A Study on FWD Deflection Bowl Parameters for Structural Evaluation of Flexible Pavement

Authors

  • Ujjval J. Solanki Civil Engineering-Transportation Engineering, R.K. University, Rajkot, Gujarat, India

DOI:

https://doi.org/10.3759/ttea.v4i1.2871

Abstract

The application of falling weight deflectometer is to evaluate structural condition of the pavement. The exercise of back calculation is required to identify the modulus of elasticity of existing in service pavement. The process of back calculation required in depth field experience for the input of range of modulus of elasticity of bituminous, granular and subgrade layer, and its required number of trials to find such matching moduli with the observed FWD deflection on the field. The study was carried out at Barnala-Mansa State Highway of length 20 km at Punjab state using FWD before and after overlay; the deflections obtained at 0 on the load cell, 300, 600, 900, 1200, 1500 and 1800 mm interval from the load cell. The seven deflection results are used to calculate deflection bowl parameters such as surface curvature index (SCI), middle layer index (MLI) and lower layer index (LLI). This SCI, MLI and LLI indices are useful to predict the structural performance of in service pavement layers and also useful to identify homogeneous section for condition assessment. The study shows that the limiting value of SCI is found 240 μm; above this value, the structural condition of pavement is to be considered as poor and below 100 μm, it is considered as very good. The MLI values are found in the range of 140 and 100 μm for old and new pavement respectively; in both cases, middle layer condition is good and it also correlates with back calculated moduli value of middle layer. The average LLI values are found in 20 for old and 14 for new pavement; in both the cases, lower layer condition is good and it also correlates with back calculated moduli values of lower layer.

Downloads

Published

2019-07-20

Issue

Vol. 4 No. 1 (2017)

Section

Articles

License

Declaration and Copyright Transfer Form

(to be completed by authors)

I/ We, the undersigned author(s) of the submitted manuscript, hereby declare, that the above manuscript which is submitted for publication in the STM Journals(s), is not published already in part or whole (except in the form of abstract) in any journal or magazine for private or public circulation, and, is not under consideration of publication elsewhere.

  • I/We will not withdraw the manuscript after 1 week of submission as I have read the Author Guidelines and will adhere to the guidelines.
  • I/We Author(s ) have niether given nor will give this manuscript elsewhere for publishing after submitting in STM Journal(s).
  • I/ We have read the original version of the manuscript and am/ are responsible for the thought contents embodied in it. The work dealt in the manuscript is my/ our own, and my/ our individual contribution to this work is significant enough to qualify for authorship.
  •  I/We also agree to the authorship of the article in the following order:

Author’s name                                    

 

1. ________________

2. ________________

3. ________________

4. ________________

 

We  Author(s) tick this box and would request you to consider it as our signature as we agree to the terms of this Copyright Notice, which will apply to this submission if and when it is published by this journal.