Qualification of the material sampling technicians should be a pre-production meeting agenda item. The spray bar nozzles shall produce a uniform fan spray, and the shutoff shall be instantaneous, with no dripping. FY 2024 HSIP Streamlined Systemic Application Rollers can also be a combination of both pneumatic and steel wheel. Double-drum vibratory rollers come in single-articulated-frame and double-articulated-frame models. The hauling unit must be capable of completely protecting the mixture from the weather and ensuring that the mixture temperature is maintained during the hauling time. Projects constructed under a warranty special provision still require inspection staffing and complete documentation prior to payment, including MDOT materials certifications, MDOT yield checks, MDOT quantity measurement, and MDOT Inspectors Daily Reports. Are the mats or wheel scrapers in good operating condition? When one truck is emptied, it should pull away from the paver. The next truck should then be backed toward the paver, stopping short of the paver. Public Notice of Grand Region Bridge Council Meeting for October 10, 2022 If the mix is tender, a lower tire pressure will displace the mix less than a higher pressure. Plants are certified in accordance with the HMA Production Manual. This point is called the tow or pull point. Be extremely careful when an asphalt surface is being placed on an aggregate base adjoining a slab or curb. %PDF-1.7 One of the most important considerations in making a longitudinal joint is keeping the paver on a straight line of travel. Final Report Part 3 The rollers must be clean and free to rotate to allow smooth forward travel of the paver. In general, the vibrators should be used near the maximum possible frequency. Refer to Figure 502-9. If trucks backing into the paver pick up emulsion, thus leaving the pavement clean, the bond coat is not cured. The augers must be extended if the screed is extended. Research Administration supports and promotes innovative research that encourages safe, sustainable and cost-effective transportation solutions throughout Michigan. Whenever a rigid screed extension is employed on the basic screed, auger extensions and the accompanying auger tunnel extensions should also be added. Consultant Selection The batch plant consists of the cold feed system, individual bins that hold and feed the aggregate to the drum dryer (Figure 501 3). The applied amplitude is determined by the location of the eccentric weights that are located on the shaft. endstream endobj Slick, highly polished surfaces, potholes, old patches, cracks and joints may require repairs. Care should be taken to neatly construct the joint at a right angle to the centerline of the roadway. The paver speed has a major effect on the forces acting on the screed. Selection. Pavement Type Selection Process; Ride Specification . Aggregate of different sizes should be stockpiled separate from one another. Can speed be locked in on vibratory rollers? Yield = 93920 pounds/561.33 square yards= 167.3 lbs/square yard. It is necessary for the screed to be the same temperature as the mixture being placed in order to assure that the mix does not stick to the screed plate and tear the mat, causing a rough texture to the surface. This skirt will help keep the tires hot by holding the heat from the mix under the roller. 2023 HSIP Selection List The dump bed should not hit the paver when dumped. Information on what occurred on the paving operation must be recorded on the inspectors daily report and should include: What was the temperature of the mix delivered? As the layer thickness increases, it may help to increase the amplitude applied to the mix as recommended by the manufacturer. 111 0 obj <>stream If this yield is found to be high or low from that specified on the plans, a slight adjustment of the thickness controls should be made and the yield rechecked. The rollers behind the first paver should stay 1 foot away from the free edge toward the second paver. The method for determining the binder grade in HMA mixtures incorporating RAP and/or RAS is divided into three categories designated Tier 1, Tier 2 and Tier 3. 0PpdR7Lof One procedure should constantly be followed: if in doubt about whether the information is important or beneficial, write it down. Plan Approval. Emptying the paver wings when the hopper is empty. Are circulating systems working properly? The Veteran Internship Program assists honorably discharged veterans of the United States Armed Forces as they transition into the civilian workforce. Qualifications of material sampling technicians. Thus, the samples will be taken at 1985 and 6.3 feet from the beginning of the pavement. Improper adjustments of catch basins can create drainage problems, which will lead to early deterioration of the roadway. endstream endobj If the wedging is greater than 3 inches, two courses of HMA mixture may be required. Job mix formula adjustments, retroactive. This arrangement permits an average to be taken from the grade surface and another to be taken from the freshly laid mat. The front-end loader operator should work the full face of the stockpile. The faster the paver moves, the less time the screed sits over any particular point in the new mat, thus the amount of compactive effort applied by the screed decreases. FY 2024 Time of Return (TOR) spreadsheet Compaction is the single most important factor that affects the ultimate performance of a hot mix asphalt pavement. Do vibratory rollers have automatic shutoff when speed is less than .5 mph? Asphalt paving projects, like many construction projects, are not always built as originally scheduled. The rolling zone should be kept as short as possible. Easy method to calculate roller speeds for proper Impact Spacing, VPM / Impacts per foot = feet per minute, 2500 / 10 = 250 fpm, 2500 / 12 = 208 fpm, 2500 / 14 = 179 fpm, fpm x 0.01136 = fpm / 88 = mph, 208 fpm x 0.01136 = 208 fpm / 88 = 2.36 mph. All nozzles should be turned at the same angle to the spray bar: approximately 30 degrees, depending upon the manufacturers recommendations. Several different organizations publish short, concise safety presentations that can be completed in two to three minutes. These guidelines have been reviewed and approved by the County Road Association of Michigan (CRA) Engineering Committee, and concurred with by Federal Highway Administration (FHWA) Michigan Section, and MDOT. Included are examples of calculations, documentation requirements, and . The TRAC Internship is an extension of the TRAC Program and is designed to provide opportunities for 12th grade students interested in transportation and engineering careers. This type rollers compactive effort is a function of the wheel load, the tire pressure, the tire design and the depth of penetration of the tires into the mix. Our goal is to keep Michigan's motorists safe, informed, and mobile. A superstructure that spans the screed and auger areas ties the two together and supports the grade sensor. FY 2024 Safety (HSIP and HRRR) Call Letter The HBCU TDRP is a unique partnership between MDOT and Michigan colleges and universities to offer on-the-job training to undergraduate students pursuing degrees in engineering or transportation-related careers. At MDOT, we want to ensure your voice is not only heard, but makes a difference in moving Michigan forward. Ensure mixture temperature is high enough for proper compaction. <> If the push rollers are not cleaned periodically and do not rotate freely, the truck tires will slide on the rollers and increase the load on the paver. Trying to reconstruct events at a later time without written notes and complete test data is usually frustrating and often results in conflicting opinions as to exactly what happened. Material from the existing surface is milled out to a depth as shown on the plans, or equal to the top course, across the entire width of the joint and to a length of 35 feet minimum. The paver hopper must be at least half full at the time the wings are dumped. The tractor unit provides the motive power to the paver and to transfer the mixture from the receiving hopper on the front of the paver to the spreading augers at the back of the paver. Whenever the temperature of the previously placed mats falls below 170F prior to placement of the adjacent mat, or when placing base mix and the air temperature is below 50F, the vertical edges of the initial mat shall be coated with HMA bond coat material before the mixture is placed in the adjacent section. See Figure 502-2. As the first load of mixture is being spread, the texture of the unrolled surface should be checked to determine uniformity. When such changes do occur, it is important that they be communicated between the Contractor and MDOT and between MDOT and the Contractor. }szvn?w -L7C#qV_?[tp}Ts E[3M;oW|90}!v$z3* On structures in the curb line out of the traveled roadway, the top of the cover should be 3/8 inch (8 mm) below the wearing surface after final compaction is completed. These defects can be divided into two primary categories: equipment related and mixture related. MDOT's seven region offices each handle transportation-related construction, maintenance and programs within the region's geographic boundaries. Ride Specification provides guidance to using the Pavement Surface Profile. Requesting a ProjectWise Folder, Ryan Doyle, P.E., Supervisor, 989-220-9447, Michele Zawerucha, Project Development Engineer, 517-335-0878, Urban Area Staff Engineer Contact Information, Instructions for Preparing to Bid Federal Aid Projects Through MDOT A new plant inspector can easily get burned if not aware that asphalt samples are very hot. Any severely distressed areas in the old rigid pavement surface should be cut out, removed and replaced using full depth repairs with PCC, or hot mix asphalt. Multiple drops of the mix are necessary. The roller pattern should be set up as soon as paving starts. MDOT Highway Safety To minimize mat problems, the paver operator should dump the wings as little as possible. 4643 0 obj <>stream The Office of Procurement and Contract Management (OPCM) Consultant Services Division (CSD) procures all Maryland Department of Transportation State Highway Administration (MDOT SHA) A/E contracts using Qualifications-Based Selection (QBS), as defined in Code of Maryland Regulations (COMAR) Title 21, Subtitle 12, "Procurement of Architectural Services and Engineering Services" and 23 CFR . The bond coat material should be heated to the proper temperature so that it is fluid enough to be sprayed from the nozzles. The inspector should also check the structure to determine that the casting is firmly set in place. Open texture areas in the joint should be filled using the HMA mixture with the large stones removed. Stop-and-go paving operations must be avoided; every time the paver stops more than momentarily, the screed settles, producing roughness. Please update to a modern browser such as Chrome, Firefox or Edge to experience all features Michigan.gov has to offer. The operator should not make manual changes while automation is working. It is the Contractors responsibility to obtain the proper pavement density. Do all trucks have working backup warning systems? This type of reference device is used only when the grade being sensed is relatively smooth. Proper subsurface drainage should be installed as necessary. Mixture temperature should be checked regularly when the mix arrives on the project and recorded on the load tickets. The truck push rollers, located on the front of the paver hopper, are used to maintain contact with the tires of the truck and to push the truck ahead of the paver. **If in line crushing and/or screening is being used to ensure that the RAP being introduced into the HMA mixture contains no aggregate larger than the top size aggregate allowed in the mix design a RAP scalper screen may not be required. The insulation should be tight against the body of the bed; there should be no gaps between the side of the truck and the insulation through which air could move. Resources for local governments regarding grant & economic development opportunities, project coordination, and state and federal requirements. MaineDOT Best Management Practices for Erosion & Sedimentation Control ( 3/27/2008 update) MaineDOT Construction Manual MaineDOT Elation System Users Manual ( 1/1/2021 update) MaineDOT Maintenance Fast-dry Water-Based Traffic Paint ( 3/23/2016 update) Standard Details Book & Updates ( 7/8/2022 update) The breakdown roller should be as close to the paver as possible. Once the line is set at the proper elevation, it is imperative that the line remain untouched both before and after the paver sensor passes over. Forms The substitution of another HMA mixture type other than the recommended mixture is acceptable if it has demonstrated to perform under similar traffic conditions. This report include report of all producer's topsoil material that meet the Section 920 Specification requirements as Landscaping material. If it exceeds optimum placement temperature, but does not exceed the specification limit, the truckload is usually not discarded, but immediate steps should be taken to correct the condition. It is the Contractors responsibility to uniformly place the HMA mixture to the specified grade and thickness. The temperature should be checked immediately. Once this has been done, complete the rolling of the joint. Most drum mixer plants heat the aggregate, add the asphalt cement and recycled asphalt pavement (RAP), if used, and mix all the ingredients in the same drum. . This is caused by an improperly adjusted screed angle of attack. This article returns the responsibility for these tasks to MDOT for all concrete paving projects, including those that contain special provisions 03SP602A and/or 03SP602E. 2022 Selected Projects for FY 2025 endobj Is spray bar capable of having its height adjusted for uniform height, both sides? These tasks include: In the past, special provisions 03SP505A, 03SP507A, 03SP508A, and 03SP508C delegated certain aspects of project oversight to the contractor. If a hydraulically extendable screed is being used with the paver, the crown can be introduced in the center of the main screed and also at the points between the main screed and the hydraulic extensions. Placing the mat too thin based upon the aggregate size. MDOT's Highway Programs focus on the development and management of the department's roadsides, environmental efforts and policies, and federal-aid highway information. Submit the HMA-QC Plan to the Engineer for review and acceptance a minimum of 10 calendar days prior to the pre-production meeting. If a good bond is not formed between the existing surface and the new overlay, a slippage, or sliding-type, failure can easily occur. If the temperature exceeds specification limits, 350F, it should be discarded. The degree of preparation depends upon the condition of the existing surface. Dividing the tonnage placed, by the area covered, will give the yield. The amount of crown that can be introduced into the screed varies with the width of the basic screed and with the make and model of the equipment. The Internship Program offers undergraduate and graduate students interested in civil engineering and construction management careers, valuable experience by working with professional field staff. This floating screed principle is employed on all modern pavers in use today. The department also produces numerous geographic information system maps to assist commuters, tourists, and businesses. Plan Submittal. Asphalt cement is the material that holds the aggregate together. The contractor must demonstrate that additional screens are installed on the RAP feed system to ensure that the RAP being introduced into the HMA mixture contains no aggregate larger than the top size aggregate allowed in the mix design. Keep the level of mix at the augers as uniform as possible. Excess Moisture. The desired degree of cross slope is dialed into the slope controller. The bond coat material shall be applied ahead of the paving operation for a distance of at least 1500 feet, depending upon traffic conditions, as determined by the Engineer. See Figure 502-5 for paver speed based on yield and plant production rates. A new folder, 107 Warranty Documentation, has been created in ProjectWise to house all documentation regarding each projects warranty. Bond coat, also referred to as tack coat, is an asphalt emulsion. The density obtained by the paver screed is also a function of the speed of the paver. The details of the quality control program, both on the part of the Contractor and MDOT, should be discussed so that everyone is aware of who is responsible for performing the procedures and when they will be done. 3 0 obj Does the paver have two operating warning lights? 2024 HRRR Selection List One type of reference device, termed a floating ski or beam, is a series of feet, or shoes, attached to the bottom of the floating beam. An end gate is attached to the end of the screed to restrict the outward movement of the mix around the end of the screed. I3 Q[LSP'@Df]]nt .Q1-^zAi"AN|.Tc All horizontal and vertical surfaces that will be in contact with the new HMA mixture must be thoroughly cleaned. The elevation of the string line must be set by a survey crew and the set line must be very taut. (Example: 6 percent grade - 6 inches (6 m) of elevation change in 100 feet (100 m) of horizontal longitudinal run). If the inspector observes the Contractor not providing a specification product, the paving process should be stopped until the Contractor makes the corrections needed before being allowed to continue. Raveled, dried-out surfaces must be re-compacted and restored to the proper cross section. Check the mixture thickness, or yield, within the first three truckloads. For layers 1-1/2 inch and greater, a low amplitude setting should be used on the vibratory roller. PLANT PRODUCTION (TONS PER HOUR) YIELD IS POUNDS PER SQUARE YARD. Structures located in the roadway should have the top of the cover flush with the wearing surface when the final compaction is completed. Resources for consultants and local partners including consultant advisories, prequalification information, contracts and proposals. Most of our manuals, publications, and forms are available online. In addition, a RAP scalper screen is required**. Transportation Reality Check takes on some of these myths, and explains why MDOT does things the way they do. Short waves can be caused by a screed in poor mechanical condition, such as too much play in the screed control connections. Transportation Grant Programs, Letting Process, Local vs. MDOT for Enhancement Projects, Heidi Spangler, Safety Engineer, 517-230-4605, FY 2024 Local Safety Program Applications Received For vibratory rollers, the following can be controlled by the operator: vibration frequency, vibration amplitude and direction of travel, when frequency and amplitude are engaged according to the manufacturers recommendations. The HMA mixture used for patching should be the top course mixture called for on the plans, or in the proposal. 2024 HSIP Selection List The aggregate base must provide a firm foundation before paving commences. It is required that accurate and complete records be kept for all paving projects. Some pavers may be equipped with augers that extend automatically as the screed is extended. The slope control operates through a slope sensor that is located on a cross beam between the two side arms on the screed. The paver hopper is used to receive and temporarily hold the mixture from the trucks. The screed is attached to the tractor unit at only one point on each side of the paver. Design It is important that the augers carry a consistent amount of mix across the front of the screed so that the pressure on the screed is kept as constant as possible. This is why it is important to set the flow gates properly, keep the slat feeders operating uniformly, keep a uniform head of material in front of the screed and not overcontrol the screed. What number and type of rollers were used? 30 to 70m 3 /h; EMA Compact plant, perfect for prefabricated. Forms The design may have been approved for another project; however, a JMF must be prepared for each mixture used on the project. Each type of reference can be used on either side of the paver, or on both sides at the same time. That is why MDOT offers many ways to help ease the stress of commuting by providing information that commuters want and need as they make daily travel decisions. Typical Use: Item 340 is typically used for projects with small quantities of hot mix asphalt (HMA). Phone: 443-572-5045 Fax: 410-787-0483 Email: TDavis5@mdot.maryland.gov Admixtures for Concrete Admixtures for Concrete Product Qualification Procedures (PDF, 200 KB) Qualified Products Air Entraining Agents (PDF, 200 KB) Drycast Admixtures (PDF, 200 KB) Precast Admixture (PDF, 200 KB) Type A - Water Reducing (PDF, 200 KB) It is good practice to keep the speed of the paver as constant as possible during the paving operations. The mix that is carried to the back of the tractor unit by the slat conveyors is deposited in front of the augers. At MDOT, safety is paramount. Steam rising from the mix as it is dumped into the hopper of the spreader indicates moisture in the mix. Common Safety Countermeasures for Local Agencies for Segments and Intersections It is very important to know what special provisions are contained in the proposal. Fuel oil is not to be used as a release agent. No paving shall occur using RAP from the project until a mix design is approved. See Figure 502-7. Following is a list of things that can cause a rough riding surface: A special provision for pavement ride quality measurement is included in many paving contracts. Things to look for during the paving operation include: The trucks should be loaded in multiple drops. The auger and the slat conveyor on the same side must be operated together. After the paver has passed over the structure and the breakdown rolling around the structure has started, the inspector should check the surface elevation with respect to the top of the cover to ensure a smooth ride when completed. A diagnostic guide is included here to help in identifying the cause and fix for a range of segregation problems. It may be necessary for the Contractor to make adjustments of the screed, vibrators, hopper flow gates, or the screed augers, to ensure a uniform surface texture. Depending upon the gate settings, more or less mixture is permitted to enter the tunnel. The aggregate base course must meet all the requirements for moisture content, density and smoothness. There are four basic types of grade references that can be employed to maintain the elevation of the screed pull point: the erected string line, the mobile mat reference, 30 foot floating ski, and the joint matching shoe. Moved Permanently. There are also two privately-owned and operated border crossings: Ambassador Bridge and Detroit-Windsor Tunnel. The screed of the second paver must be set at the same level as the screed of the first paver; this will prevent the screed of the second paver from dragging on the mix placed by the first paver. Most paver manufacturers have developed hydraulically extendable screeds that trail the main screed on the paver. Trim the joint at right angles to the roadway centerline. The grade sensor usually rides directly on the beam at its midpoint. The amount of compaction imparted to the asphalt mixture is a function of many variables. MDOTs Local Agency Program assists local agencies with preserving state and federal aid in a fair and consistent manner and serves as an information resource. All pavers are equipped with an automatic feed system that, when properly adjusted, supplies mixture to the paver screed to maintain a uniform head of material. Figure 502-11 illustrates the wedging process. Care should be taken to avoid overheating, which can cause permanent warping of the screed. Many pavers are equipped with a truck hitch that is located beside the push rollers. Pavement ride quality is affected by all phases of the construction process; to ensure a smooth finished product, good construction practices must be followed throughout the entire paving process. Unless otherwise noted, the patching and wedging work is done with the mixture that will be used for the leveling course. An asphalt mix that has all the desirable mix design characteristics will perform poorly, if not compacted to the proper density. It is very easy to visually observe a nonuniform application, as the surface will look streaked. If the millings have aggregates larger than what is required for the mix design, it should be processed (crushed and/or screened) prior to stockpiling*. The old saying Safety is Everyones Business is certainly true on an HMA paving project. Intermittent operation of the slat conveyors and auger system could cause both auger shadows and ripples in the mat behind the screed. If the required smoothness is obtained in the first course, the subsequent courses can usually be placed uniformly by simply setting the paver for the thickness desired. These adjustments are based upon the mixture acceptance test results and the pavement in-place density, and are explained in the contract special provisions. Therefore, the first sample should be taken 1985 feet from the beginning of the pavement and 6.3 feet from the designated (right or left) edge of the pavement. A paving schedule for the project should be presented and discussed with MDOT. Sampling frequency required is based on the percentage/tonnage of RAP that will be utilized on the project. Bond coat material must be applied with an approved distributor with a uniform spray. t6h ($Y+q One side of the paver is controlled by the grade referencing sensor and the other side is controlled by the slope controller. FY 2013 Before and After Crash Study The uniform application of the emulsion is a function of the asphalt distributor and the skill of the operator. Risk analysis is specifically used to select appropriate performance standards for various bridge . Too Hot: Blue smoke rising from the mix usually indicates an overheated truckload. Mixture types to be used and the sampling and testing procedures vary depending on the specifications used. The HMA Selection Guidelines for design with the 2012 MDOT Standard Both versions will remain available on the website until the 2012 MDOT Standard Specifications for Construction is phased out. A mean average is thus obtained over the entire span. Communication cannot stop once the pre-production meeting is concluded. x 0 ;r0Do9r\( [v9pWnY?xF See Figure 502-6. All mixtures specified for a project must have an approved mixture design before mix production can proceed. On two-course projects, the first course should be reduced gradually at a rate of 1 inch in 33 feet and end at a point 33 feet or more from the butt joint. The second unit is the paver screed. Checking is short transverse cracks, usually 1 inch to 4 inches in length and 1 inch to 3 inches apart. The roller should not sit and wait on the hot mat. 26.65 (b) is still subject to the 3-year gross receipts average. The existing surface texture will determine the rate of application up to the maximum rate of 0.10 gallons/square yards. See Figure 502-1. Long waves may correspond to the distance between truckloads and may be associated with the reversal points of the rollers. The bond coat, also called the tack coat, consists of an asphaltic emulsion applied to an existing surface to promote adhesion between the old surface and the new asphalt overlay. Slow and steady is the key to good vibratory compaction procedures. The flow gates should be adjusted to provide a uniform head of material in front of the screed. Stop the paver at this point, remove it from the roadway and remove any excess HMA material from the roadway. Rollers are used to compact the mixture to the required density. A porous surface texture may require the maximum rate, whereas a smooth, glazed surface would require a minimum amount of 0.05 gallons/square yards. 1918 provides <> After production begins, the Contractor may ask for JMF adjustments. Adjust catch basins after the leveling course has been placed. In the past, special provisions 03SP502D and 03SP502E delegated certain aspects of project oversight to the contractor. Real Estate Guidance This checklist may be placed in the project files. These guidelines have been reviewed and approved by the County Road Association of Michigan Engineering Hot Mix Asphalt (HMA) Sub-Committee. One of the greatest contributors to a poor ride on an urban project is the improper adjustment of manholes. The street inspector can easily get hurt if they are not aware of the number of vehicles operating on the paving site. Pavers spread the hot mix asphalt to the desired width and thickness and produce a smooth, uniform mat texture. If the extensions on the extendable portion of the screed are not properly aligned with the main screed, a longitudinal mark, or ridge, will occur in the surface of the mix at the junction between the two screeds. The screed is continually attempting to keep in balance all the forces acting on it. The tiers identified below apply to Superpave The distance between the end of the auger extension and the end gate should be about 12 inches. These trucks are loaded in the same manner directly from the silo at the plant. of seven wheels? If the feed system is set and operating properly, the slat conveyors on each side of the paver will rarely shut off. A vibratory compactor should never exceed a rolling speed that will provide less than one impact of the drum per inch of travel. The Bureau of Transportation Planning develops and implements a comprehensive transportation planning process which results in investments that are consistent with the policies of the State Transportation Commission. If a conversation is held with other project personnel concerning project activity, the date and location of the conversation should be recorded. Because continuity of the asphalt paving operation is critical to providing a quality pavement, the discussion between MDOT and the Contractor personnel should include such items as those listed below. Transverse screed marks are transverse indentations in the mat, which may occur when the paver stops between truckloads. This section serves to provide guidance for utilizing Reclaimed Asphalt Pavement (RAP) millings from the same project when using a portable Hot Mix Asphalt (HMA) plant. The certification is normally completed by the Region Traveling Mixture Inspector (TMI) before the Contractor starts his first project in the spring. Pavement sags and rough areas may require a wedging course. Only enough bond coat should be applied that can be covered the same day. This continuous action of the slat conveyors and augers is accomplished by setting the proper position for the hopper flow gates and determining the correct speed setting for the slat conveyors and augers. This check is done by roughly measuring the area covered by one truckload; the tonnage placed is known from the load ticket. Figure 502-14 shows some typical surface patterns and the causes. If temperatures warrant, the sides and bottom of the truck bed should be insulated. Alignment of the front edge of the extension is typically controlled independently of the alignment of the rear edge of the extension. Non-biodegradable agents that dissolve the HMA mixture, such as fuel oil, shall not be used at the paving site. MDOT's A/E internal guidelines, and federal laws and regulations. The aggregate used to make the mix can be a single aggregate, but it is generally different sizes blended together through the cold feed bins to produce proper gradation. Are guards placed on end of spray bar to protect over spray where necessary? There are many common myths and misconceptions about transportation in Michigan. FHWA Emergency Relief Program Video This is a certified product and the suppliers must be on the Certified Products List. In the event that an inspection is not completed prior to the expiration of the warranty, it is the departments responsibility to ensure that the inspection still takes place; however, this inspection should be completed only with MDOT forces. The following guidelines for sampling, mix design, and processing of RAP should be followed when a contractor chooses to utilize RAP millings from the same project when using a portable HMA plant. Rigid extensions come in several widths, usually 6 inch, 12 inch, 2, 3, and 5 foot sections. A result of specified mix contaminated with inferior performing, non-specification mix. Document when immediate possession of the extracted cores occurs (core ID, date, time, etc.). These asphalt cements may also contain anti-strip agents. The mix is then dumped into a truck, or transferred to a hot storage silo to be loaded into a truck later. When using drum mix plants, the aggregate moisture content of each stockpile should be taken at least once a day and the number entered into the plant control system. Obviously the higher the frequency, the faster the vibratory compactor may roll. A fast means of communication should be established between the plant and the paving crew so that any changes to the mixture can be promptly communicated. Long and short waves can be caused by a fluctuating head of material in front of the screed. x\YoF~A4 M!"Gcy-3_}TA(z #*v}Ow>~_c~y}On}]mvy}Rc*UQ]n/?]v./8:~o?Q`Sv;WE]f_MAuOF}@,c?uQUYcmEEPuB',~WMQsE$XF-,V-g6mMa%[+ndv6>%T&G/fQx&[0{Rm z5WB3^sha!QBk`LB#D1V'iuZtDW}} . These tasks include: In the past, special provisions 03SP602A and 03SP602E delegated certain aspects of project oversight to the contractor. If the random core location falls over a tapered joint, it should be moved to the first point that the mat is full depth. MDOT should not rely on the contractors daily report for quantities or as a replacement for the MDOT Inspectors Daily Report. Road Safety Audit Rakes, shovels and lutes are frequently used by personnel around the paver. Pneumatic tire rollers are required for initial compaction on all base and some leveling courses to knead the material into all cracks and depressions for better density. Instructions for Construction of Federally Funded Local Agency projects by Non-Competitive Bid Contract (Force Account), Bruce Kadzban, P.E., Supervisor, 517-335-2229, Monica Uribe, P.E., Project Development Engineer, 517-335-4522, Rural Area Staff Engineer Contact Information, Keith Cooper, P.E., Supervisor, 517-331-1395, Bridge Area Staff Engineer Contact Information It is generally the responsibility of the Engineer to outline the scope of the project and to discuss the information provided in the contract documents. Is distributor tachometer working properly? 2023 HRRR Selection List, Highway Safety Manual (HSM) Process This will allow for a better understanding later if deficiencies develop in the performance of the final product. Once these forms are complete, all pertinent information needs to be entered into the Statewide Warranty Administration Database (SWAD) and letters sent directly to the contractor and directly to the Surety Company notifying them of the results of the inspection and status of the warranty prior to the expiration date. Final Report Part 2 Static steel wheel rollers normally range in weight from 3 to 6 tons and have compression drums or rolls that vary in diameter from 30 to more than 60 inches. When the paving operation is discontinued, a transverse joint must be constructed. If the aggregate surface is left exposed to the weather, either allowed to dry out or become saturated by rain, sufficient tests must be made immediately prior to placing the mixture to ensure that density requirements are met. Drum mixers come in many different types, such as parallel flow, counter flow, double barrel, drum-within-a-drum and drums with separate mixing chambers (Figure 501-4). At the bottom of the paver hopper is a set of slat conveyors. Try to keep the paver moving at a constant speed. endobj When changing trucks, it would be best if the transfer could be done without slowing or stopping the paver. The MST time zone is the least populated time zone in the USA. This type of roller must be equipped with a skirt around the bottom of the roller and within 3 inches of the new surface. Before overlaying an old HMA pavement, it should be inspected. A listing of key Contractor personnel who will be assigned to the project, with clear lines of authority, should be provided to MDOT. Stopping the paver and allowing the screed to settle into the mat. tf@ciT$`|ntC62(t;p_XN(eM1$ONC8C8:LsA){#lt,:Gb{.mGjN,gVJeBm8Vs= The augers are used to distribute the mixture across the total width of the screed. This special provision applies to all Hot Mix Asphalt (HMA) acceptance testing for all Road Commission for Oakland County (RCOC) roads. The finished mat should be smooth and free of blemishes. The inspector should ensure that the Contractor is not causing damage to the mat during the compaction process, such as heat checking or cracking stone (white surface appearance). If required, the truck bed should be insulated. All personnel involved in the project must be required to comply with all safety standards applicable to the type of construction and asphalt paving work to be carried out. This page was last edited on 19 January 2022, at 13:44. Mesgana Ayele Assistant Division Chief, Materials Management Division - Materials Management Systems MDOT SHA Office of Materials Technology 7450 Traffic Drive Hanover, Maryland 21076 Office: 443-572-5021 Toll Free: 1-866-926-8501 MAyele@mdot.maryland.gov Mountain Standard Time is the second westernmost time zone in the United States and Canada. Ensure the bond coat has been applied uniformly at the proper yield. The proposal and plans should be reviewed to see if the cold-milling will be for profiling, or for a specified depth. This device consists of a short 12 inch shoe or ski that is used to reference the grade of an adjacent piece of pavement or curb. Daily talks are one way to continuously remind people that they are working in a potentially dangerous environment at both the plant and the paving site. All things related to pavement engineering. Screed plates first wear out about four to six inches from the trailing edge. A multi-unit culvert is considered a bridge if the total length, as measured along the centerline of the roadway, is greater than 20 feet and the distance between the culvert units is less than half the diameter of the smallest unit. The bond coat material must be applied with an approved distributor with a uniform spray. Field experience and test data have shown that a vibratory compactor will produce required density in fewer passes than a static roller, while moving at a slower speed. The mobile reference system, illustrated in Figure 502-8, combines the front mounted 30 foot floating beam with a 20 foot mat reference beam. &[a);8fUcK@=fCW ?Qdo The field application of the applied mix design is called the Job Mix Formula (JMF), (Figure 501-2). Materials FY 2023 Project Planning Guide FY 2022 Project Planning Guide Requesting a ProjectWise Folder Federal Aid Buyout Program Urban Road Program Rural Road Program Bridge Program TAP Keep the level of mix in the hopper above the flow gates. Public Notice of Bay Region Bridge Council Meeting for October 3, 2022 The length of the auger extensions should, in general, be the same length as the screed extensions. The trucks should not be loaded by slowly driving forward while the mix is being delivered from the silo. The gross weight of the roller can be altered by adding ballast water to the roller drums. Every HMA paving project must have an approved mix design for each mixture used on the project. In the surface course, the entire affected area should be removed promptly and sufficient new material placed to form a true and even surface. 311 0 obj <>stream Public participation is integral to efficient, effective and responsive transportation decisions. It is important for the screed extension to be attached securely to the main screed. This system spans a distance greater than three wire reference stakes spaced at 25 foot intervals to produce a better average reference and eliminates potential errors inducted into the mat by an improperly maintained wire reference. Automatic screed controls are employed to keep the elevation of the pull points on the paver at a more constant elevation relative to the grade reference being used. The faster a roller passes over a point on the asphalt surface, the less time the weight of the roller has to work on that point; this means that less compactive effort is applied to the mixture. A scalping screen should be placed in the aggregate cold feed charging system and the RAP feed system to remove any oversize material. x DH,YZ`XUNC9*F !c+6N MDOT's commissions, councils, task forces, and partnerships are responsible for establishing policies, supervising programs, overseeing state and federal funds, providing recommendations and advisement, and acting as a resource. significado de paloma blanca volando, eva mendoza pagano, dixie stampede barrel trick revealed, fatal accident in geauga county, product movement technologies grand junction, co, paraway pastoral board of directors, caroline falwell engagement ended, nhs forth valley values, marine corps marathon start time, switzerland crime rate 2022, mlb managers who never played professional baseball, jeans with stretch waist, torrey pines gliderport overnight parking, tyler odyssey portal wichita county, what are the similarities of luzon, visayas and mindanao, Referred to as tack coat, is an asphalt surface is being spread, the slat and... 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