| บทคัดย่อ(English) |
This study aims to compare the performances of the overlay of flexible pavementin terms of deflection, thickness and serviceability using pavement data obtained by twodifferent instruments, the Benkelman Beam and Falling Weight Deflectometer as inputs intothe design methods. Flexible type of pavement which has been in service only was chosen for thestudy. Ten routes of different deflections under structural loading, appearances ofsurface condition, length of services and the conditions of structural layers in centralThailand were chosen. The test sections were grouped according to the traffic volume,pavement thickness and length of service, Benkelman Beam (BB) and Falling WeightDeflectometer (FWD) Model 8000 of DYNATEST, Denmark were used to measure pavementdeflections in conjunction with other methods to measure thickness, ruts depth,temperatures, thickness of different structural layers, traffic volume and percentage ofcracks. The data from Benkelman Beam was employed in the design based on the Department ofHighways Standard (DOH Standard) and Analytical Overlay Design method employing ELMOD(Evaluation of Layer Moduli and Design) with Back-Calculation was used for the data fromFalling Weight Deflectometer. After that, correlation analysis was calculated to show therelationship between pavement deflections obtained by Benkelman Beam and Falling WeightDeflectometer respectively. It was found that the pavement data obtained by Falling Weight Deflectometer whenused as inputs in the design of overlay gave a better spread of deflections and overlaythickness with lower values of standard deviation which led to better quality of designresult, better road surface, less damage lower construction and maintenance costs. |
