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THE STRONGER WAY TO BUILD A ROAD

Granular base improvement

Stabilization is defined as the uniform blending, shaping and compaction of carefully selected gravel materials with 1% by weight calcium chloride so as to achieve maximum granular base improvement.

GRANULAR BASE EQUIVALENCY

The degree of granular base improvement or stabilization can be measured by the granular base equivalency (GBE) factor comparing the strength of stabilized aggregates to standard unstabilized materials.

The granular base equivalency factor for calcium chloride base stabilization treatments should prove to be 1.30 for carefully selected materials according to engineering reports. In other terms, 100 mm of calcium chloride stabilized granular base equates to 130 mm of untreated granular base. That means a 30% increase in strength!

CALCIUM CHLORIDE GIVES OPTIMUM RESULTS

A road is only as strong and durable as its base… and the stability of the road base depends on the proper interlocking of the aggregate. Calcium chloride

  • penetrates the road aggregate, coating the particles and binding them together
  • binding action keeps the road dense and compacted
  • speeds compaction of the base materials
  • maintains moisture in road base to minimize the loss of fines, and maximize the service level of the wearing course
  • reduces gravel costs during construction and maintenance
  • cost-effective alternate in recycled asphalt bases

Base stabilization is an excellent way to preserve the road when funds are not available to asphalt the surface.

ROADS THAT LAST

RECOMMENDED PROCEDURE

  1. Scarify existing granular surface.
  2. Select and add aggregate if required.
  3. Add calcium chloride at .75% of gravel weight.
  4. Mix all materials adequately.
  5. Shape cross-section to provide 4% slope from crown of road.
  6. Compact surface uniformly to required density.
  7. Seal surface with 0.25% calcium chloride by weight of aggregate.

REQUIREMENTS

In general, the following criteria should exist for proper stabilization and maximum granular base improvement:

  • calcium chloride content in road materials to be 1% by weight:
  • selection of well-graded crushed aggregates, at least 80% fractured faces, 16 mm (5/8 inch) maximum stone size and 10% by weight passing #200 U.S. sieve, or equivalent:
  • sub-base materials should be proven adequate to support loaded vehicles and the required efforts of a compactor:
  • strict process control and site supervision by qualified personnel.

Application rate – 12 tons/km (20 tons/mile) for 6.5 m (21.3 ft.) width.