Better Roads Digital Magazine
Issue link: http://read.dmtmag.com/i/291564
Better Roads April 2014 9 the model may be validated and how it might work. So part of it will be training designers, consultants, engineers and road agencies how the model works and could be applied to their part of the country." For IL 59, Seal/No Seal cooperated with the Illinois Chapter of the ACPA on the test project for the Illinois DOT. Walsh Construction was the prime contractor and Quality Saw & Seal was the subcontractor for control joint sawing. "We did 10 test sections – various types of sealed and unsealed joints – and TTI came out in September 2013 and conducted the first round of testing on those sections," Eilken says. "They will come out a second time in 2014, and to make sure the model is validated properly, it will have to be visited periodically to measure the damage, or no damage, to the base material." The work may be extended to other regions. That field work complements work undertaken at TTI's sprawling test facility at Bryan, Texas. There, the entire Phase I study centered on test sections. "We went in there and provided different joints, sawed and sealed," Eilken says. "Dan also put in extendable anchoring systems in those test sec- tions, in which he could pull joints apart and put them back together, measuring different types of infiltration. He mea- sured against hot pours, neoprene, silicone and against sealed versus unsealed. The entire Phase I work just to see if continu- ing was an option was done at the TTI facility, and it paved the way for Phase II." Also, new research at the National Concrete Pavement Tech- nology Center at Iowa State University at Ames is finding that keeping moisture and water out of concrete pavement is the most critical piece of the puzzle, Eilken tells Better Roads. "But it doesn't address whether the water is coming from the top-down, or in bases from the bottom-up," he says. "It doesn't matter; we are finding that much of the concrete joint deterioration is coming from the constant infiltration of water. Now the task becomes determining whether the cost of joint sealing offsets the value we are getting out of it at the other end." Bringing answers to play In the meantime, the Seal/No Seal Group is getting a lot of in- put from industry and the DOTs, Eilken says. "While there is a handful of people who are trying to make sure we are headed down the same road," he adds, "we've been able to take a lot of parameters from the ACPA, the various state chapters and the state DOTs, so we think we've got a pretty good direction and will be able to finally bring some answers into play that can be applied to local regions." Time – and effective technology transfer – should clear these issues up for today's highway-owning agencies and road contractors. "Perhaps new research will once again change the expecta- tions that pavement engineers place on joint sealing materi- als for new concrete pavements," says the American Concrete Pavement Association (ACPA). "In the meantime, it appears that the current practice of sealing transverse joints with either hot-pour, silicone or compression seals will remain un- changed by most state agencies across the country." For more information and additional resources, visit sealnoseal.org, acpa.org, cptechcenter.org, concrete.org or roadwaystandards.dot. wi.gov/standards/cmm/cm-04-21.pdf. Following a grooving operation, a Tennessee transverse joint awaits sealing. A successful sawed control joint, PCC pavement cracks along the joint sawed in green or curing concrete pavement. Photo courtesy of FP2 Inc Photo courtesy of FP2 Inc