Pavement Preservation Project 2017

Program Overview

The goal of the annual Pavement Preservation Program is for the City of Moscow to maximize the impact that the annual pavement management repair budget will have on the quality and durability of the City streets. Roads experience wear from many different sources. Northern climes, such as Moscow's, can be particularly harsh on pavement. The continual freeze/thaw cycle, the impact of snow removal operations, and the wear from studded snow tires all contribute to pavement degradation.

Asphalt Lifespan

All asphalt streets have a limited lifespan, from the first time a car drives on a new road it begins to wear from the top down. If left untreated the only option that is left to the City is to wait until the condition deteriorates to the point of failure, and perform a complete road replacement. A complete replacement requires the existing asphalt and road base to be removed and completely new material is brought in. This replacement option produces a very high quality new road but the cost is also very high.

The City's Pavement Preservation Program seeks to maximize the lifespan of the roadways within the City while minimizing the whole life cost of the road. This is done by conducting routine surface treatments that can be used to maximize the lifespan of a road at a far lower cost than a rebuild. We have a variety of treatments that are used based on the condition, location, age, and use of a road to help stretch the life of our pavement and maximize the returns on Moscow's investment in its transportation network. One of the surface treatments selected for the 2107 Pavement Preservation Project was a slurry seal.

Slurry Seal Map

2017 Slurry Seal Vicinity Map

Slurry Seal

A slurry seal is a thin layer of fine rock that is mixed with asphalt and applied to the surface of the road. It is a very inexpensive treatment option and it can have dramatic effects on the longevity of a road. Slurry seal is typically performed on a 10 to 15 year old road that is beginning to show some surface wear. The thin layer of rock will help to fill in the areas of surface wear and the asphalt will seal the surface of the road. Sealing the surface helps to prevent water from damaging the asphalt and road base which will maximize the lifespan of the road.

Initial Surface Wear

Timeline

The contract for the 2017 Pavement Preservation Program was awarded to Intermountain Slurry Seal, Inc. from Salt Lake City, Utah. The available construction window is from the beginning of July to mid August.

Construction Update - September 11, 2017

The Slurry Seal Project has completed. This layer will seal the surface and provide a wearing course that will protect and extend the lifespan of the road.

Slurry Seal After Photo

Terminology

  • Asset Management - A plan to ensure that each section of roadway can be maintained for the lowest possible whole life cost which calculates the cost of a road from the time it is built until it finally needs to be replaced.
  • Slurry Seal - A thin layer of asphalt and aggregate, the aggregate size ranges from one-eight to three-eight inches depending on the type of slurry, which is blended by a piece of equipment and then applied in a uniform layer to the road surface.
  • Whole Life Cost - The amount of money that is spent on a road from the time it is brand new until it is finally rebuilt. The goal of the City of Moscow Pavement Preservation Program is to minimize the Whole Life Cost of a road while maximizing its lifespan.