Title: Methodology for Better Performance
Author(s): E. Owusu-Antwi and M. Darter
Publication: Symposium Paper
Appears on pages(s): 17-42
Keywords: Concrete pavements; finite element method; strains; stresses
Concrete pavement design is still largely empirical, although, there are instances where analytical methods based on theoretical principals have been used. This paper presents the results of work to formulate the concepts for the development of a unified pavement analysis and design system for the improved performance of airport concrete pavements. The improved analysis and design system takes into account realistic material behavior over service life; environmental efffects; realistic pavement loading and a realistic assessment of pavement damage in the anlysis and design prcess, to come up with better performing pavements. Theses concepts are to form the basis of a pavement analysis and design system to be developed in subsequent applied research. A central component of the system proposed is a 3-dimensional finite element analysis based primary response model, applicable to the nonlinear analysis of concrete pavements. This primary response model incorporates the appropriate material constituitive models that will permit a realistic representation of the behavior of hte current and future materials used in concrete pavements. Using this primary response model, a data base of the outputs of nodal displacements, stresses, strains and local damage measures can be generated for a given pavement structure, for the applicable traffic and environmental loading conditions. The data generated is then used in a damage assessment procedure the results of which are used to predict the development of the key distress types and roughness for concrete pavements. This provides for greater design reliability and cost-effective pavement design. A major advantage of the mechanistic design procedure envisaged is its applicability to realistic rehabilitation design, which is likely to become very important in the coming decades, during which the demand for rehabilitation design is expected to supersede that for new construction design. The unified pavement analysis and design concept provides an effective system for the evaluation of the performance of existing concrete pavements from nondestructive testing results. This includes the evaluation of the in-situ material properties of existing pavements from the results of such nondestructive testing, using backcalculation procedures.