Explain the Hydraulically extendible
Most paver manufacturers have developed hydraulically extendable paver screeds hat trail the primary or basic screed on the paver. One make of pavers, however, is equipped with a power extendable screed that places the extendable portion of the screed n front of the main screed. For all hydraulically extendable screeds, it is very important hat the angle of attack for the extendable screeds is the same as the basic screed. If the extensions on the extendable portion of the screed arenot properly aligned with the main screed, a longitudinal mark or ridge will occur in the surface of the mix at the junction between the two screeds. In addition to the longitudinal mark, a mismatch in the elevation between the two screeds can also result in a possible difference in surface texture in the mix. Finally, the lack of proper alignment between the two screeds can cause a difference
in the degree of compaction that is obtained in the mix under the extendable screed. In addition, proper placement of the material feed sensor is important to avoid segregation problems.