Our Falling Weight Deflectometer (FWD)

Quality Engineering Solutions (QES) owns and operates a Dynatest 8000 Falling Weight Deflectometer Test System (FWD). We have qualified equipment operators and engineering staff who have successfully completed numerous projects involving non-destructive testing. We also possess state-of-the-art computing facilities, software, and well trained and experienced engineers for processing and analysis of the FWD Data.

The FWD is a non-destructive testing device, which is designed for multi-purpose pavement applications, ranging from unpaved roads to airfields. FWD generated data, combined with layer thickness, which is determined by our core drilling & sampling equipment, can be confidently used to obtain the "in-situ" resilient elastic moduli of the structural layers within a pavement. This information can, in turn, be used in a structural analysis to determine the bearing capacity, estimated life expectancy, and to design a rehabilitation plan. Additionally, the FWD can be used to test load transfer efficiency of joints within concrete pavements.

The FWD owned by QES is a one-man operational system that is accurate and fast with a measuring capacity of up to 60 test points per hour. It has a wide loading range (8-104 kN) or (1,600-23,500 lbf) and shows excellent repeatability. During FWD testing, both pavement and air temperature are recorded so that the proper adjustments can be included in the data analysis procedures. Field testing is generally performed in accordance with the standard ASTM procedures as described in ASTM D 4695-03, Standard Guide for General Pavement Deflection Measurements, and the calibration of our equipment is verified annually at the Long Term Pavement Performance Calibration Center in Harrisburg, PA.

Deflection testing using our Falling Weight Deflectometer and coring & sampling can occur concurrently, requiring only temporary traffic disruption of a single lane during operations.

Our Core Drilling & Sampling Equipment

Quality Engineering Solutions (QES) owns and operates coring equipment capable of extracting two, four, or six inch pavement cores. We also have the capabilities of auguring unbound pavement sublayer materials with either four or six inch augers.

The construction information often does not sufficiently provide the precise pavement structure that is required in order to accurately analyze Falling Weight Deflectometer (FWD) data. In order to accurately determine the layer types and thickness, destructive tests often need to be performed. This means removing a pavement core from the bound materials, then auguring through any base and subbase material down into the subgrade. QES engineers and technicians have utilized this sampling technique on numerous occasions and find it to be a relatively quick and easy method for allowing both layer type and layer thickness determination.

An additional benefit of pavement coring is the determination of cracking propagation. For purposes of developing the most effective rehabilitation strategies, it is important to understand whether the visible cracking is initiated from the top down or from the bottom up. Taking cores over cracked sections of pavements provides great insight into the pavement distress mechanism. This enables an accurate measurement of layer thickness and provides samples for soil classification and laboratory testing.

Coring & sampling and deflection testing using our FWD can occur concurrently, requiring only temporary traffic disruption of a single lane during operations.