Recycling payment methods and different streategies among states in the USA.

CEG 4126 & TTE 5835 Course Project

INVESTIGATION OF ASPHALT RECYCLING STRATEGIES FOR FLORIDA’S ROADWAYS

Introduction

Population growth and economic development in the second half of the twentieth century led to the construction of an extensive network of asphalt paved roadways in the United States. Thousands of miles were constructed to meet the demands of traffic and the environment for design periods of 20 to 40 years. However, time and traffic have taken their toll on these pavements, many of which have exceeded their original design life.

The concept of pavement preservation is to place a higher emphasis on keeping good roads in good condition while spending minimum resources on roads in poor condition and of lesser importance. Since funding for preventive maintenance, preservation, rehabilitation, and reconstruction of roadways has to compete with other demands on public funding, innovation is required to do more with less. Asphalt recycling is one way of increasing the effectiveness of existing budgets in order to maintain, preserve, rehabilitate, and reconstruct more miles of roadway for each dollar spent. (ARRA 2015)

Five broad categories have been defined by Asphalt Recycling and Reclaiming Association (ARRA) are:

· Hot Recycling (HR)

· Cold Planing or Milling(CP)

· Hot In-place Recycling(HIR)

· Cold Recycling (CR) that includes Cold-In Place Recycling(CIR) and Cold Central Plant Recycling(CCPR)

· Full Depth Reclamation(FDR)

The Federal Highway Administration (FHWA) supports and promotes the use of recycled highway materials (RAP) in pavement construction to preserve the natural environment, reduce waste, and provide a cost-effective material for constructing highways. The primary objective is to encourage the use of recycled materials in the construction of highways to the maximum economical and practical extent possible with equal or improved performance.

Background

In Florida, Mill & Fill is a commonly used structural pavement treatment that involves the removal of the existing surface layer with a milling machine (CP) and the replacement of the milled location with new asphalt. Reconstruction is another conventional method that involves the complete replacement of the road with new asphalt which can have a useful life upwards of 20 years. On the other hand, the benefits of using recycled asphalt materials (RAP) in asphalt pavements include economics, conservation of natural resources (aggregate, binder, and fuel), reduction in energy consumption, and a decrease in emissions (including greenhouse gases). Thus, there is a need to investigate the efficiency of asphalt recycling solutions with reclaimed asphalt pavement in Florida.

The purpose of this project is to inform legislators and department officials on pavement recycling strategies that can be used for pavement maintenance and rehabilitation.

Scenario 1

Roadway Information: Two-way two-lane arterial roadway, Design ESALS: 2,000,000, Subgrade Modulus (Mr): 9000 psi.

Problem: The roadways is facing a top-down fatigue cracking distresses. Top two inches of the pavement structure needs repair.

Conventional solution is milling the two inches from the existing surface layer and replacing it with a new hot-mix asphalt. One of the recycling (Green) solutions for this problem is Hot-In-Place Recycling (HIR).

Scenario 2

Roadway Information: Two-way six-lane interstate roadway, Design ESALS: 9,500,000, Subgrade Modulus (Mr): 7000 psi.

Problem: The asphalt surface has numerous types of the stresses. Top six inches of the pavement structure needs to be treated.

The conventional solution is milling the top six inches from the existing surface and replacing it with new asphalt. The green solution is implementing Cold-In Place Recycling and using a thin HMA layer on the top of the surface.

Scenario 3

Roadway Information: Two-way four-lane arterial roadway, Design ESALS: 6,000,000. Subgrade Modulus (Mr): 12000 psi

Problem: The roadway is no longer able to serve due to the high-level of deterioration.

The conventional solution to this problem is reconstructing the pavement structure. Full-Depth Reclamation (FDR) is the recycling solution to be considered.

Instructions

1. Conduct a literature review to see how asphalt recycling methods implemented as maintenance and rehabilitation strategies by other states. Report this Literature Review.(20 points)

2. Determine the Florida pavement structures for each scenario and solution regarding the roadway information.(25 points)

3. Evaluate the efficiency of recycling solutions and conventional methods. Conduct a Life Cycle Cost Analysis(LCCA) for the roadways.(40 points)

4. Prepare a presentation to present your findings and recommendations to the State Legislators. (15 Points)