Abstract

This study focused on improving light weight deflectometer (LWD) testing protocols and understanding material and equipment variability. The Indiana Department of Transportation (INDOT) adopted the LWD test for its efficiency and effectiveness in measuring soil stiffness, a crucial parameter for pavement structural layers. However, challenges remain for implementing LWD testing, particularly in small construction areas. There are also challenges with establishing standardized performance-related criteria for various subgrade treatments. To address these obstacles, this research aimed to develop maximum allowable deflections for compaction quality assurance without relying on site-specific test sections. A large-scale laboratory testing facility was established at the INDOT research center and equipped with advanced sensing systems and a sandbox for controlled testing environments. Finite element (FE) models simulate material behavior under LWD testing conditions by using the viscoelastic plastic model to predict realistic deflection basins for different materials. Initial findings suggest that Dynatest LWD equipment provides more reliable results compared to Zorn LWD equipment, based on FE simulations. This study underscored the need for standardized calculation protocols and aimed to refine LWD testing procedures, enhancing the durability and reliability of pavement structures across various construction scenarios.

Keywords

viscoelastic plastic model, light weight deflectometer (LWD), impulsive loading hysteresis effect, time-dependent behavior

Report Number

FHWA/IN/JTRP-2024/35

SPR Number

4623

Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, Indiana

Date of Version

2024

DOI

10.5703/1288284317813

Additional Files
SPR-4623 Technical Summary.pdf (353 kB)
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