Falling Weight Deflectometer Tables
Falling Weight Deflectometer (FWD) tests are conducted on top of the pavement test section on a quarterly basis. FWD tests are performed for several purposes:
- to test the operational status of each sensor - Pavement is loaded on top of the sensor and sensor response is examined to determine that tested sensor is working.
- to study the efficiency of the joints - Pavement is loaded on both sides of a joint and deflection values are measured. Ratios of deflection values are computed and compared. These ratios are used to determine the efficiency of the tested joint.
- to study the deflection behavior of the pavement structure over the seasons
- to relate long term pavement performance to deflection values.
More about FWD
The Falling Weight Deflectometer (FWD) device is used regularly to test the pavement test section. The FWD use is divided into three categories:
- Pavement Perfomance: Pavement surface deflection is obtained at specific locations for every season. This provides comparative data that can be used to a) compare pavement response at different times of the year, b) compare pavement deflection against pavement performance determined by field surveys, and c) backcalculate pavement structure material properties.
FWD Principal Test
Transverse Reference Lanes
Longitudinal Reference Lanes
- Joint Transfer: Studies of joint transfer are a very important part of this project. Some joint gages have been installed at specific joints and are used for these studies. The FWD device complements the use of the joint gages at those specific locations by providing data for other all the other joints (with no sensors).
FWD Joint Load Transfer Test
Transverse Reference Lanes
Longitudinal Reference Lanes
- Gage Verification: The FWD is used to test the functioning the sensors on a periodic basis. The device is placed at locations on or near the top of each sensor and the pavement is loaded. Sensor response is obtained and checked for reasonableness.
FWD Gage Verification Tests