Environmental Factors Relevant to Pavement Cracking in West Texas (18-1)

Environmental variables important in pavement cracking studies are catalogued for west Texas. This portion of the state is shown to receive the most severe environmental changes. Results from other studies, mainly in Canada, are interpreted in terms of the information gathered for west Texas. These data indicate that pavement deterioration in west Texas is more likely the result of thermal fatigue than low temperature cracking. Environmental influence in the base and subgrade which has not been properly considered previously is discussed. Moisture redistribution is related to the Thornthwaite Moisture Index. This index predicts moisture-suction levels in the subgrade which may dry out the base course causing shrinkage cracking. A regression analysis verified the applicability of these indices to west Texas.