HWD-NJ-M is a non-destructive testing instrument for pavement and airport upgraded from original FWD, besides pavements bearing capacity, it also can be used for non-destructive testing of stiff bound material as found on Airport Runways and truck car parks. A four-part split loading plate is placed on the surface of pavement and a load pulse is applied to the plate. The load pulse is generated by the impact of a falling weight. The load pulse is designed to cause a deflection that closely simulates the deflection of actual aircraft wheel loading up to 250KN.
Utilising 9 pcs deflection sensors to measure deflection basin and collect the information to determine surface material strength. By combining this data with Layer thickness, resilient E-moduli can be determined, and further analysis can determine bearing capacity, structural strength, overlay design and expected surface life, then achieve proper maintenance.