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The inspection method is designed to allow the calculation of a composite rating index called the pavement condition index .The steps for determining the PCI of an
inspection unit are shown in next chapter .The PCI scale is shown in table 2.2. The distress types, severity levels, and methods of estimating quantities are keyed to the deduct
curves presented in the area. This effort investigates to obtain field data that both increases safety and reduce
labor requirements during the data collection for streets, roads and parking lots. The primary objectives are to evaluate the ability of the PCI survey system to assess the
condition of roadway pavement, to use the resulting data to create and populate database
Cline et al,2002.
Using visual inspection to evaluate pavement surface conditions. The key to a useful evaluation is identifying different types of pavement distress and linking them to a
cause. Understanding the cause for current conditions is important in selecting an appropriate maintenance or rehabilitation technique Walker, 2002.
2.4.1 Pavement Condition Index PCI
The detailed field inspections categorize and quantify the pavement deficiencies such as cracks, patches and utility trench cuts. These deficiencies are entered into the PMS
program that calculates a Pavement Condition index PCI for each roadway. PCI values range from zero very poor to 100 excellent Weil, 2009.
2.4.2 Pavement Condition Rating
The pavement condition rating is a description of pavement condition as a function of the PCI value that varies from failed to excellent as shown in Table 2.2.
Table 2.2 pavement condition ratings and pavement condition index ranges Seiler,
2009.Weil, 2009.U.S DOT, 2009.
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Pavement Condition Rating
Pavement Condition Index
Excellent 86-100
Very Good 71-85
Good 56-70
Fair 41-55
Poor 26-40
Very Poor 11-25
Failed 0-10
The PCI is a quick method of comparing the overall condition of pavement and magnitude of rehabilitation needs. The following figure shows how pavement condition
typically deteriorates over time. The new pavement holds its good condition for a long period, but once it begins to fail; its condition drops rapidly Weil, 2009.
Figure 2.19 Relationship between pavement condition and time U.S DOT, 2009.
2.4.3 Definition Pavement Condition
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a. Excellent
Pavement is new construction .Nothing would improve the roadway at this time.
b. Very Good
Pavement structure is stable, with no cracking, no patching, and no deformation evident. Roadways in this category are usually fairly new.
Riding qualities are excellent. Nothing would improve the roadway at this time.
c. Good
Pavement structure is stable, little cracking and no deformation evident. Little maintenance would improve the roadway at this time.
d. Fair
Pavement structure is generally stable with minor areas of structural weakness evident. Cracking is easier to detect. The pavement may be
patched but not excessively. Although riding qualities are good, deformation is more pronounced and easily noticed.
e. Poor
Areas of instability, marked evidence of structural deficiency, large crack patterns alligator heavy and numerous patches, deformation very
noticeable. Riding qualities range from acceptable to poor.
f. Very Poor
Pavement is in extremely deteriorated condition. Numerous areas of instability. Majority of section is showing structural deficiency. Riding
quality is unacceptable probably should slow down.
g. Failed
Pavement structure is failed, with cracking and deformation evident. Roadways in this category are usually failed. Reconstruction at this time
Bashir, 2006.
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Fig 2.20 Pavement Condition Index PCI and Rating Scale ASTM standard D 6433
2.5 Maintenance Activities
According to the Foundation for Pavement Preservation, pavement maintenance involves doing the right treatment, at the right place, at the right time. To achieve this,
good management and an understanding of the choices are required David, 2006. There are different categories of maintenance activities. Some can be performed before
significant deterioration occurs. An example is a chip seal done before cracks develop. Preventive maintenance must be done before even moderate cracking occurs, or it will not
last as long as it should. Pavement maintenance can be described by two different categories Lavin, 2003:
a. Preventative maintenance: Activities that prevent or reduce further damage to the
pavement.
Crack filling and sealing.
