The new era of performance contracts means that contractors can not simply follow method specifications under close supervision by road controlling authorities, then get paid in full after a 48-hour defects liability period. Thus, a number of changes are occurring in the road contracting industry in New Zealand. This paper describes the background, rationale and development of new or improved equipment, technology and processes required by one modern contractor when engaged under performance contracts. One of the highest priorities for all road authorities is the safety of road users, by maintaining an adequate level of skid resistance. A major cause of reduced skid resistance is a flushed (or bitumen-rich) pavement surface, especially in the wheelpaths normally followed by traffic. In order to prevent or at least mitigate flushing, a New Zealand-based contractor, Fulton Hogan, has designed and fabricated an advanced bitumen sprayer, called Multispray, that can vary the application rate transversely and uses telescopic bars to vary the width of spraying. The background to and proven advantages of the Multispray, including improved productivity and ability to spray various application rates accurately, are discussed in some detail. (a)
Abstract