The Regional Municipality of Ottawa-Carleton (RMOC) and the City of Ottawa have adopted SUPERPAVEë binder specifications (Performance Grade 58-34) to address the problem of low-temperature cracking of pavements. Historically, 80/100 penetration grade asphalt has been used in the area. 80/100 binder typically has a Performance Grade (PG) of 58-22. The low pavement temperature in Ottawa-Carleton generally drops below -22ÑC, resulting in a high frequency of transverse cracking. Based on actual pavement temperature data, PG 58-34 was selected to address the problem. If the PG binders reduce low temperature cracking as expected, the benefits will be decreased on-going maintenance costs. In addition, increased road life-cycles will further offset the premium paid for PG binder. RMOC and the City of Ottawa have also adopted End Result Specifications (ERS) for the construction of hot mix asphalt pavements. This specification provides for contract price adjustments if the hot mix asphalt does not meet, meets, or exceeds specifications. The contractor faces a price reduction for substandard work, but can earn a bonus for excellent work. To date, ERS has resulted in improved quality pavements, with net bonus payments to contractors on the order of 0.3 to 0.6%. Improved product are anticipated to result in improved road life-cycles and cost effectiveness. (A)
Abstract