Asphalt rubber applications asphalt rubber is the process of adding recycled, crumb rubber to hot mix asphalt called dry process or the asphalt binder called wet process to modify the final mixture difficult to use in densegraded mixtures due to residual crumb rubber best used in gapgraded type mixtures sma and ogfc. Asphalt materials and mix design manual pdf the laboratory work is designed to develop an understanding of asphalt properties, characteristics, testing procedures, and specifications. About hot mix asphalt construction every year, the state of california invests millions of dollars in construction of hot mixed asphalt hma, previously known as asphalt concrete ac, pavement. Scales of appropriate capacity and design to weigh the required samples. If the supporting documentation listed in subsection 4. Balance to weigh up to 20 kg with an accuracy of 1g. Quality asphalt pavement may be constructed in a wide range of soil, weather, and loading conditions. The marshall mix design method can use any suitable method for estimating optimum asphalt content and usually relies on local procedures or experience.
The pavement mix types targeted are ogfc, sma, and fineand coarsegraded dense mixes. Pdf on mar 6, 2006, khalid alshamsi and others published laboratory optimization of asphalt concrete mixture design find, read and cite all the research. These guidelines provide for the selection of hot mixed asphalt hma and application rates utilizing the superpave mix design system along with the marshall mix design system. Warm mix asphalt wma has quickly become a popular topic in the asphalt industry, and the federal highway administration fhwa is actively encouraging implementation of wma in all states. Hot mix asphalt may be referred to by several names. Properties considered in mix design superpave mix design.
This design guide provides general information for proper parking area design, construction, and facility layout. Special mixture design considerations and methods for warm mix asphalt. The intention is to advance the move towards performancerelated specifications for the design of asphalt pavement materials, which started with the publication in. The superpave hot mix asphalt asphalt mixes that are recommended for paving parking lots can vary from fine graded mixes to coarse graded mixes. Hma mix design is the process of determining what aggregate to use, what asphalt binder to use and what the optimum combination of these two ingredients ought. In different sections of the state it may also be referred to as bituminous concrete,hot plant mix,asphalt concrete, blacktop or superpave. The cover letter describing the asphalt mix design, as a minimum, shall be stamped by a registered professional engineer in the state of colorado.
The relative proportions of these materials determine the physical properties of the hma and ultimately how the hma performs as a finished pavement. Sop 723 pdf 939 kb standard operating procedure for submitting hot mix asphalt hma mix designs for verification. The procedures outlined are all derived from astm designations and practice as recommended by the asphalt institute. Marshall method of mix design the basic concepts of the marshall mix design method were originally developed by bruce marshall of the mississippi highway department around 1939 and then refined by the u. Design mixtures conforming to table 4601 and table 4602.
Pdf design methods asphalt mix 7th edition ms2 asphalt. This 2016 asphalt pavement design guide has been prepared to assist readers in understanding asphalt mix pavement design, construction, and rehabilitation. A balanced mix design bmd sets a maximum asphalt content based on the rutting criterion and a minimum asphalt content based on cracking criterion. Batch, mix, and compact more samples with this gradation with four asphalt contents. Practical approaches to hotmix asphalt mix design and production. Hma pavement mix type selection guide transportation.
There are four important hma parameters which the owner must specify in order to ensure the proper design. Calculate the limiting asphalt content at the tentative design asphalt content. Equations for the above calculations follow in this text and their application may be expedited by use of the appropriate worksheet figure 1. The marshall stability of the mix design is defined as a maximum load carried by a compacted specimen at a standard temperature of 60 oc. Asphalt mix designs submitted to the tdot must exhibit certain physical performance properties indicated in standard specifications including but. A manual for design of hot mix asphalt with commentary. The report presents special mixture design considerations and. The hma pavement mix type selection guide provides designers with methods for selecting appropriate mix types while considering factors such as traffic, environment, subsurface pavement structure, existing pavement condition and preparation, and economics. The mix design technology certification mdt course provides advanced technicians, designers, and engineers responsible for mix designs with a thorough understanding of the properties of the materials which compose asphalt mixtures, as well as the physical and mathematical processes involved in producing a successful asphalt mixture design. This is generally accomplished by adding some type of additive to the liquid asphalt to change its viscosity or act as a lubricant at various temperature ranges. Download a pdf of mix design practices for warmmix asphalt by the national academies of sciences, engineering, and medicine for free. Mix design technology certification asphalt institute. Hot mix asphalt is composed of aggregate bound together. Asphalt mixtures, regressed air voids, balanced mix design, laboratory performance testing, hamburg wheel tracking device, illinois flexibility index test, discshaped compact.
Hma mix design strength stability rut resistance raveling durability crack resistance shoving flushing smooth quite ride. Chapter 2 design and control of bituminous mixtures using. The substitution of another hma mixture type other than the recommended mixture is acceptable if it has demonstrated to perform under similar traffic conditions. Sixth edition 2019 the new jersey asphalt pavement. Wearing courses binder courses base courses type of asphalt mix. Much of what determines long term pavement performance of the asphalt mixture, such as air voids, vma and vfa, are based on volume not weight. This guide presents examples of designs, procedures, and applications that have. The superpave mix design manual for new construction and overlays ronald j.
Superpave mix design 48 determining the design asphalt content the selected trial blend becomes the design aggregate structure. Stamped mix design submittals in pdf format are acceptable. Pdf laboratory optimization of asphalt concrete mixture design. Asphalt pavement cracking is a nationwide problem faced by every highway agency. Mix design practices for warmmix asphalt the national. The contractor may submit a new job mix formula on form cem3511 with a new form cem3512, contractor hot mix asphalt design data, or the contractor may adjust the job mix formula on form cem3511 with allowable adjustments specified in section 392. Sample asphalt binder contents based on the results of the optimum asphalt binder content estimate, samples are typically prepared at 0. Asphalt mix design 2 australian asphalt pavement association 2012 2 design process asphalt mix design involves the following basic steps that are similar in concept, regardless of the actual tests and procedures used. Development of an ideal cracking test for asphalt mix. Kennedy university of texas at austin michael anderson the asphalt institute strategic highway research program national research council washington, dc 1994. This project developed a bmd framework for the minnesota department of transportation mndot and used it to evaluate materials from four minnesota projects using the. Hot mix asphalt hma selection guidance december 2017. Background of superpave asphalt mixture design and. Superpave overview nthe final product of the shrp asphalt.
Design and optimum are often used interchangeably however, they mean two different things there can be many design binder contents for a mix, but only one truly optimum optimum indicates the best binder content based on intended application, performance requirementsneeds, and ultimately economics. Designmarshall method and this turkish standard 3720. The purpose of this document is to establish an acceptance procedure for hot mix asphalt mix designs. This mix design procedure incorporates the use of the texas gyratory compactor tgc and the. As asphalt mix designs become more complex with the use of recycled materials, rejuvenators, and asphalt binders with various additives, pavement engineers and asphalt industry urgently need a simple, repeatable, and reliable cracking test for mix design, quality. In different sections of the state it may also be referred to as bituminous concrete,hot plant mix, asphalt concrete, blacktop or superpave. Component and construction effects on mixture properties. Thermometer to measure a temperature from 0c to 200c with the accuracy of. Asphalt institute regional engineer tuttle, oklahoma asphalt materials, mix designs, and plants. Producing high quality hma pavement requires a good partnership between caltrans, the plant producing the hma material and the contractor placing the hma. A manual for design of hotmix asphalt with commentary.
Superpave asphalt binder technology and superpave asphalt mixture design and analysis. Mix design in hot mix asphalt, binder and aggregate are blended together in precise proportions. The final mix design should be workable and contain the most suitable gradation and amount of asphalt binder to produce a mix that embodies the best possible combination of all parameters. A volumetric mixture shall be designed in accordance with aashto r 35 and the respective aashto reference as listed below. The publication of aprg report no 18 selection and design of asphalt mixes. T 724 pdf 324 kb method for preparation of aggregate for hma job mix design. The purpose of this guidance note is to ensure that a standardized method is applied to the design procedure. T 726 pdf 383 kb mixing procedure for hot mix asphalt. Asphalt materials and mix design manual pdf download.
Well graded aggregates and mineral filler resulting in maximum density when mixed with optimum quantity of bitumen results in a mix with very high stability. Calculate the bearing capacity for each asphalt content. Submittal and approval of hot mix asphalt mix designs sop. Asphalt mix design guide australian asphalt pavement association. The superpave mix design manual for new construction and. While a fair assessment plan has been developed with regard to mix design for wma technologies using. Cominsky university of texas at austin with contributions by. Cl2 model specifications for small paving jobs pdf 1.
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