Screed
Screed turns up in 2 fields: concrete, asphalt. Here is what it means to the people in each one.
Screed in concrete
To strike off fresh concrete to the right height, or the straightedge, board or machine that does it.
Screeding is the first finishing step: a straight board, aluminum straightedge, vibrating truss or laser-guided machine is drawn across forms or screed rails in a sawing motion, cutting off high spots and filling lows. It sets the grade and flatness that later steps can only refine. Laser screeds strike off large slabs to tight tolerances in one pass, while hand screeding relies on wet screed strips or grade pins, and in Britain the word also names a cement-sand floor topping.
"Two guys on the screed, one on the come-along, and keep a little extra mud in front of that board."
Screed in asphalt
The heated, floating plate assembly at the back of a paver that levels and pre-compacts the mat.
The heated plate and frame towed behind the paver on long side arms, which floats on the mix and sets mat thickness, slope and texture. It finds its own height as the forces from forward speed, the head of mix in front of it and its angle of attack come into balance, which is why paving speed and feed must stay steady. Tamper bars or vibrators in the screed give the mat roughly 75 to 85 percent of maximum density before the rollers arrive.
"Screed's cold, it's tearing the mat, give the heaters another fifteen minutes before we pull off."