Agenda - Council - 02/11/2020 - Laserfiche WebLink

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details. I would encourage everyone that this study include street maintenace personnel (field people) in addtion to City engineers/Public Works Directors (office people). • As a rule of thumb, we will seal coat a street twice over a 15 to 20 year period prior to mill and overlay. Stripping more common after second seal coat. • We have one road we sealed when it was only a year old and the stripping has not occured on that road yet • • You know all our comments about the chip seal material on sticking to our truck engines and tranny's... • • The City has been very consistent over the last 10 years or more about seal coating and keeping up with the 5 year timing. To date we have not noticed any problems with the surface coat below the chip seal. • We use MC oil and no emulsifiers which helps prevent this from happening. • Our experience is limited to stripping on 61 wear course roads, we haven't seen other significant stripping issues on other roads. • We have attributed the problem more to the wear course being chip sealed then the chip seal itself • Maplewood, like other metro cities is dealing with this issue and there are a number of state aid roadways with this problem. • We are currently formulating an approach to fix these streets since it is very difficult to patch the great number of thin failures areas. • According to our Street Superintendent the issue could be a result of using trap rock which is left for only 2-3 days before being swept up. • Streets with pea rock left down for 2-3 weeks such as North Saint Paul and Lake Elmo don't seem to be having the failures. • We have not seen this problem in Faribault County. • Marshall County has not completed a chip seal. • So far this has only shown up in our first recycled asphalt wear courses installed from 1996 to 1998. We have heard that there was a problem with the Mn/DOT formula that hopefully has been corrected. A-8