Title:
Durability of Ternary Blend Concrete with Silica Fume
and Blast-Furnace Slag: Laboratory and Outdoor Exposure Site Studies
Author(s):
Roland Bleszynski, R. Doug Hooton, Michael D. A. Thomas, and Chris A. Rogers
Publication:
Materials Journal
Volume:
99
Issue:
5
Appears on pages(s):
499-508
Keywords:
alkali-silica reaction; blast-furnace slag; concrete; durability; silica fume.
DOI:
10.14359/12329
Date:
9/1/2002
Abstract:
In September 1998, an outdoor exposure site was constructed in Picton, Ontario, Canada, to investigate the durability of ternary cementitious systems. Seven concrete mixtures, including three ternary concrete mixtures consisting of various combinations of silica fume, blast-furnace slag, and portland cement were studied. Large slabs-on-ground were cast in the field, and corresponding specimens were simultaneously cast for laboratory testing to assess durability performance of alkali-silica reaction, deicer salt scaling, and ingress of chlorides. This paper describes this project in detail and presents field observations and laboratory findings up to 2 years. Significant expansion due to alkali-silica reaction has occurred in the concrete made with high-alkali portland cement used as a control but has not been observed in any of the ternary blend mixtures. A salt scaling test performed on the formed surfaces of laboratory specimens revealed mass losses slightly greater than the control but less than the specified threshold. Inspection of the field slabs showed no signs of salt scaling damage with the exception of the 50% slag mixture, which is experiencing light scaling after 2 years. Rapid chloride penetration tests, chloride bulk diffusion tests, and chloride profiles of cores taken from the field indicate that ternary blends have a greater resistance to chloride ingress than the control mixture and mixtures with a single supplementary cementing material. A comparative summary revealed that the ternary blend concretes tested have a greater durability performance than the other mixtures tested.