Chapter 1: Introduction

4.0 Framework for Treatment Selection

At the network level, there is a general relationship between pavement condition and pavement age (see Figure 7). Figure 7 shows the maintenance actions employed based on the existing pavement’s condition index, and shows that the action selected to maintain the integrity of a pavement depends on the condition of the pavement at the time of the assessment, i.e., the location of the pavement on the curve. Factors in selecting the appropriate maintenance strategy during the pavement’s service life include: pavement age, pavement condition, traffic levels, expected future plans, available funding, and agency policy.

For a properly constructed new pavement, only preventive maintenance actions are required – that is, maintenance that delays the onset of distress. As the pavement ages, it becomes a candidate first for structural overlay, then rehabilitation, and eventually reconstruction. The assumption for this discussion is that the pavement’s condition falls within the preventive maintenance area of the upper part of the curve. This section provides guidance on selecting the most cost-effective maintenance strategy from a number of options. Those potential maintenance strategies encompass one or more surface treatment types that meet the selection criteria established by the agency; e.g., traffic, number of trucks, distress type, distress severity, structural or material damage.

The first step in selecting the appropriate maintenance strategy is to place the pavement in a maintenance category based on its life-cycle age and pavement condition index. Figure 7 illustrates the treatment categories based on the condition index. (Note: This manual addresses the decision process for maintaining pavements in the “Preventive Maintenance” category in this figure. It does not address selection of maintenance strategies for the other categories shown.)

A number of potential maintenance strategies are identified that correct specific distress mechanism(s) affecting the existing pavement. The most important issues to consider when choosing a maintenance treatment include:

• Will the treatment address the distress(es) present?
• Can the required preparation for the treatment be carried out?
• Is the treatment cost-effective?
• Will the treatment be performed before the distress situation changes?

4.1 Selection Process

There are three basic steps in the maintenance treatment selection process:

• Assessing the existing conditions
• Determining the feasible treatment options
• Selecting the most cost-effective feasible option

4.2 Assess the Existing Conditions

The first step of the treatment selection process is to evaluate the existing conditions. The evaluation involves three processes:

• Inspecting the site
• Considering project information from a database or records
• Testing the existing pavement, as conditions require
• Defining the performance requirements for the treatment

Later chapters discuss specific treatments for pavement distresses.

It is recommended to assess pavements using a form; a well-developed form promotes uniformity of the assessment process. Field reviewers fill out a pavement assessment form on site for each pavement being considered for treatment. Figure 8 illustrates a pavement assessment form (6) and the type of information that should be collected.