Of the common types of surfaces in modern cities, there is a 4 dB difference between the loudest and the softest : chip seal type and grooved roads being the loudest, and concrete surfaces without spacers being the quietest, and asphaltic surfaces being about average.
32.
"' Cooper Research Technology Limited " "'( also known as "'Cooper Technology " "') is a British manufacturer of high-performance testing equipment for asphaltic and unbound materials based in Ripley, Derbyshire, England.
33.
While at the University of Nottingham in the 1980s, founder Keith Cooper designed a method of measuring and assessing the mechanical properties of asphaltic materials with the equipment known as the Nottingham Asphalt Tester ( NAT ), later superseded by the UTM-NU ( Servo-Pneumatic Universal Testing Machine ).
34.
Initially, the remedy was oiling, whereby heavy asphaltic oil was sprayed atop a layer of gravel or other base material; a process was also referred to as inverted penetration . Oiling was soon supplanted by paving with bituminous mix ( asphalt ), a process still in wide use.
35.
Acquisitions in the late 1990s included " WKT " and " Golinski " of Germany in 1996, and " Asphaltic ", a major UK roofing supplier, " CP Supplies " and " Branton Industries and Distribution International " in the United States in 1997.
