Iowa County Hosts Asphalt Interlayer Open House
Thirty-two engineers and highway professionals gathered on August 10 to view the installation of a flexible asphalt interlay on Iowa County Route V38 from I-80 interchange 205 north to Victor. The existing 6” PCC pavement was not only very rough but was requiring annual patching that had become a financial burden to the county. Portions of the road also needed to be widened.
County Engineer Nick Amelon choose asphalt as the rehabilitation tool because of its speed of construction. “I simply could not close the road for the lengthy time required of other rehabilitation products”. He chose the asphalt interlayer because of its ability to retard reflective cracks with less grade raise. He added “The finished roadway should be very smooth”.
The original plan called for full depth asphalt patching followed by a 1” asphalt interlayer, 2½“ intermediate course and a 1½” surface course. The route passed under the Interstate and that area called for a 2½” milling of the concrete followed by the 1” interlayer and a 1½” surface course in order to maintain a minimum clearance between the finished pavement and overhead structure.
As construction began it was determined that the existing roadway was so rough that it would not be cost effective to use the asphalt interlayer as both a crack retarder and leveling course, It was decided to change the design to a 1” leveling course, then the 1” asphalt interlayer followed by a 2” intermediate and 1½” surface courses.
The changes enhanced the Open House Demonstration as we were now able show not only the use of the interlayer as a reflective crack retarder when placed directly over a PC pavement but also when used between asphalt layers along with over longitudinal widening joints.
Those in attendance asked many questions and it was evident of the great interest in and future plans for the use of the interlayer.
Iowa county staff praised the work of the L.L. Pelling Company and how easy they were to work with as the project scope changed.
Brett Finnegan, Vice President of the L.L. Pelling Company stated, “The asphalt interlayer is an exciting new tool in the PCC rehabilitation tool box. This product provides longer performance for the HMA overlay through retarding the reflective cracking while also adding strength and smoothness to the roadway. This is a win-win for local agencies.”
A special thanks to Brett Finnegan, Nick Amelon and their staffs for hosting this Open House.