Patent ID: 6367310
Filing Date: 2002-04-09
Classification: G01N

Abstract:
A field apparatus for the determination of the drainage properties of a porous asphalt road surface or slab using a falling head test method, said drainage properties including a permeability coefficient (k) and a flow exponent (m), said field apparatus comprising:(i) a water containing cylinder having a rubber lined flanged base; (ii) weighting means providing pressure for sealing the rubber lined flanged base of the cylinder to the road surface; (iii) releasable means providing a water retaining closure at the base of the cylinder to hold back water in the cylinder before a start of testing, and to release the water suddenly from the cylinder onto the road surface at the start of testing; and (iv) a pressure transducer located in a lower part of the cylinder for measurement of the falling head of water in the cylinder during the test.