paving the way | i8 In the same process, PMB maintains lower stiffness and enhances relaxation properties at low service temperatures, thus reducing thermal cracking. Finally, PMB increases adhesion between the asphalt binder and the aggregate, thus reducing damage and moisture susceptibility of the mix. The pavement design team analyzed the road area’s climate, geography and future traffic. As a result of the analysis, they settled on a PG 76-10 PMB. The bitumen can perform through a pavement temperature range of 76 °C to -10 °C, covering the wide spectrum of temperatures that can be encountered on the project site. In order to guarantee the proper application of the bitumen, the pavement section at the head office offered technical support to local supervision staff, building on the unit’s extensive experience in the field of PMB technology. The coordination was necessary for quality control and in order to ensure that the special PG asphalt, in use for the first time in Oman, was being laid out properly and consistently. The production process was challenging, including mixing with high shear mixers, and ensuring consistent quality and compatibility of the mixture components during storage, and upon laying and execution. The site team set up on-site laboratories as part of the project requirements. These labs conducted Superpave PG tests, studying the rheological properties of the modified bitumen to ensure proper pavement performance measures against rutting, fatigue cracking and thermal cracking. overheating leading to early aging problems and high brittleness. Therefore, the temperature of the mix needed to be controlled and maintained at a restricted range between 160 °C and 170 °C, in order to allow proper laying and compaction. For this reason, the contractor had to provide an extensive crew and an effective suite of spreaders and rollers working in close harmony to make sure that laying and compaction were executed before the cooling of asphalt mixes. Another challenge was to pave the whole width of the roadway (around 20 m) without the formation of cold longitudinal joints. The challenge was resolved by spreading the asphalt using several spreaders in echelon, as illustrated in the photographs, followed by rollers (both tire and smooth) to ensure proper bonding of the joint without leaving any seams. A road for tomorrow The final perfect state of Bidbid-Sur’s roads would not have been possible without a thorough, unrelenting involvement of Dar’s teams and the collaboration with other consultants. The specifications and requirements needed full control, and our people supervised the selection of experienced builders and suppliers, and the material acquisition and testing, among other things. Furthermore, there was the complex matter of continuous follow-up with all decision makers. The cooperation between the different parties led to the implementation of the first site trials, which in turn prepared for the actual paving. In addition to all this, Dar’s site team maintained rigorous quality assurance and quality control standards over the entire process of production and execution. The result of our hard efforts was an impressive production that will contribute to the country’s welfare and growth. Challenges Mix temperature was a deal breaker. PG asphalt will not perform properly if applied at lower temperatures. At the same time, excessively high temperatures would expose the bitumen to 21