Asphalt institute effective depth method

The effective depth method developed by the Asphalt Institute (Asphalt Institute MS-17 3rd Edition) is an alternative asphalt overlay design method to the deflection method. It is based on the concept that the pavement deteriorates and at any time there is a remaining life that could be utilised in designing the pavement for future conditions. This remaining life is provided by a pavement with a depth less than the original, called effective depth . 

To convert the existing pavement into an effective depth pavement (full-depth pavement), conversion factors are used related to the condition of each layer. The determination of the condition of each layer is carried out by visual inspection/survey. 

The effective method can be used for asphalt overlay design for either flexible or rigid pavements. 

The procedure for determining the thickness of the asphalt overlay for flexible pavements consists of the following steps  

To calculate the effective pavement, it is necessary to know the condition, composition and thickness of each pavement layer. 

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