APE November 2022 | Page 30

ASPHALT ANSWERS
Now , I know what are thinking . He ’ s not talking to me . And you ’ re right . I ’ m talking to those other guys that don ’ t read these trade magazines or go into paving classes on a consistent basis . But just humor me for a while if you don ’ t mind . What we ’ ll discuss this month is a few of the things that happen when the mix hits the paver . Let ’ s start with what we need to do before the asphalt even hits the jobsite .
Screed Setup : Every paver manufacturer has a specific procedure for bringing the screed back to 0 , as I call it . That is to say making the screed ready to pave each day . That ’ s right , screed setup should be done every day before you pave . You wouldn ’ t start out on a trip with the tire pressure in your car varying 30-50 % between tires , so why start with your screed out of alignment ? The steps may vary between manufacturers , but the end result is the same . Consult your Dealer for this procedure . Now let ’ s discuss all the factors that affect the screed . The paver and screed operator must understand what happens to the mat every time he makes a change in speed , angle of attack and head of material . Let ’ s touch on each one of these so you can better understand .
Paving Speed : Many of today ’ s pavers are equipped with electronically controlled steering , which helps in governing your travel speed , but many still have the old reliable cable controlled steering . At a constant speed , the “ shear factor ” or the process that allows the asphalt to travel under the screed remains constant , thus your depth remains constant . When you increase your speed , your shear factor decreases and your screed begins to “ dive ”. www . callape . com [ 30 ] 1.800.210.5923