Assessment of High Early Strength Limestone Blended Cement for Next Generation Transportation Structures

This research on Type IL cements for high early strength concretes demonstrated that Type IL cements satisfying American Association of State Highway and Transportation Officials (AASHTO) M 240 specifications may be used in place of Type I/II cements which satisfy AASHTO M 85 specifications for construction of transportation structures such as precast prestressed bridge girders. Type I/II and Type IL cements from five producers were investigated. The cements and both mortars and concretes made with these cements were studied to determine material characteristics; material properties including setting time, strength development, shrinkage, creep, permeability; and structural properties for use in precast prestressed bridge girders. Tests of 30-ft long beams made with 8,000 psi design strength concrete using Type IL and with Type I/II cements and ½-in. diameter 270 ksi prestressing strands showed that the prestress losses were about 5% less than those predicted using the refined method of AASHTO LRFD (7th edition, 2016). Further, strand transfer length was less than one-half of that specified, and the development length was less than 45% of the length specified in AASHTO LRFD (7th edition, 2016). Flexural strength of the beams was greater than that calculated based on actual concrete strength and prestressing forces. The fineness of portland-limestone cements leads to higher shrinkage than Type I/II cements for water-cementitious materials ratios (w/cm) greater than 0.45, but for the high early strength concretes with w/cm less than 0.4, no significant difference in shrinkage was noted.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Maps; Photos; References; Tables;
  • Pagination: 85p

Subject/Index Terms

Filing Info

  • Accession Number: 01638782
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-GA-17-1433, 14-33
  • Contract Numbers: DTRT12GUTC12
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Jun 9 2017 10:20AM