Falling Weight Deflectometer (FWD)

The Falling Weight Deflectometer (FWD) is a non-destructive testing device used to evaluate the structural capacity of road pavements. FWD is an impulse-loading device in which a transient load is applied to the pavement and the deflected shape of the pavement surface is measured. The working principle of FWD is a mass of weights is dropped from pre-determined height on to a series of springs placed on top of a loading plate. The corresponding peak load and vertical surface deflections at different radial distances are measured.

FWD testing is quick and widely used for both asphalt and concrete roads. It plays an important role in road maintenance, helping to ensure safer and longer-lasting roads.

The data collected from FWD testing helps engineers understand how strong and durable a road is. It provides insights into subgrade strength, showing how well the ground beneath the pavement can support traffic. It also checks pavement layer quality and thickness, ensuring the road is built properly. Additionally, FWD helps identify drainage conditions, as poor drainage can weaken the pavement over time. Most importantly, it helps estimate the remaining life of the pavement, allowing for better planning of repairs and maintenance to keep roads safe and long-lasting.