Pavement Evaluation Flashcards
(19 cards)
Expedient
100 passes or initial surge of mission aircraft
Small number of tests/basic tests
Sustainment
5000 passes or throughout anticipated operation
Med number of test/intermediate tests
Permanent
50000 passes or long term operations
Large number of tests/advanced tests
What are the six steps in the airfield pavement evaluation process?
Define Airfield Layout
Perform Field Tests
Obtain Mission Data
Assess PCI
Compile PPD
Compute AGLs/Passes
Two main parts of assessing a PCI?
No strength capacity/ops
PCI<40 leads to a 25% reduction in structural capacity
What is the failure criteria for Semi-prepared surfaces?
3in. deep rutting
What is the failure criteria for flexible pavements?
1in. deep rutting
What is the failure criteria for Rigid Pavements?
50% of slabs in a section are shattered into three or more pieces
Explain Miner’s Rule
Allows for mixing and matching
What are the inputs that determine the PCI?
Distress type, quantity, and severity
Distress Severity?
Low, Medium, High
What are the limitations of the PCI?
Based on surface distresses only, only based on a portion of pavement
What is the purpose of condition surveys?
Keep the PCI for pavement above 70
What are the different types of PCI evaluation and who performs them?
Standard PCI - computer automated - contractor or APE team
Simplified PCI - computer automated/by hand - base level or contingency evaluations
Cursory PCI - by hand - base level or contingency evaluations
What is the difference between a pavement section and sample unit?
Section - construction, condition, usage
Sample Unit -
PCC - 20 contiguous slabs (+/-8)
ACC - 5000 contiguous square feet (+-2000SF)
What is the process to select which sample units to inspect from the pavement section?
Randomly selected sample units!
i = N/n
What distress properties are used to calculate PCI deduct values?
Asphalt Distresses - Alligator Cracking, Patching Utility Cut, Depression, Rutting, Slippage Crack
Concrete Distresses
Blow-Up
Corner Break
Longitudinal/Transverse Cracks
Settlement Faulting
Shattered Slab
What is the process to convert an individual distress deduct values to a section PCI?
- Find total of each distress and severity
- Calculate distress density
- Based on distress type, density, and severity, find the proper deduct value with the table
- Determine max corrected deduct value
- Subtract corrected deduct value from 100 to calculate PCI for sample units
- Average the PCIs for all sample units to determine the section PCI
