Download or read book Analysis of Permanent Deformations of Flexible Airport Pavements written by Yu T. Chou and published by . This book was released on 1977 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was conducted to investigate the deformation characteristics of component materials in a flexible pavement system subject to moving aircraft loadings, and to attempt to develop a prediction model to estimate permanent deformation. Series of laboratory repeated load tests measuring permanent strain were performed on subgrade soil and untreated granular materials. The results were used as input to a layered elastic computer program to determine the accumulated permanent deformation that occurred in each layer of the pavement. Pavements used in the analysis were full-scale multiple-wheel heavy gear load test sections and pavements designed by using the CBR equation. The permanent deformation occurring in the subgrade soil of many pavements was computed using the linear layered elastic computer program and laboratory repeated load test data. Results of the analysis indicate that the current concept of the control of subgrade rutting in flexible pavements by the limitation of elastic strain is not strictly correct. When subgrade strain is limited, subgrade rutting may not be limited and may not be controlled.