Durability of self-consolidating concrete incorporating high-volume replacement composite cements

Self-consolidating concrete (SCC) decreases construction time, labor and equipment on construction sites, makes the construction of heavily congested structural elements and hard to reach areas easier, reduces noise- and vibration-related injuries, and helps in achieving higher quality finish surfaces. However, because it usually requires a larger content of binder and chemical admixtures compared to ordinary concrete, its material cost is generally 20-50% higher, which has been a major hindrance to a wider implementation of its use. There is growing evidence that incorporating high volumes of mineral admixtures and microfillers as partial replacement for portland cement in SCC can make it cost effective. However, the durability of such SCC needs to be proven. This research investigates the rapid chloride ion penetrability, sulfate expansion and deicing salt surface scaling resistance of SCC mixtures made with high-volume replacement binary, ternary and quaternary cements. The fresh concrete properties and compressive strength at 1, 7, 28 and 91 days of such SCC mixtures were measured. Moreover, rapid chloride ion penetrability was investigated for the various SCC mixtures at 28 and 91 days, while the deicing salt surface scaling under 50 freezing-thawing cycles and sulfate expansion after up to 9 months of immersion in a 5% Na2SO4 solution were investigated as per the ASTM C-672 and ASTM C1012 guidelines, respectively. Results indicate that SCC can be made with high-volume replacement composite cements and achieve good workability, high long-term strength, good deicing salt surface scaling resistance, low sulfate expansion and very low chloride ion penetrability. (C) 2004 Elsevier Ltd. All rights reserved.