CONSTRUCTION SPECIFICATION FOR MICROSURFACING

Transcription

1 ONTARIO PROVINCIAL STANDARD SPECIFICATION METRIC OPSS 336 NOVEMBER 2000 CONSTRUCTION SPECIFICATION FOR MICROSURFACING TABLE OF CONTENTS SCOPE REFERENCES DEFINITIONS - Not Used SUBMISSION AND DESIGN REQUIREMENTS MATERIALS EQUIPMENT CONSTRUCTION QUALITY ASSURANCE MEASUREMENT FOR PAYMENT BASIS OF PAYMENT Appendices: 336-A Commentary SCOPE This specification covers the requirements for microsurfacing and includes all surface preparation, material application, handwork, joints, protection while curing, clean up, and trial area. Microsurfacing can be composed of a scratch and surface coat, or surface coat only, as specified in the Contract Documents. Page 1 Rev. Date: 11/2000 OPSS 336

2 Significance and Use of Appendices Appendices are not a mandatory part of this specification and must be invoked by the Owner. Appendix 336-A: is a commentary appendix to provide designers with information on the use of this specification in a Contract REFERENCES This specification refers to the following standards, specifications, or publications: Ontario Provincial Standards, General: OPSS 180 Management and Disposal of Excess Material Ontario Provincial Standard Specifications, Material: OPSS 1001 OPSS 1003 OPSS 1103 Aggregates - General Aggregates - Hot Mixed, Hot Laid, Asphaltic Concrete Emulsified Asphalt Ministry of Transportation, Ontario Publications: MTO Laboratory Testing Manual: LS 202 LS 602 Kinematic Viscosity of Asphalt Sieve Analysis of Aggregates American Society for Testing and Materials: D D D Softening Point of Bitumen - Ring and Ball Apparatus Kinematic Viscosity of Asphalts - Bitumens Sand Equivalent Value of Soils and Fine Aggregate International Slurry Surfacing Association: TB TB TB TB TB TB TB Test Method for Wet Track Abrasion of Slurry Surfaces Test Method for Measurement of Excess Asphalt in Bituminous Mixtures by Use of a Loaded Wheel Tester and Sand Adhesion Trial Mix Procedure for Slurry Seal Design Wet Stripping Test for Cured Slurry Seal Mix Test Method to Classify Emulsified Asphalt/Aggregate Mixture Systems by Modified Cohesion Tester Measurement of Set and Cure Characteristics Test Method for Classification of Aggregate Filler - Bitumen Compatibility by Schulze- Breuer and Ruck Procedures Test Methods for Measurement of Stability and Resistance to Compaction, Vertical and Lateral Displacement of Multi-layered Fine Aggregate Cold Mixes - Method A Page 2 Rev. Date: 11/2000 OPSS 336

3 SUBMISSION AND DESIGN REQUIREMENTS Mix Design A construction material laboratory equipped to carry out microsurfacing mix designs shall designate the mix proportions and prepare the job mix formula. The compatibility of the aggregate and the polymer modified emulsified asphalt shall be confirmed by the laboratory designing the mix. All component materials used in the mix design shall be representative of the material proposed by the Contractor for use on the Contract. Two weeks prior to the start of microsurfacing, the final mix design shall be submitted in writing to the Contract Administrator together with the results of the tests listed in Table 1. The material shall only be placed after the mix design is reviewed by the Contract Administrator. The mix design proportions shall be within the following limits. Residual Asphalt: % by dry mass of aggregate Mineral Filler: 0-3.0% by dry mass of aggregate The microsurfacing material shall be designed so that traffic can be allowed on the surface within one hour MATERIALS Polymer Modified Emulsified Asphalt The emulsified asphalt shall be according to OPSS 1103 for a quick set polymer modified cationic type CSS- 1H emulsion and the amendments in Table 2. Polymer modified emulsified asphalt shall be homogeneous after mixing. To facilitate sampling and testing, the emulsion shall be stable for 14 Days after delivery to the job site. The addition of polymers or other additives after the manufacture of the emulsified asphalt is not permitted Aggregates Microsurfacing Type II Microsurfacing Type III The aggregates shall be according to OPSS 1001 and the information in Tables 3 and Mineral Filler Mineral filler shall be Portland cement Type 10. Page 3 Rev. Date: 11/2000 OPSS 336

4 Water The water shall be potable and shall be free of harmful salts and contaminants Polymer Modifier The polymer modifier shall be a minimum of 3% polymer solids by mass of asphalt residue. The polymer material shall be milled or blended into the asphalt or blended into the emulsifier solution prior to the emulsification process Mix Additives Additives may be added to the microsurfacing mix during construction to provide control of the quick-set properties and to increase adhesion. They must be included as part of the mix design and be compatible with the other components of the microsurfacing mix EQUIPMENT Rotary Power Brooms Rotary power brooms shall be capable of cleaning gravel, sand, dirt, and other debris from the roadway surfaces Mixing Equipment The mixing equipment shall be specifically designed and manufactured to mix and place microsurfacing material. The material shall be mixed by an automatic sequenced, self-propelled, continuous flow microsurfacing mixing machine. The mixing unit shall be capable of accurately delivering and proportioning the aggregate, emulsified asphalt, mineral filler, additive, and water to a revolving multi-blade double shaft mixer and discharge the mixed product on a continuous flow basis. The mixing equipment shall have sufficient storage capacity for aggregate, emulsified asphalt, mineral filler, additive, and water to maintain an adequate supply to meet mix design properties Proportioning Devices Individual volume or weight controls for proportioning aggregate, mineral filler, emulsified asphalt, additives, and water to be added to the mix shall be provided and properly marked Spreading Equipment The mixture shall be spread uniformly by means of a conventional augured surfacing spreader box attached to the mixing machine and equipped with paddles to agitate and spread the material evenly throughout the box. A front seal shall be provided to ensure no loss of the mixture at the pavement contact point. The rear seal shall act as final strike off and shall be adjustable. The spreader box and rear strike off shall be so designed and operated that a uniform consistency is achieved to produce a free flow of material to the rear strike off. The spreader box shall have suitable means provided to adjust the box to compensate for variations in the pavement geometry. Rut filling spreader boxes shall be specifically designed for rut filling applications. Page 4 Rev. Date: 11/2000 OPSS 336

5 For continuous work, the equipment shall be capable of being resupplied with the microsurfacing materials within the working lane to continuously place material for a minimum 2 lane-km distance. The machine shall be equipped to allow the operator to have full control of the forward and reverse speeds during applications of the microsurfacing material Alignment Control A stringline or other device shall be provided to ensure that the longitudinal edges of the new surface meet the existing pavement edge Pilot Vehicle The pilot vehicle shall be equipped with an amber rotating light and a sign mounted with clearance not less than 1 metre above the road. The sign shall be at least 1.5 m in width and 0.75 m in height, orange with black lettering and shall display the words: "Pilot Vehicle, Do Not Pass" CONSTRUCTION Operational Constraints The mixture shall be placed only when the atmospheric temperature is at least 10 C and rising and the weather is free of fog or rain and there is no forecast of temperatures below 0 C within 24 hours from the time of application. The mixture proportions shall be adjusted when weather conditions prolong opening to traffic beyond one hour. Traffic, including construction traffic, shall be kept off the freshly placed mixture, as required, to prevent damage to the surface. Microsurfacing shall be carried out between May 15 and September Documentation A summary of the quantity and application rate of microsurfacing placed and a list of the quantities used for each of the components: aggregate, emulsified asphalt, water, mineral filler, and additive shall be submitted daily to the Contract Administrator Surface Preparation The area to be surfaced shall be thoroughly cleaned using a rotary power broom to remove all sand, dirt, and other debris. Water shall be applied to the surface immediately ahead of the spreader to dampen the pavement surface without allowing any free-standing or free-flowing water. All roadway appurtenances within the area to be surfaced shall be properly covered and protected immediately prior to microsurfacing Material Application A sufficient amount of the mixture shall be carried in all parts of the spreader box at all times so that complete coverage is obtained. Water used to spray the spreader box to facilitate spreading shall not harm the mix. Lumping, balling, or unmixed aggregate shall not be permitted in the finished surface. Any oversized aggregate or foreign materials shall be screened from the aggregate prior to delivery to the mixing equipment. Page 5 Rev. Date: 11/2000 OPSS 336

6 Handwork In restricted areas where hand spreading is necessary, adjustments to the mix formula may be used to retard the setting time. The mixture shall be placed along one edge of the surface to be covered and spread uniformly with squeegees or other suitable Hand Tools Appearance The finished microsurfacing shall have a uniform texture free from excessive scratch marks, tears or other surface irregularities. Tear marks in any 12 square metre area per-lane are considered excessive if there are: a) four or more marks 12 mm wide and 100 mm long. b) any marks 25 mm wide and 25 mm long. There shall be no longitudinal ripples, raking, wash- boarding, chatter, or other irregularities that will affect the ride quality. The edges of the microsurfacing shall be finished uniformly, with a neat appearance along the roadway centreline, lane lines, shoulder, pavement edge, and curb lines Joints The longitudinal and transverse joints shall be neat and uniform in appearance, with no excessive buildup. Longitudinal joints shall be placed on lane lines when possible. The longitudinal joints in the scratch coat shall be constructed as a butt joint. The longitudinal joint in the surface course shall have an overlap of 50 to 100 mm Clean Up All areas, such as shoulders and gutters, shall have the microsurfacing material removed. Removal of any debris associated with the performance of the work shall be done on a daily basis Trial Area A trial area 100 m in length and one lane wide shall be placed at the commencement of the microsurfacing operation to demonstrate the ability to produce microsurfacing in conformance with this specification. After one hour, the Contract Administrator will inspect the microsurfacing for conformance. The trial areas shall be repeated until the microsurfacing meets the requirements of this specification. All costs associated with unacceptable trial areas shall be borne by the Contractor. The location of the trial area shall be approved by the Contract Administrator Traffic Convoy Traffic shall be convoyed when specified in the Contract Documents. A pilot vehicle with an operator shall be used to guide one-way traffic through or around construction. The maximum speed of the convoy shall be 30 km/h and the convoying shall be maintained until such time the microsurfacing mixture mat is able to carry traffic without damage. Page 6 Rev. Date: 11/2000 OPSS 336

7 Management and Disposal of Excess Material Management and disposal of excess material shall be according to OPSS QUALITY ASSURANCE Sampling The aggregate shall be stockpiled two weeks prior to construction for sampling and testing. Two samples for gradation testing shall be taken from the stockpile as determined by the Contract Administrator MEASUREMENT FOR PAYMENT Actual Measurement Microsurfacing Type II Microsurfacing Type III Measurement of the area of microsurfacing placed shall be in square metres Plan Quantity Measurement When measurement is by Plan Quantity, such measurement shall be based on the units shown in the clause under Actual Measurement BASIS OF PAYMENT Microsurfacing Type II - Item Microsurfacing Type III - Item Traffic Convoy - Item Payment at the contract price for the above items shall be full compensation for all labour, equipment, and material required to do the work. Removal, disposal and replacement of any damaged or defective microsurfacing is at the Contractor's expense. The accepted trial area shall be paid for at the contract unit price for microsurfacing. Page 7 Rev. Date: 11/2000 OPSS 336

8 Table 1 Mix Design Requirements Test Description Requirements TB-139 TB-109 TB-114 TB-100 TB-147 Method A TB-144 Wet Cohesion -@30 minutes min. (set) -@60 minutes min. (traffic) Excess Asphalt by LWT Sand Adhesion Wet Stripping Wet Track Abrasion Loss-One Hour Soak Loss-Six Day Soak Lateral Displacement Specific Gravity After 1000 cycles of 57 kg Classification Compatibility 12 kg-cm minimum 20 kg-cm minimum 538 g/m 2 maximum 90% minimum 538 g/m 2 maximum 807 g/m 2 maximum 5 % maximum 2.10 maximum (AAA, BAA) 11 Grade Points minimum TB-113 Mix 25 C Controllable to 120 seconds minimum Table 2 Tests on Residue Test Description Requirements MTO LS-216 Residue by Distillation 62% by mass minimum ASTM D36 Softening Point 57 C minimum MTO LS-200 Penetration at (25 C, 100 g, 5 s) mm MTO LS-202 Kinematic 135 C 650 mm 2 /s minimum Page 8 Rev. Date: 11/2000 OPSS 336

9 Type Table 3 Microsurfacing Aggregates % Crushed Bedrock Physical Requirements OPSS 1003 II 100 HL3 III 100 HL1 Table 4 Microsurfacing Gradation Requirements - LS-602 MTO Sieve Designation 9.5 mm 4.75 mm 2.36 mm 1.18 mm 600 µm 300 µm 150 µm 75 µm Type II Percent Passing Type III Percent Passing Page 9 Rev. Date: 11/2000 OPSS 336

10 Appendix 336-A: Commentary for OPSS 336, November 2000 Note: This appendix does not form part of the standard specification. It is intended to provide information to the designer on the use of this specification in a Contract. Designer Action/Considerations Designer must determine if this application is to be one or two coats, i.e., scratch and surface, or surface only, and the Contract Documents should specify accordingly. Typically two coats are specified to remove severe surface defects. If required, the designer shall specify equipment for continuous placement operations in the Contract Documents. The designer shall select either Type II or Type III Microsurfacing. - Type II is used on local residential streets and low volume arterial collectors. - Type III is used on highways, high volume arterials and collectors. Location of trial area and use of traffic control are to be identified in the Contract Documents. When traffic convoy is required, the designer shall specify the traffic convoy requirements. Microsurfacing should be carried out in warm dry weather. Routing and crack sealing should not be carried out prior to microsurfacing. When extensive crack sealant material is present, the designer should consider removal of sealant as part of surface preparation. Quality is critically dependent on appropriate mix design, equipment, and construction experience. Significant Clauses Microsurfacing shall be carried out between May 15 and September 30. ( ) Related Ontario Provincial Standard Drawings None. Page 10 Rev. Date: 11/2000 OPSS 336