Freeze-Thaw Durability and Digital Hardened Air Void Analysis of Self Consolidating Concrete

The use of Self Consolidated Concrete in West Virginia is very limited. The freeze-thaw durability of Self Consolidated Concrete must be validated to ensure longevity of Self Consolidated Concrete structures used for construction in West Virginia.;Researchers at West Virginia University worked with WVDOH in constructing a bridge using 3 SCC prestressed, precast box beams and 3 traditional concrete prestressed, precast box beams. Upon freeze-thaw testing of concrete prisms, the SCC concrete mix was found to have very low freeze-thaw durability. The mix design for the SCC was replicated twice in the laboratory. For both batches, the effects of steam curing vs. traditional moist curing were observed. Hardened air void analysis was digitally performed using a flat-bed scanner and two programs. The first program used Adobe Photoshop and was developed by Michigan Tech University, and the second program was developed in the WVU laboratory and uses MATLAB. Both batches of laboratory SCC had fresh air contents below the air content of SCC used in the bridge.;Air void analysis showed that none of the specimens had acceptable air void structure. In freeze-thaw testing, almost all of the laboratory SCC specimens failed. The steam-cured specimens from the second batch successfully survived freeze-thaw testing.;The failure of the SCC specimens in freeze-thaw testing shows the need for a proper air void structure in SCC as well as traditional concrete. Analysis of the air void structure of concrete can be used to predict freeze-thaw durability without the need for performing the time-consuming and expensive freeze-thaw test.