Details:

Creators:
Elseifi, Mostafa ; Abdel-Khalek , Ahmed M. ; Dasari, Karthik
Elseifi, Mostafa ; Abdel-Khalek , Ahmed M. ; Dasari, Karthik Less -
Corporate Creators:
Louisiana State University (Baton Rouge, La.). Dept. of Civil and Environmental Engineering
Corporate Contributors:
Louisiana Transportation Research Center ; Louisiana. Dept. of Transportation and Development ; United States. Federal Highway Administration
Louisiana Transportation Research Center ; Louisiana. Dept. of Transportation and Development ; United States. Federal Highway Administration Less -
Subject/TRT Terms:
[+]
Continuous Deflection Testing Pavement Management Rolling Wheel Deflectometer Deflection Tests Falling Weight Deflectometers Pavement Maintenance Pavement Management Systems Pavements
Publication/ Report Number:
FHWA/11.492
Resource Type:
Tech Report
Geographical Coverage:
Louisiana
Edition:
Final report; 2009-2011.
Corporate Publisher:
Louisiana Transportation Research Center
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATIONNTL-HIGHWAY/ROAD TRANSPORTATION-MaterialsNTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and Performance
Abstract:
The rolling wheel deflectometer (RWD) offers the benefit to measure pavement deflection without causing any traffic interruption or compromising safety

along tested road segments. This study describes a detailed field evaluation of the RWD system in Louisiana in which 16 different test sites representing a

wide array of pavement conditions were tested. Measurements were used to assess the repeatability of RWD measurements, the effect of truck speeds, and

to study the relationship between RWD and falling weight deflectometer (FWD) deflection measurements and pavement conditions. Based on the results

of the experimental program, it was determined that the repeatability of RWD measurements was acceptable with an average coefficient of variation at all

test speeds of 15 percent. In addition, the influence of the testing speed on the measured deflections was minimal. The scattering and uniformity of the

FWD and RWD data appears to closely follow the conditions of the roadway. Both test methods appear to properly reflect pavement conditions and

structural integrity of the road network by measuring a greater average deflection and scattering for sites in poor conditions. RWD deflection

measurements were in general agreement with FWD deflections measurements; however, the mean center deflections from RWD and FWD were

statistically different for 15 of the 16 sites.

This study developed and validated a direct and simple model for determining the pavement structural number (SN) using RWD deflection data.

To develop this model, the relationship between the average RWD surface deflection and the peak FWD deflection was investigated. The developed model

correlates a pavement’s SN to two RWD-measured properties (average RWD deflection and RWD index). The developed model was fitted to RWD data

collected in 16 road sections (each 1.5 miles), referred to as research sites, in Louisiana. The model was then validated based on FWD and RWD data

collected on 52 road sections in Louisiana. Results showed a good agreement between SN calculations obtained from FWD and RWD deflection testing.

While the developed model is independent of the pavement thickness and layer properties, it provides promising results as an indicator of structural

integrity of the pavement structure at the network level. The fitting statistics support the use of the proposed model as a screening tool for identifying

structurally deficient pavements at the network level.

Based on the RWD evaluation conducted in District 05, this study recommends extending the use of RWD to the other districts in Louisiana.

The RWD index (RI) is recommended to be adopted on a provisional basis by the Louisiana Department of Transportation and Development (LADOTD)

Pavement Management System (PMS) as a network structural analysis index with three categories: thin pavements less than 3 in. thick, medium pavements

between 3 to 6 in., and thick pavements greater than 6 in. It should be incorporated into the PMS system and placed on Geographic Information System

(GIS) maps.

The structural number equation should be considered valid and used as a tool to evaluate the structural condition of pavements for network

purposes with similar categories as the RI. The PMS section will incorporate the SN values in their process using trigger values outlined in the report. If

the PMS section considers the new index to be of significant value, then another district will be assessed with the RWD.


Format:
PDF
Funding:
LTRC project number: 09-2P ; SIO number: 30000143
LTRC project number: 09-2P ; SIO number: 30000143 Less -
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:b0c513b87c1b53f9f3c140e4a0cc0455fdc243ddc5ca8dea2a0b81c6798b0ec2
Download URL:
https://rosap.ntl.bts.gov/view/dot/24897/dot_24897_DS1.pdf
File Type:

Supporting Files

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