Pilot Study on Shrinkage and Fracture of Materials Based on the Alkali-Activated Slag: Influence of Curing Regime

Abstract

The paper presents the results of a pilot study focused on the shrinkage process and fracture parameters of two fine-grained materials prepared from ground granulated blast furnace slag and silica sand. Two different activators were used - liquid sodium silicate and sodium hydroxide. The components ratio and the activator dose were the same for both materials and were as follows: activator dose of 6% Na2O by the slag weight, 1% of lignosulfonate plasticizer, and the ratio of slag:water:sand of 1:0.45:3. All specimens matured at room temperature. For each material, four curing regimes were designed with respect to the potential application on-site (especially different upper surface treatment and demoulding time). The shrinkage measurement lasted more than 2.5 years, after which fracture tests were performed on the same sets of specimens. Although only a slight nuance was in designed curing conditions, the results showed different sensitivity of investigated materials and monitored parameters to the particular curing regimes.The paper presents the results of a pilot study focused on the shrinkage process and fracture parameters of two fine-grained materials prepared from ground granulated blast furnace slag and silica sand. Two different activators were used - liquid sodium silicate and sodium hydroxide. The components ratio and the activator dose were the same for both materials and were as follows: activator dose of 6% Na2O by the slag weight, 1% of lignosulfonate plasticizer, and the ratio of slag:water:sand of 1:0.45:3. All specimens matured at room temperature. For each material, four curing regimes were designed with respect to the potential application on-site (especially different upper surface treatment and demoulding time). The shrinkage measurement lasted more than 2.5 years, after which fracture tests were performed on the same sets of specimens. Although only a slight nuance was in designed curing conditions, the results showed different sensitivity of investigated materials and monitored parameters to the particular curing regimes.