Agenda - Council - 02/10/2009 - Laserfiche WebLink

Home

The 2009 program cOlisists of overlay projects on approximately 1.85 miles of City streets. Streets proposed for overlay will receive a one and one half inch layer of bituminous wear course. Again, the Public Works department will repair failed areas prior to the overlay. This year the proposed overlay proj.ect will be limited to: . The Hunters Hill subdivision located east of CR 57 and south of Sunwood Drive; and . Barthels Rum River Acres 2nd Addition which is located north of the Boys Scout Camp Assessment Policies: This year is the second year of a seven year program to phase out the previous policy of assessing property owners 50% of the sealcoating project cost. The 2009 sea1coating project will assess 36% of the total cost. This will decrease by 7% per year until the entire assessment on sealcoating will be eliminated in 2014. The assessment policies for sealcoating / crackfilling and bituminous overlays has evolved into the list of assessment procedures attached to this case. This policy has been modified and expanded over the years as needed. The Committee may wish to review these policies. Technical Program Changes: Pea gravel has been historically used as the sea1coat cover aggregate on the City's programs. It is the lowest cost cover aggregate available. Because it not as likely to lie on its most stable side, it tends to be more susceptible to plow damage and being rolled by turning tires which can lead to tracking complaints. Beginning last year in 2008 crushed aggregate was specified for cover aggregate. While slightly more expensive this aggregate becomes embedded on its flattest side and is less prone to stripping and tracking. Staff did learn that from the 2008 program experience that where heavy truck traffic or a high volume of turning movements were encountered flushing of the bitumino~s (bituminous covered the entire aggregate particle making the pavement black in appearance) occurred. Although this is an aesthetic issue which has since mitigated itself by fading of the exposed bituminous, staff has learneq. after consulting with the MnDot lab to modify its specification by using a slightly larger sized aggregate along with a slightly heavier application of bituminous. A revised specification will be used on the high volume MSA roads that are to be seal coated this year. A second modification that proved successful in the 2008 program which will again be repeated this year is the use of a polymer modified asphalt emulsion on cuI de sacs and MSA streets. The polymer creates a strong electrical bond between the oil and the aggregate which greatly increases the adherence of the chip to the street surface. The cost of polymer modified asphalt is about 25% higher than regular CRS 2 oil so its use will be limited to higher speed MSA Streets -176-