From gypsum-alumina expansive cement to expansive cement Type M. Changes in the expansion kinetics
Abstract
From gypsum-alumina expansive cement to expansive cement Type M. Changes in the expansion kinetics
Incoming article date: 18.11.2013The composition, basic properties and application scope of the two main types of expanding binders historically most widespread in Russia such as gypsum-alumina expansive cement and expansive cement Type M are given. The expansion kinetics of the binders ranging from gypsum-alumina expansive cement to expansive cement Type M is observed. The role of lime as a supplement and as a hydration product of the Portland cement in the expansion process is shown: as a supplement in small values (2-4%) to gypsum-alumina expansive cement with higher gypsum concentration stabilizes the hardening and expansion process, in higher values boosts the expansion process to self-destruction. Optimization criteria of the expansion kinetics aimed at obtaining project expansion in 10 days of hardening without any additional chemical additives are proposed.
Keywords: gypsum-alumina expansive cement, expansive cement type M, expansion kinetics, lime