Best Practice

BEST PRACTICE:

G1−5: Rubblization

DESCRIPTION:

Rubblization is a technique in which existing Portland cement concrete pavement (PCCP) is broken into coarse granular material and rolled in place to provide a sub−base, generally for an asphalt overlay. Rubblization techniques eliminate the need to perform a pre−overlay repair of concrete pavement that has extensive cracking and/or materials−related deterioration.

Many States, including Illinois, Iowa, Maine, and Michigan, have successfully used rubblization to improve their repair operations of PCCP roadways that have significant cracking or damage, thus mitigating the risk of reflective cracking on asphalt overlays on their roadways. In Maine, rubblization has been recognized as a "green" alternative for roadway repairs. The use of rubblization on I−295 allowed the Maine DOT to address the alkali−silica reaction that was taking place in the existing concrete pavement without removing the material. Since the rubblized materials were used in place and along adjacent shoulders, the process reduced waste material and was considered a "green" practice.

REASON(S) FOR ADOPTING:

As deterioration of PCCP occurs, rubblization provides agencies a cost−effective, environmentally−friendly method to rehabilitate a pavement without wasting the pavement asset.. Agencies that have used rubblization have found that construction time and cost savings could be realized while providing a high quality base product and lessening the time and expense of transporting waste materials from the construction site.

PRIMARY BENEFIT(S):

Environmentally−friendly: Use of the rubblized concrete decreases the amount of construction materials going to landfills.
Higher quality product at lower costs: The rubblized material acts as an interlocked unbound layer comparable to a high−quality aggregate base, and has costs that are estimated at one−third compared to removal and replacement of the PCCP with a different base material.
Construction time savings: Rubbliz¬ing and overlaying takes about one−third as much time as removing old concrete and reconstructing pavement.
Addresses recurring pavement flaws: Rubblizing the underlying concrete layer before overlaying with asphalt provides a sound base level that minimizes reflective cracking.

MOST APPLICABLE LOCATION(S)/PROJECT(S):

The use of rubblization techniques are most suited to locations where existing PCCP pavement has extensive reflective cracking or deterioration and an overlay will be used to provide structure and smoothness. Rubblization is particularly useful where environmental concerns would stem from hauling existing materials from the construction site and introducing new materials to the location. Rubblization may not be suitable in locations where there is a high water table or weak subgrade. Some States provide drainage a year prior to rubblization in order to help dry out the base and subgrade.

RELATED BEST PRACTICE(S):

Nighttime Lighting Specification (Practice G5-4)

STATE(S) WHERE USED:

Illinois, Iowa, Maine, Michigan

SOURCE/CONTACT(S):

LaDonna Rowden, Illinois DOT
Phone: (217) 782−8582
E−mail: LaDonna.Rowden@illinois.gov