A STUDY ON STRUCTURAL ADEQUACY OF FLEXIBLE PAVEMENT WITH DIFFERENT TYPES OF SHOULDERS

Abstract

Shoulders are the integral part of the highway cross section which affects greatly safety, strength and lane capacity. A shoulder is the portion of roadway contiguous with the traveled way for the accommodation of stopped vehicles for the emergency use, and for lateral support. Well planned shoulders provide definite and improved engineering functions to the overall roadway and to the carriageway in particular. In the present study, an attempt has been made to observe the effect of different types and widths of shoulders on structural capacity of flexible pavement. In order to attain the required target, tests were conducted on 3 - layer pavement model sections. Plate load test was conducted on pavement model using 30cm diameter plate to find the load carrying capacity as well as the pressure distribution in the pavement as well as in the shoulders. The test results indicate that the load carrying capacity of the pavement will increase with a better type of shoulder having more width. It is found that the load carryimg capacity of the pavement with gravel shoulder is 33 % more as compared to the pavement with earthen shoulders. Results also indicate the lateral confinement provided by the gravel shoulder is more. The pressure distribution in the pavement as well as in the shoulder is good with a better quality of shoulder and it is 31 % more for the pavement with gravel shoulder as compared to the pavement with earthen shoulder.