AUTh flexible pavement design methodology

The surfacing layer is chosen from the following bituminous mixtures asphalt concrete for very thin layers, PA, SMA, dense asphalt concrete (for low traffic areas) or micro-surfacing. 

The pavement thickness can be determined for three MAATs, 13°C, 16°C or 19°C, representing warm environments. 

The nomographs were developed using the principles of the elastic layered system where materials are characterised by their stiffness and Poisson s ratio. The stresses and strains developed were calculated using BISAR software (de Jong et al. 1973) incorporated in Shell s pavement design software SPDM-PC (Valkering and Stapel 1992). 

The design criteria used were the horizontal strain in the asphalt layer and the vertical strain on the subgrade, as outlined in Section 13.7. Rutting of the asphalt layers was also considered so that the thickness of the asphalt layers does not reach more than 25 mm (maximum) during the design life of the pavement. 

At the end of the design life, the pavement is expected to fail owing to fatigue cracking or surface deformation. During the lifetime of the pavement, the surfacing material is expected to be rehabilitated to meet surface characteristic requirements. The frequency of the rehabilitation depends entirely on the life expectancy of the surfacing material used in relation to traffic volume. 

---

Figure 13.20 Flow chart of AUTh flexible pavement design methodology. (From Nikolaides, A.F., Flexible Pavements Pavement Design Methodology, Bituminous Mixtures, Antiskidding Layers, 1st Edition. Thessaloniki, Greece A.F. Nikolaides. ISBN 960-91849-1-X, 2005.)...

---