Abstract:Airport cement concrete pavement condition survey and evaluation procedure was introduced,and the effect of sample unit size,shape and distress severity on pavement condition index (PCI) accuracy was investigated by altering inspection unit size and shape and distress degree based on field data collected from 390 standard inspection units.The results show that sample unit size has little effect on PCI accuracy,and as long as the unit size is within 20±5 slabs,the error is about 1 point.Altering unit shape leads to significant difference of section PCI value,therefore units dividing cannot be altered arbitrarily.PCI value calculated by horizontal units is lower relatively,but it is more conservative for management.The effect of severity deviation of a single main distress due to manual data collection on section PCI is insignificant,and the error is limited to about 2 points,however,the average error reaches up to 10 points if severity degrees of all distress are deviated.