Influence of Geogrid Properties on Rutting and Stress Distribution in Reinforced Flexible Pavements under Repetitive Wheel Loading

Baadiga, Ramu and B, Umashankar and Saride, Sireesh and Madhav, Madhira R. (2021) Influence of Geogrid Properties on Rutting and Stress Distribution in Reinforced Flexible Pavements under Repetitive Wheel Loading. Journal of Materials in Civil Engineering, 33 (12). pp. 1-14. ISSN 0899-1561

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Abstract

Geogrid reinforcement effectively controls the rutting of pavements under traffic loads, especially when constructed over soft subgrades. In this study, extensive large-scale model pavement experiments (LSMPEs) were performed to quantify the rut depths of flexible pavements. In all, 20 LSMPEs were performed on pavement sections overlying subgrades of different strengths with California bearing ratio (CBR) values varying from 1% to 5%. Three geogrid types were considered to study the effects of material type [polypropylene (PP) and polyester (PET)] and tensile strengths (30-60 kN/m) on the rutting behavior of flexible pavements. LSMPEs were first performed under monotonic loading to obtain the optimum depth of reinforcement within the base layer of flexible pavement. Thereafter, a series of repetitive load (haversine loading) was applied on paved sections of reinforced flexible pavements using a high-end, linear, double-acting actuator system. Rut deformations were measured at both the surface and the subgrade levels of the model pavements. The rut deformations were found to distinctly vary in accordance with the condition of the subgrade, the thickness of the pavement layers, and the type of geogrid used. The rut depth reduction (RDR) at the pavement surface was found to range from 22% to 69% for PP- and PET-geogrid reinforced base layers. Geogrid reinforcement significantly reduced the rut depths at the subgrade level (as high as 90%) compared to unreinforced sections. In addition, the model pavements were instrumented with the earth pressure cells to measure the vertical pressures transferred to the subgrade due to surface loading. The ability of geogrid reinforcement to distribute loads to wider areas was quantified in terms of the vertical stress distribution angle, αmax, at the end of the load cycles (N=100,000 cycles). The αmax maximum values for geogrid (GG1/GG2/GG3)-reinforced pavements built over weak subgrade (CBR=1%) varied from 28.4° to 32.2°, while it was 25.7° for unreinforced pavements. Likewise, αmax values for geogrid-reinforced pavements overlying a relatively fair subgrade (CBR=5%) varied from 34.5° to 43.6° against 30.4° for an unreinforced case. © 2021 American Society of Civil Engineers.

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IITH Creators:

IITH Creators	ORCiD
B, Umashankar	https://orcid.org/0000-0003-0813-7872
Saride, Sireesh	https://orcid.org/0000-0002-7380-0880

Item Type:

Article

Additional Information:

The authors thank the National Highway Authority of India (NHAI) for funding this research project under Grant No. NHAI/TIC/R&D/108/2016. The authors also thank Strata Geosys-tems (India) Pvt. Ltd and TechFab (India) Pvt. Ltd. for supplying the geogrids used in the testing. The authors are grateful to the anonymous reviewers for reviewing this research manuscript.

Uncontrolled Keywords:

Geogrid; Polyester (PET); Polypropylene (PP); Rut depth reductions; Rutting; Subgrade

Subjects:

Civil Engineering

Divisions:

Department of Civil Engineering

Depositing User:

. LibTrainee 2021

Date Deposited:

29 Aug 2022 12:00

Last Modified:

29 Aug 2022 12:00