ASTM D5858-96 (R2020) PDF Download

ASTM D5858-96 (R2020) standard provides a methodology for estimating the layer moduli of pavement structures using deflection measurements. This guide is intended for use in pavement evaluation and overlay design. It highlights the importance of resilient modulus as a key parameter for characterizing pavement materials and emphasizes the use of equivalent layer elastic modulus as an approximation of resilient modulus under in situ stress conditions. The guide also acknowledges that adjustments for temperature, season, and design load may be required when using the calculated layer moduli for pavement evaluations and overlay design.

The standard assumes the existence of a representative set of layer moduli for a specific loading and temperature condition, such that the calculated deflection basin closely matches the measured deflection basin. It recognizes that different combinations of moduli may produce reasonable matching results, requiring engineering judgment to select the most applicable combination or eliminate unreasonable solutions. Additionally, the standard acknowledges the variability observed in the results obtained using different equipment and analysis methods. It notes the need for standardization of the "true" in situ modulus, based on resilient modulus testing or other field or laboratory tests, to establish the bias of the calculation method.

The guide does not recommend a specific method for calculating the in situ equivalent layer elastic moduli but outlines the general approach. It covers flexible pavements and, in some cases, rigid pavements, using layered elastic theory as the analysis method. However, it mentions that different layered elastic computer modeling techniques can yield different results. The standard also mentions the possibility of using other analysis procedures, such as finite element modeling, with necessary modifications.

It is important to note that this standard does not offer specific recommendations but provides general information and options. Professional judgment, education, and experience should be exercised in conjunction with this guide. The document highlights that not all aspects of this guide may be applicable in all circumstances, and it should not replace the standard of care by which professional services are judged. The title of the document indicating "Standard" means it has been approved through the ASTM consensus process.