How does your asphalt paver work?



Like many pieces of heavy machinery, road asphalt pavers may seem to most, incomprehensible and archaic at a glance, but they are extremely powerful and highly technical tools. Though requiring trained and skilled operators to man the paver, the process it uses to lay the asphalt is actually fairly simple once you take a closer look.


The task of the asphalt paver is to provide an even surface layer and homogenous precompaction with enough stability to enable the roller to follow and start the compaction process. The reliable performance of the paver is the most important factor when it comes to achieving these requirements. All modern asphalt pavers consist of two main units, a tractor and a floating screed. The tractor unit is driven either by wheels or crawler tracks. Wheeled pavers are easier to transport and to move around sites while the good traction of tracked pavers makes them suitable for use on unbound surfaces and when laying unbound base materials. Tracked pavers are also needed to lay extra-wide sections and on steep inclinations.


The screed levels and pre-compacts the asphalt mix to a specified thickness, grade, crossfall and crown profile. The self-levelling floating screed is attached by side arms at tow points located on either side of the tractor unit near its central point. Here the vertical movements caused by any surface unevenness are at a minimum.


The most intelligent part of the paver's design means that the desired thickness of the mix can be obtained by adjusting the toe points which increases or decreases the angle of attack of the screed until the forces on the screed are in equilibrium. Any movement of the two toe points upsets the equilibrium and results in a rise or fall of the screed. Once the screed has attained the new level, the angle of attack is restored and the forces revert to a state of equilibrium.


Screeds are heated mainly by electricity today but the older design of gas heated screeds is still available. Heat prevents the soleplate from picking up hot asphalt.


The main parameter affecting the screeds ability to precompact the asphalt is it's weight. The heavier the screed the better the precompaction. The VOGELE AB500 TP2 screed is the heaviest screed we offer from our extensive VOGELE fleet, and the results are outstanding. Compaction systems such as tampers, vibration units and pressure bars are used to assist precompaction but they also help the screed to float. The choice of tamping and/or vibrating screed depends on the applications as well as the mix types, layer thickness and local preferences and specifications.


AP Pavers has an extensive fleet of VOGELE pavers that are available for hire nationwide; so please feel free to call our technical department on 01889 560920 where we can fine tune all details to accommodate any requirements.