Local Ca-structure variation and microstructural characteristics on one-part activated slag system with various activators

Abstract Material characteristics including local Ca-structure of activated slag with various activators (Mg-, Ca-, and Ba-based) were investigated. The use of an activator with less bound water increased compressive strength regardless of the types of main element in an activator even at an identical molar ratio, but this effect diminished as the atomic number of the main elements in the activators increased. A heavier activator at an identical molar ratio produced a higher compressive strength at 28 days, but Ba-based activation showed dormant period for 3 days due to the late participation of Ba-activator in slag reaction. It was firstly found out that the Mg-based system negligibly changed local Ca-structure of the raw slag whereas the Ba-based system has larger radial distance and smaller coordination number of Ca-O bond than those of Ca-based system. This is explained by increased degree of slag dissolution by using activators with heavier main elements.