Multipave framework to compare the design outputs with other design methods. Rigid pavement empirical design example pavement interactive. Called rigid since pccs high modulus of elasticity does not allow them to flex appreciably. The major purpose for applying such methods was to. For help on the use of this excel tool, you can download its instruction text file. The mechanistic approach for rigid pavements has its origins in westergaards. Each layer receives loads from the above layer, spreads th. Use the 1993 aashto empirical equation using the previously calculated esal results and the 1993 aashto empirical rigid pavement design equation the following pavement thickness designs can be calculated. The aashto pavement design guides fhwa us department of. Empirical equations are used to relate observed or measurable phenomena with outcomes. Arizonas present pavement design guide was developed by the materials section in 1989 with revisions issued in 1991 and 1992. Comparative studies of flexible and rigid pavement design. Performing organization name and address applied pavement technology inc. Difference between flexible pavement and rigid pavement duration.
Pavement system design engineering professional development. The design of rigid pavements by the westergaard method is still commonly used today for rigid pavements loaded by nonhighway vehicles. Highwaytransportation lec 24u4 pavement design part b3 rigid pavement. The 1993 aashto guide for design of pavement structures is the only approved design method for cpcd projects at txdot. Implementation of the aashto pavement design procedures. The current aashto method is a regression method based on the results of road tests. Empirical equations are used to relate observed or measurable phenomena pavement characteristics with outcomes pavement performance. In this video, you will know how to design a rigid pavement using aashto method and curves to make you available to develop structure pavement. The common design method for flexible pavement are the aashto method, asphalt institute and two layer system. It estimates the support of the layers below a rigid pavement surface course the pcc slab. Aastho flexible pavement design method objectives know the factors considered in the aashto design method become familiar with use of tables 20. All versions of the aashto design guide are empirical methods based on field. Appendix c nhi05037 federal highway administration. Introduction to rigid pavement design ced engineering.
Westergaard method for rigid pavement design spreadsheet. The overall approach of the 1993 aashto procedure for both flexible and rigid pavements. Approximately 80% of all states use the aashto pavement design procedures, with the majority using the 1993 version. What are the various flexible pavement design methods. Highway engineering became prominent towards the latter half of the 20th century after world war ii. Lecture 39 concrete pavement design pca and aashto methods duration. By default, the tool uses a layer coefficient a of 0. Pavexpress, a webbased pavement scoping tool that simplifies the design of flexible and rigid pavements, is also based on aashto 93. The present study applied the aashto and pca method for design of rigid pavements, for both pavement types using 20 year design life and 5% annual growth rate. It serves as a resource for contractors, government agencies, consultants, and others in.
Which is defined as the pressure per unit deflection of the foundations as determined by plate load test the modulus of subgrade reaction k is used as a primary input for rigid pavement design. Geotechnical aspects of pavements reference manual appendix d. This spreadsheet can be used to design concrete pavements in accordance with the tr 34 method. Christos drakos university of florida topic 10 aashto rigid pavement design 1. Pdf flexible pavement designaashto method abdulrahman. The rigid pavement design methods in this guide utilizes any of the following procedures. Modified aashto design method for geogrid reinforced flexible pavements existing design methods for flexible pavements include. Lecture 39 concrete pavement design pca and aashto methods. This is the design thickness used in other calculations an b rigid pavement design based on aashto supplemental guide reference. In this video, you will know how to design a rigid pavement using aashto method and curves to make you available to develop structure.
Design, types, flexible and rigid pavement, notes and functions. The guide for the mechanisticempirical design of new and rehabilitated pavement structures developed under nchrp project 7a is the stateoftheart procedure for the design of flexible and rigid pavement structures. In the aashto methodology, the anticipated spectrum of truck axle loads over the design. Design of rigid pavement using aashto method duration.
Cut across the e sb cut across m r to the tl vertically meet other line read kvalue k600pci topic 10 aashto rigid pavement design figure 12. The following inputs are used for concrete pavement design. It is not intended as definitive treatise, and it does not encompass the design of flexible pavements. Relevant design data where obtained from dar consult and technique cone. State of the art and practice in rigid pavement design. The structural condition assessment is used as a pavement health monitoring method and the decisionmaking factor in the pavement management at the network. The 1993 aashto guide for design of pavement structures is the only approved design method for cpcd projects. There are many different types of empirical equations available today but this section will present the 1993 aashto guide basic design equation for rigid pavements as an example. The aashto guide for design of pavement structures aashto, 1993 is the primary document used to design new and rehabilitated highway pavements. Three main stress need to be consider in rigid pavement. As a result, the following structural pavement design methodologies were developed or updated for inclusion in chapter 54. The concept of reliability in pavement design, introduced by the aashto 1993, is relatively recent.
Pavement interactive is a free online knowledge base for the paving industry. This design produces a rigid slab thickness in inches required to support the estimated traffic under a selected serviceability interval and. Probabilistic design of flexible and rigid pavements using. This empirical equation is widely used and has the following form. Engineers are cautioned that much of pavement design is governed by codes. Jointed plain concrete pavement jpcp continuously reinforced concrete pavement crcp pavement design.
The aashto method of rigid pavement design was developed from performance data of jointed plain concrete pavements jpcp. Improve the design and performance of your pavement systems and learn how to predict their performance by starting with the fundamentals. Pca pavement design spreadsheet civilweb spreadsheets. The mechanisticempirical approach at the heart of the nchrp. A flexible pavement structure is typically composed of several layers of materials. Appendix d nhi05037 federal highway administration. Nchrp 7a design method 621 trial cross sections for nchrp 7a flexible pavement design. Flexible pavement design according to the aashto 1993 guide can be very time consuming. Aashto 93 guide for design of pavement structures and acpa current version of streetpave. Unlike the aashto rigid pavement design method which is empirically based on road test data, the pca method was an early attempt at a mechanistic design method. Albalbissr this paper applies statistical and probabilistic methods to the design of pavements, using the existing aashto equations. You will learn the principles of stress and strain analyses in typical highway pavement structures, how to design new and rehabilitated flexible and rigid pavement structures, and how to use various mechanisticempirical methods to conduct pavement analysis.
Aashto pavement thickness design guide when designing pavement thickness for flexible and rigid pavements, the following considerations should be used. Aashto guide for design of pavement structures 1993. The westergaard method for rigid pavement design involves a calculation of the stresses acting in the pavement under the wheel load. This is an introduction to rigid pavement design for engineers. This is a simple method of inspecting a pavement surface for assessing the magnitude and severity of various types of. Stress induced by bendingstress due to traffic wheel loadsstress due to temperature effects. Aashto design method accounts for these uncertainties by incorporating a. The pca method was developed based on finite element calculations of pavement stresses and deflections which were then calibrated with some simple design and performance criteria to. Calculate proper pavement thickness with free online tool. This spreadsheet can be used to design concrete roads in accordance with the aashto method. For jointed concrete pavements, regardless of whether reinforced or nonreinforced, the aashto odot method of pavement design calculates the same.
Aashto design procedure 1993 for cpcd rigid pavements. This article presents the 1993 aashto guide basic design equation for flexible pavements. Design of rigid pavement using aashto method youtube. Pavement design guide for subdivision and secondary roads. Aashto design procedureobjectivethickness of the concrete pavement. Subbase thickness10 subbase modulus30,000 psi subgrade m r10,000 psi to get k. In this work the design procedure by aashto is implemented by matlab.
Antonis michael frederick university notes courtesy of dr. Flexible pavements are so named because the total pavement structure deflects, or flexes, under loading. The joint spacing was the focus of the alterations made to the original aashto 1993 rigid pavement design equations and for this reason the aashto 1998 rigid pavement design supplement is best suited to the design of jpcps. Rigid pavement design of pavements lec14 part1 youtube. Approximately 80% of all states use the aashto pavement design. Aashto design procedure is a result of empirical equations which were developed as a result of. Section 5 rigid pavement construction standard specification for urban infrastructure works 55 edition 1, revision 0 september 2002 testing a testing authority shall be employed by the contractor to carry out all testing. The aashto 1993 method is based on an empirical equation developed from road performance information gathered from the aashto road test.
Introduction empirical design based on the aasho road test. Lecture 39 concrete pavement design pca and aashto. Aashto method of flexible pavement design road surface. Geotechnical aspects of pavements reference manual appendix c. Using fwd data with me design and analysis, volume i. The site is a repository for encyclopedic articles, news, and information on all topics related to pavements. Highway engineering is an engineering discipline branching from civil engineering that involves the planning, design, construction, operation, and maintenance of roads, bridges, and tunnels to ensure safe and effective transportation of people and goods. Aashto design procedure is one of the approved design methods recognized globally. Pavement designanalysis software university of idaho. Over 200 test sections jpcp 15spacing and jrpc 40spacing range of slab thickness. There are different methods for the design of pavement structures. A revision was not issued to formally adopt the 1993 version of aashto guide for the design of pavement structures because adot had. Probabilistic design of flexible and rigid pavements using aashto equations annan a. This design produces a rigid slab thickness in inches required to support the estimated traffic under a selected serviceability interval and estimated support and environmental conditions.