mdot hma selection guidelines

MDOT is committed to ensuring that projects, programs and services are performed without discrimination, under Title VI. If the end of the lane is to be left open overnight, a ramp joint should be used. 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. As the department strives to monitor warranties more closely and ensure that inspections are completed timely prior to the warranty expiration, staff should ensure canned reports are being utilized from SWAD and monthly reminder emails are being sent to the correct people in each Transportation Service Center (TSC) to ensure inspections are occurring timely. <>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> The slope control operates through a slope sensor that is located on a cross beam between the two side arms on the screed. This method uses paper, canvas or burlap as the separator, making it easier to remove the mix when the paving operation starts again. When meeting either a concrete slab or gutter pan, keep the asphalt surface about 1/4 inch above the concrete after rolling. String line allows for the smoothest possible asphalt mat behind the paver screed. When such changes do occur, it is important that they be communicated between the Contractor and MDOT and between MDOT and the Contractor. %PDF-1.7 % 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. Moreover, if one roller rotates freely and the other does not, the paver may tend to change direction. Ride Specification provides guidance to using the Pavement Surface Profile. 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. Two types of trucks are generally employed to transport the mixture: end dump and rear discharge. To convert the yield to mat thickness, the following will be helpful: 110 pounds/square yard = 1 inch of thickness. Thus, the amount of mixture that can be carried back to the augers on one side can be different from the other side. If a conversation is held with other project personnel concerning project activity, the date and location of the conversation should be recorded. From 30 to 100 m 3 /h; MODULMIX Plant for large productions and special concretes. It is very easy to visually observe a nonuniform application, as the surface will look streaked. <>/Metadata 445 0 R/ViewerPreferences 446 0 R>> 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. Bond coat material must be applied with an approved distributor with a uniform spray. Is heating system in good working condition? When butt joints are called for on the plans or in the proposal, construction should be as follows. Final Report Part 3 Thus, the samples will be taken at 1985 and 6.3 feet from the beginning of the pavement. Checking can be caused by many things, including an excessive deflection of the pavement structure and improper mix properties (high asphalt content, too much middle size sand, or low dust). b. 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 Once the truck bed has been emptied of mix, the truck hitch is withdrawn and the truck is able to pull away from the paver. The street inspector can easily get hurt if they are not aware of the number of vehicles operating on the paving site. MDOT provides technologies and partnerships in order to make the transportation system safer and less congested. Plan Approval. If two pavers running in echelon are used, the construction of the joint is similar to the building of a joint against a cold compacted pavement. A specified number of samples are to be taken from each sublot. The auger on each side of the paver is operated independently of the other. It can be configured for automatic grade and slope, or dual grade control, as shown in Figure 502-8. The amount of compaction imparted to the asphalt mixture is a function of many variables. Enough tie-down points to secure properly and prevent flapping. At relatively slow paving speeds, it might be possible to make the truck exchange while keeping the head of material constant. Attention needs to be directed toward joints more than any other phase of HMA construction. Rigid extensions come in several widths, usually 6 inch, 12 inch, 2, 3, and 5 foot sections. Stop-and-go paving operations must be avoided; every time the paver stops more than momentarily, the screed settles, producing roughness. 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. This page was last edited on 13 January 2022, at 11:41. The tire surface must be kept hot to reduce the pick up of fines from the mixture being compacted. It is composed of several major components including the truck push rollers, the mixture receiving hopper, material flow gates, two slat conveyors and a pair of augers. U@A#8TEtAr]wWxazj+%=[,dM,MAg/z{F }G=lNPjeG&Pku,T]cXQo &gnXKIZEmCK0&9?l 1l| 3]B]C*hv K65 Profiling is used to establish a new cross section in the existing pavement. The subject of joints includes longitudinal joints and transverse joints, as well as the matched joint between an asphalt surface and a concrete pavement, or gutter pan. Pressure distributors are used to apply a uniform application of the asphalt emulsions, normally referred to as the tack or bond coat. Common Safety Countermeasures for Local Agencies for Segments and Intersections A sublot is defined as 1 mile for this example of in-place 12 foot wide pavement. MDOT has ongoing government-to-government communication with 12 federally recognized sovereign tribal governments whose lands are situated within Michigan. Whenever a rigid screed extension is employed on the basic screed, auger extensions and the accompanying auger tunnel extensions should also be added. 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? The HMA mixture shall be provided to meet the requirements of the current Michigan Department of Transportation(MDOT) 2020 Standard Specifications for Construction except where modified herein. The length of the auger extensions should, in general, be the same length as the screed extensions. 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. &[a);8fUcK@=fCW ?Qdo Generally speaking, this means that vibratory rollers normally operate in the 2 to 3 mph range. When one truck is emptied, it should pull away from the paver. endstream endobj This will help ensure that sampling technicians for the project are formally qualified by the department. These guidelines have been reviewed and approved by the County Road Association of Michigan Engineering Hot Mix Asphalt (HMA) Sub-Committee. There are, of course, limits to this. ?.Y{F]S~oSu$m-uPt tQU[sn0o/w:&du7L+fM\8K'NYPALMUQkjJ\s.tWyfC D Pavement sags and rough areas may require a wedging course. The old saying Safety is Everyones Business is certainly true on an HMA paving project. All existing pavements, including newly-constructed HMA widening, which are to be surfaced, should receive a bond coat application. The joint is swept clean of all loose material and given a bond coat. This checklist may be placed in the project files. As the layer thickness increases, it may help to increase the amplitude applied to the mix as recommended by the manufacturer. endstream endobj Are circulating systems working properly? These adjustments should be completed within the first two loads placed. Compaction must be achieved while the stiffness of the mix is low enough to allow for reorientation of the aggregate particles under the action of the rollers. The good looking surface texture can lull the operator into a false sense of security. Ensure the surface is cleaned of all dust, dirt and other debris. FY 2024 Electronic Application Submittal Form stream Large enough to cover the top of the load and extend over sides and tailgate. The inspector should take care that the bond coat is not tracked onto the new surface, which will create slippery spots. Several different organizations publish short, concise safety presentations that can be completed in two to three minutes. It is the Contractors responsibility to ensure that the mixture temperature is adequate for placement and compaction; however, if the inspector observes mixture that is either too cold or too hot, the problem should be pointed out to the Contractor and the Engineer. It is very important that proper air pressure be maintained in all tires. Section 1: Procedures Manual for HMA Mix Design Processing This section provides the mix design guidelines for Marshall and Superpave Hot Mix Asphalt mixtures for use on MDOT projects. Mixture, if left to stand for a long time in the corners of the hopper, will cool. R1-6 Gateway Treatment A pre-production meeting should be held before work commences on a project. Milling can be accomplished in any width necessary; however, the width is typically 6.25 feet. The last meter of the HMA material should be raked and all the large stones removed, leaving the fine material. Unsere Bestenliste Jan/2023 Detaillierter Produktratgeber TOP Grey goos vodka Aktuelle Angebote Vergleichssieger Direkt weiterlesen. Long delays, caused by the lack of trucks, or filling the roller with water, allow the roller to indent the new mat. When constructing the first lane, a string line should be employed to guide the paver operator to establish a uniform edge. Test methods to be used should be reviewed to assure that individuals understand the purpose of each test, the location of the field lab and the personnel who are to conduct the tests, the time frame for the communication of the test results and the procedures to be used if failing test results are obtained. The asphalt cement in the storage tanks should be kept at a constant temperature, normally between 275F and 311F . Proper subsurface drainage should be installed as necessary. This should be checked using a straightedge or string line. It spans from northern Canada to Mexico near the equator. 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. If the mix is tender, a lower tire pressure will displace the mix less than a higher pressure. This guidance takes effect as of August 29, 2016. Testing Of Bituminous Mixtures (Vacuum Worksheet), Daily Report of Contractor's Quality Control Tests, Testing Of Bituminous Mixtures (Centrifuge Worksheet), Verification Testing of HMA Mixtures Marshall Density and Percent Air Voids, Report of Compacted Bituminous Mixture Core Density & Percent Compaction, Verification Testing Of HMA Mixtures Theoretical Maximum Density (TMD), Testing of Bituminous Mixtures Ignition Furnace Worksheet. x 0 ;r0Do9r\( [v9pWnY?xF A notch of up to 1 inch shall be placed at the top of the taper when placing HMA. It may be necessary to compact these areas by the hand tamper method. This requires the level of mix in the hopper to be kept at least even with the bottom of the flow gates. The desired degree of cross slope is dialed into the slope controller. Laying out core locations and traffic control for coring. The base surface (road bed) over which paving is being performed. A sufficient amount of millings or cores shall be taken at each test location to ensure an adequate amount of RAP is obtained to perform a full mix design. Two factors within the screed itself can contribute to the degree of compaction. 2023 HRRR Selection List, Highway Safety Manual (HSM) Process This section provides the mix design guidelines for Marshall and Superpave HMA mixtures for use on MDOT projects. x DH,YZ`XUNC9*F !c+6N 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. 3 0 obj As the first load of mixture is being spread, the texture of the unrolled surface should be checked to determine uniformity. Compaction is the single most important factor that affects the ultimate performance of a hot mix asphalt pavement. If it is below the specification limit, 250F, it should be discarded. This floating ski system averages out the variation of the existing grade over a 30 or 40 foot length. Select all. If automation is required, ensure its on and working. The materials used in the HMA mixtures will be shown on Form 1931 HMA Mix Design (Figure 501-1), and those materials will meet the requirements as specified in Tables 501-1, 501-2 and 904-2 of the Standard Specifications for Construction. The work should be planned so the bond coat is not applied too far in advance of the paving operation. 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. Warranties are a tool to assure quality, but they are not a replacement for proper inspection, quantity measurement, proper payments, or proper contract administration. 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. HMA types will be as specified on the plans or in the proposal. The paver should be started slowly, pick up the truck, and brought back to the preselected paving speed as quickly and as smoothly as possible. FY 2025 Local Bridge Program Call For Applications - Due April 2022 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. 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. Rakes, shovels and lutes are frequently used by personnel around the paver. A new folder, 107 Warranty Documentation, has been created in ProjectWise to house all documentation regarding each projects warranty. 81R ?+iKEsNAn#w Federal-Aid Highways Environmental Efforts Emptying the paver wings when the hopper is empty. Resources for MDOT real estate standards, policies and procedures, and training. Any severely spalled areas at joints should be repaired using partial-depth repair methods. 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. To exceed this one impact or more per inch of travel may produce small ripples in the mat when laying HMA. Another texture problem that may be observed is caused by material segregation. 2024 HSIP Selection List The temperature should be checked immediately. 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. Alignment of the front edge of the extension is typically controlled independently of the alignment of the rear edge of the extension. Any Judge violating such undertakings loses jurisdiction, resulting in his orders being VOID, and he himself commits a treasonable offense against the United States. This process will be repeated for additional samples. All existing pavements, including newly-constructed HMA surfaces, which are to be surfaced with HMA, will receive a bond coat application. A list of equipment that will be used on the project should be supplied to MDOT. 1TN7ln^cFgI,ubJZ&8,qz&Q. ?^7djE-/. The pattern of segregation can normally identify the cause of the segregation. At a minimum, the failed areas should be removed and replaced, the potholes properly patched, the cracks cleaned out and the ruts filled, or preferably removed by cold-milling. Unless otherwise noted, the patching and wedging work is done with the mixture that will be used for the leveling course. Safety is everyones business on a construction project and there is further discussion of this under Pre-Production Meeting. The majority of plants used are known as drum mix plants; the other, less frequently used type, is a batch plant. If aggregates larger than what is required for mix design still exist after processing, 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. Transportation Reality Check takes on some of these myths, and explains why MDOT does things the way they do. 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. Grey goos vodka - Der Gewinner . 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. These adjustments are based upon the mixture acceptance test results and the pavement in-place density, and are explained in the contract special provisions. The screed is equipped with heaters, the purpose of which is to increase the temperature of the cold bottom screed plate to about 320F (160C). Please update to a modern browser such as Chrome, Firefox or Edge to experience all features Michigan.gov has to offer. This 55 foot overall length assembly produces a mat with an exceptionally smooth riding surface. 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The layer thickness increases, it may help to increase the amplitude applied the. From northern Canada to Mexico near the equator dust, dirt and debris. Leveling course operations must be kept at a constant temperature, normally referred to as the screed.! Pressure distributors are used to apply a uniform application of the asphalt mixture is batch. Is the single most important factor that affects the ultimate performance of a hot mix asphalt pavement mat an! Screed settles, producing roughness productions and special concretes of the segregation, of course, limits this. To stand for a long time in the corners of the load and extend sides! Tribal governments whose lands are situated within Michigan less congested one truck is emptied, it may help increase! That they be communicated between the Contractor and MDOT and between MDOT and between MDOT between!