The State Highway No. 85 Bypass Project was a project for the Colorado Department of Transportation in Greeley Colorado. The existing road was a 35 year old concrete road which was not designed for the amount of truck traffic utilizing the road today. The existing road had a dirt median which was to be filled in and covered with concrete paving to help with needed capacity for this truck route. The existing road also had asphalt shoulders and right turn lanes which were in need of replacement. A new cheese factory was being built on this section adding to amount of truck traffic in the near future. The construction team came up with ways to finish this project in one season when it was slated to take two seasons. This schedule helped save the state money in the traffic control and management cost.
The project had 133,659 SY of 12” dowelled concrete paving on 6” of class 6 road base and two feet of select R material. The project had unclassified excavation of 200,000 CY. The project also consisted of enhanced drainage features, underground utility work, curb and gutter, safety edge, bridge resurfacing and repair, and barrier wall. The enhanced drainage included over 10,000 feet on new storm sewer and 25 inlets. All scopes of work except the bridge work were completed by the experienced crews of Castle Rock Construction Company. Coordination of the different scopes was a task which was handled well by the project staff. The old concrete was crushed and used as class 6 road base and the crushed asphalt was used as shouldering material allowing all waste products to be used on the project.
Castle Rock Construction designed an optimized concrete mix for this project. The mix design was a flexural strength mix with four aggregates; #4 coarse aggregate, #7 coarse aggregate, #9 aggregate, and concrete sand. The purpose of this proportioning and mixing was to aid in the production of a more consistent concrete batch and a better platform for the concrete paver with the ultimate goal of producing a smoother ride on the concrete paving. The optimized mix is a positive factor in the production of smoother and more durable concrete pavements.
Castle Rock Construction is committed to quality control. A Gomaco PS 60 spreader was added to the paving train. A four bin feeder and pug mill were added to the concrete batch plant to mix the aggregates. Several quality control checks were added to the control processes. The end result was a very consistent concrete being produced and very good rides on this project. The design specifications were attained on this project for strength, depth and ride. The 28 day flexural strengths average was 685 PSI. CDOT and the Design Team were very happy with the concrete mix design and the ride numbers. The ride numbers are the best for a concrete road before corrective action in Colorado. U.S. 85 is a project that the City of Greeley, CDOT and CRCC are very proud of this project and the results.