Heavy Loadman is a full size falling weight deflectometer for measurement of bearing capacity and for compaction control of bound and unbound materials. Heavy Loadman is constructed inside a trailer or a vehicle and it is operated by using a laptop pc and the necessary electronics. The power is taken from a 12V battery and the lifting and lowering of the device is done with air cylinders powered by an electic or gasoline powered air compressor.
The measuring procedure is handled by one person. When measuring on roads the vehicle's odometer or an extra pulse detector is used to locate the measuring sites. A GPS unit is optional.
The measuring principle is the same as that of Loadman's. The deflection caused by the load of a free falling weight is measured by an accelerometer in the middle of the loading plate. The acceleration is double integrated and thus the deflection can be calculated. The measuring results are given as the maximum deflection, the calculated bearing capacity modulus E, the length of the loading impulse and the percentage (approx.) of the rebound deflection compared to the maximum deflection as well as the compaction ratio, that is the ratio of the second and further on deflections compared to the first measured deflection (effectiveness of compaction).
Technically the device can be used on practically all kinds of construction sites and materials to measure bearing capacity and for compaction control on bound and unbound constructions and layers, for example on roads and streets.
|Diameter of loading plate||300mm|
|Mass of the falling weight||50kg|
|Loading force||50kN approx.|
|Measuring range||0.1-5mm approx.|
|Duration of loading/unloading impulse||25-30ms approx.|