PROJECT OVERVIEW The project is a high-volume 10-mile rehabilitation that is located on U.S.-89 in Kane County. This stretch of highway serves the town of Big Water, Utah, and is the access to the famous Lake Powell, the Glen Canyon Dam and the Colorado River Horseshoe Bend, which collectively recorded over five million visitors in 2023. The interval includes 177,000 square yards of 2-inch hot-in-place structural pavement recycle, 28,000 tons of 2-inch stone matrix asphalt (SMA) surface course, 43,000-lineal feet of void reducing asphalt membrane (VRAM), 19,500-lineal feet of new guardrail installed adjacent to improved shoulders and side slopes. Other key items include 159,000 lineal feet of rumble strips, 1,800 gallons of pavement marking paint, 72 thermoplastic messages/symbols and 14 new guide signs. WHAT MAKES THE PROJECT UNIQUE Project Challenges and Successes Hot-in-place recycle-volume metric is primarily driven by existing binder content. Shortly after the notice to proceed, mix design core sampling determined undesirable high oil content present in the asphalt mat. We were able to facilitate an atypical value engineering proposal wherein unconsidered roto mill costs were reduced by an oil and mobilization credit. The value engineering was formalized, and the roto mill scope was inserted into the schedule with minimal disruption to the project’s critical path. SMA provides the greatest volume metric challenges, wherein other mix types do not require fibers. Fiber segregation is difficult to control and, in turn, can quickly jeopardize gradation-sieve-targets and or percent binder content. Each of the 17 lots was paved at an average of 1,650 tons, and they met acceptance criteria without measurable rework. Project Innovations During the scoping phase, two separate innovations were slated for the project. First, hot-in-place recycling, also known as mobile asphalt recycle system (MARS), provides significant cost savings when compared to a typical hot mix asphalt overlay (new pavement). Elimination of the hot mix asphalt process in a rehabilitation not only saves the cost of aggregates and oil, it saves the cost of trucking the mix. Total MARS vs. HMA cost savings is 50-60%. Other benefits include significant work zone ingress and egress, which improves safety and increased roadway smoothness due to the elimination of starts and stops that occur when truck cycle times are disrupted by traffic, plant or various issues. Second, void reducing asphalt membrane is an additional innovative joint application that the department elected to test on this project. Joint band or j-band is the common name used in other states where, like it sounds, the membrane is sprayed onto the structural pavement where the joint of the surface course will be paved. The membrane is highly modified with polymer, and the heat and compaction that occurs during surface course placement help draw the membrane upward into the joint, thus reducing air voids and improving its impervious character. SAFETY RECORD ON THE PROJECT There was zero harm achieved with over 11,000 person-hours worked and zero motorist claims received from the traveling public. Site-specific training was conducted for all supervision and craft. Additionally, contractor orientation was conducted prior to the commencement of subcontractor tasks. Finally, a pilot car service was provided for the duration of key activities, where motorists were escorted into and out of the work zone. PROJECT QUALITY The project captured 53% of available compaction or density incentives. Pavement smoothness or ride quality achieved a 48 on the mean roughness index (MRI) which is Tier 2 of 6, with 6 being the least tolerated. As such, the project captured 31% of the available smoothness incentive. Lastly, the project reached substantial completion in a timely manner and therefore did capture the five-day maximum early completion incentive. 25
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