Flexible Pavement Performance in relation to In Situ Mechanistic and Volumetric Properties Using LTPP Data

Table 4

Rut life as a function of air voids sorted by base type and thickness of HMA layer.

HMA thickness	Base type	State ID	No. of points	Transformation function	𝑅^2 value
	GB	SC, CA, TX, ID, AK, and NC	7	Linear	0.99
Total thickness of HMA < 10 cm	GS	MS, GA, PQ, NJ, CO, and NM	7	Exponential	0.78
	TB	OK, MS, GA, DE, AR, MD, NS, and MN	11	Linear	0.05
	GB	CT, NC, TX, GA, PE, MA, NV, MT, ID, and AK	18	Exponential	0.06
Total thickness of HMA 10–20 cm	GS	NM, AR, NJ, HI, TN, WA, and CO	3	Linear	0.98
	TB	NC, TX, OK, GA, CA, MD, CO, and WY	12	Linear	0.04
Total thickness of HMA > 20 cm	GB, GS	TX, GA, AK, WA, MD, CO, and PQ	4	Power	0.33
	TB	OK, TX, NJ, TN, and MD	5	Exponential	0.13