A concrete pavement is to be designed to support loading from mining trucks with an axle load of 640 kn with a wheel spacing of 4. Differences in predicted flexible pavement performance using the. The conversion of traffic to the esal is accomplished with the use of axle load equivalency factors. Historically, procedures for axle load characterization in pavement design include. Historically, numerous techniques have been applied by a multitude of jurisdictions dealing with roadway pavements. Loads on other axle configurations that cause equivalent damage to the standard axle. So ingrained is this assumption that it is even known as the fourth power law and may be expressed thus. This quantification is usually done in one of two ways.
If classification studies have shown that the truck factor can be taken as 0. Pavement thickness must be designed to withstand the anticipated traffic, categorized by type and weight of vehicles, and measured by average daily volume adv of each type for the design life of the pavement. The rigid pavement design procedure presented herein is based upon the criti cal tensile stresses produced within the slab by the. Equivalent single axle loads esals during their lifetime see ptad2. The traffic on the design lane of a proposed fourlane rural interstate highway consists of 40 percent trucks. To design a pavement section the damage caused by all axle loads that. Highway and pavement design plays an important role in the dpr projects. Analysis period n n is the period of time for which the analysis is to be conducted. It should be noted that esals as calculated by the esal equations are.
The pavement designer usually possesses raw traffic count data, which must then be converted to esals in order to design the pavement. The determination of traffic volume in asphalt pavement design has not considered the effects of seasonal variability on vehicle axle loads in china. The current aashto pavement design guide converts different axle load configurations to a standard axle load 18 kips using load equivalency factors lefs. For highways the maximum legal axle load in india, specified by irc, is 10 tonnes. Therefore, pavement structural design requires a quantification of all expected loads a pavement will encounter over its design life. Pavement deflection was measured using instruments contained within the road structure. One measure of the durability of a road is the degree to which its pavement sections bend under a given load.
Design of rigid and flexible pavements by various methods. The pavement design engineer must integrate this information into the materials design package materials design report, pavement design summary and preliminary pavement structure cost estimate that will provide the necessary documentation and communication of this design process. Pavement analysis and design pdf download free ebooks. The mechanisticempirical pavement design guide mepdg developed under national cooperative highway research program project 7a requires the use of axle load spectra or load distribution factors ldfs for pavement thickness designs. Deacon, assistant professor of civil engineering, university of kentucky. Differences in predicted flexible pavement performance using. Equivalent standard axle first principles global road. As a guide in achieving this goal, this publication provides adequate designs that will result in. Modification and application of axle load conversion formula to. Design data hand book department of civil engineering 1 1. May 10, 2019 pavement design wheel loading using ccaa approach. Pdf road geometric design suitable for sudan find, read and cite all the research you need on researchgate.
Traffic loading principles of pavement engineering. Although the basic geometry of a pavement system is quite simple, everything else is not. All areas of the pavement may be traversed by the mining truck. However, the effects of the different traffic axle load and configuration on the pavement performance were the main achievements of the various fullscale road. This paper is a report of a recent study in singapore to characterize the axle loads of heavy vehicles for use in pavement design and performance analysis. Pavement design for roads, streets, walks, and open storage areas. Modification and application of axle load conversion formula. Estimating the design traffic loading is a critical step in designing a pavement. As a general guide, factors elaborated in section 3. One significant means for evaluating the relative destructive effects of repetitive vehicular loading on highway pavements is the equivalent axle load concept. Deen, assistant director of research, kentucky department of highways one significant means for evaluating the relative destructive effects of repetitive vehicular loading on highway pavements is. In defining these strains, the displacement field considered is twodimensional.
Pavement design manual alaska department of transportation. Determination of axle load spectra based on percentage of. American concrete pavement association design of concrete pavement for city streets design and construction standards forcitystreets should provide for pavements with both long service life and low maintenance. Trafload is based on a new mechanisticempirical approach to pavement design, it relies on axle load spectra rather than equivalent single axle loads. As a result, we felt that the time was right for recapturing the pavement engineering state of the art in a textbook. In addition to references previously cited regarding mechanistic design, textbooks by yoder and witczak, 10. It is a single axle load with dual wheel carrying 80 kn load and the design of pavement is based on the standard axle load.
Design traffic esals esals is the estimate of number of equivalent 18 kip single axle. This is the third edition of this book for second edition see irrd 846333 which. Specific chapter topics include stresses and strains in flexible pavements, stresses and deflections in rigid pavements, traffic loading and volume, material characterization, drainage design, pavement performance, reliability, flexible pavement design, rigid pavement design, design of overlays, theory of viscoelasticity, theory of elastic layer systems. Pavement analysis and design 2nd edition huang, yang h. Axle load kips single axles 2830 2628 2426 2224 2022 1820 1618 1416 1214 1012 tandem axles 4852 4448 4044 3640 3236 2832 2428 2024. Rdgn042 pavement design for carriageway construction page 7 of 42 pavement type for different sections andor different lanes on the same road. The basic loading unit is known as an equivalent standard axle esa and is the result of work carried out at the aasho road tests in 19581960. Estimation of axle loads of heavy vehicles for pavement studies. The mepdg allows for various levels of ldf inputs, varying from sitespecific level 1 to regional average level 2 and national average level 3. If detailed axle load data are not available, the design can be accomplished as described in chapter 4, by the selection of one of several categories of data that represent a range of pavement facilities varying from residential streets up to. Using single and tandem axles of the vehicle class 9 as examples, this study analyzed the spatial and temporal variations of the load distributions from the longterm pavement performance program traffic database. Pavement design and materials is a practical reference for both students and practicing engineers that explores all the aspects of pavement engineering, including materials, analysis, design, evaluation, and economic analysis. This is accomplished by using equivalency factors, such as those presented in chapter 54 of the illinois department of transportation idot.
Irc recommendations for design of plain jointed rigid. For most pavements, the magnitude of the axle load is of greater importance than the gross. A comprehensive, stateoftheart guide to pavement design and materials with innovations ranging from the advent of superpave, the data generated by the long term pavement performance ltpp project, to the recent release of the mechanisticempirical pavement design guide developed under nchrp study 7a, the field of pavement engineering is experiencing significant development. Pavement design in road construction design parameters. Pavement analysis and design 2nd edition 97801424739 by huang, yang h. This paper describes the experiment, the loading conditions investigated. Where sufficient information on axle loads is not available and project does not. The maximum allowed axle load on the roads is called legal axle load. Sum fatigue and erosion damage factors over all of the axle. A falling weight deflectometer, or fwd, is often used to. Aashto load equivalency factors for rigid pavements based on terminal serviceability index of 2.
The standard axle loading is defined as an axle with dual tyres loaded to 80kn 8. Allowable axle loads on pavements what was the need. One of the key parameters required for the asphaltbased pavement performance evaluation is the dynamic modulus of each sublayer. Axle load analysis for bituminous pavement design youtube.
Step by step free download as powerpoint presentation. These lefs are based on loss of pavement serviceability index psi, and were developed for a limited number of pavement and axle types, load magnitudes, load applications, age and. Equivalent single axle load although it is not too difficult to determine a wheel or an axle load for an individual vehicle, it becomes quite complicated to determine the number and types of wheel axle loads that a particular pavement will be subject to over its design life. Jan 09, 2008 pavement design and materials is a practical reference for both students and practicing engineers that explores all the aspects of pavement engineering, including materials, analysis, design, evaluation, and economic analysis. The dynamic axle loads were induced by bumps on the road surface and the magnitude of these axle loads was measured onboard the vehicle. The combined damaging effect of vehicular traffic is collectively expressed as a cumulative number of equivalent standard axles with a 80kn single axle dualwheel configuration with tyre pressure of 0.
Introduction to flexible pavement design ced engineering. Pcapav design traffic axle loads distribution the number of single and tandem axles over the design period expressed as axles per trucks does not include panel and pickup trucks and other fourtire vehicles. The alaska flexible pavement design method akfpd, a com puter program. This parameter is widely used in numerous approaches, including the mechanisticempirical pavement design guide mepdg to calculate the deformation, critical strain and stress of the pavement, and its value controls the pavement response directly. Traffic loading is a heterogeneous mix of vehicles, axle types, and axle loads with distributions that vary with time throughout the day, from season to season, and over the pavement design life. A highway pavement is a structure consisting of superimposed layers of processed materials above the natural soil subgrade, whose primary function is to distribute the applied vehicle loads to the subgrade. Traffic data collection, analysis, and forecasting for mechanistic. Main flexible pavement and mix design methods in europe and. Introduction the loading of traffic over the design life of the pavement is a fundamental input, and is an area that is subject to much debate and inaccuracy. Traffic loading deterioration and maintenance of pavements. Generally, the first procedure is adopted for airport pavements, the latter both characterizations are used for the design of highway pavements. Pavement design is the major component in the road construction. Axle load distribution for mechanisticempirical pavement design.
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