Abstract

Equilibrium moisture beneath highway pavements is critical to pavement design because moisture directly affects the strength and stiffness of pavement systems. Moisture is related to soil suction by means of the soil-water characteristic curve (SWCC). Previous research has indicated a correlation of suction with Thornthwaite Moisture Index (TMI) and soil type; however, these suction correlations exhibited large variability. Under an NCHRP project sponsored by the Federal Highway Administration, soil samples were collected from beneath thirty pavement sections throughout the United States: two from the WesTrack test facility, one from the MnRoad Project, and twenty-seven from the Long Term Pavement Performance sites. SWCCs and index properties were measured on collected samples at Arizona State University. The in-situ degree of saturation was obtained from soil index properties, dry unit weight, and moisture content, and the corresponding in-situ soil suction was obtained from SWCCs. Based on the field and laboratory data, an algorithm was developed to predict suction under the pavement using TMI, percent passing 200 (P 200), and Plasticity Index. The suction prediction models, named the TMI-P200 model and the TMI-P 200wPI model, showed good results with variability within acceptable limits.

Original languageEnglish (US)
Title of host publicationGeotechnical Special Publication
EditorsM.K. Yegian, E. Kavazanjian
Pages1132-1143
Number of pages12
Edition126 I
StatePublished - 2004
EventGeotechnical Engineering for Transportation Projects: Proceedings of Geo-Trans 2004 - Los Angeles, CA, United States
Duration: Jul 27 2004Jul 31 2004

Other

OtherGeotechnical Engineering for Transportation Projects: Proceedings of Geo-Trans 2004
CountryUnited States
CityLos Angeles, CA
Period7/27/047/31/04

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ASJC Scopus subject areas

  • Building and Construction
  • Architecture
  • Soil Science

Cite this

Perera, Y. Y., Zapata, C., Houston, W. N., & Houston, S. (2004). Long-term moisture conditions under highway pavements. In M. K. Yegian, & E. Kavazanjian (Eds.), Geotechnical Special Publication (126 I ed., pp. 1132-1143)