Based on the sensitivity results, the input parameters were ranked and categorized from those to which pavement performance is most sensitive to least sensitive (or insensitive). In addition, the binder grade was varied for the flexible pavements. The input parameters that were varied included traffic variables and pavement structure for selected rigid and flexible pavements. It also included smoothness, longitudinal cracking, alligator cracking, transverse cracking, and permanent deformation for flexible pavements. Pavement performance included specifically faulting, transverse cracking, and smoothness for rigid pavements.
The sensitivity analyses were conducted using the Mechanistic-Empirical Pavement Design Guide software (version 8.1). This report is focused on using the American Association of State Highway and Transportation Officials (AASHTO) M-E Design Guide (MEPDG) to show the results of quantitative sensitivity analyses of typical pavement structures (rigid and flexible pavements) to highlight the main factors that affect pavement performance in terms of critical distresses and smoothness. To do this theoretical mutual spacings can become insight to change the equations to give a suitable outcome for pavement thickness.įor JRCPs the real combined spacing should become used up to a optimum of 9m.Optimization of transportation facilities for capacity and pavement condition could be achieved with mechanistic analysis of pavement structures. The mutual spacing has been the focus of the alterations produced to the original AASHTO 1993 firm pavement design equations and for this reason the AASHTO 1998 inflexible pavement design Supplement is usually best suited to the style of JPCPs. These weather inputs can furthermore be insight directly by the designer for make use of in various other parts of the US or for any areas outside of the US. The CivilWeb AASHTO Rigid Pavement Style Spreadsheet consists of typical environment info for more than 130 main US towns and regions. This is calculated using the below equation where f is certainly the rubbing coefficient as shown for in the below table for various road base materials. This is typically taken as 1.0 for standard 3.66m wide concrete road lanes, 0.94 where a linked concrete shoulder is integrated and 0.92 for a 0.6m increased slab. This will be computed in the exact same way as for the Westergaard Method, the equation is produced below where is usually Poissons Ratio for tangible, typically used as 0.15 or 0.2. This can become calculated using the below equation where At the c is definitely the concrete floor slabs modulus of flexibility, E w is usually the road basis modulus of firmness, H w is usually the street foundation width, k is certainly the efficient flexible modulus of the subgrade. This must become calculated for both the AASHTO Road Check constants and making use of the 1998 stiff pavement style supplement constants. This formula assumes a 50 reliability where W will be the amount of standard axles for the traffic lane regarded. The updated 1998 procedure works in a related manner to the 1993 method but consists of for the results of joints spacing.Īs such this was a great enhancement on the original 1993 technique and it can be the 1998 Supplement technique which is definitely most suitable to creating concrete roads.įor this reason it is definitely the AASHTO 1998 health supplement which forces the CivilWeb AASHTO Rigid Pavement Design Spreadsheet. This period the technique was not really structured upon data acquired from the AASHTO Road Test but on the LTPP data source NCHRP task 1-30. However, the AASHTO 1993 rigorous pavement style model can be still frequently used in many parts of the globe and is definitely very useful as a simple device for evaluating required concrete street thicknesses at primary stage. This offers since been replaced by a significantly more complicated mechanistic design procedure identified as the Mechanistic-Empirical Style Guide (MEDG).