with the falling weight deflectometer used as benchmarking tool. Pretoria, ZA, s.n. Horak, E., 2008. Benchmarking the structural condition of flexible pavements with deflection bowl parameters. Journal of the South African Institution of Civil Engineering, 50(2), pp. 2-9. Horak, E., 2009. Evaluation of airport pavements with FWD deflection bowl parameter benchmarking methodology. Amsterdam, s.n. Paine, D., 1998. The incorporation of structural data in a pavement management system. s.l., 4th International Conference on
Franco Pigozzi, Silvia Portas, Francesca Maltinti and Mauro Coni
Márton Karoliny and László Gáspár
Preservation of the appropriate quality of road assets needs timely rehabilitation of high-level design and construction. Since the actual life cycles of Hungarian road rehabilitation projects are often much lower than expected, research activities of the authors were concentrated on the development of an updated design technology of road pavement rehabilitation using scientifically based algorithms. The paper outlines the elements of a pavement rehabilitation design based on Hungarian and foreign literature survey, detailed own laboratory test series and trial section monitoring. The main steps of the design methodology comprise the Client’s data supply and disposition, site condition evaluation by the designer, deflection measurement in carefully selected points, eventual additional laboratory tests, choosing design subsections, correction of the equivalent thickness of the new asphalt layer, calculation of strain in wearing course. Besides, relationships are presented between various condition parameter data like bearing capacity values, unevenness measuring data and rut depth values. The pavement rehabilitation design technique suggested here – if widely in Hungary – can significantly contribute to attaining a much longer life cycle of rehabilitated roads than by now, and it is (would be) extremely efficient due to the very limited funds available for highway purposes.
Paola Dalla Valle and Nick Thom
This paper presents the results of a review on variability of key pavement design input variables (asphalt modulus and thickness, subgrade modulus) and assesses effects on pavement performance (fatigue and deformation life). Variability is described by statistical terms such as mean and standard deviation and by its probability density distribution.
The subject of reliability in pavement design has pushed many highway organisations around the world to review their design methodologies, mainly empirical, to move towards mechanistic-empirical analysis and design which provide the tools for the designer to evaluate the effect of variations in materials on pavement performance. This research has reinforced this need for understanding how the variability of design parameters affects the pavement performance.
This study has only considered flexible pavements. The sites considered for the analysis, all in the UK (including Northern Ireland), were mainly motorways or major trunk roads. Pavement survey data analysed were for Lane 1, the most heavily trafficked lane. Sections 1km long were considered wherever possible.
Statistical characterisation of the variation of layer thickness, asphalt stiffness and subgrade stiffness is addressed. A sensitivity analysis is then carried out to assess which parameter(s) have the greater influence on the pavement life.
The research shows that, combining the effect of all the parameters considered, the maximum range of 15th and 85th percentiles (as percentages of the mean) was found to be 64% to 558% for the fatigue life and 94% to 808% for the deformation life.