Relationship between FWD Data and Visual Survey Conditions for Cement Concrete Pavement

The main areas that can be evaluated by Falling Weight Deflectometer(FWD)testing of PCC(Portland Cement Concrete)pavement includes:joint load transfer,voids under the slabs,roadbed's strength,slab's rigidity,uniformity of strength for the subgrade and pavement.At present,researchers have developed many evaluation models with the FWD testing data;however,few of them are practical.The main problem is lack of basic in-situ data,so none of the models are feasible without excessive field testing.Based on FWD field testing data and a large number of pictures of a highway,analyzed the relationships between values derived from FWD measurement in-situ and pavement condition data which was collected by means of field visual surveying or testing on an existing PCC pavement of a highway.Some qualitative or quantitative methods for obtaining joint load transfer and pavement stiffness and load-bearing capacity of the existing PCC slab were discussed.The concept of evaluating the overall load-bearing capacity of the pavement structure with a summation of FWD deflections in center of the loading plate is proposed.