Topcon Paver System 5 - How a Screed Operates

Paving Principles & Control Methods
Topcon Paver System Five Operator’s Manual
2-2
How a Screed Works
The screed on all modern pavers is of the “floating, self leveling”
type. As the paver tows the screed unit forward, paving material
flows under the screed. This causes the screed to float on the mat of
material, thus establishing mat thickness. Since the screed is
mounted to the paver only at the tow points, the screed is
completely free to float up or down (Figure 2-2). The screed will
always seek it's own “Planing Angle”, or angle of attack, dependent
on the combination of forces acting upon the screed (Figure 2-2).
Figure 2-2. Tow Point Path and Planning Angle
• If the screed angle of attack is increased the screed rises,
increasing the mat thickness (Figure 2-3).
• If the angle of attack is decreased, the screed will settle,
providing a thinner mat surface (Figure 2-3).
Figure 2-3. Screed Determines Mat Thickness
T ow P oin t P a t h
E x i s t ing
S u r f ace
S c r ee d A ngl e o f A tt ack