Properties of some blended high-alumina cements

✍ Scribed by A.J. Majumdar; B. Singh

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 795 KB
• Volume: 22
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(92)90040-3

✦ Synopsis

The compressive strength of concretes made from mixtures of 'Ciment Fondu' high-alumina cement and granulated blastfurnace slag has shown an increasing trend up to 5 years when kept under water at 20 ° and 38°C. Concretes made from neat HAC have shown much reduced strength at 38°C after only one week, following the well known 'conversion' reactions. The presence of slag and of pozzolanas such as microsilica and metakaolin in blended HAC is responsible for the formation of str~tlingite in the hydrated product and the opportunity for reactions leading to the 'conversion' phenomenon to proceed is severely limited. The sulphate resistance of mixtures of HAC and ggbs is excellent. Concretes made from blended HAC containing ggbs are expected to show a much lower rise in temperature when placed than those made from HAC alone. The hydration chemistry of blends of Ciment Fondu and several mineral admixtures has been studied using conduction calorimetry, x-ray diffraction, thermogravimetry and electron beam microanalysis.