adverse weather conditions expected? (High temperatures, hu mi dity, and wind will affect how long the emulsion takes to break.) Is application of the mi cro-surfacing postponed if rain is likely? Are freezing temperatures expected within 24 hours of the completion of any application runs? Traffic Control Do the signs and devices used match the traffic control plan ? Does the work zone comply with the agency’s requirements? Are flaggers holding the traffic for reasonable periods of time? Are unsafe conditions, if any, prom ptly reported to a supervisor (contractor or agency)? Does the pilot car lead traffic slowly, 40 kph (24 m ph) or less, over fresh mi cro-surfacing? Are signs removed or covered when they no longer apply? 112

113 Application Considerations Determining Applicatio n Rates Have agency guidelines and requirements been followed? Have rut filling and leveling course application rates been calculated or estimated separately? Has a full mi x design been done? Is mo re material applied to dried-out and porous surfaces? Is mo re material applied on roads with low traffic volum es ? Is less material applied to smooth, non-porous, and asphalt-rich surfaces ? Has moisture content been adjusted when calculating the application rate ? Project Inspection Responsibilities Micro-surfacing Applicatio n Has a satisfactory test strip been done ? Have field tests been carried out and are the results within specification? Are enough trucks on hand to provide a steady supply of ma terial for the slurry m achine? Does the application start and stop with neat, straight edges? Will an edge box be used? Is a rut box is used for ruts deeper than 12 mm (1/2”)? Is a leveling course used with a steel strike-off for ruts less than 12 mm (1/2”)? (Two courses are used where rut filling or leveling is employed.) Does the application start and stop on building paper or roofing felt ? Are drag ma rks present due to oversize aggregate or dirty rubbers ? Are rubbers cleaned regularly and at the end of each day? Does the machine follow a straight, even line with mi ni mal passes to cover the pavement? Is the mi x even and consistent ? Are fines mi grating to the surface? Is the application stopped as soon as any problems are detected ? Does the application appear uniform ? Does the surface have an even and unifor m texture ? Is the application rate checked based on amounts of aggregate and em ulsion used? Wh at is the time between spreading, foot traffic, and opening to vehicular traffic? Rollin g Does rolling wait until the ma t is stable? (Roller is 5-6 tonnes maximum) Is the entire surface rolled only once? Do the rollers travel slowly, 8-9 kph (5 mp h) maximu m? Truck Operation Are trucks staggered across the fresh seal coat to avoid driving over the same area? Do trucks travel slowly on the fresh seal ? Are stops and turns made gradually ? Do truck operators avoid driving over the mi cro-surfacing? Do truck operators stagger their wheel paths when backing into the paving unit ? Longitudinal Joints Is the me et line overlapped a maximu m of 75 mm (3 in)? Do the spreader box runners avoid running on the fresh mat? Are the me et lines at the center of the road, center of a lane, or edge of a lane, not in the wheel paths? Transverse Joints Do all applications begin and end on building paper ? Is the mi xture not too wet at start up ? Is the building paper disposed of properly? Brooming Does brooming begin after the micro-surfacing can carry traffic? Does brooming dislodge the mi cro-surfacing? Is the surface raveling? (Follow-up brooming should be done if raveling is high or if traffic is high.) Opening the Microsurfacing to Traffic Does the traffic travel slowly — 40 kph (24 mph) or less over the fresh mi cro-surfacing? Are reduced speed li mi t signs used when pilot cars are not used? After broo mi ng, have pavement ma rkings been placed before opening to traffic? Clean Up Has all loose aggregate been removed fro m the traveled way prior to opening to traffic ? Have all binder spills been cleaned up?

Troubleshooting This section provides infor mat ion to assist the ma intenance personnel in troubleshooting problems with mi cro-surfacing, along with “dos and don’ts” that address common problems that ma y be encountered during the course of a project. The troubleshooting guide presented in Table associates common problems with their potential causes. For example, an unstable emulsion, too little water in the mi x, incompatibility between the emulsion and the aggregate, and so on, ma y cause a slurry surface to delaminate. Trouble Shooting Microsurfacing Job Problems Problem Cause Br ow n W hi tis h Fa ilu re to S et Po or C oa tin g D el ay ed O pe ni ng to T ra ffi c Br ea ks in B ox R av el s Fl us he s D el am in at io n Se gr eg at io n Emulsio n Em ulsion unstable No No No • Yes No • Yes No No • Yes No Em ulsion too stable • Yes No • Yes No • Yes No • Yes No No No Em ulsion too hot No No No No No • Yes No No No No Too little em ulsion • Yes No No • Yes No No • Yes No No No Too mu ch emulsion No No No No No No No • Yes No No Mi x Mix: Too many fines No No No • Yes No • Yes • Yes No No No Mix: Too mu ch cement No • Yes No No No • Yes No No No No Mix: Too little cement No No • Yes No • Yes No • Yes No No • Yes Mix: Too little additive No No No • Yes No • Yes • Yes No No No Mix: Too mu ch additive No • Yes • Yes No • Yes No • Yes No No No Mix: Too mu ch water • Yes No • Yes No • Yes No • Yes • Yes No • Yes Mix: Too little water No • Yes No • Yes No • Yes • Yes No • Yes No Mix: Aggregate/emulsion not co mp atible No No • Yes • Yes • Yes No • Yes No • Yes • Yes 114

115 Conditions Condition: Too hot • Yes No No • Yes No • Yes • Yes • Yes No No Condition: Too cold No No • Yes No • Yes No • Yes No • Yes No Condition: Rain • Yes No • Yes • Yes • Yes No • Yes • Yes • Yes No Condition: High hu mi dity No • Yes • Yes No No No No No No No Surface Surface: Fatty No No • Yes No No No No • Yes No No In addition to the troubleshooting guide, the table below contains some co mmo nly encountered problems and their recommended solutions. Common Problems and Related Solutions Problem Solution Uneven Surface – Wa sh Boarding Ensure the spreader box is correctly set up. Ensure the viscosity of the mi x is not too high. Make adjustments so that the mix does not break too fast. Wa it until the ambient temperature is lower. Use water sprays on the front of the spreader. Poor Joints Reduce the amount of water at start up. Use water spray if runners of spreader box are running on fresh ma terial. Excessive Ravel Add cement and reduce additive so that the mi x breaks and cures faster. Check aggregate to ensure the clay fines are not too high. Control traffic longer and at low speeds. Wa it until fully cured before allowing traffic. Wa it until mi x is properly set before broo mi ng or opening to traffic.

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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 411: Microsurfacing explores highway microsurfacing project selection, design, contracting, equipment, construction, and performance measurement processes used by transportation agencies in the United States and Canada.

Microsurfacing is a polymer-modified cold-mix surface treatment that has the potential to address a broad range of problems on today’s highways.

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