Strength and Durability of a 70% Ground Granulated Blast Furnace ...

TECHNICAL REPORT DOCUMENTATION PAGE
1. Report No. OR06-008 2. Government Accession No. 3. Recipient's Catalog No.
4. Title and Subtitle 5. Report Date
Strength and Durability Characteristics of a 70%
February 2006
Ground Granulated Blast Furnace Slag (GGBFS) Concrete Mix
6. Performing Organization Code
MoDOT
7. Author(s) 8. Performing Organization Report No.
David N. Richardson
RI99-035/RI99-035B
9. Performing Organization Name and Address 10. Work Unit No.
University of Missouri-Rolla
1870 Miner Circle
11. Contract or Grant No.
Rolla, Missouri 65409
12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered
Missouri Department of Transportation
Final Report
105 West Capitol Avenue
14. Sponsoring Agency Code
PO Box 270
MoDOT
Jefferson City, MO 65102
15. Supplementary Notes
This investigation was conducted in cooperation with the U.S. Department of Transportation, Federal Highway Administration.
16. Abstract
For a bridge pier and abutment mass concrete project, three mixes were studied: an ordinary portland cement (OPC)
mix (Type I PC) and two 70% by weight ground granulated blast furnace slag (GGBFS) mixes (Type II Low Heat
PC). One of the slag mixes contained a high range water reducer (HRWR). Tests for compressive strength, freezethaw
durability, rapid chloride permeability, and salt scaling were conducted on field samples. Results showed that the
strengths of the slag mixes were lower than the OPC mix at all ages up to one year, although the use of HRWR did
improve the strength somewhat. Freeze-thaw durability and salt scaling resistance of both slag mixes were inferior
compared to the OPC control. However, under optimized wet plus dry curing periods, slag mix durability did
approach that of the OPC mix. Chloride permeability of both slag mixes was significantly lower than the OPC mix.
Analysis of past studies indicates that, although slag replacements up to 80% have been used successfully, in order for
slag mixes to reach strength parity with OPC mixes, the optimum replacement of PC by slag usually falls between 40
and 60%, depending on the nature and proportions of the materials. Laboratory mixes were made which reflected
variables of age, PC type, w/cm, and total cementitious material content. It was concluded that although the optimum
slag proportion for strength was 50%, slag replacement levels of up to 70% could be used to achieve moderate
strength levels. Strength parity with zero slag mixes is possible with 70 % slag under proper conditions, which include
sufficient activity of the slag-PC system.
17. Key Words 18. Distribution Statement
Ground granulated blast furnace slag, concrete mixes, slag, No restrictions. This document is available to the public
GGBFS, high range water reducer, HRWR, portland cement, through the National Technical Information Center,
freeze-thaw, compressive strength
Springfield, Virginia 22161
19. Security Classification (of this report) 20. Security Classification (of this 21. No. of Pages 22. Price
page)
Unclassified Unclassified 85
Form DOT F 1700.7 (06/98)
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