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3.4.4 Analysis of data
Figure 3.4 Analysis steps
Record data in data sheet
Calculate: Total quantity each type and each level
Density each type and each level Determine DV
Procedure to determine CDV: List the individual DV descending order.
Determine m ≤ 10 Determine total DV
Reduce the smallest value to 2 Determine q
Determine CDV Yes
No Determine CDV:
If none or only one individual deduct value is greater 2
Calculate PCI: PCI=100- max CDV
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Calculation of PCI for Asphalt Concrete AC Pavement ASTM standard D 6433, 1999
:
1. Inspect sample units. Determine distress types, severity levels and measure
density: Add up the total quantity of each distress type at each severity level, and
record them in the Total Severities section. The units for the quantities may be either in square feet square meters, linear feet meters, or number of
occurrences, depending on the distress type. For example as show in Table 3.1.
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Table 3.1 Example of a flexible Pavement Condition Survey Data Sheet for Sample Unit ASTM standard D 6433
Asphalt surfaced roads Condition survey data sheet for sample unit
N
Street : SPRING FLEED No. of sample: Section 01 sample 1 Surveyed by: KAK Date: Jul 93
1 AlligatorFatigue cracking 6 Depression 11 Patching Utility patch 16 Shoving 2 Bleeding 7 Edge cracking 12 Polished Aggregate 17 Slippage
3 Block cracking 8 Reflection cracking 13 Potholes 18 Swell 4 Bumps and sags 9 Lane shoulder drop 14 Rutting 19 Raveling Weathering
5 corrugation 10 Longitudinal Transverse 15 Railroad crossing
Distress severity
Quantity Total
Density Deduct
value 1 L
15 15
14 13
0.52 7.9
1 H 18
16 14
0.56 23.4
7 L
32 15
18 24
41
130 5.20
7.5 8 M
20 15
18 24
41 143
5.72 25.1
11 H 34
25 22
0.88 17.9
13 L 1
1 0.04
11.2 15 L
4 9
8 21
0.84 6.9
19 L 250
250 10.0
5.30
100
ft
25
ft
Direction of survey
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2. Divide the total quantity of each distress type at each severity level by the
total area of the sample unit and multiply by 100 to obtain the percent density of each distress type and severity.
3. Determine the deduct value DV for each distress type and severity level
combination from the distress deduct value curves in ASTM standard D 6433, as show in figure
3.5 deduct value curves for asphalt for Alligator Cracking.
Figure 3.5 Deduct values for Alligator cracking ASTM standard D 6433
4. Determine the maximum Corrected Deduct Value CDV. The procedure for
determining maximum CDV from individual DV is identical for both AC. 5.
The following procedure must be used to determine the maximum CDV: a.
If none or only one individual deduct value is greater than two, the total value is used in place of the maximum CDV in determining the PCI;
otherwise, maximum CDV must be determined using the procedure described in ASTM standard D 6433.
b. List the individual deduct values in descending order.
c.
Determine the allowable number of deducts, m, from Figure 3.6. or using
the following formula in ASTM standard D 6433:
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