THERMAL EXPANSION OF CONCRETES: CASE STUDY IN IOWA

Recommended thermal coefficients of expansion of concretes for the design of highway structures are common in design manuals, such as those provided by the American Association of State Highway and Transportation Officials (AASHTO). The current AASHTO value is 11 parts per million per deg C change, which is used often without consideration of the effect of local material properties on the overall expansion of concrete. This paper presents research findings on the thermal behavior of structural bridge concretes in Iowa. The thermal coefficients of expansion were determined in the laboratory for limestone aggregates, gravel aggregates, mortar, corresponding limestone aggregate concretes, and gravel aggregate concretes. Laboratory results were compared to actual bridge expansion data from field studies and the results from an empirical equation for determining concrete expansion. The comparisons were favorable. Findings also revealed that the coefficients of expansion derived in this study were lower than the AASHTO design value. These lower values of thermal coefficient of expansion influence the design length of integral abutment bridges in Iowa.

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  • English

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  • Accession Number: 00713722
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 5 1995 12:00AM